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1

Domain mapping of the Rad51 paralog protein complexes  

Microsoft Academic Search

The five human Rad51 paralogs are suggested to play an important role in the maintenance of genome stability through their function in DNA dou- ble-strand break repair. These proteins have been found to form two distinct complexes in vivo, Rad51B-Rad51C-Rad51D-Xrcc2 (BCDX2) and Rad51C-Xrcc3 (CX3). Based on the recent Pyrococcus furiosus Rad51 structure, we have used homology modeling to design deletion

Kristi A. Miller; Dorota Sawicka; Daniel Barsky; Joanna S. Albala

2004-01-01

2

Parameters of proteome evolution from histograms of amino-acid sequence identities of paralogous proteins  

Microsoft Academic Search

BACKGROUND: The evolution of the full repertoire of proteins encoded in a given genome is mostly driven by gene duplications, deletions, and sequence modifications of existing proteins. Indirect information about relative rates and other intrinsic parameters of these three basic processes is contained in the proteome-wide distribution of sequence identities of pairs of paralogous proteins. RESULTS: We introduce a simple

Jacob Bock Axelsen; Koon-Kiu Yan; Sergei Maslov

2007-01-01

3

Functional prediction: identification of protein orthologs and paralogs.  

PubMed Central

Orthologs typically retain the same function in the course of evolution. Using beta-decarboxylating dehydrogenase family as a model, we demonstrate that orthologs can be confidently identified. The strategy is based on our recent findings that substitutions of only a few amino acid residues in these enzymes are sufficient to exchange substrate and coenzyme specificities. Hence, the few major specificity determinants can serve as reliable markers for determining orthologous or paralogous relationships. The power of this approach has been demonstrated by correcting similarity-based functional misassignment and discovering new genes and related pathways, and should be broadly applicable to other enzyme families. PMID:11206056

Chen, R.; Jeong, S. S.

2000-01-01

4

Control of hematopoietic stem cell emergence by antagonistic functions of ribosomal protein paralogs  

PubMed Central

Summary It remains controversial whether the highly-homologous ribosomal protein (RP) paralogs found in lower eukaryotes have distinct functions and this has not been explored in vertebrates. Here we demonstrate that despite ubiquitous expression, the RP paralogs, Rpl22 and Rpl22-like1 (Rpl22l1) play essential, distinct, and antagonistic roles in hematopoietic development. Knockdown of rpl22 in zebrafish embryos selectively blocks the development of T lineage progenitors after they have seeded the thymus. In contrast, knockdown of the rpl22 paralog, rpl22l1, impairs the emergence of hematopoietic stem cells (HSC) in the aorta-gonad-mesonephros by abrogating Smad1 expression and the consequent induction of essential transcriptional regulator, Runx1. Indeed, despite the ability of both paralogs to bind Smad1 RNA, Rpl22 and Rpl22l1 have opposing effects on Smad1 expression. Accordingly, circumstances that tip the balance of these paralogs in favor of Rpl22 (e.g., Rpl22l1 knockdown or Rpl22 overexpression) result in repression of Smad1 and blockade of HSC emergence. PMID:23449473

Zhang, Yong; Duc, Anne-Cécile E.; Rao, Shuyun; Sun, Xiao-Li; Bilbee, Alison N.; Rhodes, Michele; Li, Qin; Kappes, Dietmar J.; Rhodes, Jennifer; Wiest, David L.

2013-01-01

5

Parameters of the proteome evolution from the distribution of sequence identities of paralogous proteins  

NASA Astrophysics Data System (ADS)

The evolution of the full repertoire of proteins encoded in a given genome is driven by gene duplications, deletions and modifications of amino-acid sequences of already existing proteins. The information about relative rates and other intrinsic parameters of these three basic processes is contained in the distribution of sequence identities of pairs of paralogous proteins. We introduced a simple mathematical framework that allows one to extract some of this hidden information. It was then applied to the proteome-wide set of paralogous proteins in H. pylori, E. coli, S. cerevisiae, C. elegans, D. melanogaster and H. sapiens. We estimated the stationary per-gene deletion and duplication rates, the distribution of amino-acid substitution rate of these organisms. The validity of our mathematical framework was further confirmed by numerical simulations of a simple evolutionary model of a fixed-size proteome.

Yan, Koon-Kiu; Axelsen, Jacob; Maslov, Sergei

2006-03-01

6

Identification of Paralogous Life-Cycle Stage Specific Cytoskeletal Proteins in the Parasite Trypanosoma brucei  

PubMed Central

The life cycle of the African trypanosome Trypanosoma brucei, is characterised by a transition between insect and mammalian hosts representing very different environments that present the parasite with very different challenges. These challenges are met by the expression of life-cycle stage-specific cohorts of proteins, which function in systems such as metabolism and immune evasion. These life-cycle transitions are also accompanied by morphological rearrangements orchestrated by microtubule dynamics and associated proteins of the subpellicular microtubule array. Here we employed a gel-based comparative proteomic technique, Difference Gel Electrophoresis, to identify cytoskeletal proteins that are expressed differentially in mammalian infective and insect form trypanosomes. From this analysis we identified a pair of novel, paralogous proteins, one of which is expressed in the procyclic form and the other in the bloodstream form. We show that these proteins, CAP51 and CAP51V, localise to the subpellicular corset of microtubules and are essential for correct organisation of the cytoskeleton and successful cytokinesis in their respective life cycle stages. We demonstrate for the first time redundancy of function between life-cycle stage specific paralogous sets in the cytoskeleton and reveal modification of cytoskeletal components in situ prior to their removal during differentiation from the bloodstream form to the insect form. These specific results emphasise a more generic concept that the trypanosome genome encodes a cohort of cytoskeletal components that are present in at least two forms with life-cycle stage-specific expression. PMID:25180513

Portman, Neil; Gull, Keith

2014-01-01

7

RPL39L is an example of a recently evolved ribosomal protein paralog that shows highly specific tissue expression patterns and is upregulated in ESCs and HCC tumors  

PubMed Central

Ribosomal proteins (RPs) have been shown to be able to impart selectivity on the translating ribosome implicating them in gene expression control. Many ribosomal proteins are highly conserved and recently a number of ribosomal protein paralogs have been described in mammals. We examined the expression pattern of RPs in differentiating mouse Embryonic Stem Cells (ESCs), paying particular attention to the RP paralogs. We find the RP paralog Rpl39l is highly expressed in ESC and its expression strongly correlates with hepatocellular carcinoma tumor (HCC) samples with high tumor grading and alpha-fetoprotein level giving it diagnostic potential. We further screen the expression pattern of all RPs and their paralogs across 22 different tissues. We find that the more recently evolved RP paralogs show a much greater level of tissue-specific expression. We propose that these RP paralogs evolved more recently to provide a greater level of gene expression control to higher eukaryotes. PMID:24452241

Wong, Queenie Wing-Lei; Li, Jia; Ng, Sheng Rong; Lim, Seng Gee; Yang, Henry; Vardy, Leah A

2014-01-01

8

Paralogous radiations of PIN proteins with multiple origins of noncanonical PIN structure.  

PubMed

The plant hormone auxin is a conserved regulator of development which has been implicated in the generation of morphological novelty. PIN-FORMED1 (PIN) auxin efflux carriers are central to auxin function by regulating its distribution. PIN family members have divergent structures and cellular localizations, but the origin and evolutionary significance of this variation is unresolved. To characterize PIN family evolution, we have undertaken phylogenetic and structural analyses with a massive increase in taxon sampling over previous studies. Our phylogeny shows that following the divergence of the bryophyte and lycophyte lineages, two deep duplication events gave rise to three distinct lineages of PIN proteins in euphyllophytes. Subsequent independent radiations within each of these lineages were taxonomically asymmetric, giving rise to at least 21 clades of PIN proteins, of which 15 are revealed here for the first time. Although most PIN protein clades share a conserved canonical structure with a modular central loop domain, a small number of noncanonical clades dispersed across the phylogeny have highly divergent protein structure. We propose that PIN proteins underwent sub- and neofunctionalization with substantial modification to protein structure throughout plant evolution. Our results have important implications for plant evolution as they suggest that structurally divergent PIN proteins that arose in paralogous radiations contributed to the convergent evolution of organ systems in different land plant lineages. PMID:24758777

Bennett, Tom; Brockington, Samuel F; Rothfels, Carl; Graham, Sean W; Stevenson, Dennis; Kutchan, Toni; Rolf, Megan; Thomas, Philip; Wong, Gane Ka-Shu; Leyser, Ottoline; Glover, Beverley J; Harrison, C Jill

2014-08-01

9

Protein Phosphatase 1 ? Paralogs Encode the Zebrafish Myosin Phosphatase Catalytic Subunit  

PubMed Central

Background The myosin phosphatase is a highly conserved regulator of actomyosin contractility. Zebrafish has emerged as an ideal model system to study the in vivo role of myosin phosphatase in controlling cell contractility, cell movement and epithelial biology. Most work in zebrafish has focused on the regulatory subunit of the myosin phosphatase called Mypt1. In this work, we examined the critical role of Protein Phosphatase 1, PP1, the catalytic subunit of the myosin phosphatase. Methodology/Principal Findings We observed that in zebrafish two paralogous genes encoding PP1?, called ppp1cba and ppp1cbb, are both broadly expressed during early development. Furthermore, we found that both gene products interact with Mypt1 and assemble an active myosin phosphatase complex. In addition, expression of this complex results in dephosphorylation of the myosin regulatory light chain and large scale rearrangements of the actin cytoskeleton. Morpholino knock-down of ppp1cba and ppp1cbb results in severe defects in morphogenetic cell movements during gastrulation through loss of myosin phosphatase function. Conclusions/Significance Our work demonstrates that zebrafish have two genes encoding PP1?, both of which can interact with Mypt1 and assemble an active myosin phosphatase. In addition, both genes are required for convergence and extension during gastrulation and correct dosage of the protein products is required. PMID:24040418

Jayashankar, Vaishali; Nguyen, Michael J.; Carr, Brandon W.; Zheng, Dale C.; Rosales, Joseph B.; Rosales, Joshua B.; Weiser, Douglas C.

2013-01-01

10

Functional Divergence among Silkworm Antimicrobial Peptide Paralogs by the Activities of Recombinant Proteins and the Induced Expression Profiles  

PubMed Central

Antimicrobial peptides are small-molecule proteins that are usually encoded by multiple-gene families. They play crucial roles in the innate immune response, but reports on the functional divergence of antimicrobial peptide gene families are rare. In this study, 14 paralogs of antimicrobial peptides belonging to cecropin, moricin and gloverin families were recombinantly expressed in pET expression systems. By antimicrobial activity tests, peptides representing paralogs in the same family of cecropin and moricin families, displayed remarkable differences against 10 tested bacteria. The evolutionary rates were relatively fast in the two families, which presented obvious functional divergence among paralogs of each family. Four peptides of gloverin family had similar antimicrobial spectrum and activity against tested bacteria. The gloverin family showed similar antimicrobial function and slow evolutionary rates. By induced transcriptional activity, genes encoding active antimicrobial peptides were upregulated at obviously different levels when silkworm pupae were infected by three types of microbes. Association analysis of antimicrobial activities and induced transcriptional activities indicated that the antimicrobial activities might be positively correlated with induced transcriptional activities in the cecropin and moricin families. These results suggest that representative BmcecB6, BmcecD and Bmmor as the major effector genes have broad antimicrobial spectrum, strong antimicrobial activity and high microbe-induced expression among each family and maybe play crucial roles in eliminating microbial infection. PMID:21479226

Ye, Mingqiang; Deng, Xiaojuan; Yi, Huiyu; Huang, Yadong; Tan, Xiang; Han, Dong; Wang, Bo; Xiang, Zhonghuai; Cao, Yang; Xia, Qingyou

2011-01-01

11

Targeted Identification of SUMOylation Sites in Human Proteins Using Affinity Enrichment and Paralog-specific Reporter Ions*  

PubMed Central

Protein modification by small ubiquitin-like modifier (SUMO) modulates the activities of numerous proteins involved in different cellular functions such as gene transcription, cell cycle, and DNA repair. Comprehensive identification of SUMOylated sites is a prerequisite to determine how SUMOylation regulates protein function. However, mapping SUMOylated Lys residues by mass spectrometry (MS) is challenging because of the dynamic nature of this modification, the existence of three functionally distinct human SUMO paralogs, and the large SUMO chain remnant that remains attached to tryptic peptides. To overcome these problems, we created HEK293 cell lines that stably express functional SUMO paralogs with an N-terminal His6-tag and an Arg residue near the C terminus that leave a short five amino acid SUMO remnant upon tryptic digestion. We determined the fragmentation patterns of our short SUMO remnant peptides by collisional activation and electron transfer dissociation using synthetic peptide libraries. Activation using higher energy collisional dissociation on the LTQ-Orbitrap Elite identified SUMO paralog-specific fragment ions and neutral losses of the SUMO remnant with high mass accuracy (< 5 ppm). We exploited these features to detect SUMO modified tryptic peptides in complex cell extracts by correlating mass measurements of precursor and fragment ions using a data independent acquisition method. We also generated bioinformatics tools to retrieve MS/MS spectra containing characteristic fragment ions to the identification of SUMOylated peptide by conventional Mascot database searches. In HEK293 cell extracts, this MS approach uncovered low abundance SUMOylated peptides and 37 SUMO3-modified Lys residues in target proteins, most of which were previously unknown. Interestingly, we identified mixed SUMO-ubiquitin chains with ubiquitylated SUMO proteins (K20 and K32) and SUMOylated ubiquitin (K63), suggesting a complex crosstalk between these two modifications. PMID:23750026

Lamoliatte, Frederic; Bonneil, Eric; Durette, Chantal; Caron-Lizotte, Olivier; Wildemann, Dirk; Zerweck, Johannes; Wenshuk, Holger; Thibault, Pierre

2013-01-01

12

The Ribosomal Protein Rpl22 Controls Ribosome Composition by Directly Repressing Expression of Its Own Paralog, Rpl22l1  

PubMed Central

Most yeast ribosomal protein genes are duplicated and their characterization has led to hypotheses regarding the existence of specialized ribosomes with different subunit composition or specifically-tailored functions. In yeast, ribosomal protein genes are generally duplicated and evidence has emerged that paralogs might have specific roles. Unlike yeast, most mammalian ribosomal proteins are thought to be encoded by a single gene copy, raising the possibility that heterogenous populations of ribosomes are unique to yeast. Here, we examine the roles of the mammalian Rpl22, finding that Rpl22?/? mice have only subtle phenotypes with no significant translation defects. We find that in the Rpl22?/? mouse there is a compensatory increase in Rpl22-like1 (Rpl22l1) expression and incorporation into ribosomes. Consistent with the hypothesis that either ribosomal protein can support translation, knockdown of Rpl22l1 impairs growth of cells lacking Rpl22. Mechanistically, Rpl22 regulates Rpl22l1 directly by binding to an internal hairpin structure and repressing its expression. We propose that ribosome specificity may exist in mammals, providing evidence that one ribosomal protein can influence composition of the ribosome by regulating its own paralog. PMID:23990801

O'Leary, Monique N.; Schreiber, Katherine H.; Zhang, Yong; Duc, Anne-Cécile E.; Rao, Shuyun; Hale, J. Scott; Academia, Emmeline C.; Shah, Shreya R.; Morton, John F.; Holstein, Carly A.; Martin, Dan B.; Kaeberlein, Matt; Ladiges, Warren C.; Fink, Pamela J.; MacKay, Vivian L.; Wiest, David L.; Kennedy, Brian K.

2013-01-01

13

Involvement of Rad51C in two distinct protein complexes of Rad51 paralogs in human cells  

Microsoft Academic Search

Genetic studies in rodent and chicken mutant cell lines have suggested that Rad51 paralogs (XRCC2, XRCC3, Rad51B\\/Rad51L1, Rad51C\\/Rad51L2 and Rad51D\\/Rad51L3) play important roles in homologous recombinational repair of DNA double-strand breaks and in maintaining chromosome stability. Previous studies using yeast two- and three-hybrid systems have shown interactions among these proteins, but it is not clear whether these interactions occur simultaneously

Nan Liu; David Schild; Michael P. Thelen; Larry H. Thompson

2002-01-01

14

Differential and collaborative actions of Rad51 paralog proteins in cellular response to DNA damage  

Microsoft Academic Search

Metazoan Rad51 plays a central role in homologous DNA recombination, and its activity is controlled by a number of Rad51 cofactors. These include five Rad51 paralogs, Rad51B, Rad51C, Rad51D, XRCC2 and XRCC3. We previously hypothesized that all five par- alogs participate collaboratively in repair. However, this idea was challenged by the biochemical identi- fication of two independent complexes composed of

Yasukazu Yonetani; Helfrid Hochegger; Eiichiro Sonoda; Sayoko Shiny; Hideki Yoshikawa; Shunichi Takeda; Mistuyoshi Yamazoe

2005-01-01

15

Multimodular Penicillin-Binding Proteins: An Enigmatic Family of Orthologs and Paralogs  

PubMed Central

The monofunctional penicillin-binding dd-peptidases and penicillin-hydrolyzing serine ?-lactamases diverged from a common ancestor by the acquisition of structural changes in the polypeptide chain while retaining the same folding, three-motif amino acid sequence signature, serine-assisted catalytic mechanism, and active-site topology. Fusion events gave rise to multimodular penicillin-binding proteins (PBPs). The acyl serine transferase penicillin-binding (PB) module possesses the three active-site defining motifs of the superfamily; it is linked to the carboxy end of a non-penicillin-binding (n-PB) module through a conserved fusion site; the two modules form a single polypeptide chain which folds on the exterior of the plasma membrane and is anchored by a transmembrane spanner; and the full-size PBPs cluster into two classes, A and B. In the class A PBPs, the n-PB modules are a continuum of diverging sequences; they possess a five-motif amino acid sequence signature, and conserved dicarboxylic amino acid residues are probably elements of the glycosyl transferase catalytic center. The PB modules fall into five subclasses: A1 and A2 in gram-negative bacteria and A3, A4, and A5 in gram-positive bacteria. The full-size class A PBPs combine the required enzymatic activities for peptidoglycan assembly from lipid-transported disaccharide-peptide units and almost certainly prescribe different, PB-module specific traits in peptidoglycan cross-linking. In the class B PBPs, the PB and n-PB modules cluster in a concerted manner. A PB module of subclass B2 or B3 is linked to an n-PB module of subclass B2 or B3 in gram-negative bacteria, and a PB module of subclass B1, B4, or B5 is linked to an n-PB module of subclass B1, B4, or B5 in gram-positive bacteria. Class B PBPs are involved in cell morphogenesis. The three motifs borne by the n-PB modules are probably sites for module-module interaction and the polypeptide stretches which extend between motifs 1 and 2 are sites for protein-protein interaction. The full-size class B PBPs are an assortment of orthologs and paralogs, which prescribe traits as complex as wall expansion and septum formation. PBPs of subclass B1 are unique to gram-positive bacteria. They are not essential, but they represent an important mechanism of resistance to penicillin among the enterococci and staphylococci. Natural evolution and PBP- and ?-lactamase-mediated resistance show that the ability of the catalytic centers to adapt their properties to new situations is limitless. Studies of the reaction pathways by using the methods of quantum chemistry suggest that resistance to penicillin is a road of no return. PMID:9841666

Goffin, Colette; Ghuysen, Jean-Marie

1998-01-01

16

Did Androgen-Binding Protein Paralogs Undergo Neo- and/or Subfunctionalization as the Abp Gene Region Expanded in the Mouse Genome?  

PubMed Central

The Androgen-binding protein (Abp) region of the mouse genome contains 30 Abpa genes encoding alpha subunits and 34 Abpbg genes encoding betagamma subunits, their products forming dimers composed of an alpha and a betagamma subunit. We endeavored to determine how many Abp genes are expressed as proteins in tears and saliva, and as transcripts in the exocrine glands producing them. Using standard PCR, we amplified Abp transcripts from cDNA libraries of C57BL/6 mice and found fifteen Abp gene transcripts in the lacrimal gland and five in the submandibular gland. Proteomic analyses identified proteins corresponding to eleven of the lacrimal gland transcripts, all of them different from the three salivary ABPs reported previously. Our qPCR results showed that five of the six transcripts that lacked corresponding proteins are expressed at very low levels compared to those transcripts with proteins. We found 1) no overlap in the repertoires of expressed Abp paralogs in lacrimal gland/tears and salivary glands/saliva; 2) substantial sex-limited expression of lacrimal gland/tear expressed-paralogs in males but no sex-limited expression in females; and 3) that the lacrimal gland/tear expressed-paralogs are found exclusively in ancestral clades 1, 2 and 3 of the five clades described previously while the salivary glands/saliva expressed-paralogs are found only in clade 5. The number of instances of extremely low levels of transcription without corresponding protein production in paralogs specific to tears and saliva suggested the role of subfunctionalization, a derived condition wherein genes that may have been expressed highly in both glands ancestrally were down-regulated subsequent to duplication. Thus, evidence for subfunctionalization can be seen in our data and we argue that the partitioning of paralog expression between lacrimal and salivary glands that we report here occurred as the result of adaptive evolution. PMID:25531410

Karn, Robert C.; Chung, Amanda G.; Laukaitis, Christina M.

2014-01-01

17

Ring-shaped Rad51 Paralog Protein Complexes Bind Holliday Junctions and Replication Forks as Visualized by Electron Microscopy*  

PubMed Central

In mammals, there are five Rad51 paralogs that form two distinct complexes in vivo. One complex is composed of Rad51B-Rad51C-Rad51D-Xrcc2 (BCDX2) and the other Rad51C-Xrcc3 (CX3). We co-expressed and purified human BCDX2 and CX3 protein complexes from insect cells and investigated their binding preferences and structure using transmission electron microscopy (TEM). We visualized the binding of BCDX2 and CX3 to DNA templates containing replication forks and Holliday junctions, intermediates observed during DNA replication and recombination, respectively. We show that both complexes bind with exceptionally high specificity to the DNA junctions with little binding observed elsewhere on the DNAs. Further analysis of the structure of free or DNA-bound BCDX2 and CX3 complexes revealed a multimeric ring structure whose subunits are arranged into a flat disc around a central channel. This work provides the first EM visualization of BCDX2 and CX3 binding to Holliday junctions and forked DNAs and suggests the complexes form ring-shaped structures. PMID:20207730

Compton, Sarah A.; Özgür, Sezgin; Griffith, Jack D.

2010-01-01

18

A Novel Function for Fragile X Mental Retardation Protein in Translational Activation  

E-print Network

A Novel Function for Fragile X Mental Retardation Protein in Translational Activation Elias G, Universite´ Laval, Que´bec, Canada Fragile X syndrome, the most frequent form of inherited mental retardation, is due to the absence of Fragile X Mental Retardation Protein (FMRP), an RNA-binding protein involved

Boyer, Edmond

19

The Fragile X Mental Retardation Protein in Circadian Rhythmicity and Memory Consolidation  

E-print Network

The Fragile X Mental Retardation Protein in Circadian Rhythmicity and Memory Consolidation Cheryl L. The fragile X mental retardation protein (FMRP), an RNA- binding translational regulator, is a key player causes fragile X syndrome (FraX), the most commonly inherited form of mental retardation and autism

Broadie, Kendal S.

20

Structure–function relationships of two paralogous single-stranded DNA-binding proteins from Streptomyces coelicolor: implication of SsbB in chromosome segregation during sporulation  

PubMed Central

The linear chromosome of Streptomyces coelicolor contains two paralogous ssb genes, ssbA and ssbB. Following mutational analysis, we concluded that ssbA is essential, whereas ssbB plays a key role in chromosome segregation during sporulation. In the ssbB mutant, ?30% of spores lacked DNA. The two ssb genes were expressed differently; in minimal medium, gene expression was prolonged for both genes and significantly upregulated for ssbB. The ssbA gene is transcribed as part of a polycistronic mRNA from two initiation sites, 163 bp and 75 bp upstream of the rpsF translational start codon. The ssbB gene is transcribed as a monocistronic mRNA, from an unusual promoter region, 73 bp upstream of the AUG codon. Distinctive DNA-binding affinities of single-stranded DNA-binding proteins monitored by tryptophan fluorescent quenching and electrophoretic mobility shift were observed. The crystal structure of SsbB at 1.7 Å resolution revealed a common OB-fold, lack of the clamp-like structure conserved in SsbA and previously unpublished S-S bridges between the A/B and C/D subunits. This is the first report of the determination of paralogous single-stranded DNA-binding protein structures from the same organism. Phylogenetic analysis revealed frequent duplication of ssb genes in Actinobacteria, whereas their strong retention suggests that they are involved in important cellular functions. PMID:23393191

Paradzik, Tina; Ivic, Nives; Filic, Zelimira; Manjasetty, Babu A.; Herron, Paul; Luic, Marija; Vujaklija, Dusica

2013-01-01

21

In vivo neuronal function of the fragile X mental retardation protein is regulated by phosphorylation  

E-print Network

In vivo neuronal function of the fragile X mental retardation protein is regulated November 7, 2011 Fragile X syndrome (FXS), caused by loss of the Fragile X Mental Retardation 1 (FMR1) gene,7). The X-linked neurodevelopmental disorder is caused by the loss of fragile X mental retardation 1 (FMR1

Broadie, Kendal S.

22

Intense and Specialized Dendritic Localization of the Fragile X Mental Retardation Protein in  

E-print Network

Intense and Specialized Dendritic Localization of the Fragile X Mental Retardation Protein in Binaural Brainstem Neurons: A Comparative Study in the Alligator, Chicken, Gerbil, and Human Yuan Wang,1 and functionally dynamic in response to changes in afferent activity. The fragile X mental retardation protein

Rubel, Edwin

23

Fragile X Mental Retardation Syndrome: Structure of the KH1-KH2 Domains of Fragile X Mental Retardation Protein  

SciTech Connect

Fragile X syndrome is the most common form of inherited mental retardation in humans, with an estimated prevalence of about 1 in 4000 males. Although several observations indicate that the absence of functional Fragile X Mental Retardation Protein (FMRP) is the underlying basis of Fragile X syndrome, the structure and function of FMRP are currently unknown. Here, we present an X-ray crystal structure of the tandem KH domains of human FMRP, which reveals the relative orientation of the KH1 and KH2 domains and the location of residue Ile304, whose mutation to Asn is associated with a particularly severe incidence of Fragile X syndrome. We show that the Ile304Asn mutation both perturbs the structure and destabilizes the protein.

Valverde,R.; Poznyakova, I.; Kajander, T.; Venkatraman, J.; Regan, L.

2007-01-01

24

Fragile X Mental Retardation Protein Regulates Heterosynaptic Plasticity in the Hippocampus  

ERIC Educational Resources Information Center

Silencing of a single gene, FMR1, is linked to a highly prevalent form of mental retardation, characterized by social and cognitive impairments, known as fragile X syndrome (FXS). The FMR1 gene encodes fragile X mental retardation protein (FMRP), which negatively regulates translation. Knockout of Fmr1 in mice results in enhanced long-term…

Connor, Steven A.; Hoeffer, Charles A.; Klann, Eric; Nguyen, Peter V.

2011-01-01

25

Fragile X Mental Retardation Protein Targets G Quartet mRNAs Important for Neuronal Function  

Microsoft Academic Search

Loss of fragile X mental retardation protein (FMRP) function causes the fragile X mental retardation syndrome. FMRP harbors three RNA binding domains, associates with polysomes, and is thought to regulate mRNA translation and\\/or localization, but the RNAs to which it binds are unknown. We have used RNA selection to demonstrate that the FMRP RGG box binds intramolecular G quartets. This

Jennifer C. Darnell; Kirk B. Jensen; Peng Jin; Victoria Brown; Stephen T. Warren; Robert B. Darnell

2001-01-01

26

Fragile X mental retardation protein is required for programmed cell death and clearance of developmentally-transient peptidergic neurons  

E-print Network

Fragile X mental retardation protein is required for programmed cell death and clearance Fragile X syndrome (FXS), caused by loss of fragile X mental retardation 1 (FMR1) gene function-trinucleotide repeat expansion in the 5 UTR of the fragile X mental retardation 1 (FMR1) gene (reviewed in Bassell

Broadie, Kendal S.

27

Metabotropic Glutamate Receptors and Fragile X Mental Retardation Protein: Partners in Translational Regulation at the Synapse  

NSDL National Science Digital Library

Fragile X syndrome (FXS) mental retardation is caused by loss-of-function mutations in an RNA-binding protein, fragile X mental retardation protein (FMRP). Previous studies in patients or animal models of FXS have identified alterations in dendritic spine structure, as well as synaptic plasticity induced by metabotropic glutamate receptors (mGluRs). The translation of multiple messenger RNA (mRNA) targets of FMRP is regulated by mGluRs at synapses. Here, we incorporate data from several studies into a working model of how FMRP regulates mGluR-stimulated protein synthesis and, in turn, regulates protein synthesis–dependent synaptic plasticity. Understanding the complex functions of FMRP at the synapse will lead to a better understanding of the neurobiological underpinnings of mental retardation.

Jennifer A. Ronesi (University of Texas Southwestern Medical Center;Department of Neuroscience REV); Kimberly M. Huber (Dallas;Department of Neuroscience, University of Texas Southwestern Medical Center REV)

2008-02-05

28

Fragile X mental retardation protein and synaptic plasticity  

E-print Network

Loss of the translational repressor FMRP causes Fragile X syndrome. In healthy neurons, FMRP modulates the local translation of numerous synaptic proteins. Synthesis of these proteins is required for the maintenance and ...

Sidorov, Michael Samuel

29

Deletion of PTEN Produces Deficits in Conditioned Fear and Increases Fragile X Mental Retardation Protein  

ERIC Educational Resources Information Center

The phosphatase and tensin homolog detected on chromosome 10 (PTEN) gene product modulates activation of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway. The PI3K pathway has been found to be involved in the regulation of the fragile X mental retardation protein, which is important for long-term depression and in the formation of new…

Lugo, Joaquin N.; Smith, Gregory D.; Morrison, Jessica B.; White, Jessika

2013-01-01

30

Proteomic analysis reveals CCT is a target of Fragile X mental retardation protein regulation in Drosophila  

PubMed Central

Fragile X mental retardation protein (FMRP) is an RNA-binding protein that is required for the translational regulation of specific target mRNAs. Loss of FMRP causes Fragile X Syndrome (FXS), the most common form of inherited mental retardation in humans. Understanding the basis for FXS has been limited because few in vivo targets of FMRP have been identified and mechanisms for how FMRP regulates physiological targets is unclear. We have previously demonstrated that Drosophila FMRP (dFMRP) is required in early embryos for cleavage furrow formation. In an effort to identify new targets of dFMRP-dependent regulation and new effectors of cleavage furrow formation, we used two-dimensional difference gel electrophoresis and mass spectrometry to identify proteins that are misexpressed in dfmr1 mutant embryos. Of the 28 proteins identified, we have identified three subunits of the Chaperonin containing TCP-1 (CCT) complex as new direct targets of dFMRP-dependent regulation. Furthermore, we found that the septin Peanut, a known effector of cleavage, is a likely conserved substrate of fly CCT and is mislocalized in both cct and in dfmr1 mutant embryos. Based on these results we propose that dFMRP-dependent regulation of CCT subunits is required for cleavage furrow formation and that at least one of its substrates is affected in dfmr1- embryos suggesting dFMRP-dependent regulation of CCT contributes to the cleavage furrow formation phenotype. PMID:20122915

Monzo, Kate; Dowd, Susan R.; Minden, Jonathan S.; Sisson, John C.

2010-01-01

31

The fragile X mental retardation protein is a ribonucleoprotein containing both nuclear localization and nuclear export signals  

Microsoft Academic Search

Fragile X syndrome is a frequent cause of mental retardation resulting from the absence of FMRP, the protein encoded by the FMR1 gene. FMRP is an RNA-binding protein of unknown function which is associated with ribosomes. To gain insight into FMRP function, we performed immunolocalization analysis of FMRP truncation and fusion constructs which revealed a nuclear localization signal (NLS) in

Derek E. Eberhart; Henry E. Malter; Yue Feng; Stephen T. Warren

1996-01-01

32

A Novel Function for Fragile X Mental Retardation Protein in Translational Activation  

PubMed Central

Fragile X syndrome, the most frequent form of inherited mental retardation, is due to the absence of Fragile X Mental Retardation Protein (FMRP), an RNA-binding protein involved in several steps of RNA metabolism. To date, two RNA motifs have been found to mediate FMRP/RNA interaction, the G-quartet and the “kissing complex,” which both induce translational repression in the presence of FMRP. We show here a new role for FMRP as a positive modulator of translation. FMRP specifically binds Superoxide Dismutase 1 (Sod1) mRNA with high affinity through a novel RNA motif, SoSLIP (Sod1 mRNA Stem Loops Interacting with FMRP), which is folded as three independent stem-loop structures. FMRP induces a structural modification of the SoSLIP motif upon its interaction with it. SoSLIP also behaves as a translational activator whose action is potentiated by the interaction with FMRP. The absence of FMRP results in decreased expression of Sod1. Because it has been observed that brain metabolism of FMR1 null mice is more sensitive to oxidative stress, we propose that the deregulation of Sod1 expression may be at the basis of several traits of the physiopathology of the Fragile X syndrome, such as anxiety, sleep troubles, and autism. PMID:19166269

Bechara, Elias G; Didiot, Marie Cecile; Melko, Mireille; Davidovic, Laetitia; Bensaid, Mounia; Martin, Patrick; Castets, Marie; Pognonec, Philippe; Khandjian, Edouard W; Moine, Hervé; Bardoni, Barbara

2009-01-01

33

Oligophrenin-1 encodes a rhoGAP protein involved in X-linked mental retardation.  

PubMed

Primary or nonspecific X-linked mental retardation (MRX) is a heterogeneous condition in which affected patients do not have any distinctive clinical or biochemical features in common apart from cognitive impairment. Although it is present in approximately 0.15-0.3% of males, most of the genetic defects associated with MRX, which may involve more than ten different genes, remain unknown. Here we report the characterization of a new gene on the long arm of the X-chromosome (position Xq12) and the identification in unrelated individuals of different mutations that are predicted to cause a loss of function. This gene is highly expressed in fetal brain and encodes a protein of relative molecular mass 91K, named oligophrenin-1, which contains a domain typical of a Rho-GTPase-activating protein (rhoGAP). By enhancing their GTPase activity, GAP proteins inactivate small Rho and Ras proteins, so inactivation of rhoGAP proteins might cause constitutive activation of their GTPase targets. Such activation is known to affect cell migration and outgrowth of axons and dendrites in vivo. Our results demonstrate an association between cognitive impairment and a defect in a signalling pathway that depends on a Ras-like GTPase. PMID:9582072

Billuart, P; Bienvenu, T; Ronce, N; des Portes, V; Vinet, M C; Zemni, R; Roest Crollius, H; Carrié, A; Fauchereau, F; Cherry, M; Briault, S; Hamel, B; Fryns, J P; Beldjord, C; Kahn, A; Moraine, C; Chelly, J

1998-04-30

34

Heat Shock Protein 70 Expression is Increased in the Liver of Neonatal Intrauterine Growth Retardation Piglets  

PubMed Central

Intrauterine growth retardation (IUGR) leads to the dysfunction in digestive system, as well as the alteration in the expression of some functional proteins. Heat shock protein 70 (Hsp70) could be induced by various stress factors, but whether Hsp70 expression is changed in neonatal IUGR infants has not been demonstrated. This study was conducted to explore the expression of Hsp70 in the liver by using the IUGR piglet model. Liver and plasma samples were obtained from IUGR and normal birth weight (NBW) piglets at birth. The neonatal IUGR piglets had significantly lower liver weight than their counterparts. The activities of aspartate aminotransferase and alanine aminotransferase in serum were enhanced significantly in IUGR indicating liver dysfunction. The activities of superoxide dismutase (p<0.01), glutathione peroxidase (p<0.01) and catalase (p>0.05) were lower and the level of malondialdehybe was higher (p<0.05) in IUGR liver compared with in NBW. According to the results of histological tests, fatty hepatic infiltrates and cytoplasmic vacuolization were present in the liver of IUGR piglets, but not in NBW liver. The expression of Hsp70 protein was significantly higher (p<0.05) in IUGR piglet liver than in NBW. Similar to where the hepatic injuries were observed, location of Hsp70 was mostly in the midzonal hepatic lobule indicating that oxidative stress might be responsible for the increased expression of Hsp70. PMID:25049668

Li, Wei; Zhong, Xiang; Zhang, Lili; Wang, Yuanxiao; Wang, Tian

2012-01-01

35

Differential domain evolution and complex RNA processing in a family of paralogous EPB41 (protein 4.1) genes facilitates expression of diverse tissue-specific isoforms  

SciTech Connect

The EPB41 (protein 4.1) genes epitomize the resourcefulness of the mammalian genome to encode a complex proteome from a small number of genes. By utilizing alternative transcriptional promoters and tissue-specific alternative pre-mRNA splicing, EPB41, EPB41L2, EPB41L3, and EPB41L1 encode a diverse array of structural adapter proteins. Comparative genomic and transcript analysis of these 140kb-240kb genes indicates several unusual features: differential evolution of highly conserved exons encoding known functional domains, interspersed with unique exons whose size and sequence variations contribute substantially to intergenic diversity: alternative first exons, most of which map far upstream of the coding regions; and complex tissue-specific alternative pre-mRNA splicing that facilitates synthesis of functionally different complements of 4.1 proteins in various cells. Understanding the splicing regulatory networks that control protein 4.1 expression will be critical to a full appreciation of the many roles of 4.1 proteins in normal cell biology and their proposed roles in human cancer.

Parra, Marilyn; Gee, Sherry; Chan, Nadine; Ryaboy, Dmitriy; Dubchak, Inna; Narla, Mohandas; Gascard, Philippe D.; Conboy, John G.

2004-07-15

36

Biochemical and genetic interaction between the fragile X mental retardation protein and the microRNA pathway  

Microsoft Academic Search

Fragile X syndrome is caused by a loss of expression of the fragile X mental retardation protein (FMRP). FMRP is a selective RNA-binding protein which forms a messenger ribonucleoprotein (mRNP) complex that associates with polyribosomes. Recently, mRNA ligands associated with FMRP have been identified. However, the mechanism by which FMRP regulates the translation of its mRNA ligands remains unclear. MicroRNAs

Peng Jin; Daniela C Zarnescu; Stephanie Ceman; Mika Nakamoto; Julie Mowrey; Thomas A Jongens; David L Nelson; Kevin Moses; Stephen T Warren

2004-01-01

37

Sequence variation of alcohol dehydrogenase (Adh) paralogs in cactophilic Drosophila.  

PubMed Central

This study focuses on the population genetics of alcohol dehydrogenase (Adh) in cactophilic Drosophila. Drosophila mojavensis and D. arizonae utilize cactus hosts, and each host contains a characteristic mixture of alcohol compounds. In these Drosophila species there are two functional Adh loci, an adult form (Adh-2) and a larval and ovarian form (Adh-1). Overall, the greater level of variation segregating in D. arizonae than in D. mojavensis suggests a larger population size for D. arizonae. There are markedly different patterns of variation between the paralogs across both species. A 16-bp intron haplotype segregates in both species at Adh-2, apparently the product of an ancient gene conversion event between the paralogs, which suggests that there is selection for the maintenance of the intron structure possibly for the maintenance of pre-mRNA structure. We observe a pattern of variation consistent with adaptive protein evolution in the D. mojavensis lineage at Adh-1, suggesting that the cactus host shift that occurred in the divergence of D. mojavensis from D. arizonae had an effect on the evolution of the larval expressed paralog. Contrary to previous work we estimate a recent time for both the divergence of D. mojavensis and D. arizonae (2.4 +/- 0.7 MY) and the age of the gene duplication (3.95 +/- 0.45 MY). PMID:12586706

Matzkin, Luciano M; Eanes, Walter F

2003-01-01

38

Tumor-specific silencing of COPZ2 gene encoding coatomer protein complex subunit ? 2 renders tumor cells dependent on its paralogous gene COPZ1.  

PubMed

Anticancer drugs are effective against tumors that depend on the molecular target of the drug. Known targets of cytotoxic anticancer drugs are involved in cell proliferation; drugs acting on such targets are ineffective against nonproliferating tumor cells, survival of which leads to eventual therapy failure. Function-based genomic screening identified the coatomer protein complex ?1 (COPZ1) gene as essential for different tumor cell types but not for normal cells. COPZ1 encodes a subunit of coatomer protein complex 1 (COPI) involved in intracellular traffic and autophagy. The knockdown of COPZ1, but not of COPZ2 encoding isoform coatomer protein complex ?2, caused Golgi apparatus collapse, blocked autophagy, and induced apoptosis in both proliferating and nondividing tumor cells. In contrast, inhibition of normal cell growth required simultaneous knockdown of both COPZ1 and COPZ2. COPZ2 (but not COPZ1) was down-regulated in the majority of tumor cell lines and in clinical samples of different cancer types. Reexpression of COPZ2 protected tumor cells from killing by COPZ1 knockdown, indicating that tumor cell dependence on COPZ1 is the result of COPZ2 silencing. COPZ2 displays no tumor-suppressive activities, but it harbors microRNA 152, which is silenced in tumor cells concurrently with COPZ2 and acts as a tumor suppressor in vitro and in vivo. Silencing of microRNA 152 in different cancers and the ensuing down-regulation of its host gene COPZ2 offer a therapeutic opportunity for proliferation-independent selective killing of tumor cells by COPZ1-targeting agents. PMID:21746916

Shtutman, Michael; Baig, Mirza; Levina, Elina; Hurteau, Gregory; Lim, Chang-Uk; Broude, Eugenia; Nikiforov, Mikhail; Harkins, Timothy T; Carmack, C Steven; Ding, Ye; Wieland, Felix; Buttyan, Ralph; Roninson, Igor B

2011-07-26

39

Tumor-specific silencing of COPZ2 gene encoding coatomer protein complex subunit ?2 renders tumor cells dependent on its paralogous gene COPZ1  

PubMed Central

Anticancer drugs are effective against tumors that depend on the molecular target of the drug. Known targets of cytotoxic anticancer drugs are involved in cell proliferation; drugs acting on such targets are ineffective against nonproliferating tumor cells, survival of which leads to eventual therapy failure. Function-based genomic screening identified the coatomer protein complex ?1 (COPZ1) gene as essential for different tumor cell types but not for normal cells. COPZ1 encodes a subunit of coatomer protein complex 1 (COPI) involved in intracellular traffic and autophagy. The knockdown of COPZ1, but not of COPZ2 encoding isoform coatomer protein complex ?2, caused Golgi apparatus collapse, blocked autophagy, and induced apoptosis in both proliferating and nondividing tumor cells. In contrast, inhibition of normal cell growth required simultaneous knockdown of both COPZ1 and COPZ2. COPZ2 (but not COPZ1) was down-regulated in the majority of tumor cell lines and in clinical samples of different cancer types. Reexpression of COPZ2 protected tumor cells from killing by COPZ1 knockdown, indicating that tumor cell dependence on COPZ1 is the result of COPZ2 silencing. COPZ2 displays no tumor-suppressive activities, but it harbors microRNA 152, which is silenced in tumor cells concurrently with COPZ2 and acts as a tumor suppressor in vitro and in vivo. Silencing of microRNA 152 in different cancers and the ensuing down-regulation of its host gene COPZ2 offer a therapeutic opportunity for proliferation-independent selective killing of tumor cells by COPZ1-targeting agents. PMID:21746916

Shtutman, Michael; Baig, Mirza; Levina, Elina; Hurteau, Gregory; Lim, Chang-uk; Broude, Eugenia; Nikiforov, Mikhail; Harkins, Timothy T.; Carmack, C. Steven; Ding, Ye; Wieland, Felix; Buttyan, Ralph; Roninson, Igor B.

2011-01-01

40

Structural and functional characterisation of a conserved archaeal RadA paralog with antirecombinase activity  

PubMed Central

Summary DNA recombinases (RecA in bacteria, Rad51 in eukarya and RadA in archaea) catalyse strand-exchange between homologous DNA molecules, the central reaction of homologous recombination, and are among the most conserved DNA repair proteins known. In bacteria, RecA is the sole protein responsible for this reaction, whereas, in eukaryotes, there are several RAD51 paralogs that cooperate to catalyse strand exchange. All archaea have at least one (and as many as four) RadA paralogs, but their function remains unclear. Here we show the three RadA paralogs encoded by the Sulfolobus solfataricus genome are expressed under normal growth conditions, and are not UV-inducible. We demonstrate that one of these proteins, Sso2452, which is representative of the large aRadC sub-family of archaeal RadA paralogs, functions as an ATPase that binds tightly to ssDNA. However, Sso2452 is not an active recombinase in vitro, and inhibits D-loop formation by RadA. We present the high-resolution crystal structure of Sso2452, which reveals key structural differences from the canonical RecA family recombinases that may explain its functional properties. The possible roles of the archaeal RadA paralogs in vivo are discussed. PMID:19414020

McRobbie, Anne-Marie; Carter, Lester G.; Kerou, Melina; Liu, Huanting; McMahon, Stephen A.; Johnson, Kenneth A.; Oke, Muse; Naismith, James H.; White, Malcolm F.

2012-01-01

41

Fragile X mental retardation protein stimulates ribonucleoprotein assembly of influenza A virus  

NASA Astrophysics Data System (ADS)

The ribonucleoprotein (RNP) of the influenza A virus is responsible for the transcription and replication of viral RNA in the nucleus. These processes require interplay between host factors and RNP components. Here, we report that the Fragile X mental retardation protein (FMRP) targets influenza virus RNA synthesis machinery and facilitates virus replication both in cell culture and in mice. We demonstrate that FMRP transiently associates with viral RNP and stimulates viral RNP assembly through RNA-mediated interaction with the nucleoprotein. Furthermore, the KH2 domain of FMRP mediates its association with the nucleoprotein. A point mutation (I304N) in the KH2 domain, identified from a Fragile X syndrome patient, disrupts the FMRP-nucleoprotein association and abolishes the ability of FMRP to participate in viral RNP assembly. We conclude that FMRP is a critical host factor used by influenza viruses to facilitate viral RNP assembly. Our observation reveals a mechanism of influenza virus RNA synthesis and provides insights into FMRP functions.

Zhou, Zhuo; Cao, Mengmeng; Guo, Yang; Zhao, Lili; Wang, Jingfeng; Jia, Xue; Li, Jianguo; Wang, Conghui; Gabriel, Gülsah; Xue, Qinghua; Yi, Yonghong; Cui, Sheng; Jin, Qi; Wang, Jianwei; Deng, Tao

2014-02-01

42

Retardation signal for fluorescent determination of total protein content via rapid and sensitive chip moving reaction boundary electrophoretic titration.  

PubMed

A novel concept and theory of moving reaction boundary (MRB) retardation signal (RMRB) was advanced for determination of total protein content via MRB electrophoretic titration (MRBET). The theoretical results revealed that the retardation extent of boundary displacment, viz., the RMRB value, was as a function of protein content. Thus, the RMRB value of a sample could be used to determine its total protein content according to the relevant calibration curve. To demonstrate the concept and theoretical results, a novel microdevice was designed for the relevant experiments of MRBET. The microdevice has 30 identical work cells, each of which is composed of five ultrashort single microchannels (5 mm). In the microdevice, fluorescein isothiocyanate (FITC) was used to denote MRB motion and RMRB value for the first time, the polyacrylamide gel (PAG) containing protein sample was photopolymerized in microchannels, and the MRB was created with acid or alkali and target protein sample. As compared to the classic Kjeldahl method and conventional MRBET performed in glass tube, the developed titration chip has the following merits: good sensitivity (0.3-0.4 ?g/mL vs 150-200 ?g/mL of protein concentration, 0.6-0.8 ng vs 30-2000 ?g of absolute protein content), rapid analysis (20-60 s vs 15-200 min), and portable low-power (15 V vs 200 V). PMID:24512429

Wang, Houyu; Shi, Yongting; Yan, Jian; Dong, Jingyu; Li, Si; Xiao, Hua; Xie, Haiyang; Fan, Liu-Yin; Cao, Cheng-Xi

2014-03-18

43

Characterization of paralogous protein families in rice  

E-print Network

Background: High gene numbers in plant genomes reflect polyploidy and major gene duplication events. Oryza sativa, cultivated rice, is a diploid monocotyledonous species with a ~390 Mb genome that has undergone segmental ...

Lin, Haining

44

Transcriptomic and phenotypic analysis of paralogous spx gene function in Bacillus anthracis Sterne  

PubMed Central

Abstract Spx of Bacillus subtilis is a redox-sensitive protein, which, under disulfide stress, interacts with RNA polymerase to activate genes required for maintaining thiol homeostasis. Spx orthologs are highly conserved among low %GC Gram-positive bacteria, and often exist in multiple paralogous forms. In this study, we used B. anthracis Sterne, which harbors two paralogous spx genes, spxA1 and spxA2, to examine the phenotypes of spx null mutations and to identify the genes regulated by each Spx paralog. Cells devoid of spxA1 were sensitive to diamide and hydrogen peroxide, while the spxA1 spoxA2 double mutant was hypersensitive to the thiol-specific oxidant, diamide. Bacillus anthracis Sterne strains expressing spxA1DD or spxA2DD alleles encoding protease-resistant products were used in microarray and quantitative real-time polymerase chain reaction (RT-qPCR) analyses in order to uncover genes under SpxA1, SpxA2, or SpxA1/SpxA2 control. Comparison of transcriptomes identified many genes that were upregulated when either SpxA1DD or SpxA2DD was produced, but several genes were uncovered whose transcript levels increased in only one of the two SpxADD-expression strains, suggesting that each Spx paralog governs a unique regulon. Among genes that were upregulated were those encoding orthologs of proteins that are specifically involved in maintaining intracellular thiol homeostasis or alleviating oxidative stress. Some of these genes have important roles in B. anthracis pathogenesis, and a large number of upregulated hypothetical genes have no homology outside of the B. cereus/thuringiensis group. Microarray and RT-qPCR analyses also unveiled a regulatory link that exists between the two spx paralogous genes. The data indicate that spxA1 and spxA2 are transcriptional regulators involved in relieving disulfide stress but also control a set of genes whose products function in other cellular processes. Bacillus anthracis harbors two paralogs of the global transcriptional regulator of stress response, SpxA. SpxA1 and SpxA2 contribute to disulfide stress tolerance, but only SpxA1 functions in resistance to peroxide. Transcriptome analysis uncovered potential SpxA1 and SpxA2 regulon members, which include genes activated by both paralogs. However, paralog-specific gene activation was also observed. Genes encoding glutamate racemase, CoA disulfide reductase, and products functioning in bacillithiol biosynthesis, are among the genes activated by the SpxA paralogs. PMID:23873705

Barendt, Skye; Lee, Hyunwoo; Birch, Cierra; Nakano, Michiko M; Jones, Marcus; Zuber, Peter

2013-01-01

45

Detection of aneuploidies by paralogous sequence quantification  

PubMed Central

Background: Chromosomal aneuploidies are a common cause of congenital disorders associated with cognitive impairment and multiple dysmorphic features. Pre-natal diagnosis of aneuploidies is most commonly performed by the karyotyping of fetal cells obtained by amniocentesis or chorionic villus sampling, but this method is labour intensive and requires about 14 days to complete. Methods: We have developed a PCR based method for the detection of targeted chromosome number abnormalities termed paralogous sequence quantification (PSQ), based on the use of paralogous genes. Paralogous sequences have a high degree of sequence identity, but accumulate nucleotide substitutions in a locus specific manner. These sequence differences, which we term paralogous sequence mismatches (PSMs), can be quantified using pyrosequencing technology, to estimate the relative dosage between different chromosomes. We designed 10 assays for the detection of trisomies of chromosomes 13, 18, and 21 and sex chromosome aneuploidies. Results: We evaluated the performance of this method on 175 DNAs, highly enriched for abnormal samples. A correct and unambiguous diagnosis was given for 119 out of 120 aneuploid samples as well as for all the controls. One sample which gave an intermediate value for the chromosome 13 assays could not be diagnosed. Conclusions: Our data suggests that PSQ is a robust, easy to interpret, and easy to set up method for the diagnosis of common aneuploidies, and can be performed in less than 48 h, representing a competitive alternative for widespread use in diagnostic laboratories. PMID:15591276

Deutsch, S; Choudhury, U; Merla, G; Howald, C; Sylvan, A; Antonarakis, S

2004-01-01

46

Identification of TGF-?, inhibin ?A and follistatin paralogs in the rainbow trout genome.  

PubMed

Since their initial discovery, TGF-? superfamily members have been considered multifunctional growth and differentiation factors in many cell types. Various studies have clearly demonstrated the key roles of specific TGF-? members in muscle growth, including myostatin and inhibin as well as genes, such as follistatin. By binding to TGF-? members, follistatin prevents TGF-? from binding to its receptors and thus neutralizes its activity. Here, we report the identification of the gene sequences of four TGF-? isoforms and three paralogs of TGF-?1, which we called TGF-?1a, TGF-?1b and TGF-?1c, four sequences of inhibin ?A paralogs; and two sequences of follistatin paralogs from rainbow trout. A phylogenetic analysis clearly indicated the existence of four monophyletic clades, corresponding to TGF-?1, -?2, -?3 and -?6. Based on their sequence identity TGF-?1a and -?1c are grouped together, whereas TGF-?1b appears more divergent even though it is grouped within the TGF-?1 clade. Alignments and phylogenetic analyses showed that the protein sequences of TGF-?, inhibin ?A and follistatin are extremely well conserved (>90%) relative to each other; however, their regulation and expression patterns are different. TGF-?2 and -?3 showed the most abundant expression in muscle and were the main TGF-? members expressed in this tissue. Follistatin and inhibin ?A paralogs were expressed in all tissues examined but with different patterns. Our identification of multiple copies of TGF-?, inhibin ?A and follistatin with different expression patterns suggests non-redundant functions for these paralogs in rainbow trout. PMID:25149133

de Mello, Fernanda; Streit, Danilo Pedro; Sabin, Nathalie; Gabillard, Jean-Charles

2014-01-01

47

Orthologs, paralogs and genome comparisons  

NASA Technical Reports Server (NTRS)

During the past decade, ancient gene duplications were recognized as one of the main forces in the generation of diverse gene families and the creation of new functional capabilities. New tools developed to search data banks for homologous sequences, and an increased availability of reliable three-dimensional structural information led to the recognition that proteins with diverse functions can belong to the same superfamily. Analyses of the evolution of these superfamilies promises to provide insights into early evolution but are complicated by several important evolutionary processes. Horizontal transfer of genes can lead to a vertical spread of innovations among organisms, therefore finding a certain property in some descendants of an ancestor does not guarantee that it was present in that ancestor. Complete or partial gene conversion between duplicated genes can yield phylogenetic trees with several, apparently independent gene duplications, suggesting an often surprising parallelism in the evolution of independent lineages. Additionally, the breakup of domains within a protein and the fusion of domains into multifunctional proteins makes the delineation of superfamilies a task that remains difficult to automate.

Gogarten, J. P.; Olendzenski, L.

1999-01-01

48

Structural Studies of the Tandem Tudor Domains of Fragile X Mental Retardation Related Proteins FXR1 and FXR2  

SciTech Connect

Expansion of the CGG trinucleotide repeat in the 5'-untranslated region of the FMR1, fragile X mental retardation 1, gene results in suppression of protein expression for this gene and is the underlying cause of Fragile X syndrome. In unaffected individuals, the FMRP protein, together with two additional paralogues (Fragile X Mental Retardation Syndrome-related Protein 1 and 2), associates with mRNA to form a ribonucleoprotein complex in the nucleus that is transported to dendrites and spines of neuronal cells. It is thought that the fragile X family of proteins contributes to the regulation of protein synthesis at sites where mRNAs are locally translated in response to stimuli. Here, we report the X-ray crystal structures of the non-canonical nuclear localization signals of the FXR1 and FXR2 autosomal paralogues of FMRP, which were determined at 2.50 and 1.92 {angstrom}, respectively. The nuclear localization signals of the FXR1 and FXR2 comprise tandem Tudor domain architectures, closely resembling that of UHRF1, which is proposed to bind methylated histone H3K9. The FMRP, FXR1 and FXR2 proteins comprise a small family of highly conserved proteins that appear to be important in translational regulation, particularly in neuronal cells. The crystal structures of the N-terminal tandem Tudor domains of FXR1 and FXR2 revealed a conserved architecture with that of FMRP. Biochemical analysis of the tandem Tudor doamins reveals their ability to preferentially recognize trimethylated peptides in a sequence-specific manner.

Adams-Cioaba, Melanie A.; Guo, Yahong; Bian, ChuanBing; Amaya, Maria F.; Lam, Robert; Wasney, Gregory A.; Vedadi, Masoud; Xu, Chao; Min, Jinrong (Toronto)

2011-11-23

49

Phosphorylated fragile X mental retardation protein at serine 499, is reduced in cerebellar vermis and superior frontal cortex of subjects with autism: implications for fragile X mental retardation protein-metabotropic glutamate receptor 5 signaling.  

PubMed

Lohith et al. (Mol Autism 4:15, 2013) recently identified increased metabotropic glutamate receptor 5 (mGluR5) expression in the frontal cortex (FC) of subjects with fragile X syndrome. These results are consistent with postmortem findings in cerebellar vermis and FC of subjects with autism (Fatemi and Folsom, Mol Autism 2:6, 2011; Fatemi et al. Anat Rec 294:1635-1645, 2011), suggesting that increased mGluR5 signaling is common to multiple autism spectrum disorders. Increased mGluR5 signaling may be associated with reduced phosphorylation of fragile X mental retardation protein (FMRP), which could result in the inactivation of this protein. In the current study, we report on reduced expression of phosphorylated FMRP in cerebellar vermis of adults and children with autism and in FC of adults with autism. PMID:24180586

Rustan, Oyvind G; Folsom, Timothy D; Yousefi, Mahtab K; Fatemi, S Hossein

2013-01-01

50

Phosphorylated fragile X mental retardation protein at serine 499, is reduced in cerebellar vermis and superior frontal cortex of subjects with autism: implications for fragile X mental retardation protein-metabotropic glutamate receptor 5 signaling  

PubMed Central

Lohith et al. (Mol Autism 4:15, 2013) recently identified increased metabotropic glutamate receptor 5 (mGluR5) expression in the frontal cortex (FC) of subjects with fragile X syndrome. These results are consistent with postmortem findings in cerebellar vermis and FC of subjects with autism (Fatemi and Folsom, Mol Autism 2:6, 2011; Fatemi et al. Anat Rec 294:1635–1645, 2011), suggesting that increased mGluR5 signaling is common to multiple autism spectrum disorders. Increased mGluR5 signaling may be associated with reduced phosphorylation of fragile X mental retardation protein (FMRP), which could result in the inactivation of this protein. In the current study, we report on reduced expression of phosphorylated FMRP in cerebellar vermis of adults and children with autism and in FC of adults with autism. PMID:24180586

2013-01-01

51

The Creatine Transporter Gene Paralogous at 16p11.2 Is Expressed in Human Brain  

PubMed Central

Autism is a complex neurodevelopmental disorder characterized by impairment of social interaction, language, communication, and stereotyped, repetitive behavior. Genetic predisposition to autism has been demonstrated in families and twin studies. About 5–10% of autism cases are associated with chromosomal abnormalities or monogenic disorders. The identification of genes involved in the origin of autism is expected to increase our understanding of the pathogenesis. We report on the clinical, cytogenetic, and molecular findings in a boy with autism carrying a de novo translocation t(7;16)(p22.1;p11.2). The chromosome 16 breakpoint disrupts the paralogous SLC6A8 gene also called SLC6A10 or CT2. Predicted translation of exons and RT-PCR analysis reveal specific expression of the creatine transporter paralogous in testis and brain. Several studies reported on the role of X-linked creatine transporter mutations in individuals with mental retardation, with or without autism. The existence of disruption in SLC6A8 paralogous gene associated with idiopathic autism suggests that this gene may be involved in the autistic phenotype in our patient. PMID:18509488

Bayou, Nadia; M’rad, Ridha; Belhaj, Ahlem; Daoud, Hussein; Zemni, Ramzi; Briault, Sylvain; Helayem, M. Béchir; Ben Jemaa, Lamia; Chaabouni, Habiba

2008-01-01

52

The creatine transporter gene paralogous at 16p11.2 is expressed in human brain.  

PubMed

Autism is a complex neurodevelopmental disorder characterized by impairment of social interaction, language, communication, and stereotyped, repetitive behavior. Genetic predisposition to autism has been demonstrated in families and twin studies. About 5-10% of autism cases are associated with chromosomal abnormalities or monogenic disorders. The identification of genes involved in the origin of autism is expected to increase our understanding of the pathogenesis. We report on the clinical, cytogenetic, and molecular findings in a boy with autism carrying a de novo translocation t(7;16)(p22.1;p11.2). The chromosome 16 breakpoint disrupts the paralogous SLC6A8 gene also called SLC6A10 or CT2. Predicted translation of exons and RT-PCR analysis reveal specific expression of the creatine transporter paralogous in testis and brain. Several studies reported on the role of X-linked creatine transporter mutations in individuals with mental retardation, with or without autism. The existence of disruption in SLC6A8 paralogous gene associated with idiopathic autism suggests that this gene may be involved in the autistic phenotype in our patient. PMID:18509488

Bayou, Nadia; M'rad, Ridha; Belhaj, Ahlem; Daoud, Hussein; Zemni, Ramzi; Briault, Sylvain; Helayem, M Béchir; Ben Jemaa, Lamia; Chaabouni, Habiba

2008-01-01

53

Analysis of paralogous pontin and reptin gene expression during mouse development  

Microsoft Academic Search

Evolutionarily conserved from yeast to human, the paralogous DNA helicases Pontin (Pont) and Reptin (Rept) are simultaneously\\u000a recruited in multi-protein chromatin complexes that function in different aspects of DNA metabolism (transcription, replication\\u000a and repair). When assayed, the two proteins were found to be essential for viability and to play antagonistic roles, suggesting\\u000a that the balance of Pont\\/Rept regulates epigenetic programmes

Sophie Chauvet; Fabrice Usseglio; Denise Aragnol; Jacques Pradel

2005-01-01

54

Release Retardation of Model Protein on Polyelectrolyte-Coated PLGA Nano- and Microparticles  

PubMed Central

PEM capsules have been proposed for vehicles of drug microencapsulation, with the release triggered by pH, salt, magnetic field, or light. When built on another carrier encapsulating drugs, such as nanoparticles, it could provide additional release barrier to the releasing drug, providing further control to drug release. Although liposomes have received considerable attention with PEM coating for sustained drug release, similar results employing PEM built on poly(lactic-co-lycolic acid) (PLGA) particles is scant. In this work, we demonstrate that the build-up pH and polyelectrolyte pairs of PEM affect the release retardation of BSA from PLGA particles. PAH/PSS pair, the most commonly used polyelectrolyte pair, was used in comparison with PLL/DES. In addition, we also demonstrate that the release retardation effect of PEM-coated PLGA particles diminishes as the particle size increases. We attribute this to the diminishing relative thickness of the PEM coating with respect to the size of the particle as the particle size increases, reducing the diffusional resistance of the PEM. PMID:24647768

Nugraha, Chandra; Bora, Meghali; Venkatraman, Subbu S.

2014-01-01

55

Boronate Complex Formation with Dopa Containing Mussel Adhesive Protein Retards pH-Induced Oxidation and Enables Adhesion to Mica  

PubMed Central

The biochemistry of mussel adhesion has inspired the design of surface primers, adhesives, coatings and gels for technological applications. These mussel-inspired systems often focus on incorporating the amino acid 3,4-dihydroxyphenyl-L-alanine (Dopa) or a catecholic analog into a polymer. Unfortunately, effective use of Dopa is compromised by its susceptibility to auto-oxidation at neutral pH. Oxidation can lead to loss of adhesive function and undesired covalent cross-linking. Mussel foot protein 5 (Mfp-5), which contains ?30 mole % Dopa, is a superb adhesive under reducing conditions but becomes nonadhesive after pH-induced oxidation. Here we report that the bidentate complexation of borate by Dopa to form a catecholato-boronate can be exploited to retard oxidation. Although exposure of Mfp-5 to neutral pH typically oxidizes Dopa, resulting in a>95% decrease in adhesion, inclusion of borate retards oxidation at the same pH. Remarkably, this Dopa-boronate complex dissociates upon contact with mica to allow for a reversible Dopa-mediated adhesion. The borate protection strategy allows for Dopa redox stability and maintained adhesive function in an otherwise oxidizing environment. PMID:25303409

Israelachvili, Jacob N.; Chen, Yunfei; Waite, J. Herbert

2014-01-01

56

Fragile X mental retardation protein controls synaptic vesicle exocytosis by modulating N-type calcium channel density  

PubMed Central

Fragile X syndrome (FXS), the most common heritable form of mental retardation, is characterized by synaptic dysfunction. Synaptic transmission depends critically on presynaptic calcium entry via voltage-gated calcium (CaV) channels. Here we show that the functional expression of neuronal N-type CaV channels (CaV2.2) is regulated by fragile X mental retardation protein (FMRP). We find that FMRP knockdown in dorsal root ganglion neurons increases CaV channel density in somata and in presynaptic terminals. We then show that FMRP controls CaV2.2 surface expression by targeting the channels to the proteasome for degradation. The interaction between FMRP and CaV2.2 occurs between the carboxy-terminal domain of FMRP and domains of CaV2.2 known to interact with the neurotransmitter release machinery. Finally, we show that FMRP controls synaptic exocytosis via CaV2.2 channels. Our data indicate that FMRP is a potent regulator of presynaptic activity, and its loss is likely to contribute to synaptic dysfunction in FXS. PMID:24709664

Ferron, Laurent; Nieto-Rostro, Manuela; Cassidy, John S.; Dolphin, Annette C.

2014-01-01

57

Fragile X mental retardation protein controls synaptic vesicle exocytosis by modulating N-type calcium channel density  

NASA Astrophysics Data System (ADS)

Fragile X syndrome (FXS), the most common heritable form of mental retardation, is characterized by synaptic dysfunction. Synaptic transmission depends critically on presynaptic calcium entry via voltage-gated calcium (CaV) channels. Here we show that the functional expression of neuronal N-type CaV channels (CaV2.2) is regulated by fragile X mental retardation protein (FMRP). We find that FMRP knockdown in dorsal root ganglion neurons increases CaV channel density in somata and in presynaptic terminals. We then show that FMRP controls CaV2.2 surface expression by targeting the channels to the proteasome for degradation. The interaction between FMRP and CaV2.2 occurs between the carboxy-terminal domain of FMRP and domains of CaV2.2 known to interact with the neurotransmitter release machinery. Finally, we show that FMRP controls synaptic exocytosis via CaV2.2 channels. Our data indicate that FMRP is a potent regulator of presynaptic activity, and its loss is likely to contribute to synaptic dysfunction in FXS.

Ferron, Laurent; Nieto-Rostro, Manuela; Cassidy, John S.; Dolphin, Annette C.

2014-04-01

58

Fragile X related protein 1 isoforms differentially modulate the affinity of fragile X mental retardation protein for G-quartet RNA structure  

PubMed Central

Fragile X syndrome, the most frequent form of inherited mental retardation, is due to the absence of expression of the Fragile X Mental Retardation Protein (FMRP), an RNA binding protein with high specificity for G-quartet RNA structure. FMRP is involved in several steps of mRNA metabolism: nucleocytoplasmic trafficking, translational control and transport along dendrites in neurons. Fragile X Related Protein 1 (FXR1P), a homologue and interactor of FMRP, has been postulated to have a function similar to FMRP, leading to the hypothesis that it can compensate for the absence of FMRP in Fragile X patients. Here we analyze the ability of three isoforms of FXR1P, expressed in different tissues, to bind G-quartet RNA structure specifically. Only the longest FXR1P isoform was found to be able to bind specifically the G-quartet RNA, albeit with a lower affinity as compared to FMRP, whereas the other two isoforms negatively regulate the affinity of FMRP for G-quartet RNA. This result is important to decipher the molecular basis of fragile X syndrome, through the understanding of FMRP action in the context of its multimolecular complex in different tissues. In addition, we show that the action of FXR1P is synergistic rather than compensatory for FMRP function. PMID:17170008

Bechara, Elias; Davidovic, Laetitia; Melko, Mireille; Bensaid, Mounia; Tremblay, Sandra; Grosgeorge, Josiane; Khandjian, Edouard W.; Lalli, Enzo; Bardoni, Barbara

2007-01-01

59

Contrasted patterns of selective pressure in three recent paralogous gene pairs in the Medicago genus (L.)  

PubMed Central

Background Gene duplications are a molecular mechanism potentially mediating generation of functional novelty. However, the probabilities of maintenance and functional divergence of duplicated genes are shaped by selective pressures acting on gene copies immediately after the duplication event. The ratio of non-synonymous to synonymous substitution rates in protein-coding sequences provides a means to investigate selective pressures based on genic sequences. Three molecular signatures can reveal early stages of functional divergence between gene copies: change in the level of purifying selection between paralogous genes, occurrence of positive selection, and transient relaxed purifying selection following gene duplication. We studied three pairs of genes that are known to be involved in an interaction with symbiotic bacteria and were recently duplicated in the history of the Medicago genus (Fabaceae). We sequenced two pairs of polygalacturonase genes (Pg11-Pg3 and Pg11a-Pg11c) and one pair of auxine transporter-like genes (Lax2-Lax4) in 17 species belonging to the Medicago genus, and sought for molecular signatures of differentiation between copies. Results Selective histories revealed by these three signatures of molecular differentiation were found to be markedly different between each pair of paralogs. We found sites under positive selection in the Pg11 paralogs while Pg3 has mainly evolved under purifying selection. The most recent paralogs examined Pg11a and Pg11c, are both undergoing positive selection and might be acquiring new functions. Lax2 and Lax4 paralogs are both under strong purifying selection, but still underwent a temporary relaxation of purifying selection immediately after duplication. Conclusions This study illustrates the variety of selective pressures undergone by duplicated genes and the effect of age of the duplication. We found that relaxation of selective constraints immediately after duplication might promote adaptive divergence. PMID:23025552

2012-01-01

60

Brominated flame retardants, tetrabromobisphenol A and hexabromocyclododecane, activate mitogen-activated protein kinases (MAPKs) in human natural killer cells.  

PubMed

Natural killer (NK) cells provide a vital surveillance against virally infected cells, tumor cells, and antibody-coated cells through the release of cytolytic mediators and gamma interferon (IFN-?). Hexabromocyclododecane (HBCD) is a brominated flame retardant used primarily in expanded (EPS) and extruded (XPS) polystyrene foams for thermal insulation in the building and construction industry. Tetrabromobisphenol A (TBBPA) is used both as a reactive and an additive flame retardant in a variety of materials. HBCD and TBBPA contaminate the environment and are found in human blood samples. In previous studies, we have shown that other environmental contaminants, such as the dibutyltin (DBT) and tributyltin (TBT), decrease NK lytic function by activating mitogen-activated protein kinases (MAPKs) in the NK cells. HBCD and TBBPA also interfere with NK cell(s) lytic function. The current study evaluates whether HBCD and/or TBBPA have the capacity to activate MAPKs and MAPK kinases (MAP2Ks). The effects of concentrations of HBCD and TBBPA that inhibited lytic function on the phosphorylation state and total levels of the MAPKs (p44/42, p38, and JNK) and the phosphorylation and total levels of the MAP2Ks (MEK1/2 and MKK3/6) were examined. Results indicate that exposure of human NK cells to 10-0.5 ?M HBCD or TBBPA activate MAPKs and MAP2Ks. This HBCD and TBBPA-induced activation of MAPKs may leave them unavailable for activation by virally infected or tumor target cells and thus contributes to the observed decreases in lytic function seen in NK cells exposed to HBCD and TBBPA. PMID:25341744

Cato, Anita; Celada, Lindsay; Kibakaya, Esther Caroline; Simmons, Nadia; Whalen, Margaret M

2014-12-01

61

Expression of fragile X mental retardation protein in neurons and glia of the developing and adult mouse brain.  

PubMed

Fragile X syndrome is the most common inherited form of mental retardation and autism. It is caused by a reduction or elimination of the expression of fragile X mental retardation protein (FMRP). Because fragile X syndrome is a neurodevelopmental disorder, it is important to fully document the cell type expression in the developing CNS to provide a better understanding of the molecular function of FMRP, and the pathogenesis of the syndrome. We investigated FMRP expression in the brain using double-labeling immunocytochemistry and cell type markers for neurons (NeuN), astrocytes (S100?), microglia (Iba-1), and oligodendrocyte precursor cells (NG2). The hippocampus, striatum, cingulate cortex, retrosplenial cortex, corpus callosum and cerebellum were assessed in wild-type C57/BL6 mice at postnatal days 0, 10, 20, and adult. Our results demonstrate that FMRP is ubiquitously expressed in neurons at all times and brain regions studied, except for corpus callosum where FMRP was predominantly present in astrocytes at all ages. FMRP expression in Iba-1 and NG2-positive cells was detected at postnatal day 0 and 10 and gradually decreased to very low or undetectable levels in postnatal day 20 and adult mice. Our results reveal that in addition to continuous and extensive expression in neurons in the immature and mature brain, FMRP is also present in astrocytes, oligodendrocyte precursor cells, and microglia during the early and mid-postnatal developmental stages of brain maturation. Prominent expression of FMRP in glia during these crucial stages of brain development suggests an important contribution to normal brain function, and in its absence, to the fragile X phenotype. PMID:25446451

Gholizadeh, Shervin; Halder, Sebok Kumar; Hampson, David R

2015-01-30

62

ER stress-induced protein, VIGG, disturbs plant cation homeostasis, which is correlated with growth retardation and robustness to ER stress  

SciTech Connect

Highlights: {yields} VIGG is an ER stress-induced protein in plant. {yields} We examine the characteristics of VIGG-overexpressing Arabidopsis plants. {yields} VIGG-overexpressing plants reveal growth retardation and robustness to ER stress. {yields} VIGG disturbs cation homeostasis in plant. -- Abstract: VIGG is a putative endoplasmic reticulum (ER) resident protein induced by virus infection and ER stress, and is correlated with fruit quality in grapevine. The present study was undertaken to determine the biological function of VIGG in grapevine. Experiments using fluorescent protein-VIGG fusion protein demonstrated that VIGG is localized in ER and the ER targeting sequence is in the N-terminus. The overexpression of VIGG in Arabidopsis plant led to growth retardation. The rosette leaves of VIGG-overexpressing plants were smaller than those of the control plants and rolled at 42 days after seeding. VIGG-overexpressing plants revealed robustness to ER stress as well as the low expression of ER stress marker proteins, such as the luminal binding proteins. These characteristics of VIGG-overexpressing plants were supported by a microarray experiment that demonstrated the disruption of genes related to ER stress response and flowering, as well as cation mobility, in the plants. Finally, cation homeostasis in the plants was disturbed by the overexpression of VIGG. Taken together, these results suggest that VIGG may disturb cation homeostasis in plant, which is correlated with the robustness to ER stress and growth retardation.

Katoh, Hironori; Fujita, Keiko; Takuhara, Yuki [Laboratory of Fruit Genetic Engineering, The Institute of Enology and Viticulture, University of Yamanashi, Kofu, Yamanashi 400-0005 (Japan)] [Laboratory of Fruit Genetic Engineering, The Institute of Enology and Viticulture, University of Yamanashi, Kofu, Yamanashi 400-0005 (Japan); Ogawa, Atsushi [Department of Biological Production, Akita Prefectural University, Shimosinjyou-nakano 241-438, Akita 010-0195 (Japan)] [Department of Biological Production, Akita Prefectural University, Shimosinjyou-nakano 241-438, Akita 010-0195 (Japan); Suzuki, Shunji, E-mail: suzukis@yamanashi.ac.jp [Laboratory of Fruit Genetic Engineering, The Institute of Enology and Viticulture, University of Yamanashi, Kofu, Yamanashi 400-0005 (Japan)] [Laboratory of Fruit Genetic Engineering, The Institute of Enology and Viticulture, University of Yamanashi, Kofu, Yamanashi 400-0005 (Japan)

2011-02-18

63

Subcellular Fractionation and Localization Studies Reveal a Direct Interaction of the Fragile X Mental Retardation Protein (FMRP) with Nucleolin  

PubMed Central

Fragile X mental Retardation Protein (FMRP) is a well-known regulator of local translation of its mRNA targets in neurons. However, despite its ubiquitous expression, the role of FMRP remains ill-defined in other cell types. In this study we investigated the subcellular distribution of FMRP and its protein complexes in HeLa cells using confocal imaging as well as detergent-free fractionation and size exclusion protocols. We found FMRP localized exclusively to solid compartments, including cytosolic heavy and light membranes, mitochondria, nuclear membrane and nucleoli. Interestingly, FMRP was associated with nucleolin in both a high molecular weight ribosomal and translation-associated complex (?6 MDa) in the cytosol, and a low molecular weight complex (?200 kDa) in the nucleoli. Consistently, we identified two functional nucleolar localization signals (NoLSs) in FMRP that are responsible for a strong nucleolar colocalization of the C-terminus of FMRP with nucleolin, and a direct interaction of the N-terminus of FMRP with the arginine-glycine-glycine (RGG) domain of nucleolin. Taken together, we propose a novel mechanism by which a transient nucleolar localization of FMRP underlies a strong nucleocytoplasmic translocation, most likely in a complex with nucleolin and possibly ribosomes, in order to regulate translation of its target mRNAs. PMID:24658146

Taha, Mohamed S.; Nouri, Kazem; Milroy, Lech G.; Moll, Jens M.; Herrmann, Christian; Brunsveld, Luc; Piekorz, Roland P.; Ahmadian, Mohammad R.

2014-01-01

64

Mutations in mitochondrial ribosomal protein MRPL12 leads to growth retardation, neurological deterioration and mitochondrial translation deficiency?  

PubMed Central

Multiple respiratory chain deficiencies represent a common cause of mitochondrial diseases and are associated with a wide range of clinical symptoms. We report a subject, born to consanguineous parents, with growth retardation and neurological deterioration. Multiple respiratory chain deficiency was found in muscle and fibroblasts of the subject as well as abnormal assembly of complexes I and IV. A microsatellite genotyping of the family members detected only one region of homozygosity on chromosome 17q24.2–q25.3 in which we focused our attention to genes involved in mitochondrial translation. We sequenced MRPL12, encoding the mitochondrial ribosomal protein L12 and identified a c.542C>T transition in exon 5 changing a highly conserved alanine into a valine (p.Ala181Val). This mutation resulted in a decreased steady-state level of MRPL12 protein, with altered integration into the large ribosomal subunit. Moreover, an overall mitochondrial translation defect was observed in the subject's fibroblasts with a significant reduction of synthesis of COXI, COXII and COXIII subunits. Modeling of MRPL12 shows Ala181 positioned in a helix potentially involved in an interface of interaction suggesting that the p.Ala181Val change might be predicted to alter interactions with the elongation factors. These results contrast with the eubacterial orthologues of human MRPL12, where L7/L12 proteins do not appear to have a selective effect on translation. Therefore, analysis of the mutated version found in the subject presented here suggests that the mammalian protein does not function in an entirely analogous manner to the eubacterial L7/L12 equivalent. PMID:23603806

Serre, Valérie; Rozanska, Agata; Beinat, Marine; Chretien, Dominique; Boddaert, Nathalie; Munnich, Arnold; Rötig, Agnès; Chrzanowska-Lightowlers, Zofia M.

2013-01-01

65

RAD51 paralogs: roles in DNA damage signalling, recombinational repair and tumorigenesis.  

PubMed

Chromosomal double-strand breaks (DSBs) have the potential to permanently arrest cell cycle progression and endanger cell survival. They must therefore be efficiently repaired to preserve genome integrity and functionality. Homologous recombination (HR) provides an important error-free mechanism for DSB repair in mammalian cells. In addition to RAD51, the central recombinase activity in mammalian cells, a family of proteins known as the RAD51 paralogs and consisting of five proteins (RAD51B, RAD51C, RAD51D, XRCC2 and XRCC3), play an essential role in the DNA repair reactions through HR. The RAD51 paralogs act to transduce the DNA damage signal to effector kinases and to promote break repair. However, their precise cellular functions are not fully elucidated. Here we discuss recent advances in our understanding of how these factors mediate checkpoint responses and act in the HR repair process. In addition, we highlight potential functional similarities with the BRCA2 tumour suppressor, through the recently reported links between RAD51 paralog deficiencies and tumorigenesis triggered by genome instability. PMID:21821141

Suwaki, Natsuko; Klare, Kerstin; Tarsounas, Madalena

2011-10-01

66

Evolutionary Acquisition of Cysteines Determines FOXO Paralog-Specific Redox Signaling  

PubMed Central

Abstract Reduction–oxidation (redox) signaling, the translation of an oxidative intracellular environment into a cellular response, is mediated by the reversible oxidation of specific cysteine thiols. The latter can result in disulfide formation between protein hetero- or homodimers that alter protein function until the local cellular redox environment has returned to the basal state. We have previously shown that this mechanism promotes the nuclear localization and activity of the Forkhead Box O4 (FOXO4) transcription factor. Aims: In this study, we sought to investigate whether redox signaling differentially controls the human FOXO3 and FOXO4 paralogs. Results: We present evidence that FOXO3 and FOXO4 have acquired paralog-specific cysteines throughout vertebrate evolution. Using a proteome-wide screen, we identified previously unknown redox-dependent FOXO3 interaction partners. The nuclear import receptors Importin-7 (IPO7) and Importin-8 (IPO8) form a disulfide-dependent heterodimer with FOXO3, which is required for its reactive oxygen species-induced nuclear translocation. FOXO4 does not interact with IPO7 or IPO8. Innovation and Conclusion: IPO7 and IPO8 control the nuclear import of FOXO3, but not FOXO4, in a redox-sensitive and disulfide-dependent manner. Our findings suggest that evolutionary acquisition of cysteines has contributed to regulatory divergence of FOXO paralogs, and that phylogenetic analysis can aid in the identification of cysteines involved in redox signaling. Antioxid. Redox Signal. 22, 15–28. PMID:25069953

Putker, Marrit; Vos, Harmjan R.; van Dorenmalen, Kim; de Ruiter, Hesther; Duran, Ana G.; Snel, Berend; Burgering, Boudewijn M.T.; Vermeulen, Michiel

2015-01-01

67

Differential expression and novel permeability properties of three aquaporin 8 paralogs from seawater-challenged Atlantic salmon smolts.  

PubMed

Aquaporins may facilitate transepithelial water absorption in the intestine of seawater (SW)-acclimated fish. Here we have characterized three full-length aqp8 paralogs from Atlantic salmon (Salmo salar). Bayesian inference revealed that each paralog is a representative of the three major classes of aqp8aa, aqp8ab and aqp8b genes found in other teleosts. The permeability properties were studied by heterologous expression in Xenopus laevis oocytes, and the expression levels examined by qPCR, immunofluorescence and immunoelectron microscopy, and immunoblotting of membrane fractions from intestines of SW-challenged smolts. All three Aqp8 paralogs were permeable to water and urea, whereas Aqp8ab and -8b were, surprisingly, also permeable to glycerol. The mRNA tissue distribution of each paralog was distinct, although some tissues such as the intestine showed redundant expression of more than one paralog. Immunofluorescence microscopy localized Aqp8aa(1+2) to intracellular compartments of the liver and intestine, and Aqp8ab and Aqp8b to apical plasma membrane domains of the intestinal epithelium, with Aqp8b also in goblet cells. In a control experiment with rainbow trout, immunoelectron microscopy confirmed abundant labeling of Aqp8ab and -8b at apical plasma membranes of enterocytes in the middle intestine and also in subapical vesicular structures. During SW challenge, Aqp8ab showed significantly increased levels of protein expression in plasma-membrane-enriched fractions of the intestine. These data indicate that the Atlantic salmon Aqp8 paralogs have neofunctionalized on a transcriptional as well as a functional level, and that Aqp8ab may play a central role in the intestinal transcellular uptake of water during SW acclimation. PMID:23868847

Engelund, Morten B; Chauvigné, François; Christensen, Birgitte Mønster; Finn, Roderick Nigel; Cerdà, Joan; Madsen, Steffen S

2013-10-15

68

Effects of neonatal exposure to the flame retardant tetrabromobisphenol-A, aluminum diethylphosphinate or zinc stannate on long-term potentiation and synaptic protein levels in mice.  

PubMed

Brominated flame retardants such as tetrabromobisphenol-A (TBBPA) may exert (developmental) neurotoxic effects. However, data on (neuro)toxicity of halogen-free flame retardants (HFFRs) are scarce. Recent in vitro studies indicated a high neurotoxic potential for some HFFRs, e.g., zinc stannate (ZS), whereas the neurotoxic potential of other HFFRs, such as aluminum diethylphosphinate (Alpi), appears low. However, the in vivo (neuro)toxicity of these compounds is largely unknown. We therefore investigated effects of neonatal exposure to TBBPA, Alpi or ZS on synaptic plasticity in mouse hippocampus. Male C57bl/6 mice received a single oral dose of 211 µmol/kg bw TBBPA, Alpi or ZS on postnatal day (PND) 10. On PND 17-19, effects on hippocampal synaptic plasticity were investigated using ex vivo extracellular field recordings. Additionally, we measured levels of postsynaptic proteins involved in long-term potentiation (LTP) as well as flame retardant concentrations in brain, muscle and liver tissues. All three flame retardants induced minor, but insignificant, effects on LTP. Additionally, TBBPA induced a minor decrease in post-tetanic potentiation. Despite these minor effects, expression of selected synaptic proteins involved in LTP was not affected. The flame retardants could not be measured in significant amounts in the brains, suggesting low bioavailability and/or rapid elimination/metabolism. We therefore conclude that a single neonatal exposure on PND 10 to TBBPA, Alpi or ZS does affect neurodevelopment and synaptic plasticity only to a small extent in mice. Additional data, in particular on persistence, bioaccumulation and (in vivo) toxicity, following prolonged (developmental) exposure are required for further (human) risk assessment. PMID:25253649

Hendriks, Hester S; Koolen, Lucas A E; Dingemans, Milou M L; Viberg, Henrik; Lee, Iwa; Leonards, Pim E G; Ramakers, Geert M J; Westerink, Remco H S

2014-09-25

69

Flame retardants  

NASA Technical Reports Server (NTRS)

The use of flame retardants in plastics has grown only slightly in recent years and will probably grow slowly in the future. The reasons for this are slow economic growth and the absence of fundamentally new requirements for future fire prevention. The trends are toward the increasing use of easily handled, dust-free and well-dispersed flame retardant compounds and master batches; there are no spectacular new developments. In the future, questions of smoke evolution, toxicity and corrosiveness of combustion gases will become increasingly important, especially due to new regulations and rising requirements for environmental protection.

Troitzsch, J.

1988-01-01

70

Unusual domain architecture of aminoacyl tRNA synthetases and their paralogs from Leishmania major  

PubMed Central

Background Leishmania major, a protozoan parasite, is the causative agent of cutaneous leishmaniasis. Due to the development of resistance against the currently available anti-leishmanial drugs, there is a growing need for specific inhibitors and novel drug targets. In this regards, aminoacyl tRNA synthetases, the linchpins of protein synthesis, have received recent attention among the kinetoplastid research community. This is the first comprehensive survey of the aminoacyl tRNA synthetases, their paralogs and other associated proteins from L. major. Results A total of 26 aminoacyl tRNA synthetases were identified using various computational and bioinformatics tools. Phylogenetic analysis and domain architectures of the L. major aminoacyl tRNA synthetases suggest a probable archaeal/eukaryotic origin. Presence of additional domains or N- or C-terminal extensions in 11 aminoacyl tRNA synthetases from L. major suggests possibilities such as additional tRNA binding or oligomerization or editing activity. Five freestanding editing domains were identified in L. major. Domain assignment revealed a novel asparagine tRNA synthetase paralog, asparagine synthetase A which has been so far reported from prokaryotes and archaea. Conclusions A comprehensive bioinformatic analysis revealed 26 aminoacyl tRNA synthetases and five freestanding editing domains in L. major. Identification of two EMAP (endothelial monocyte-activating polypeptide) II-like proteins similar to human EMAP II-like proteins suggests their participation in multisynthetase complex formation. While the phylogeny of tRNA synthetases suggests a probable archaeal/eukaryotic origin, phylogeny of asparagine synthetase A strongly suggests a bacterial origin. The unique features identified in this work provide rationale for designing inhibitors against parasite aminoacyl tRNA synthetases and their paralogs. PMID:23151081

2012-01-01

71

Interactions involving the Rad51 paralogs Rad51C and XRCC3 in human cells  

Microsoft Academic Search

Homologous recombinational repair of DNA double- strand breaks and crosslinks in human cells is likely to require Rad51 and the five Rad51 paralogs (XRCC2, XRCC3, Rad51B\\/Rad51L1, Rad51C\\/Rad51L2 and Rad51D\\/Rad51L3), as has been shown in chicken and rodent cells. Previously, we reported on the inter- actions among these proteins using baculovirus and two- and three-hybrid yeast systems. To test for inter-

Claudia Wiese; David W. Collins; Joanna S. Albala; Larry H. Thompson; Amy Kronenberg; David Schild

2002-01-01

72

Cell phenotypes of a mutant in the gene encoding a Rad51 paralog in fission yeast  

Microsoft Academic Search

The discovery of three Rad51 paralogs in Saccharomyces cerevisiae (Rad55, Rad57, and Dmc1), four in Schizosaccharomyces pombe (Rhp55, Rhp57, Rlp1, and Dmc1), and six in human (Rad51B, Rad51C, Rad51D, Xrcc2, Xrcc3, and Dmc1) indicate the functional\\u000a diversity and specialization of RecA-like proteins in the line from the lower to higher organisms. This paper reports characterization\\u000a of a number of mitotic

A. N. Sultanova; A. F. Salakhova; V. I. Bashkirov; F. K. Khasanov

2007-01-01

73

Sulfolobus tokodaii RadA paralog, stRadC2, is involved in DNA recombination via interaction with RadA and Hjc.  

PubMed

Rad51/RadA paralogs found in eukaryotes and euryarchaea play important roles during recombination and repair, and mutations in one of the human Rad51 paralogs, Rad51C, are associated with breast and ovarian cancers. The hyperthermophilic crenarchaeon Sulfolobus tokodaii encodes four putative RadA paralogs and studies on these proteins may assist in understanding the functions of human Rad51 paralogs. Here, we report the biochemical characterization of stRadC2, a S. tokodaii RadA paralog. Pull-down assays revealed that the protein was able to interact with the recombinase, RadA, and the Holliday junction endonuclease, Hjc. stRadC2 inhibited the strand exchange activity of RadA and facilitated Hjc-mediated Holliday junction DNA cleavage in vitro. RT-PCR analysis revealed that stRadC2 transcription was immediately reduced after UV irradiation, but was restored to normal levels at the late stages of DNA repair. Our results suggest that stRadC2 may act as an anti-recombination factor in DNA recombinational repair in S. tokodaii. PMID:22437993

Wang, Lei; Sheng, DuoHong; Han, WenYuan; Huang, Bin; Zhu, ShanShan; Ni, JinFeng; Li, Jia; Shen, YuLong

2012-03-01

74

Identification of pathways, gene networks and paralogous gene families in Daphnia pulex responding to exposure to the toxic cyanobacterium Microcystis aeruginosa  

PubMed Central

Although cyanobacteria produce a wide range of natural toxins that impact aquatic organisms, food webs and water quality, the mechanisms of toxicity are still insufficiently understood. Here, we implemented a whole-genome expression microarray to identify pathways, gene networks and paralogous gene families responsive to Microcystis stress in Daphnia pulex. Therefore, neonates of a sensitive isolate were given a diet contaminated with Microcystis to contrast with those given a control diet for sixteen days. The microarray revealed 2247 differentially expressed (DE) genes (7.6% of the array) in response to Microcystis, of which 17% are lineage specific( i.e., these genes have no detectable homology to any other gene in currently available databases) and 49% are gene duplicates (paralogs). We identified four pathways/gene networks and eight paralogous gene families affected by Microcystis. Differential regulation of the ribosome, including 3 paralogous gene families encoding 40S, 60S and mitochondrial ribosomal proteins, suggests an impact of Microcystis on protein synthesis of D. pulex. In addition, differential regulation of the oxidative phosphorylation pathway (including the NADH ubquinone oxidoreductase gene family) and the trypsin paralogous gene family (a major component of the digestive system in D. pulex) could explain why fitness is reduced based on energy budget considerations. PMID:22799445

Asselman, Jana; De Coninck, Dieter IM; Glaholt, Stephen; Colbourne, John K; Janssen, Colin R; Shaw, Joseph R; De Schamphelaere, Karel AC

2013-01-01

75

Asymmetric Signal Transduction through Paralogs That Comprise a Genetic Switch for Sugar Sensing in Saccharomyces cerevisiae*  

PubMed Central

Efficient uptake of glucose is especially critical to Saccharomyces cerevisiae because its preference to ferment this carbon source demands high flux through glycolysis. Glucose induces expression of HXT genes encoding hexose transporters through a signal generated by the Snf3 and Rgt2 glucose sensors that leads to depletion of the transcriptional regulators Mth1 and Std1. These paralogous proteins bind to Rgt1 and enable it to repress expression of HXT genes. Here we show that Mth1 and Std1 can substitute for one another and provide nearly normal regulation of their targets. However, their roles in the glucose signal transduction cascade have diverged significantly. Mth1 is the prominent effector of Rgt1 function because it is the more abundant of the two paralogs under conditions in which both are active (in the absence of glucose). Moreover, the cellular level of Mth1 is quite sensitive to the amount of available glucose. The abundance of Std1 protein, on the other hand, remains essentially constant over a similar range of glucose concentrations. The signal generated by low levels of glucose is amplified by rapid depletion of Mth1; the velocity of this depletion is dependent on both its rate of degradation and swift repression of MTH1 transcription by the Snf1-Mig1 glucose repression pathway. Quantitation of the contributions of Mth1 and Std1 to regulation of HXT expression reveals the unique roles played by each paralog in integrating nutrient availability with metabolic capacity: Mth1 is the primary regulator; Std1 serves to buffer the response to glucose. PMID:19720826

Sabina, Jeffrey; Johnston, Mark

2009-01-01

76

Ancestral paralogs and pseudoparalogs and their role in the emergence of the eukaryotic cell  

Microsoft Academic Search

Gene duplication is a crucial mechanism of evolu- tionary innovation. A substantial fraction of euka- ryotic genomes consists of paralogous gene families. We assess the extent of ancestral paralogy, which dates back to the last common ancestor of all eukaryotes, and examine the origins of the ancestral paralogs and their potential roles in the emergence of the eukaryotic cell complexity.

Kira S. Makarova; Yuri I. Wolf; Sergey L. Mekhedov; Boris G. Mirkin; Eugene V. Koonin

2005-01-01

77

The role of two LEAFY paralogs from Idahoa scapigera (Brassicaceae) in the evolution of a derived plant architecture.  

PubMed

Idahoa scapigera produces solitary flowers in the axils of rosette leaves without elongation of the shoot axis, a rosette-flowering architecture. Previous work with one of the two I. scapigera LFY paralogs, IscLFY1, showed that this gene caused aerial flowering rosettes in Arabidopsis thaliana. In this paper, we report that after three generations IscLFY1 transgenic lines are phenotypically indistinguishable from wild-type Arabidopsis, indicating that IscLFY1 protein is able to replace normal LFY function. Additionally, we found that ectopic LFY expression late in development can phenocopy aspects of the aerial rosette phenotype, suggesting that shoot compression caused by IscLFY1 could be caused by localized overexpression of a functional IscLFY protein. We also characterized the expression and function of the second I. scapigera LFY paralog, IscLFY2, in A. thaliana. In contrast to IscLFY1, this paralog was expressed in floral meristems and the shoot apical meristem (SAM). In I. scapigera, LFY-specific antibodies detected high protein levels in developing flowers but not in the apex, suggesting trans-regulatory differences between I. scapigera and A. thaliana. Most IscLFY2 transgenic A. thaliana plants were indistinguishable from wild type, but in a minority of lines the SAM was converted to a terminal flower as would be expected from the reporter-expression pattern. Taken together these results show that both I. scapigera paralogs have conserved LFY function, both proteins can rescue lfy and both can modify inflorescence architecture in an A. thaliana background: either by affecting internode elongation (IscLFY1) or by causing homeotic conversion of shoots into flowers (IscLFY2). PMID:17559504

Sliwinski, Marek K; Bosch, Justin A; Yoon, Ho-Sung; Balthazar, Maria von; Baum, David A

2007-07-01

78

Mutations of the UPF3B gene, which encodes a protein widely expressed in neurons, are associated with nonspecific mental retardation with or without autism.  

PubMed

Mutations in the UPF3B gene, which encodes a protein involved in nonsense-mediated mRNA decay, have recently been described in four families with specific (Lujan-Fryns and FG syndromes), nonspecific X-linked mental retardation (XLMR) and autism. To further elucidate the contribution of UPF3B to mental retardation (MR), we screened its coding sequence in 397 families collected by the EuroMRX consortium. We identified one nonsense mutation, c.1081C>T/p.Arg361(*), in a family with nonspecific MR (MRX62) and two amino-acid substitutions in two other, unrelated families with MR and/or autism (c.1136G>A/p.Arg379His and c.1103G>A/p.Arg368Gln). Functional studies using lymphoblastoid cell lines from affected patients revealed that c.1081C>T mutation resulted in UPF3B mRNA degradation and consequent absence of the UPF3B protein. We also studied the subcellular localization of the wild-type and mutated UPF3B proteins in mouse primary hippocampal neurons. We did not detect any obvious difference in the localization between the wild-type UPF3B and the proteins carrying the two missense changes identified. However, we show that UPF3B is widely expressed in neurons and also presents in dendritic spines, which are essential structures for proper neurotransmission and thus learning and memory processes. Our results demonstrate that in addition to Lujan-Fryns and FG syndromes, UPF3B protein truncation mutations can cause also nonspecific XLMR. We also identify comorbidity of MR and autism in another family with UPF3B mutation. The neuronal localization pattern of the UPF3B protein and its function in mRNA surveillance suggests a potential function in the regulation of the expression and degradation of various mRNAs present at the synapse. PMID:19238151

Laumonnier, F; Shoubridge, C; Antar, C; Nguyen, L S; Van Esch, H; Kleefstra, T; Briault, S; Fryns, J P; Hamel, B; Chelly, J; Ropers, H H; Ronce, N; Blesson, S; Moraine, C; Gécz, J; Raynaud, M

2010-07-01

79

Microtubule perturbation retards both the direct and the indirect apical pathway but does not affect sorting of plasma membrane proteins in intestinal epithelial cells (Caco-2).  

PubMed Central

Endogenous plasma membrane proteins are sorted from two sites in the human intestinal epithelial cell line Caco-2. Apical proteins are transported from the Golgi apparatus to the apical domain along a direct pathway and an indirect pathway via the basolateral membrane. In contrast, basolateral proteins never appear in the apical plasma membrane. Here we report on the effect of the microtubule-active drug nocodazole on the post-synthetic transport and sorting of plasma membrane proteins. Pulse-chase radiolabeling was combined with domain-specific cell surface assays to monitor the appearance of three apical and one basolateral protein in plasma membrane domains. Nocodazole was found to drastically retard both the direct transport of apical proteins from the Golgi apparatus and the indirect transport (transcytosis) from the basolateral membrane to the apical cell surface. In contrast, neither the transport rates of the basolateral membrane nor the sorting itself were significantly affected by the nocodazole treatment. We conclude that an intact microtubular network facilitates, but is not necessarily required for, the transport of apical membrane proteins along the two post-Golgi pathways to the brush border. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. PMID:2209541

Matter, K; Bucher, K; Hauri, H P

1990-01-01

80

Combined haploinsufficiency and purifying selection drive retention of RPL36a paralogs in Arabidopsis  

PubMed Central

Whole-genome duplication events have driven to a large degree the evolution of angiosperm genomes. Although the majority of redundant gene copies after a genome duplication are lost, subfunctionalization or gene balance account for the retention of gene copies. The Arabidopsis 80S ribosome represents an excellent model to test the gene balance hypothesis as it consists of 80 ribosomal proteins, all of them encoded by genes belonging to small gene families. Here, we present the isolation of mutant alleles of the APICULATA2 (API2) and RPL36aA paralogous genes, which encode identical ribosomal proteins but share a similarity of 89% in their coding sequences. RPL36aA was found expressed at a higher level than API2 in the wild type. The loss-of-function api2 and rpl36aa mutations are recessive and affect leaf development in a similar way. Their double mutant combinations with asymmetric leaves2-1 (as2-1) caused leaf polarity defects that were stronger in rpl36aa as2-1 than in api2 as2-1. Our results highlight the role of combined haploinsufficiency and purifying selection in the retention of these paralogous genes in the Arabidopsis genome. PMID:24535089

Casanova-Sáez, Rubén; Candela, Héctor; Micol, José Luis

2014-01-01

81

Crystal structure of the C-terminal globular domain of the third paralog of the Archaeoglobus fulgidus oligosaccharyltransferases  

PubMed Central

Background Protein N-glycosylation occurs in the three domains of life. Oligosaccharyltransferase (OST) transfers an oligosaccharide chain to the asparagine residue in the N-glycosylation sequons. The catalytic subunits of the OST enzyme are STT3 in eukaryotes, AglB in archaea and PglB in eubacteria. The genome of a hyperthermophilic archaeon, Archaeoglobus fulgidus, encodes three paralogous AglB proteins. We previously solved the crystal structures of the C-terminal globular domains of two paralogs, AglB-Short 1 and AglB-Short 2. Results We determined the crystal structure of the C-terminal globular domain of the third AglB paralog, AglB-Long, at 1.9 Å resolutions. The crystallization of the fusion protein with maltose binding protein (MBP) afforded high quality protein crystals. Two MBP-AglB-L molecules formed a swapped dimer in the crystal. Since the fusion protein behaved as a monomer upon gel filtration, we reconstituted the monomer structure from the swapped dimer by exchanging the swapped segments. The C-terminal domain of A. fulgidus AglB-L includes a structural unit common to AglB-S1 and AglB-S2. This structural unit contains the evolutionally conserved WWDYG and DK motifs. The present structure revealed that A. fulgidus AglB-L contained a variant type of the DK motif with a short insertion, and confirmed that the second signature residue, Lys, of the DK motif participates in the formation of a pocket that binds to the serine and threonine residues at the +2 position of the N-glycosylation sequon. Conclusions The structure of A. fulgidus AglB-L, together with the two previously solved structures of AglB-S1 and AglB-S2, provides a complete overview of the three AglB paralogs encoded in the A. fulgidus genome. All three AglBs contain a variant type of the DK motif. This finding supports a previously proposed rule: The STT3/AglB/PglB paralogs in one organism always contain the same type of Ser/Thr-binding pocket. The present structure will be useful as a search model for molecular replacement in the structural determination of the full-length A. fulgidus AglB-L. PMID:23815857

2013-01-01

82

Optical retarder system with programmable spectral retardance.  

PubMed

An optical system that works as a retarder waveplate with programmable spectral retardance is proposed. The system is based on a pixelated liquid crystal on silicon (LCoS) spatial light modulator (SLM). The input light beam is spectrally dispersed and different spectral components are projected onto different pixels of the LCoS-SLM. A different retardance is then addressed for each pixel, adapted to the incoming wavelength. Light reflected from the SLM is then recombined by the same setup. In this way a programmable polarization spectrum can be encoded. We illustrate the broadband characterization that is required for proper use of the system. Then several examples are shown, including spectral compensation to yield retarders with constant retardance, retarders with abrupt changes in the spectral retardance function, or bandpass variable retarder filters. The system is also demonstrated to provide programmable light spectrum generation. PMID:25360908

Moreno, Ignacio; Carrión, José V; Martínez, José Luis; García-Martínez, Pascuala; Sánchez-López, María M; Campos, Juan

2014-10-01

83

Reconstructing the Evolutionary History of Paralogous APETALA1/FRUITFULL-Like Genes in Grasses (Poaceae)  

PubMed Central

Gene duplication is an important mechanism for the generation of evolutionary novelty. Paralogous genes that are not silenced may evolve new functions (neofunctionalization) that will alter the developmental outcome of preexisting genetic pathways, partition ancestral functions (subfunctionalization) into divergent developmental modules, or function redundantly. Functional divergence can occur by changes in the spatio-temporal patterns of gene expression and/or by changes in the activities of their protein products. We reconstructed the evolutionary history of two paralogous monocot MADS-box transcription factors, FUL1 and FUL2, and determined the evolution of sequence and gene expression in grass AP1/FUL-like genes. Monocot AP1/FUL-like genes duplicated at the base of Poaceae and codon substitutions occurred under relaxed selection mostly along the branch leading to FUL2. Following the duplication, FUL1 was apparently lost from early diverging taxa, a pattern consistent with major changes in grass floral morphology. Overlapping gene expression patterns in leaves and spikelets indicate that FUL1 and FUL2 probably share some redundant functions, but that FUL2 may have become temporally restricted under partial subfunctionalization to particular stages of floret development. These data have allowed us to reconstruct the history of AP1/FUL-like genes in Poaceae and to hypothesize a role for this gene duplication in the evolution of the grass spikelet. PMID:16816429

Preston, Jill C.; Kellogg, Elizabeth A.

2006-01-01

84

On the role of AtDMC1, AtRAD51 and its paralogs during Arabidopsis meiosis  

PubMed Central

Meiotic recombination plays a critical role in achieving accurate chromosome segregation and increasing genetic diversity. Many studies, mostly in yeast, have provided important insights into the coordination and interplay between the proteins involved in the homologous recombination pathway, especially the recombinase RAD51 and the meiosis-specific DMC1. Here we summarize the current progresses on the function of both recombinases and the CX3 complex encoded by AtRAD51 paralogs, in the plant model species Arabidopsis thaliana. Similarities and differences respect to the function of these proteins in other organisms are also indicated. PMID:24596572

Pradillo, Mónica; Varas, Javier; Oliver, Cecilia; Santos, Juan L.

2014-01-01

85

Biophysical characterization of G-quadruplex forming FMR1 mRNA and of its interactions with different fragile X mental retardation protein isoforms  

PubMed Central

Fragile X syndrome, the most common form of inherited mental impairment in humans, is caused by the absence of the fragile X mental retardation protein (FMRP) due to a CGG trinucleotide repeat expansion in the 5?-untranslated region (UTR) and subsequent translational silencing of the fragile x mental retardation-1 (FMR1) gene. FMRP, which is proposed to be involved in the translational regulation of specific neuronal messenger RNA (mRNA) targets, contains an arginine-glycine-glycine (RGG) box RNA binding domain that has been shown to bind with high affinity to G-quadruplex forming mRNA structures. FMRP undergoes alternative splicing, and the binding of FMRP to a proposed G-quadruplex structure in the coding region of its mRNA (named FBS) has been proposed to affect the mRNA splicing events at exon 15. In this study, we used biophysical methods to directly demonstrate the folding of FMR1 FBS into a secondary structure that contains two specific G-quadruplexes and analyze its interactions with several FMRP isoforms. Our results show that minor splice isoforms, ISO2 and ISO3, created by the usage of the second and third acceptor sites at exon 15, bind with higher affinity to FBS than FMRP ISO1, which is created by the usage of the first acceptor site. FMRP ISO2 and ISO3 cannot undergo phosphorylation, an FMRP post-translational modification shown to modulate the protein translation regulation. Thus, their expression has to be tightly regulated, and this might be accomplished by a feedback mechanism involving the FMRP interactions with the G-quadruplex structures formed within FMR1 mRNA. PMID:24249225

Blice-Baum, Anna C.; Mihailescu, Mihaela-Rita

2014-01-01

86

Gene targeting of Desrt, a novel ARID class DNA-binding protein, causes growth retardation and abnormal development of reproductive organs.  

PubMed

We have cloned and characterized a novel murine DNA-binding protein Desrt, with a motif characteristic of the ARID (A-T rich interaction domain) family of transcription factors. The Desrt gene encodes an 83-kD protein that is shown to bind DNA and is widely expressed in adult tissues. To examine the in vivo function of Desrt, we have generated mice with a targeted mutation in the ARID domain of Desrt. Homozygous mutants have reduced viability, pronounced growth retardation, and a high incidence of abnormalities of the female and male reproductive organs including cryptorchidism. This may thus serve as a model to dissect the mechanisms involved in the development of the reproductive tract including testicular descent. Gene-targeted mice also display a reduction in the thickness of the zona reticularis of the adrenal gland and transient aberrations of the T and B cell compartments of primary lymphoid organs. These data show that this novel DNA-binding protein, Desrt, has a nonredundant function during growth and in the development of the reproductive system. PMID:11483573

Lahoud, M H; Ristevski, S; Venter, D J; Jermiin, L S; Bertoncello, I; Zavarsek, S; Hasthorpe, S; Drago, J; de Kretser, D; Hertzog, P J; Kola, I

2001-08-01

87

The fragile X mental retardation protein is associated with poly(A)+ mRNA in actively translating polyribosomes  

Microsoft Academic Search

The fragile X syndrome results from a transcriptional silencing of the FMR1 gene and the absence of its encoded protein. FMRP is a cytoplasmic RNA-binding protein, whose specific cellular function is still unknown. We present evidence that virtually all detectable cytoplasmic FMRP in mouse NIH 3T3 and human HeLa cells is found strictly in association with mRNA in actively translating

François Corbin; Marlène Bouillon; Anny Fortin; Stanislas Morin; François Rousseau; Edouard W. Khandjian

1997-01-01

88

The X-linked mental retardation protein OPHN1 interacts with Homer1b/c to control spine endocytic zone positioning and expression of synaptic potentiation.  

PubMed

At glutamatergic synapses, local endocytic recycling of AMPA receptors (AMPARs) is important for the supply of a mobile pool of AMPARs required for synaptic potentiation. This local recycling of AMPARs critically relies on the presence of an endocytic zone (EZ) near the postsynaptic density (PSD). The precise mechanisms that couple the EZ to the PSD still remain largely elusive, with the large GTPase Dynamin-3 and the multimeric PSD adaptor protein Homer1 as the two main players identified. Here, we demonstrate that a physical interaction between the X-linked mental retardation protein oligophrenin-1 (OPHN1) and Homer1b/c is crucial for the positioning of the EZ adjacent to the PSD, and present evidence that this interaction is important for OPHN1's role in controlling activity-dependent strengthening of excitatory synapses in the rat hippocampus. Disruption of the OPHN1-Homer1b/c interaction causes a displacement of EZs from the PSD, along with impaired AMPAR recycling and reduced AMPAR accumulation at synapses, in both basal conditions and conditions that can induce synaptic potentiation. Together, our findings unveil a novel role for OPHN1 as an interaction partner of Homer1b/c in spine EZ positioning, and provide new mechanistic insight into how genetic deficits in OPHN1 can lead to impaired synapse maturation and plasticity. PMID:24966368

Nakano-Kobayashi, Akiko; Tai, Yilin; Nadif Kasri, Nael; Van Aelst, Linda

2014-06-25

89

Dual regulation of fragile X mental retardation protein by group I metabotropic glutamate receptors controls translation-dependent epileptogenesis in the hippocampus.  

PubMed

Group I metabotropic glutamate receptors (mGluRs) stimulation activates translation-dependent epileptogenesis in the hippocampus. This translation is regulated by repressors, including BC1 RNA and fragile X mental retardation protein (FMRP). Recent data indicate that group I mGluR stimulation exerts bidirectional control over FMRP level by activating translation and ubiquitin-proteasome system (UPS)-dependent proteolysis for the up- and downregulation of the protein, respectively. At present, the temporal relationship of translation and proteolysis on FMRP and their interplay for group I mGluR-mediated translation and epileptogenesis are unknown. We addressed these issues by using mouse hippocampal slices. Agonist [(S)-3,5-dihydroxyphenylglycine (DHPG)] stimulation of group I mGluRs caused a biphasic change in FMRP level. An initial decrease (within 10 min) was followed by an increase at 30 min. When slices were pretreated with translation inhibitor (anisomycin or cycloheximide), group I mGluRs elicited a sustained decrease in FMRP. This decrease was prevented by a proteasome inhibitor [Z-Leu-Leu-Leu-CHO (MG-132)]. When slices were pretreated with MG-132 alone, DHPG no longer elicited any change in FMRP. MG-132 also suppressed increase in other proteins, including postsynaptic density-95 and ?-calcium/calmodulin-dependent protein kinase II, normally elicited by group I mGluR stimulation. Physiological experiments showed that proteasome inhibitor suppressed group I mGluR-induced prolonged synchronized discharges. However, proteasome inhibitor did not affect group I mGluR-induced prolonged synchronized discharges in Fmr1(-/-) preparations, where functional FMRP is absent. The results suggest that constitutive FMRP in hippocampal cells acts as a brake on group I mGluR-mediated translation and epileptogenesis. FMRP downregulation via UPS removes this brake enabling group I mGluR-mediated translation and epileptogenesis. PMID:21228181

Zhao, Wangfa; Chuang, Shih-Chieh; Bianchi, Riccardo; Wong, Robert K S

2011-01-12

90

Mildly Retarded Adults: Their Attitudes Toward Retardation  

ERIC Educational Resources Information Center

Responses to a 40-item questionnaire distributed to 50 mildly mentally retarded (MR) adults indicate that the majority possess accurate information about MR, hold realistic attitudes toward their own needs and abilities, and advocate community integration of the retarded. (Author/JG)

Gan, Jennifer; And Others

1977-01-01

91

Introduction to Mental Retardation  

ERIC Educational Resources Information Center

The purpose of this document is to define mental retardation and answer questions related to this topic. According to the American Association on Mental Retardation (AAMR), mental retardation is a disability that occurs before age 18. It is characterized by significant limitations in intellectual functioning and adaptive behaviors as expressed in…

Arc of the United States, 2004

2004-01-01

92

Metabotropic glutamate receptor-mediated use-dependent down-regulation of synaptic excitability involves the fragile X mental retardation protein.  

PubMed

Loss of the mRNA-binding protein FMRP results in the most common inherited form of both mental retardation and autism spectrum disorders: fragile X syndrome (FXS). The leading FXS hypothesis proposes that metabotropic glutamate receptor (mGluR) signaling at the synapse controls FMRP function in the regulation of local protein translation to modulate synaptic transmission strength. In this study, we use the Drosophila FXS disease model to test the relationship between Drosophila FMRP (dFMRP) and the sole Drosophila mGluR (dmGluRA) in regulation of synaptic function, using two-electrode voltage-clamp recording at the glutamatergic neuromuscular junction (NMJ). Null dmGluRA mutants show minimal changes in basal synapse properties but pronounced defects during sustained high-frequency stimulation (HFS). The double null dfmr1;dmGluRA mutant shows repression of enhanced augmentation and delayed onset of premature long-term facilitation (LTF) and strongly reduces grossly elevated post-tetanic potentiation (PTP) phenotypes present in dmGluRA-null animals. Null dfmr1 mutants show features of synaptic hyperexcitability, including multiple transmission events in response to a single stimulus and cyclic modulation of transmission amplitude during prolonged HFS. The double null dfmr1;dmGluRA mutant shows amelioration of these defects but does not fully restore wildtype properties in dfmr1-null animals. These data suggest that dmGluRA functions in a negative feedback loop in which excess glutamate released during high-frequency transmission binds the glutamate receptor to dampen synaptic excitability, and dFMRP functions to suppress the translation of proteins regulating this synaptic excitability. Removal of the translational regulator partially compensates for loss of the receptor and, similarly, loss of the receptor weakly compensates for loss of the translational regulator. PMID:19036865

Repicky, Sarah; Broadie, Kendal

2009-02-01

93

Deficiency of a Protein-Repair Enzyme Results in the Accumulation of Altered Proteins, Retardation of Growth, and Fatal Seizures in Mice  

Microsoft Academic Search

L-Asparaginyl and L-aspartyl residues in proteins are subject to spontaneous degradation reactions that generate isomerized and racemized aspartyl derivatives. Proteins containing L-isoaspartyl and D-aspartyl residues can have altered structures and diminished biological activity. These residues are recognized by a highly conserved cytosolic enzyme, the protein L-isoaspartate (D-aspartate) O-methyltransferase (EC 2.1.1.77). The enzymatic methyl esterification of these abnormal residues in vitro

Edward Kim; Jonathan D. Lowenson; Duncan C. MacLaren; Steven Clarke; Stephen G. Young

1997-01-01

94

Characterization of paralogous and orthologous members of the superoxide dismutase gene family from genera of the halophilic archaebacteria.  

PubMed Central

Four species representing three genera of halophilic archaebacteria were examined for the presence of genomic sequences that encode proteins of the superoxide dismutase family. Three species, Halobacterium cutirubrum, Halobacterium sp. strain GRB, and Haloferax volcanii, contain duplicated (paralogous) genes of the sod family; a fourth species, Haloarcula marismortui, contains only a single gene. These seven genes were cloned and sequenced, and their transcripts were characterized by Northern (RNA) hybridization, S1 nuclease protection, and primer extension. The expression of one of the two genes in H. cutirubrum, Halobacterium sp. strain GRB, and Haloferax volcanii was shown to be elevated in the presence of paraquat, a generator of superoxide radicals. The other genes, including the single gene from Haloarcula marismortui, exhibited no elevated expression in the presence of paraquat. The 5' and 3' flanking regions of all the genes contain recognizable promoter and terminator elements that are appropriately positioned relative to the 5' and 3' transcript end sites. Between genera, the orthologous paraquat-responsive genes exhibit no sequence similarity in either their 5' or 3' flanking regions, whereas the orthologous nonresponsive genes exhibit limited sequence similarity but only in the 5' flanking region. Within the coding region, the two paralogous genes of Haloferax volcanii are virtually identical (99.5%) despite the absence of similarity in the flanking regions. In contrast, the paralogous genes of H. cutirubrum and Halobacterium sp. strain GRB are only about 87% identical. In the alignment of all seven sequences, there are nine codon positions where both the TCN and AGY serine codons are utilized; some or all of these may well be examples of convergent evolution. Images PMID:8449865

Joshi, P; Dennis, P P

1993-01-01

95

Parallel reduction in expression, but no loss of functional constraint, in two opsin paralogs within cave populations of Gammarus minus (Crustacea: Amphipoda)  

PubMed Central

Background Gammarus minus, a freshwater amphipod living in the cave and surface streams in the eastern USA, is a premier candidate for studying the evolution of troglomorphic traits such as pigmentation loss, elongated appendages, and reduced eyes. In G. minus, multiple pairs of genetically related, physically proximate cave and surface populations exist which exhibit a high degree of intraspecific morphological divergence. The morphology, ecology, and genetic structure of these sister populations are well characterized, yet the genetic basis of their morphological divergence remains unknown. Results We used degenerate PCR primers designed to amplify opsin genes within the subphylum Crustacea and discovered two distinct opsin paralogs (average inter-paralog protein divergence???20%) in the genome of three independently derived pairs of G. minus cave and surface populations. Both opsin paralogs were found to be related to other crustacean middle wavelength sensitive opsins. Low levels of nucleotide sequence variation (< 1% within populations) were detected in both opsin genes, regardless of habitat, and dN/dS ratios did not indicate a relaxation of functional constraint in the cave populations with reduced or absent eyes. Maximum likelihood analyses using codon-based models also did not detect a relaxation of functional constraint in the cave lineages. We quantified expression level of both opsin genes and found that the expression of both paralogs was significantly reduced in all three cave populations relative to their sister surface populations. Conclusions The concordantly lowered expression level of both opsin genes in cave populations of G. minus compared to sister surface populations, combined with evidence for persistent purifying selection in the cave populations, is consistent with an unspecified pleiotropic function of opsin proteins. Our results indicate that phototransduction proteins such as opsins may have retained their function in cave-adapted organisms because they may play a pleiotropic role in other important processes that are unrelated to vision. PMID:23617561

2013-01-01

96

Faster evolving Drosophila paralogs lose expression rate and ubiquity and accumulate more non-synonymous SNPs  

PubMed Central

Background Duplicated genes can indefinately persist in genomes if either both copies retain the original function due to dosage benefit (gene conservation), or one of the copies assumes a novel function (neofunctionalization), or both copies become required to perform the function previously accomplished by a single copy (subfunctionalization), or through a combination of these mechanisms. Different models of duplication retention imply different predictions about substitution rates in the coding portion of paralogs and about asymmetry of these rates. Results We analyse sequence evolution asymmetry in paralogs present in 12 Drosophila genomes using the nearest non-duplicated orthologous outgroup as a reference. Those paralogs present in D. melanogaster are analysed in conjunction with the asymmetry of expression rate and ubiquity and of segregating non-synonymous polymorphisms in the same paralogs. Paralogs accumulate substitutions, on average, faster than their nearest singleton orthologs. The distribution of paralogs’ substitution rate asymmetry is overdispersed relative to that of orthologous clades, containing disproportionally more unusually symmetric and unusually asymmetric clades. We show that paralogs are more asymmetric in: a) clades orthologous to highly constrained singleton genes; b) genes with high expression level; c) genes with ubiquitous expression and d) non-tandem duplications. We further demonstrate that, in each asymmetrically evolving pair of paralogs, the faster evolving member of the pair tends to have lower average expression rate, lower expression uniformity and higher frequency of non-synonymous SNPs than its slower evolving counterpart. Conclusions Our findings are consistent with the hypothesis that many duplications in Drosophila are retained despite stabilising selection being more relaxed in one of the paralogs than in the other, suggesting a widespread unfinished pseudogenization. This phenomenon is likely to make detection of neo- and subfunctionalization signatures difficult, as these models of duplication retention also predict asymmetries in substitution rates and expression profiles. Reviewers This article has been reviewed by Dr. Jia Zeng (nominated by Dr. I. King Jordan), Dr. Fyodor Kondrashov and Dr. Yuri Wolf. PMID:24438455

2014-01-01

97

The Rad51 paralog Rad51B promotes homologous recombinational repair.  

PubMed

The highly conserved Saccharomyces cerevisiae Rad51 protein plays a central role in both mitotic and meiotic homologous DNA recombination. Seven members of the Rad51 family have been identified in vertebrate cells, including Rad51, Dmc1, and five Rad51-related proteins referred to as Rad51 paralogs, which share 20 to 30% sequence identity with Rad51. In chicken B lymphocyte DT40 cells, we generated a mutant with RAD51B/RAD51L1, a member of the Rad51 family, knocked out. RAD51B(-/-) cells are viable, although spontaneous chromosomal aberrations kill about 20% of the cells in each cell cycle. Rad51B deficiency impairs homologous recombinational repair (HRR), as measured by targeted integration, sister chromatid exchange, and intragenic recombination at the immunoglobulin locus. RAD51B(-/-) cells are quite sensitive to the cross-linking agents cisplatin and mitomycin C and mildly sensitive to gamma-rays. The formation of damage-induced Rad51 nuclear foci is much reduced in RAD51B(-/-) cells, suggesting that Rad51B promotes the assembly of Rad51 nucleoprotein filaments during HRR. These findings show that Rad51B is important for repairing various types of DNA lesions and maintaining chromosome integrity. PMID:10938124

Takata, M; Sasaki, M S; Sonoda, E; Fukushima, T; Morrison, C; Albala, J S; Swagemakers, S M; Kanaar, R; Thompson, L H; Takeda, S

2000-09-01

98

The Rad51 Paralog Rad51B Promotes Homologous Recombinational Repair  

PubMed Central

The highly conserved Saccharomyces cerevisiae Rad51 protein plays a central role in both mitotic and meiotic homologous DNA recombination. Seven members of the Rad51 family have been identified in vertebrate cells, including Rad51, Dmc1, and five Rad51-related proteins referred to as Rad51 paralogs, which share 20 to 30% sequence identity with Rad51. In chicken B lymphocyte DT40 cells, we generated a mutant with RAD51B/RAD51L1, a member of the Rad51 family, knocked out. RAD51B?/? cells are viable, although spontaneous chromosomal aberrations kill about 20% of the cells in each cell cycle. Rad51B deficiency impairs homologous recombinational repair (HRR), as measured by targeted integration, sister chromatid exchange, and intragenic recombination at the immunoglobulin locus. RAD51B?/? cells are quite sensitive to the cross-linking agents cisplatin and mitomycin C and mildly sensitive to ?-rays. The formation of damage-induced Rad51 nuclear foci is much reduced in RAD51B?/? cells, suggesting that Rad51B promotes the assembly of Rad51 nucleoprotein filaments during HRR. These findings show that Rad51B is important for repairing various types of DNA lesions and maintaining chromosome integrity. PMID:10938124

Takata, Minoru; Sasaki, Masao S.; Sonoda, Eiichiro; Fukushima, Toru; Morrison, Ciaran; Albala, Joanna S.; Swagemakers, Sigrid M. A.; Kanaar, Roland; Thompson, Larry H.; Takeda, Shunichi

2000-01-01

99

Origins and functional diversification of salinity-responsive Na(+) , K(+) ATPase ?1 paralogs in salmonids.  

PubMed

The Salmoniform whole-genome duplication is hypothesized to have facilitated the evolution of anadromy, but little is known about the contribution of paralogs from this event to the physiological performance traits required for anadromy, such as salinity tolerance. Here, we determined when two candidate, salinity-responsive paralogs of the Na(+) , K(+) ATPase ? subunit (?1a and ?1b) evolved and studied their evolutionary trajectories and tissue-specific expression patterns. We found that these paralogs arose during a small-scale duplication event prior to the Salmoniform, but after the teleost, whole-genome duplication. The 'freshwater paralog' (?1a) is primarily expressed in the gills of Salmoniformes and an unduplicated freshwater sister species (Esox lucius) and experienced positive selection in the freshwater ancestor of Salmoniformes and Esociformes. Contrary to our predictions, the 'saltwater paralog' (?1b), which is more widely expressed than ?1a, did not experience positive selection during the evolution of anadromy in the Coregoninae and Salmonine. To determine whether parallel mutations in Na(+) , K(+) ATPase ?1 may contribute to salinity tolerance in other fishes, we studied independently evolved salinity-responsive Na(+) , K(+) ATPase ?1 paralogs in Anabas testudineus and Oreochromis mossambicus. We found that a quarter of the mutations occurring between salmonid ?1a and ?1b in functionally important sites also evolved in parallel in at least one of these species. Together, these data argue that paralogs contributing to salinity tolerance evolved prior to the Salmoniform whole-genome duplication and that strong selection and/or functional constraints have led to parallel evolution in salinity-responsive Na(+) , K(+) ATPase ?1 paralogs in fishes. PMID:24917532

Dalziel, Anne C; Bittman, Jesse; Mandic, Milica; Ou, Michelle; Schulte, Patricia M

2014-07-01

100

Brominated Flame Retardants  

EPA Science Inventory

Brominated flame retardants (BFRs) belong to a large class of compounds known as organohalogens. BFRs are currently the largest marketed flame retardant group due to their high performance efficiency and low cost. In the commercial market, more than 75 different BFRs are recogniz...

101

Diversification of transcription factor paralogs via noncanonical modularity in C2H2 zinc finger DNA binding.  

PubMed

A major challenge in obtaining a full molecular description of evolutionary adaptation is to characterize how transcription factor (TF) DNA-binding specificity can change. To identify mechanisms of TF diversification, we performed detailed comparisons of yeast C2H2 ZF proteins with identical canonical recognition residues that are expected to bind the same DNA sequences. Unexpectedly, we found that ZF proteins can adapt to recognize new binding sites in a modular fashion whereby binding to common core sites remains unaffected. We identified two distinct mechanisms, conserved across multiple Ascomycota species, by which this molecular adaptation occurred. Our results suggest a route for TF evolution that alleviates negative pleiotropic effects by modularly gaining new binding sites. These findings expand our current understanding of ZF DNA binding and provide evidence for paralogous ZFs utilizing alternate modes of DNA binding to recognize unique sets of noncanonical binding sites. PMID:25042805

Siggers, Trevor; Reddy, Jessica; Barron, Brian; Bulyk, Martha L

2014-08-21

102

Therapeutic implications of the mGluR theory of fragile X mental retardation  

E-print Network

Review Therapeutic implications of the mGluR theory of fragile X mental retardation M. F. Bear mGluR) activ- ation are exaggerated in the absence of the fragile X mental retardation protein. The fragile X mental retardation protein (FMRP) has attracted considerable interest as a potential regulator

Bear, Mark

103

Fire-Retardant, Decorative Inks  

NASA Technical Reports Server (NTRS)

Effectiveness of fire-retardant additives evaluated. Fire retardance of decorative acrylic printing inks for aircraft interiors enhanced by certain commercial and experimental fire-retardant additives, according to study.

Kourtides, D.; Nir, Z.; Mikroyannidis, J.

1987-01-01

104

The cytohesin paralog Sec7 of Dictyostelium discoideum is required for phagocytosis and cell motility  

PubMed Central

Background Dictyostelium harbors several paralogous Sec7 genes that encode members of three subfamilies of the Sec7 superfamily of guanine nucleotide exchange factors. One of them is the cytohesin family represented by three members in D. discoideum, SecG, Sec7 and a further protein distinguished by several transmembrane domains. Cytohesins are characterized by a Sec7-PH tandem domain and have roles in cell adhesion and migration. Results We study here Sec7. In vitro its PH domain bound preferentially to phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2), phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3). When following the distribution of GFP-Sec7 in vivo we observed the protein in the cytosol and at the plasma membrane. Strikingly, when cells formed pseudopods, macropinosomes or phagosomes, GFP-Sec7 was conspicuously absent from areas of the plasma membrane which were involved in these processes. Mutant cells lacking Sec7 exhibited an impaired phagocytosis and showed significantly reduced speed and less persistence during migration. Cellular properties associated with mammalian cytohesins like cell-cell and cell-substratum adhesion were not altered. Proteins with roles in membrane trafficking and signal transduction have been identified as putative interaction partners consistent with the data obtained from mutant analysis. Conclusions Sec7 is a cytosolic component and is associated with the plasma membrane in a pattern distinctly different from the accumulation of PI(3,4,5)P3. Mutant analysis reveals that loss of the protein affects cellular processes that involve membrane flow and the actin cytoskeleton. PMID:23915312

2013-01-01

105

Sost and its paralog Sostdc1 coordinate digit number in a Gli3-dependent manner?  

PubMed Central

WNT signaling is critical in most aspects of skeletal development and homeostasis, and antagonists of WNT signaling are emerging as key regulatory proteins with great promise as therapeutic agents for bone disorders. Here we show that Sost and its paralog Sostdc1 emerged through ancestral genome duplication and their expression patterns have diverged to delineate non-overlapping domains in most organ systems including musculoskeletal, cardiovascular, nervous, digestive, reproductive and respiratory. In the developing limb, Sost and Sostdc1 display dynamic expression patterns with Sost being restricted to the distal ectoderm and Sostdc1 to the proximal ectoderm and the mesenchyme. While Sostdc1–/– mice lack any obvious limb or skeletal defects, Sost–/– mice recapitulate the hand defects described for Sclerosteosis patients. However, elevated WNT signaling in Sost–/–; Sostdc1–/– mice causes misregulation of SHH signaling, ectopic activation of Sox9 in the digit 1 field and preaxial polydactyly in a Gli1- and Gli3-dependent manner. In addition, we show that the syndactyly documented in Sclerosteosis is present in both Sost–/– and Sost–/–; Sostdc1–/– mice, and is driven by misregulation of Fgf8 in the AER, a region lacking Sost and Sostdc1 expression. This study highlights the complexity of WNT signaling in skeletal biology and disease and emphasizes how redundant mechanism and non-cell autonomous effects can synergize to unveil new intricate phenotypes caused by elevated WNT signaling. PMID:23994639

Collette, Nicole M.; Yee, Cristal S.; Murugesh, Deepa; Sebastian, Aimy; Taher, Leila; Gale, Nicholas W.; Economides, Aris N.; Harland, Richard M.; Loots, Gabriela G.

2013-01-01

106

HELQ promotes RAD51 paralog-dependent repair to avert germ cell attrition and tumourigenesis  

PubMed Central

Repair of interstrand crosslinks (ICLs) requires the coordinate action of the intra-S phase checkpoint and the Fanconi Anemia (FA) pathway, which promote ICL incision, translesion synthesis, and homologous recombination (reviewed in 1,2). Previous studies have implicated the 3?-5? superfamily 2 helicase HELQ/Hel308 in ICL repair in D. melanogaster (known as Mus301 or Spn-C3) and C. elegans (known as Helq-1 or Hel-3084). While in vitro analysis suggests that HELQ preferentially unwinds synthetic replication fork substrates with 3? ssDNA overhangs and also disrupts protein/DNA interactions while translocating along DNA5,6, little is known regarding its functions in mammalian organisms. Here we report that HELQ helicase-deficient mice exhibit subfertility, germ cell attrition, ICL sensitivity and tumour predisposition, with HelQ heterozygous mice exhibiting a similar, albeit less severe, phenotype than the null, indicative of haploinsufficiency. We establish that HELQ interacts directly with the RAD51 paralog complex, BCDX2, and functions in parallel to the FA pathway to promote efficient HR at damaged replication forks. Thus, our results reveal a critical role for HELQ in replication-coupled DNA repair, germ cell maintenance and tumour suppression in mammals. PMID:24005329

Adelman, Carrie A.; Lolo, Rafal L.; Birkbak, Nicolai J.; Murina, Olga; Matsuzaki, Kenichiro; Horejsi, Zuzana; Parmar, Kalindi; Borel, Valérie; Skehel, J. Mark; Stamp, Gordon; D’Andrea, Alan; Sartori, Alessandro A.; Swanton, Charles; Boulton, Simon J.

2013-01-01

107

The Impact of Paralogy on Phylogenomic Studies – A Case Study on Annelid Relationships  

PubMed Central

Phylogenomic studies based on hundreds of genes derived from expressed sequence tags libraries are increasingly used to reveal the phylogeny of taxa. A prerequisite for these studies is the assignment of genes into clusters of orthologous sequences. Sophisticated methods of orthology prediction are used in such analyses, but it is rarely assessed whether paralogous sequences have been erroneously grouped together as orthologous sequences after the prediction, and whether this had an impact on the phylogenetic reconstruction using a super-matrix approach. Herein, I tested the impact of paralogous sequences on the reconstruction of annelid relationships based on phylogenomic datasets. Using single-partition analyses, screening for bootstrap support, blast searches and pruning of sequences in the supermatrix, wrongly assigned paralogous sequences were found in eight partitions and the placement of five taxa (the annelids Owenia, Scoloplos, Sthenelais and Eurythoe and the nemertean Cerebratulus) including the robust bootstrap support could be attributed to the presence of paralogous sequences in two partitions. Excluding these sequences resulted in a different, weaker supported placement for these taxa. Moreover, the analyses revealed that paralogous sequences impacted the reconstruction when only a single taxon represented a previously supported higher taxon such as a polychaete family. One possibility of a priori detection of wrongly assigned paralogous sequences could combine 1) a screening of single-partition analyses based on criteria such as nodal support or internal branch length with 2) blast searches of suspicious cases as presented herein. Also possible are a posteriori approaches in which support for specific clades is investigated by comparing alternative hypotheses based on differences in per-site likelihoods. Increasing the sizes of EST libraries will also decrease the likelihood of wrongly assigned paralogous sequences, and in the case of orthology prediction methods like HaMStR it is likewise decreased by using more than one reference taxon. PMID:23667537

Struck, Torsten H.

2013-01-01

108

Close association between paralogous multiple isomiRs and paralogous/orthologues miRNA sequences implicates dominant sequence selection across various animal species.  

PubMed

MicroRNAs (miRNAs) are crucial negative regulators of gene expression at the post-transcriptional level. Next-generation sequencing technologies have identified a series of miRNA variants (named isomiRs). In this study, paralogous isomiR assemblies (from the miRNA locus) were systematically analyzed based on data acquired from deep sequencing data sets. Evolutionary analysis of paralogous (members in miRNA gene family in a specific species) and orthologues (across different animal species) miRNAs was also performed. The sequence diversity of paralogous isomiRs was found to be similar to the diversity of paralogous and orthologues miRNAs. Additionally, both isomiRs and paralogous/orthologues miRNAs were implicated in 5' and 3' ends (especially 3' ends), nucleotide substitutions, and insertions and deletions. Generally, multiple isomiRs can be produced from a single miRNA locus, but most of them had lower enrichment levels, and only several dominant isomiR sequences were detected. These dominant isomiR groups were always stable, and one of them would be selected as the most abundant miRNA sequence in specific animal species. Some isomiRs might be consistent to miRNA sequences in some species but not the other. Homologous miRNAs were often detected in similar isomiR repertoires, and showed similar expression patterns, while dominant isomiRs showed complex evolutionary patterns from miRNA sequences across the animal kingdom. These results indicate that the phenomenon of multiple isomiRs is not a random event, but rather the result of evolutionary pressures. The existence of multiple isomiRs enables different species to express advantageous sequences in different environments. Thus, dominant sequences emerge in response to functional and evolutionary pressures, allowing an organism to adapt to complex intra- and extra-cellular events. PMID:23856130

Guo, Li; Zhao, Yang; Zhang, Hui; Yang, Sheng; Chen, Feng

2013-09-25

109

Fire retardant polyisocyanurate foam  

NASA Technical Reports Server (NTRS)

Fire retardant properties of low density polymer foam are increased. Foam has pendant nitrile groups which form thermally-stable heterocyclic structures at temperature below degradation temperature of urethane linkages.

Riccitiello, S. R.; Parker, J. A.

1972-01-01

110

Litter-Spinning Retarders  

NASA Technical Reports Server (NTRS)

Aerodynamic plates stop litter from spinning during hoisting by helicopter. Features of proposed litter-spinning retarders include convenience of deployment and independence from ground restraint. Retarder plate(s) folded flat against bottom of litter during storage or while litter is loaded. Plate(s) held in storage position by latch that releases manually or automatically as litter is hoisted. Upon release, springs move plates into deployed position.

Wilson, John C.

1995-01-01

111

Identical Substitutions in Magnesium Chelatase Paralogs Result in Chlorophyll-Deficient Soybean Mutants  

PubMed Central

The soybean [Glycine max (L.) Merr.] chlorophyll-deficient line MinnGold is a spontaneous mutant characterized by yellow foliage. Map-based cloning and transgenic complementation revealed that the mutant phenotype is caused by a nonsynonymous nucleotide substitution in the third exon of a Mg-chelatase subunit gene (ChlI1a) on chromosome 13. This gene was selected as a candidate for a different yellow foliage mutant, T219H (Y11y11), that had been previously mapped to chromosome 13. Although the phenotypes of MinnGold and T219H are clearly distinct, sequencing of ChlI1a in T219H identified a different nonsynonymous mutation in the third exon, only six base pairs from the MinnGold mutation. This information, along with previously published allelic tests, were used to identify and clone a third yellow foliage mutation, CD-5, which was previously mapped to chromosome 15. This mutation was identified in the ChlI1b gene, a paralog of ChlI1a. Sequencing of the ChlI1b allele in CD-5 identified a nonsynonymous substitution in the third exon that confers an identical amino acid change as the T219H substitution at ChlI1a. Protein sequence alignments of the two Mg-chelatase subunits indicated that the sites of amino acid modification in MinnGold, T219H, and CD-5 are highly conserved among photosynthetic species. These results suggest that amino acid alterations in this critical domain may create competitive inhibitory interactions between the mutant and wild-type ChlI1a and ChlI1b proteins. PMID:25452420

Campbell, Benjamin W.; Mani, Dhananjay; Curtin, Shaun J.; Slattery, Rebecca A.; Michno, Jean-Michel; Ort, Donald R.; Schaus, Philip J.; Palmer, Reid G.; Orf, James H.; Stupar, Robert M.

2014-01-01

112

NLR-Associating Transcription Factor bHLH84 and Its Paralogs Function Redundantly in Plant Immunity  

PubMed Central

In plants and animals, nucleotide-binding and leucine-rich repeat domain containing (NLR) immune receptors are utilized to detect the presence or activities of pathogen-derived molecules. However, the mechanisms by which NLR proteins induce defense responses remain unclear. Here, we report the characterization of one basic Helix-loop-Helix (bHLH) type transcription factor (TF), bHLH84, identified from a reverse genetic screen. It functions as a transcriptional activator that enhances the autoimmunity of NLR mutant snc1 (suppressor of npr1-1, constitutive 1) and confers enhanced immunity in wild-type backgrounds when overexpressed. Simultaneously knocking out three closely related bHLH paralogs attenuates RPS4-mediated immunity and partially suppresses the autoimmune phenotypes of snc1, while overexpression of the other two close paralogs also renders strong autoimmunity, suggesting functional redundancy in the gene family. Intriguingly, the autoimmunity conferred by bHLH84 overexpression can be largely suppressed by the loss-of-function snc1-r1 mutation, suggesting that SNC1 is required for its proper function. In planta co-immunoprecipitation revealed interactions between not only bHLH84 and SNC1, but also bHLH84 and RPS4, indicating that bHLH84 associates with these NLRs. Together with previous finding that SNC1 associates with repressor TPR1 to repress negative regulators, we hypothesize that nuclear NLR proteins may interact with both transcriptional repressors and activators during immune responses, enabling potentially faster and more robust transcriptional reprogramming upon pathogen recognition. PMID:25144198

Xu, Fang; Kapos, Paul; Cheng, Yu Ti; Li, Meng; Zhang, Yuelin; Li, Xin

2014-01-01

113

Systematic variation in the pattern of gene paralog retention between the teleost superorders Ostariophysi and Acanthopterygii.  

PubMed

Teleost fish underwent whole-genome duplication around 450 Ma followed by diploidization and loss of 80-85% of the duplicated genes. To identify a deep signature of this teleost-specific whole-genome duplication (TSGD), we searched for duplicated genes that were systematically and uniquely retained in one or other of the superorders Ostariophysi and Acanthopterygii. TSGD paralogs comprised 17-21% of total gene content. Some 2.6% (510) of TSGD paralogs were present as pairs in the Ostariophysi genomes of Danio rerio (Cypriniformes) and Astyanax mexicanus (Characiformes) but not in species from four orders of Acanthopterygii (Gasterosteiformes, Gasterosteus aculeatus; Tetraodontiformes, Tetraodon nigroviridis; Perciformes, Oreochromis niloticus; and Beloniformes, Oryzias latipes) where a single copy was identified. Similarly, 1.3% (418) of total gene number represented cases where TSGD paralogs pairs were systematically retained in the Acanthopterygian but conserved as a single copy in Ostariophysi genomes. We confirmed the generality of these results by phylogenetic and synteny analysis of 40 randomly selected linage-specific paralogs (LSPs) from each superorder and completed with the transcriptomes of three additional Ostariophysi species (Ictalurus punctatus [Siluriformes], Sinocyclocheilus species [Cypriniformes], and Piaractus mesopotamicus [Characiformes]). No chromosome bias was detected in TSGD paralog retention. Gene ontology (GO) analysis revealed significant enrichment of GO terms relative to the human GO SLIM database for "growth," "Cell differentiation," and "Embryo development" in Ostariophysi and for "Transport," "Signal Transduction," and "Vesicle mediated transport" in Acanthopterygii. The observed patterns of paralog retention are consistent with different diploidization outcomes having contributed to the evolution/diversification of each superorder. PMID:24732281

Garcia de la Serrana, Daniel; Mareco, Edson A; Johnston, Ian A

2014-04-01

114

Increased rates of cerebral glucose metabolism in a mouse model of fragile X mental retardation  

E-print Network

Increased rates of cerebral glucose metabolism in a mouse model of fragile X mental retardation Mei mental retardation protein (FMRP) gives rise to fragile X syndrome, the most common form of inherited mental retardation. A fragile X knockout (fmr1 KO) mouse has been described that has some

Smith, Carolyn Beebe

115

The mGluR theory of fragile X mental retardation  

E-print Network

The mGluR theory of fragile X mental retardation Mark F. Bear1 , Kimberly M. Huber2 and Stephen T-term depression (LTD) of transmission at hippocampal synapses. Loss of fragile X mental retardation protein (FMRP frequent inherited cause of mental retardation and an identified cause of autism. Fragile X is the most

Bear, Mark

116

Altered synaptic plasticity in a mouse model of fragile X mental retardation  

E-print Network

Altered synaptic plasticity in a mouse model of fragile X mental retardation Kimberly M. Huber syndrome, the most common inherited form of human mental retardation, is caused by mutations of the Fmr1 gene that encodes the fragile X mental retardation protein (FMRP). Biochem- ical evidence indicates

Bear, Mark

117

Fragile X Mental Retardation Syndrome: Structure of the KH1-KH2 Domains  

E-print Network

Structure Article Fragile X Mental Retardation Syndrome: Structure of the KH1-KH2 Domains of Fragile X Mental Retardation Protein Roberto Valverde,1 Irina Pozdnyakova,1 Tommi Kajander,1,3 Janani.06.022 SUMMARY Fragile X syndrome is the most common form of inherited mental retardation in humans

Regan, Lynne

118

Control of Copper Resistance and Inorganic Sulfur Metabolism by Paralogous Regulators in Staphylococcus aureus*  

PubMed Central

All strains of Staphylococcus aureus encode a putative copper-sensitive operon repressor (CsoR) and one other CsoR-like protein of unknown function. We show here that NWMN_1991 encodes a bona fide Cu(I)-inducible CsoR of a genetically unlinked copA-copZ copper resistance operon in S. aureus strain Newman. In contrast, an unannotated open reading frame found between NWMN_0027 and NWMN_0026 (denoted NWMN_0026.5) encodes a CsoR-like regulator that represses expression of adjacent genes by binding specifically to a pair of canonical operator sites positioned in the NWMN_0027–0026.5 intergenic region. Inspection of these regulated genes suggests a role in assimilation of inorganic sulfur from thiosulfate and vectorial sulfur transfer, and we designate NWMN_0026.5 as CstR (CsoR-like sulfur transferase repressor). Expression analysis demonstrates that CsoR and CstR control their respective regulons in response to distinct stimuli with no overlap in vivo. Unlike CsoR, CstR does not form a stable complex with Cu(I); operator binding is instead inhibited by oxidation of the intersubunit cysteine pair to a mixture of disulfide and trisulfide linkages by a likely metabolite of thiosulfate assimilation, sulfite. CsoR is unreactive toward sulfite under the same conditions. We conclude that CsoR and CstR are paralogs in S. aureus that function in the same cytoplasm to control distinct physiological processes. PMID:21339296

Grossoehme, Nicholas; Kehl-Fie, Thomas E.; Ma, Zhen; Adams, Keith W.; Cowart, Darin M.; Scott, Robert A.; Skaar, Eric P.; Giedroc, David P.

2011-01-01

119

Fire retardant polyetherimide nanocomposites  

SciTech Connect

Polyetherimide-layered silicates nanocomposites with increased char yield and fire retardancy are described. The use of nanocomposites is a new, environmentally-benign approach to improve fire resistance of polymers. An increase in the aromaticity yields high char residues that normally correlate with higher oxygen index and lower flammability. The often high cost of these materials and the specialized processing techniques required, however, have limited the use of these polymers to certain specialized applications. The effectiveness of fire retardant fillers is also limited since the large amounts required make processing difficult and might inadvertently affect mechanical properties.

Lee, J.; Takekoshi, T.; Giannelis, E.P. [Cornell Univ., Ithaca, NY (United States). Dept. of Materials Science

1997-09-01

120

DEATH AND MENTALLY RETARDED PERSONS  

E-print Network

Special images associated with the concept ofdeath are applied to people who are mentally retarded. The images reflect, and are reflected in, social attitudes which often lead to alienating expertences for retarded persons. These experiences...

Evans, Daryl

1981-01-01

121

Flame retardant spandex type polyurethanes  

NASA Technical Reports Server (NTRS)

Flame retardant elastomeric compositions were developed, comprised of: (1) spandex type polyurethane having incorporated into the polymer chain, halogen containing polyols; (2) conventional spandex type polyurethanes in physical admixture flame retardant additives; and (3) fluoroelastomeric resins in physical admixture with flame retardant additives. Methods of preparing fibers of the flame retardant elastomeric materials are presented and articles of manufacture comprised of the elastomeric materials are mentioned.

Howarth, J. T.; Sheth, S.; Sidman, K. R.; Massucco, A. A. (inventors)

1978-01-01

122

Meiotic recombination between paralogous RBCSB genes on sister chromatids of Arabidopsis thaliana.  

PubMed

Paralogous genes organized as a gene cluster can rapidly evolve by recombination between misaligned paralogs during meiosis, leading to duplications, deletions, and novel chimeric genes. To model unequal recombination within a specific gene cluster, we utilized a synthetic RBCSB gene cluster to isolate recombinant chimeric genes resulting from meiotic recombination between paralogous genes on sister chromatids. Several F1 populations hemizygous for the synthRBCSB1 gene cluster gave rise to Luc+ F2 plants at frequencies ranging from 1 to 3 x 10(-6). A nonuniform distribution of recombination resolution sites resulted in the biased formation of recombinant RBCS3B/1B::LUC genes with nonchimeric exons. The positioning of approximately half of the mapped resolution sites was effectively modeled by the fractional length of identical DNA sequences. In contrast, the other mapped resolution sites fit an alternative model in which recombination resolution was stimulated by an abrupt transition from a region of relatively high sequence similarity to a region of low sequence similarity. Thus, unequal recombination between paralogous RBCSB genes on sister chromatids created an allelic series of novel chimeric genes that effectively resulted in the diversification rather than the homogenization of the synthRBCSB1 gene cluster. PMID:15020479

Jelesko, John G; Carter, Kristy; Thompson, Whitney; Kinoshita, Yuki; Gruissem, Wilhelm

2004-02-01

123

A Theory of Utility Conditionals: Paralogical Reasoning from Decision-Theoretic Leakage  

ERIC Educational Resources Information Center

Many "if p, then q" conditionals have decision-theoretic features, such as antecedents or consequents that relate to the utility functions of various agents. These decision-theoretic features leak into reasoning processes, resulting in various paralogical conclusions. The theory of utility conditionals offers a unified account of the various forms…

Bonnefon, Jean-Francois

2009-01-01

124

EPGD: a comprehensive web resource for integrating and displaying eukaryotic paralog\\/paralogon information  

Microsoft Academic Search

Gene duplication is common in all three domains of life, especially in eukaryotic genomes. The duplicates provide new material for the action of evolutionary forces such as selection or genetic drift. Here we describe a sophisticated procedure to extract duplicated genes (paralogs) from 26 available eukaryotic genomes, to pre-calculate several evolutionary indexes (evolutionary rate, synonymous distance\\/clock, transition redundant exchange clock,

Guohui Ding; Yan Sun; Hong Li; Zhen Wang; Haiwei Fan; Chuan Wang; Dan Yang; Yixue Li

2008-01-01

125

Meiotic recombination between paralogous RBCSB genes on sister chromatids of Arabidopsis thaliana.  

PubMed Central

Paralogous genes organized as a gene cluster can rapidly evolve by recombination between misaligned paralogs during meiosis, leading to duplications, deletions, and novel chimeric genes. To model unequal recombination within a specific gene cluster, we utilized a synthetic RBCSB gene cluster to isolate recombinant chimeric genes resulting from meiotic recombination between paralogous genes on sister chromatids. Several F1 populations hemizygous for the synthRBCSB1 gene cluster gave rise to Luc+ F2 plants at frequencies ranging from 1 to 3 x 10(-6). A nonuniform distribution of recombination resolution sites resulted in the biased formation of recombinant RBCS3B/1B::LUC genes with nonchimeric exons. The positioning of approximately half of the mapped resolution sites was effectively modeled by the fractional length of identical DNA sequences. In contrast, the other mapped resolution sites fit an alternative model in which recombination resolution was stimulated by an abrupt transition from a region of relatively high sequence similarity to a region of low sequence similarity. Thus, unequal recombination between paralogous RBCSB genes on sister chromatids created an allelic series of novel chimeric genes that effectively resulted in the diversification rather than the homogenization of the synthRBCSB1 gene cluster. PMID:15020479

Jelesko, John G; Carter, Kristy; Thompson, Whitney; Kinoshita, Yuki; Gruissem, Wilhelm

2004-01-01

126

Fire-retardant foams  

NASA Technical Reports Server (NTRS)

Family of polyimide resins are being developed as foams with exceptional fire-retardant properties. Foams are potentially useful for seat cushions in aircraft and ground vehicles and for applications such as home furnishings and building-construction materials. Basic formulations can be modified with reinforcing fibers or fillers to produce celular materials for variety of applications. By selecting reactants, polymer structure can be modified to give foams with properties ranging from high resiliency and flexibility to brittleness and rigidity.

Gagliani, J.

1978-01-01

127

Retarded Gravitation Theory  

E-print Network

We propose a Lorentz-covariant theory of gravity, and explain its theoretical origins in the problem of time in Newtonian physics. In this retarded gravitation theory (RGT), the gravitational force depends upon both retarded position and velocity, and the equations of motion are time-asymmetric retarded functional differential equations. We explicitly solve these equations, under simplifying assumptions, for various NASA spacecraft. This shows that the differences from Newtonian gravity, though tiny within the solar system, are just appropriate to explain the flyby anomaly as a v/c effect due to earth's rotation. The differences can, however, be large in the case of a spiral galaxy, and we show that the combined velocity drag from a large number of co-rotating stars enormously speeds up a test particle. Thus, the non-Newtonian behaviour of rotation curves in a spiral galaxy may be explained as being due to velocity drag rather than dark matter. RGT can also be tested in the laboratory. It necessitates a reappraisal of current laboratory methods of determining the Newtonian gravitational constant G. Since RGT makes no speculative assumptions, its refutation would have serious implications across physics.

C. K. Raju

2011-02-15

128

germline-specialized paralogs and other germline-specific genes.  

E-print Network

with the terminator (O'Sullivan et al., 2004). Intragenic looping is transcription dependent and requires components not as comprehensive as the analysis of A. suum described above, this study clearly demonstrates that hundreds to thousands of protein- encoding genes are eliminated from somatic cells in the process, in addition

Brickner, Jason

129

Systematic identification of functional orthologs based on protein network comparison  

Microsoft Academic Search

Annotating protein function across species is an important task that is often complicated by the presence of large paralogous gene families. Here, we report a novel strategy for identifying functionally related proteins that supplements sequence-based comparisons with information on conserved protein-protein interactions. First, the protein interaction networks of two species are aligned by assigning proteins to sequence homology clusters using

Sourav Bandyopadhyay; Roded Sharan; Trey Ideker

2006-01-01

130

ß-tubulin Paralogs Provide a Qualitative Test for a Phylogeny of Cyst Nematodes  

PubMed Central

Evolutionary relationships among cyst nematodes based on predicted ß-tubulin amino acid and DNA sequence data were compared with phylogenies inferred from ribosomal DNA (ITS1, 5.8S gene, ITS2). The ß-tubulin amino acid data were highly conserved and not useful for phylogenetic inference at the taxonomic level of genus and species. Phylogenetic trees based on ß-tubulin DNA sequence data were better resolved, but the relationships at lower taxonomic levels could not be inferred with confidence. Sequences from single species often appeared in more than one monophyletic clade, indicating the presence of ß-tubulin paralogs (confirmed by Southern blot analysis). For a subset of taxa, good congruence between the two data sets was revealed by the presence of the same putative ß-tubulin gene paralogs in monophyletic groups on the rDNA tree, corroborating the taxon relationships inferred from ribosomal DNA data. PMID:19262824

Sabo, A.; Ferris, V. R.

2004-01-01

131

Contrasting Patterns of Sequence Evolution at the Functionally Redundant bric à brac Paralogs in Drosophila melanogaster  

Microsoft Academic Search

Genes with overlapping expression and function may gradually diverge despite retaining some common functions. To test whether\\u000a such genes show distinct patterns of molecular evolution within species, we examined sequence variation at the bric à brac (bab) locus of Drosophila melanogaster. This locus is composed of two anciently duplicated paralogs, bab1 and bab2, which are involved in patterning the adult

Ryan D. Bickel; Wendy S. Schackwitz; Len A. Pennacchio; Sergey V. Nuzhdin; Artyom Kopp

2009-01-01

132

Heterogeneous Conservation of Dlx Paralog Co-Expression in Jawed Vertebrates  

PubMed Central

Background The Dlx gene family encodes transcription factors involved in the development of a wide variety of morphological innovations that first evolved at the origins of vertebrates or of the jawed vertebrates. This gene family expanded with the two rounds of genome duplications that occurred before jawed vertebrates diversified. It includes at least three bigene pairs sharing conserved regulatory sequences in tetrapods and teleost fish, but has been only partially characterized in chondrichthyans, the third major group of jawed vertebrates. Here we take advantage of developmental and molecular tools applied to the shark Scyliorhinus canicula to fill in the gap and provide an overview of the evolution of the Dlx family in the jawed vertebrates. These results are analyzed in the theoretical framework of the DDC (Duplication-Degeneration-Complementation) model. Results The genomic organisation of the catshark Dlx genes is similar to that previously described for tetrapods. Conserved non-coding elements identified in bony fish were also identified in catshark Dlx clusters and showed regulatory activity in transgenic zebrafish. Gene expression patterns in the catshark showed that there are some expression sites with high conservation of the expressed paralog(s) and other expression sites with events of paralog sub-functionalization during jawed vertebrate diversification, resulting in a wide variety of evolutionary scenarios within this gene family. Conclusion Dlx gene expression patterns in the catshark show that there has been little neo-functionalization in Dlx genes over gnathostome evolution. In most cases, one tandem duplication and two rounds of vertebrate genome duplication have led to at least six Dlx coding sequences with redundant expression patterns followed by some instances of paralog sub-functionalization. Regulatory constraints such as shared enhancers, and functional constraints including gene pleiotropy, may have contributed to the evolutionary inertia leading to high redundancy between gene expression patterns. PMID:23840829

Debiais-Thibaud, Mélanie; Metcalfe, Cushla J.; Pollack, Jacob; Germon, Isabelle; Ekker, Marc; Depew, Michael; Laurenti, Patrick

2013-01-01

133

Avoiding paralogy: diploid loci for allotetraploid blue sucker fish ( Cycleptus elongatus , Catostomidae)  

Microsoft Academic Search

The blue sucker (Cycleptus elongatus) is a widespread North American catostomid fish that appears to be declining throughout much of its range. Here, we describe\\u000a the isolation and characterization of eleven microsatellite loci developed for population genetic studies in the genus. We\\u000a show that an additional step of cloning and sequencing can be useful in isolating paralogous loci that often

Michael L. Bessert; Craig Sitzman; Guillermo Ortí

2007-01-01

134

Accelerating and Retarding Anomalous Diffusion  

E-print Network

In this paper Gaussian models of retarded and accelerated anomalous diffusion are considered. Stochastic differential equations of fractional order driven by single or multiple fractional Gaussian noise terms are introduced to describe retarding and accelerating subdiffusion and superdiffusion. Short and long time asymptotic limits of the mean squared displacement of the stochastic processes associated with the solutions of these equations are studied. Specific cases of these equations are shown to provide possible descriptions of retarding or accelerating anomalous diffusion.

Chai Hok Eab; S. C. Lim

2012-01-27

135

DNA repair. PAXX, a paralog of XRCC4 and XLF, interacts with Ku to promote DNA double-strand break repair.  

PubMed

XRCC4 and XLF are two structurally related proteins that function in DNA double-strand break (DSB) repair. Here, we identify human PAXX (PAralog of XRCC4 and XLF, also called C9orf142) as a new XRCC4 superfamily member and show that its crystal structure resembles that of XRCC4. PAXX interacts directly with the DSB-repair protein Ku and is recruited to DNA-damage sites in cells. Using RNA interference and CRISPR-Cas9 to generate PAXX(-/-) cells, we demonstrate that PAXX functions with XRCC4 and XLF to mediate DSB repair and cell survival in response to DSB-inducing agents. Finally, we reveal that PAXX promotes Ku-dependent DNA ligation in vitro and assembly of core nonhomologous end-joining (NHEJ) factors on damaged chromatin in cells. These findings identify PAXX as a new component of the NHEJ machinery. PMID:25574025

Ochi, Takashi; Blackford, Andrew N; Coates, Julia; Jhujh, Satpal; Mehmood, Shahid; Tamura, Naoka; Travers, Jon; Wu, Qian; Draviam, Viji M; Robinson, Carol V; Blundell, Tom L; Jackson, Stephen P

2015-01-01

136

Two Rac paralogs regulate polarized growth in the human fungal pathogen Cryptococcus neoformans  

PubMed Central

A genome wide analysis of the human fungal pathogen Cryptococcus neoformans var. grubii has revealed a number of duplications of highly conserved genes involved in morphogenesis. Previously, we reported that duplicate Cdc42 paralogs provide C. neoformans with niche-specific responses to environmental stresses: Cdc42 is required for thermotolerance, while Cdc420 supports the formation of titan cells. The related Rho-GTPase Rac1 has been shown in C. neoformans var. neoformans to play a major role in filamentation and to share Cdc42/Cdc420 binding partners. Here we report the characterization of a second Rac paralog in C. neoformans, Rac2, and describe its overlapping function with the previously described CnRac, Rac1. Further, we demonstrate that the Rac paralogs play a primary role in polarized growth via the organization of reactive oxygen species and play only a minor role in the organization of actin. Finally, we provide preliminary evidence that pharmacological inhibitors of Rac activity and actin stability have synergistic activity. PMID:23748012

Ballou, Elizabeth Ripley; Selvig, Kyla; Narloch, Jessica L.; Nichols, Connie B.; Alspaugh, J. Andrew

2013-01-01

137

A caspase-like decoy molecule enhances the activity of a paralogous caspase in the yellow fever mosquito, Aedes aegypti  

PubMed Central

Caspases are cysteine proteases that play critical roles in apoptosis and other key cellular processes. A mechanism of caspase regulation that has been described in mammals and nematodes involves caspase-like decoy molecules, enzymatically inactive caspase homologs that have arisen by gene duplication and acquired the ability to regulate other caspases. Caspase-like decoy molecules are not found in Drosophila melanogaster, raising the question of whether this type of caspase regulation exists in insects. Phylogenomic analysis of caspase genes from twelve Drosophila and three mosquito species revealed several examples of duplicated caspase homologs lacking critical catalytic residues, making them candidate caspase-like decoy molecules. One of these, CASPS18 from the mosquito Aedes aegypti, is a homolog of the D. melanogaster caspase Decay and contains substitutions in two critical amino acid positions, including the catalytic cysteine residue. As expected, CASPS18 lacked caspase activity, but co-expression of CASPS18 with a paralogous caspase, CASPS19, in mosquito cells or co-incubation of CASPS18 and CASPS19 recombinant proteins resulted in greatly enhanced CASPS19 activity. The discovery of potential caspase-like decoy molecules in several insect species opens new avenues for investigating caspase regulation in insects, particularly in disease vectors such as mosquitoes. PMID:20417712

Bryant, Bart; Ungerer, Mark C.; Liu, Qingzhen; Waterhouse, Robert M.; Clem, Rollie J.

2010-01-01

138

Competitive inhibition of a set of endoplasmic reticulum protein genes (GRP78, GRP94, and ERp72) retards cell growth and lowers viability after ionophore treatment.  

PubMed Central

GRP78, a 78-kDa protein localized in the endoplasmic reticulum (ER), has been implicated in protein processing and stress protection. Its promoter contains a 36-bp region which is conserved among GRP genes across species and has the ability to compete for trans-acting factors mediating GRP gene expression. Integration of about 800 tandem copies of this sequence into the genome of a Chinese hamster ovary cell line (DG44) results in transfectants with the following phenotypes: (i) the induction level of GRP78 by the calcium ionophore A23187 and tunicamycin is reduced 4- and 2-fold, respectively, (ii) the induction levels of two other ER luminal protein genes, GRP94 and ERp72, are simultaneously down-regulated, (iii) the growth rate of these cells is half that of transfectants without the amplified sequence, and (iv) cell viability is decreased by 25-fold after A23187 treatment. These results provide new evidence that ERp72 shares common trans-acting regulatory factors with the GRP genes and that a reduction of this set of ER proteins correlates with lower viability after ionophore treatment. Images PMID:2046663

Li, X A; Lee, A S

1991-01-01

139

Career Education for the Retarded?  

ERIC Educational Resources Information Center

There is a need for societal changes to accommodate the handicapped and retarded in the labor force. Career education has become the primary component of many programs for the mentally retarded. Because of the job market, equal time must be given to leisure skill training and job skill training. (JOW)

Schill, William J.; Ryckman, David B.

1980-01-01

140

The Mentally Retarded in Sweden.  

ERIC Educational Resources Information Center

Described are residential and educational services provided for mentally retarded (MC) children and adults in Sweden. Normalization is the focus of the services which make maximum use of mental and physical capacities to reduce the handicap of mental retardation. Described are general principles, and four stages involving development of services…

Grunewald, Karl

141

Fire-Retardant Epoxy Adhesives  

NASA Technical Reports Server (NTRS)

Phosphorus-containing epoxy is fire-retardant and translucent. Intended as adhesive for laminated plastic sheets, new material bonds well to titanium dioxide-filled plastic film, which ordinarily shows little surface interaction with adhesives. Fire retardancy has been demonstrated, and smoke density is low enough to avoid smoke obscuration.

Bilow, N.; Giants, T. W.

1982-01-01

142

Flame retarded asphalt blend composition  

SciTech Connect

This patent describes a flame retarded asphalt composition consisting essentially of a blend of: (a) thermoplastic elastomer modified bitumen; (b) 20-30 wt % inert filler; (c) 1-20 wt % of at least one halogenated flame retardant; and (d) 1-5 wt % of at least one inorganic phosphorus containing compound selected from the group consisting of ammonium phosphate compounds and red phosphorus.

Walters, R.B.

1987-04-21

143

X-linked mental retardation  

Microsoft Academic Search

Genetic factors have an important role in the aetiology of mental retardation. However, their contribution is often underestimated because in developed countries, severely affected patients are mainly sporadic cases and familial cases are rare. X-chromosomal mental retardation is the exception to this rule, and this is one of the reasons why research into the genetic and molecular causes of mental

H.-Hilger Ropers; Pietro Chiurazzi

1980-01-01

144

Nanocomposite fire retardants ? a review  

Microsoft Academic Search

Most 5re retardant nanocomposites are made from layered silicates and organic polymers, a variety of methods are used in their synthesis. The mechanism for the 5re retardancy of these composites is generally considered to be due to the structure of the char formed during combustion, which enables the char to thermally insulate the polymer and inhibit the formation and escape

D. Porter; E. Metcalfe; M. J. K. Thomas

2000-01-01

145

Intrauterine Growth Retardation – A Developmental Model of Type 2 Diabetes  

PubMed Central

Intrauterine growth retardation has been linked to the development of type 2 diabetes later in life and the mechanisms underlying this phenomena are unknown. Epidemiological studies in humans show a distinct link with the exposure to an intrauterine insult that results in low birth weight and the development of type 2 diabetes in adulthood. Intrauterine growth retardation can be induced in rodent models by exposing the pregnant rat to a low protein diet, total calorie restriction, high dose glucocorticoids or inducing uteroplacental insufficiency, all which result in abnormalities in glucose homeostasis in the offspring later in life. Animal models of intrauterine growth retardation allow for a better characterization of changes in glucose homeostasis and corresponding changes in gene expression that can provide insight in the mechanisms by which intrauterine growth retardation leads to type 2 diabetes. PMID:24949076

Pinney, Sara E.

2013-01-01

146

Diet and retarded growth.  

PubMed Central

The diets of 36 children below the third centile for height but with no organic disease were compared with the diets of a control group. In most cases retarded growth was associated with a long-continued deficiency in calorie intake. When the diets were reassessed about a year later the shortfall in calorie intake was significantly reduced. This improvement, which tended to be followed by an increase in the rate of growth in height, might have been due to alteration in the child's circumstances or improvement in the family attitudes and feeding habits or both. Advice given at the clinic is thought to have played a part in bringing these changes about. PMID:630213

Davis, D R; Apley, J; Fill, G; Grimaldi, C

1978-01-01

147

Characterization of the Drosophila Group Ortholog to the Amino-Terminus of the Alpha-Thalassemia and Mental Retardation X-Linked (ATRX) Vertebrate Protein.  

PubMed

The human ATRX gene encodes hATRX, a chromatin-remodeling protein harboring an helicase/ATPase and ADD domains. The ADD domain has two zinc fingers that bind to histone tails and mediate hATRX binding to chromatin. dAtrx, the putative ATRX homolog in Drosophila melanogaster, has a conserved helicase/ATPase domain but lacks the ADD domain. A bioinformatic search of the Drosophila genome using the human ADD sequence allowed us to identify the CG8290 annotated gene, which encodes three ADD harboring- isoforms generated by alternative splicing. This Drosophila ADD domain is highly similar in structure and in the amino acids which mediate the histone tail contacts to the ADD domain of hATRX as shown by 3D modeling. Very recently the CG8290 annotated gene has been named dadd1. We show through pull-down and CoIP assays that the products of the dadd1 gene interact physically with dAtrxL and HP1a and all of them mainly co-localize in the chromocenter, although euchromatic localization can also be observed through the chromosome arms. We confirm through ChIP analyses that these proteins are present in vivo in the same heterochromatic regions. The three isoforms are expressed throughout development. Flies carrying transheterozygous combinations of the dadd1 and atrx alleles are semi-viable and have different phenotypes including the appearance of melanotic masses. Interestingly, the dAdd1-b and c isoforms have extra domains, such as MADF, which suggest newly acquired functions of these proteins. These results strongly support that, in Drosophila, the atrx gene diverged and that the dadd1-encoded proteins participate with dAtrx in some cellular functions such as heterochromatin maintenance. PMID:25437195

López-Falcón, Brenda; Meyer-Nava, Silvia; Hernández-Rodríguez, Benjamín; Campos, Adam; Montero, Daniel; Rudiño, Enrique; Vázquez, Martha; Zurita, Mario; Valadez-Graham, Viviana

2014-01-01

148

Elongation factor 2 and fragile X mental retardation protein control the dynamic translation of Arc/Arg3.1 essential for mGluR-LTD.  

PubMed

Group I metabotropic glutamate receptors (mGluR) induce long-term depression (LTD) that requires protein synthesis. Here, we demonstrate that Arc/Arg3.1 is translationally induced within 5 min of mGluR activation, and this response is essential for mGluR-dependent LTD. The increase in Arc/Arg3.1 translation requires eEF2K, a Ca(2+)/calmodulin-dependent kinase that binds mGluR and dissociates upon mGluR activation, whereupon it phosphorylates eEF2. Phospho-eEF2 acts to slow the elongation step of translation and inhibits general protein synthesis but simultaneously increases Arc/Arg3.1 translation. Genetic deletion of eEF2K results in a selective deficit of rapid mGluR-dependent Arc/Arg3.1 translation and mGluR-LTD. This rapid translational mechanism is disrupted in the fragile X disease mouse (Fmr1 KO) in which mGluR-LTD does not require de novo protein synthesis but does require Arc/Arg3.1. We propose a model in which eEF2K-eEF2 and FMRP coordinately control the dynamic translation of Arc/Arg3.1 mRNA in dendrites that is critical for synapse-specific LTD. PMID:18614030

Park, Sungjin; Park, Joo Min; Kim, Sangmok; Kim, Jin-Ah; Shepherd, Jason D; Smith-Hicks, Constance L; Chowdhury, Shoaib; Kaufmann, Walter; Kuhl, Dietmar; Ryazanov, Alexey G; Huganir, Richard L; Linden, David J; Worley, Paul F

2008-07-10

149

Case Review: Rights of the Retarded  

ERIC Educational Resources Information Center

The author reviews approximately 28 recent court cases which focus on protection of students mislabeled mentally retarded and which inadvertently may have discriminated against mentally retarded students. (MC)

Collings, Gary D.

1973-01-01

150

An enhanced method for sequence walking and paralog mining: TOPO® Vector-Ligation PCR  

PubMed Central

Background Although technological advances allow for the economical acquisition of whole genome sequences, many organisms' genomes remain unsequenced, and fully sequenced genomes may contain gaps. Researchers reliant upon partial genomic or heterologous sequence information require methods for obtaining unknown sequences from loci of interest. Various PCR based techniques are available for sequence walking - i.e., the acquisition of unknown DNA sequence adjacent to known sequence. Many such methods require rigid, elaborate protocols and/or impose narrowly confined options in the choice of restriction enzymes for necessary genomic digests. We describe a new method, TOPO® Vector-Ligation PCR (or TVL-PCR) that innovatively integrates available tools and familiar concepts to offer advantages as a means of both targeted sequence walking and paralog mining. Findings TVL-PCR exploits the ligation efficiency of the pCR®4-TOPO® (Invitrogen, Carlsbad, California) vector system to capture fragments of unknown sequence by creating chimeric molecules containing defined priming sites at both ends. Initially, restriction enzyme-digested genomic DNA is end-repaired to create 3' adenosine overhangs and is then ligated to pCR4-TOPO vectors. The ligation product pool is used directly as a template for nested PCR, using specific primers to target orthologous sequences, or degenerate primers to enable capture of paralogous gene family members. We demonstrated the efficacy of this method by capturing entire coding and partial promoter sequences of several strawberry Superman-like genes. Conclusions TVL-PCR is a convenient and efficient method for DNA sequence walking and paralog mining that is applicable to any organism for which relevant DNA sequence is available as a basis for primer design. PMID:20202219

2010-01-01

151

Independent evolutionary origin of fem paralogous genes and complementary sex determination in hymenopteran insects.  

PubMed

The primary signal of sex determination in the honeybee, the complementary sex determiner (csd) gene, evolved from a gene duplication event from an ancestral copy of the fem gene. Recently, other paralogs of the fem gene have been identified in several ant and bumblebee genomes. This discovery and the close phylogenetic relationship of the paralogous gene sequences led to the hypothesis of a single ancestry of the csd genetic system of complementary sex determination in the Hymenopteran insects, in which the fem and csd gene copies evolved as a unit in concert with the mutual transfers of sequences (concerted evolution). Here, we show that the paralogous gene copies evolved repeatedly through independent gene duplication events in the honeybee, bumblebee, and ant lineage. We detected no sequence tracts that would indicate a DNA transfer between the fem and the fem1/csd genes between different ant and bee species. Instead, we found tracts of duplication events in other genomic locations, suggesting that gene duplication was a frequent event in the evolution of these genes. These and other evidences suggest that the fem1/csd gene originated repeatedly through gene duplications in the bumblebee, honeybee, and ant lineages in the last 100 million years. Signatures of concerted evolution were not detectable, implicating that the gene tree based on neutral synonymous sites represents the phylogenetic relationships and origins of the fem and fem1/csd genes. Our results further imply that the fem1 and csd gene in bumblebees, honeybees, and ants are not orthologs, because they originated independently from the fem gene. Hence, the widely shared and conserved complementary sex determination mechanism in Hymenopteran insects is controlled by different genes and molecular processes. These findings highlight the limits of comparative genomics and emphasize the requirement to study gene functions in different species and major hymenopteran lineages. PMID:24743790

Koch, Vasco; Nissen, Inga; Schmitt, Björn D; Beye, Martin

2014-01-01

152

Independent Evolutionary Origin of fem Paralogous Genes and Complementary Sex Determination in Hymenopteran Insects  

PubMed Central

The primary signal of sex determination in the honeybee, the complementary sex determiner (csd) gene, evolved from a gene duplication event from an ancestral copy of the fem gene. Recently, other paralogs of the fem gene have been identified in several ant and bumblebee genomes. This discovery and the close phylogenetic relationship of the paralogous gene sequences led to the hypothesis of a single ancestry of the csd genetic system of complementary sex determination in the Hymenopteran insects, in which the fem and csd gene copies evolved as a unit in concert with the mutual transfers of sequences (concerted evolution). Here, we show that the paralogous gene copies evolved repeatedly through independent gene duplication events in the honeybee, bumblebee, and ant lineage. We detected no sequence tracts that would indicate a DNA transfer between the fem and the fem1/csd genes between different ant and bee species. Instead, we found tracts of duplication events in other genomic locations, suggesting that gene duplication was a frequent event in the evolution of these genes. These and other evidences suggest that the fem1/csd gene originated repeatedly through gene duplications in the bumblebee, honeybee, and ant lineages in the last 100 million years. Signatures of concerted evolution were not detectable, implicating that the gene tree based on neutral synonymous sites represents the phylogenetic relationships and origins of the fem and fem1/csd genes. Our results further imply that the fem1 and csd gene in bumblebees, honeybees, and ants are not orthologs, because they originated independently from the fem gene. Hence, the widely shared and conserved complementary sex determination mechanism in Hymenopteran insects is controlled by different genes and molecular processes. These findings highlight the limits of comparative genomics and emphasize the requirement to study gene functions in different species and major hymenopteran lineages. PMID:24743790

Koch, Vasco; Nissen, Inga; Schmitt, Björn D.; Beye, Martin

2014-01-01

153

A single allele of Hdac2 but not Hdac1 is sufficient for normal mouse brain development in the absence of its paralog.  

PubMed

The histone deacetylases HDAC1 and HDAC2 are crucial regulators of chromatin structure and gene expression, thereby controlling important developmental processes. In the mouse brain, HDAC1 and HDAC2 exhibit different developmental stage- and lineage-specific expression patterns. To examine the individual contribution of these deacetylases during brain development, we deleted different combinations of Hdac1 and Hdac2 alleles in neural cells. Ablation of Hdac1 or Hdac2 by Nestin-Cre had no obvious consequences on brain development and architecture owing to compensation by the paralog. By contrast, combined deletion of Hdac1 and Hdac2 resulted in impaired chromatin structure, DNA damage, apoptosis and embryonic lethality. To dissect the individual roles of HDAC1 and HDAC2, we expressed single alleles of either Hdac1 or Hdac2 in the absence of the respective paralog in neural cells. The DNA-damage phenotype observed in double knockout brains was prevented by expression of a single allele of either Hdac1 or Hdac2. Strikingly, Hdac1(-/-)Hdac2(+/-) brains showed normal development and no obvious phenotype, whereas Hdac1(+/-)Hdac2(-/-) mice displayed impaired brain development and perinatal lethality. Hdac1(+/-)Hdac2(-/-) neural precursor cells showed reduced proliferation and premature differentiation mediated by overexpression of protein kinase C, delta, which is a direct target of HDAC2. Importantly, chemical inhibition or knockdown of protein kinase C delta was sufficient to rescue the phenotype of neural progenitor cells in vitro. Our data indicate that HDAC1 and HDAC2 have a common function in maintaining proper chromatin structures and show that HDAC2 has a unique role by controlling the fate of neural progenitors during normal brain development. PMID:24449838

Hagelkruys, Astrid; Lagger, Sabine; Krahmer, Julia; Leopoldi, Alexandra; Artaker, Matthias; Pusch, Oliver; Zezula, Jürgen; Weissmann, Simon; Xie, Yunli; Schöfer, Christian; Schlederer, Michaela; Brosch, Gerald; Matthias, Patrick; Selfridge, Jim; Lassmann, Hans; Knoblich, Jürgen A; Seiser, Christian

2014-02-01

154

INTRODUCTION TO BROMINATED FLAME RETARDANTS  

EPA Science Inventory

Brominated flame retardants (BFRs) are a large and diverse class of major industrial products used to provide fire safety. Tetrabromobisphenol A (TBBPA), Hexabromocylocodecane (HBCD), and Polybrominated Diphenyl Ethers (PBDEs) are the major commercial compounds. TBBPA is a react...

155

Deinstitutionalization of the Mentally Retarded.  

ERIC Educational Resources Information Center

Literature on deinstitutionalization of mentally retarded persons is reviewed. Cited are studies showing positive aspects, including improved communication abilities, increased adaptive behavior and personal satisfaction. Community adjustment findings focus on effects of involuntary relocation to another facility, age differences, and…

Cortez, Patricia

156

Neurotoxicity of brominated flame retardants  

EPA Science Inventory

Polybrominated diphenyl ethers (PBDEs) have been commonly used as commercial flame retardants in a variety of products including plastics and textiles. Despite their decreasing usage worldwide, congeners continue to accumulate in the environment, including soil, dust, food, anima...

157

Can earthworms survive fire retardants?  

USGS Publications Warehouse

Most common fire retardants are foams or are similar to common agricultural fertilizers, such as ammonium sulfate and ammonium phosphate. Although fire retardants are widely applied to soils, we lack basic information about their toxicities to soil organisms. We measured the toxicity of five fire retardants (Firetrol LCG-R, Firetrol GTS-R, Silv-Ex Foam Concentrate, Phos-chek D-75, and Phos-chek WD-881) to earthworms using the pesticide toxicity test developed for earthworms by the European Economic Community. None was lethal at 1,000 ppm in the soil, which was suggested as a relatively high exposure under normal applications. We concluded that the fire retardants tested are relatively nontoxic to soil organisms compared with other environmental chemicals and that they probably do not reduce earthworm populations when applied under usual firefighting conditions.

Beyer, W.N.; Olson, A.

1996-01-01

158

Intumescent coatings as fire retardants  

NASA Technical Reports Server (NTRS)

Fire-retardant paint, when activated by the heat of fire, reacts to form a thick, low-density, polymeric coating or char layer. Water vapor and sulphur dioxide are released during the intumescent reaction.

Fish, R. H.; Fohlen, G. M.; Parker, J. A.; Sawko, P. M.

1970-01-01

159

The Mentally Retarded Offender: Annotated Bibliography.  

ERIC Educational Resources Information Center

An annotated bibliography of approximately 150 books and articles on the mentally retarded offender as well as 30 nonannotated entries are provided. Topics covered include such areas as characteristics of mentally retarded delinquents, rehabilitation of the retarded offender, community services for retarded persons, rights of the mentally…

Schilit, Jeffrey; And Others

160

Employer Concerns in Hiring Mentally Retarded Persons.  

ERIC Educational Resources Information Center

Seventy-four potential employers of mentally retarded persons were surveyed regarding their concerns in hiring the mentally retarded. Results revealed that most businesses did not employ the mentally retarded. The majority indicated they had jobs appropriate for the retarded and were willing to hire members of this group. (Author)

Smith, Tom E.C.

1981-01-01

161

Age of walking and mental retardation.  

PubMed Central

The age of independent walking was noted for 200 retarded children aged 30-60 months living in the community. The onset of walking tended to be later in more severely retarded children, but early walkers were found even among the most retarded. The majority of children with mild, moderate, and severe retardation walked by 17 months. Only in the group which was profoundly retarded did the majority begin to walk after 17 months. Onset of walking before 17 months is usual in retarded children and is compatible with all levels of mental retardation. Images FIGURE 1 PMID:6881409

Kaminer, R K; Jedrysek, E

1983-01-01

162

Extensive local gene duplication and functional divergence among paralogs in Atlantic salmon.  

PubMed

Many organisms can generate alternative phenotypes from the same genome, enabling individuals to exploit diverse and variable environments. A prevailing hypothesis is that such adaptation has been favored by gene duplication events, which generate redundant genomic material that may evolve divergent functions. Vertebrate examples of recent whole-genome duplications are sparse although one example is the salmonids, which have undergone a whole-genome duplication event within the last 100 Myr. The life-cycle of the Atlantic salmon, Salmo salar, depends on the ability to produce alternating phenotypes from the same genome, to facilitate migration and maintain its anadromous life history. Here, we investigate the hypothesis that genome-wide and local gene duplication events have contributed to the salmonid adaptation. We used high-throughput sequencing to characterize the transcriptomes of three key organs involved in regulating migration in S. salar: Brain, pituitary, and olfactory epithelium. We identified over 10,000 undescribed S. salar sequences and designed an analytic workflow to distinguish between paralogs originating from local gene duplication events or from whole-genome duplication events. These data reveal that substantial local gene duplications took place shortly after the whole-genome duplication event. Many of the identified paralog pairs have either diverged in function or become noncoding. Future functional genomics studies will reveal to what extent this rich source of divergence in genetic sequence is likely to have facilitated the evolution of extreme phenotypic plasticity required for an anadromous life-cycle. PMID:24951567

Warren, Ian A; Ciborowski, Kate L; Casadei, Elisa; Hazlerigg, David G; Martin, Sam; Jordan, William C; Sumner, Seirian

2014-07-01

163

Human DNA helicase HELQ participates in DNA interstrand crosslink tolerance with ATR and RAD51 paralogs  

PubMed Central

Mammalian HELQ is a 3?–5? DNA helicase with strand displacement activity. Here we show that HELQ participates in a pathway of resistance to DNA interstrand crosslinks (ICLs). Genetic disruption of HELQ in human cells enhances cellular sensitivity and chromosome radial formation by the ICL-inducing agent mitomycin C (MMC). A significant fraction of MMC sensitivity is independent of the Fanconi anaemia pathway. Sister chromatid exchange frequency and sensitivity to UV radiation or topoisomerase inhibitors is unaltered. Proteomic analysis reveals that HELQ is associated with the RAD51 paralogs RAD51B/C/D and XRCC2, and with the DNA damage-responsive kinase ATR. After treatment with MMC, reduced phosphorylation of the ATR substrate CHK1 occurs in HELQ-knockout cells, and accumulation of G2/M cells is reduced. The results indicate that HELQ operates in an arm of DNA repair and signalling in response to ICL. Further, the association with RAD51 paralogs suggests HELQ as a candidate ovarian cancer gene. PMID:24005565

Takata, Kei-ichi; Reh, Shelley; Tomida, Junya; Person, Maria D.; Wood, Richard D.

2013-01-01

164

The RAD51 paralogs ensure cellular protection against mitotic defects and aneuploidy.  

PubMed

The interplay between homologous DNA recombination and mitotic progression is poorly understood. The five RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2 and XRCC3) are key enzymes for DNA double-strand break repair. In our search for specific functions of the various RAD51 paralogs, we found that inhibition of XRCC3 elicits checkpoint defects, while inhibition of RAD51B or RAD51C induces G2/M cell cycle arrest in HeLa cells. Using live-cell microscopy we show that in XRCC3-knockdown cells the spindle assembly checkpoint persists and there is a higher frequency of chromosome misalignments, anaphase bridges, and aneuploidy. We observed centrosome defects in the absence of XRCC3. While RAD51B and RAD51C act early in homologous recombination, XRCC3 functions jointly with GEN1 later in the pathway at the stage of Holliday junction resolution. Our data demonstrate that Holliday junction resolution has critical functions for preventing aberrant mitosis and aneuploidy in mitotic cells. PMID:23108668

Rodrigue, Amélie; Coulombe, Yan; Jacquet, Karine; Gagné, Jean-Phillipe; Roques, Céline; Gobeil, Stéphane; Poirier, Guy; Masson, Jean-Yves

2013-01-01

165

Impairment of fragile X mental retardation protein-metabotropic glutamate receptor 5 signaling and its downstream cognates ras-related C3 botulinum toxin substrate 1, amyloid beta A4 precursor protein, striatal-enriched protein tyrosine phosphatase, and homer 1, in autism: a postmortem study in cerebellar vermis and superior frontal cortex  

PubMed Central

Background Candidate genes associated with idiopathic forms of autism overlap with other disorders including fragile X syndrome. Our laboratory has previously shown reduction in fragile X mental retardation protein (FMRP) and increase in metabotropic glutamate receptor 5 (mGluR5) in cerebellar vermis and superior frontal cortex (BA9) of individuals with autism. Methods In the current study we have investigated expression of four targets of FMRP and mGluR5 signaling - homer 1, amyloid beta A4 precursor protein (APP), ras-related C3 botulinum toxin substrate 1 (RAC1), and striatal-enriched protein tyrosine phosphatase (STEP) - in the cerebellar vermis and superior frontal cortex (BA9) via SDS-PAGE and western blotting. Data were analyzed based on stratification with respect to age (children and adolescents vs. adults), anatomic region of the brain (BA9 vs. cerebellar vermis), and impact of medications (children and adolescents on medications (n = 4) vs. total children and adolescents (n = 12); adults on medications (n = 6) vs. total adults (n = 12)). Results There were significant increases in RAC1, APP 120 kDa and APP 80 kDa proteins in BA9 of children with autism vs. healthy controls. None of the same proteins were significantly affected in cerebellar vermis of children with autism. In BA9 of adults with autism there were significant increases in RAC1 and STEP 46 kDa and a significant decrease in homer 1 vs. controls. In the vermis of adult subjects with autism, RAC1 was significantly increased while APP 120, STEP 66 kDa, STEP 27 kDa, and homer 1 were significantly decreased when compared with healthy controls. No changes were observed in vermis of children with autism. There was a significant effect of anticonvulsant use on STEP 46 kDa/?-actin and a potential effect on homer 1/NSE, in BA9 of adults with autism. However, no other significant confound effects were observed in this study. Conclusions Our findings provide further evidence of abnormalities in FMRP and mGluR5 signaling partners in brains of individuals with autism and open the door to potential targeted treatments which could help ameliorate the symptoms of autism. PMID:23803181

2013-01-01

166

PHOG-BLAST – a new generation tool for fast similarity search of protein families  

Microsoft Academic Search

BACKGROUND: The need to compare protein profiles frequently arises in various protein research areas: comparison of protein families, domain searches, resolution of orthology and paralogy. The existing fast algorithms can only compare a protein sequence with a protein sequence and a profile with a sequence. Algorithms to compare profiles use dynamic programming and complex scoring functions. RESULTS: We developed a

Igor V Merkeev; Andrey A Mironov

2006-01-01

167

Numerous groups of chromosomal regional paralogies strongly indicate two genome doublings at the root of the vertebrates  

Microsoft Academic Search

The appearance of the vertebrates demarcates some of the most far-reaching changes of structure and function seen during the evolution of the metazoans. These drastic changes of body plan and expansion of the central nervous system among other organs coincide with increased gene numbers. The presence of several groups of paralogous chromosomal regions in the human genome is a reflection

Lars-Gustav Lundin; Dan Larhammar; Finn Hallböök

2003-01-01

168

Recurrence risks in mental retardation.  

PubMed Central

Despite improvements in diagnostic techniques and progress made in mapping genes associated with syndromal mental handicap, the estimation of recurrence risks in non-syndromal mental retardation is still dependent on empirical data. Unfortunately, few studies are available to guide the clinician and their results differ significantly. For example, recurrence risks to all sibs of a male index patient with severe mental retardation vary between 3.5% and 14% in commonly quoted series. The present review highlights the problems involved in interpreting the previous work in this area and discusses the definition of mental retardation according to the degree of severity, phenotype, and its pattern of inheritance. In planning future studies, an appreciation of these issues should allow us to derive accurate and comparable risk figures for use in counselling affected subjects and their families. PMID:9541099

Crow, Y J; Tolmie, J L

1998-01-01

169

Physiology, pharmacology, and therapeutic relevance of urocortins in mammals: ancient CRF paralogs  

PubMed Central

Urocortins, three paralogs of the stress-related peptide corticotropin-releasing factor (CRF) found in bony fish, amphibians, birds and mammals, have unique phylogenies, pharmacologies, and tissue distributions. As a result and despite a structural family resemblance, the natural functions of urocortins and CRF in mammalian homeostatic responses differ substantially. Endogenous urocortins are neither simply counterpoints nor mimics of endogenous CRF action. In their own right, urocortins may be clinically relevant molecules in the pathogenesis or management of many conditions, including congestive heart failure, hypertension, gastrointestinal and inflammatory disorders (irritable bowel syndrome, active gastritis, gastroparesis, rheumatoid arthritis), atopic/allergic disorders (dermatitis, urticaria, asthma), pregnancy and parturition (preeclampsia, spontaneous abortion, onset and maintenance of effective labor), major depression and obesity. Safety trials for intravenous urocortin treatment have already begun for the treatment of congestive heart failure. Further understanding the unique functions of urocortin 1, urocortin 2 and urocortin 3 action may uncover other therapeutic opportunities. PMID:17083971

Fekete, Éva M.; Zorrilla, Eric P.

2007-01-01

170

Auto cannibalism in mental retardation  

PubMed Central

Mental retardation (MR) deems an individual more vulnerable to psychopathologies. The individual may develop an array of behavioral disturbances manifesting themselves in the form of aggressive and destructive conduct, violent fits of anger, stereotyped, or self-injuring behavior. Self-injurious behavior is heterogeneous in nature ranging from mild to severe variant. We report a case of a 7-year-old boy with MR with self-inflicted severe oral injuries of cannibalistic nature presenting as cleft lip and palate. A more extensive research is needed on the problem behaviors in mentally retarded patients for early detection and effective and timely intervention leading to a better outcome. PMID:24891909

Verma, Rohit; Mina, Shaily; Sachdeva, Ankur

2014-01-01

171

Expression of POTE protein in human testis detected by novel monoclonal antibodies  

SciTech Connect

The POTE gene family is composed of 13 highly homologous paralogs preferentially expressed in prostate, ovary, testis, and placenta. We produced 10 monoclonal antibodies (MAbs) against three representative POTE paralogs: POTE-21, POTE-2{gamma}C, and POTE-22. One reacted with all three paralogs, six MAbs reacted with POTE-2{gamma}C and POTE-22, and three MAbs were specific to POTE-21. Epitopes of all 10 MAbs were located in the cysteine-rich repeats (CRRs) motifs located at the N-terminus of each POTE paralog. Testing the reactivity of each MAb with 12 different CRRs revealed slight differences among the antigenic determinants, which accounts for differences in cross-reactivity. Using MAbs HP8 and PG5 we were able to detect a POTE-actin fusion protein in human testis by immunoprecipitation followed by Western blotting. By immunohistochemistry we demonstrated that the POTE protein is expressed in primary spermatocytes, implying a role in spermatogenesis.

Ise, Tomoko; Das, Sudipto; Nagata, Satoshi; Maeda, Hiroshi; Lee, Yoomi; Onda, Masanori [Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4264 (United States); Anver, Miriam R. [Pathology/Histotechnology Laboratory, SAIC-Frederick, National Cancer Institute-Frederick, Frederick, MD 21702-1201 (United States); Bera, Tapan K. [Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4264 (United States); Pastan, Ira [Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4264 (United States)], E-mail: pastani@mail.nih.gov

2008-01-25

172

First Aid and the Mentally Retarded.  

ERIC Educational Resources Information Center

A first aid course for the mentally retarded is described. It adapts the standard American National Red Cross Course to the specific needs of the mentally retarded by use of a multimedia approach. (JMF)

And Others; Hauser, Carol

1979-01-01

173

HANDBOOK OF MENTAL RETARDATION SYNDROMES.  

ERIC Educational Resources Information Center

THE CLINICAL SYNDROMES WHICH CONTRIBUTE TO THE PRODUCTION OF MENTAL RETARDATION ARE DESCRIBED BY SIGNS, SYMPTOMS, AND ETIOLOGY. SYNDROMES TREATED ARE (1) PRENATAL AND POSTNATAL INFECTIONS, (2) PRENATAL INTOXICATION AND ALLERGIC REACTIONS, (3) PRENATAL TRAUMA, PHYSICAL AGENTS, OR INTOXICATION, (4) BIRTH INJURIES, (5) POSTNATAL POISONS AND ALLERGIC…

CARTER, CHARLES H.

174

Mental Retardation: Diagnosis and Treatment.  

ERIC Educational Resources Information Center

A collection of writings by 17 authors, the text includes the following discussions: general principles of diagnosis and management of mental retardation, neurologic evaluation of the infant and child, psychological evaluation, educational information, and treatment of pseudoretardation, communicative disorders, and metabolic and endocrine causes.…

Poser, Charles M., Ed.

175

Genetic Counseling in Mental Retardation.  

ERIC Educational Resources Information Center

The task of the genetic counselor who identifies genetic causes of mental retardation and assists families to understand risk of recurrence is described. Considered are chromosomal genetic disorders such as Down's syndrome, inherited disorders such as Tay-Sachs disease, identification by testing the amniotic fluid cells (amniocentresis) in time…

Bowen, Peter

176

Fire-retardant epoxy polymers  

NASA Technical Reports Server (NTRS)

Phosphorus atoms in molecular structure of epoxies make them fire-retardant without degrading their adhesive strength. Moreover, polymers are transparent, unlike compounds that contain arsenic or other inorganics. They have been used to bond polyvinylfluoride and polyether sulfone films onto polyimide glass laminates.

Akawie, R. I.; Bilow, N.; Giants, T. W.

1978-01-01

177

Dichotic Stimulation and Mental Retardation.  

ERIC Educational Resources Information Center

This paper reviews literature on the use of dichotic stimulation in individuals with mental retardation, and examines how noninvasive dichotic stimulation relates to hemisphere lateralization. Common findings are discussed concerning direction and magnitude of ear asymmetries, patterns of intrusion errors, and speech lateralization of Down…

Mosley, James L.; Virbancic, Mirna I.

1990-01-01

178

Detection of Malingered Mental Retardation  

ERIC Educational Resources Information Center

In a cross-validation of results from L. O. Graue et al. (2007), standard psychological assessment instruments, as well as tests of neurocognitive and psychiatric feigning, were administered under standard instructions to 24 participants diagnosed with mild mental retardation (MR) and 10 demographically matched community volunteers (CVH). A 2nd…

Shandera, Anne L.; Berry, David T. R.; Clark, Jessica A.; Schipper, Lindsey J.; Graue, Lili O.; Harp, Jordan P.

2010-01-01

179

People with Mental Retardation Are Dying, Legally.  

ERIC Educational Resources Information Center

Criticizes the institution of the death penalty for convicted criminals with mental retardation. Examples are given of cases in which juries were not told of the defendant's mental retardation before sentencing, and a list of defendants with mental retardation that have been executed since 1976 is provided. (CR)

Keyes, Denis; And Others

1997-01-01

180

Low Elevated Lead Levels and Mental Retardation.  

ERIC Educational Resources Information Center

The relationship between low elevated lead absorption and mild mental retardation was investigated in 40 rural children (preschool to grade 12) without demonstrable cause for their retardation. Trace mineral analysis of hair samples from Ss and a control group (N=20) indicated the mean hair lead concentrations for the retarded Ss were considerably…

Marlowe, Mike; And Others

181

International Review of Research in Mental Retardation.  

ERIC Educational Resources Information Center

The text of Volume 4 represents an international review of research in mental retardation dealing primarily with human and animal laboratory behavior. The contents range through the following topics: memory processes in retardates and normals by Norman Ellis; a theory of primary and secondary familial mental retardation by Arthur Jensen;…

Ellis, Norman R., Ed.

182

ZINC-INDUCED FACILITATOR-LIKE family in plants: lineage-specific expansion in monocotyledons and conserved genomic and expression features among rice (Oryza sativa) paralogs  

PubMed Central

Background Duplications are very common in the evolution of plant genomes, explaining the high number of members in plant gene families. New genes born after duplication can undergo pseudogenization, neofunctionalization or subfunctionalization. Rice is a model for functional genomics research, an important crop for human nutrition and a target for biofortification. Increased zinc and iron content in the rice grain could be achieved by manipulation of metal transporters. Here, we describe the ZINC-INDUCED FACILITATOR-LIKE (ZIFL) gene family in plants, and characterize the genomic structure and expression of rice paralogs, which are highly affected by segmental duplication. Results Sequences of sixty-eight ZIFL genes, from nine plant species, were comparatively analyzed. Although related to MSF_1 proteins, ZIFL protein sequences consistently grouped separately. Specific ZIFL sequence signatures were identified. Monocots harbor a larger number of ZIFL genes in their genomes than dicots, probably a result of a lineage-specific expansion. The rice ZIFL paralogs were named OsZIFL1 to OsZIFL13 and characterized. The genomic organization of the rice ZIFL genes seems to be highly influenced by segmental and tandem duplications and concerted evolution, as rice genome contains five highly similar ZIFL gene pairs. Most rice ZIFL promoters are enriched for the core sequence of the Fe-deficiency-related box IDE1. Gene expression analyses of different plant organs, growth stages and treatments, both from our qPCR data and from microarray databases, revealed that the duplicated ZIFL gene pairs are mostly co-expressed. Transcripts of OsZIFL4, OsZIFL5, OsZIFL7, and OsZIFL12 accumulate in response to Zn-excess and Fe-deficiency in roots, two stresses with partially overlapping responses. Conclusions We suggest that ZIFL genes have different evolutionary histories in monocot and dicot lineages. In rice, concerted evolution affected ZIFL duplicated genes, possibly maintaining similar expression patterns between pairs. The enrichment for IDE1 boxes in rice ZIFL gene promoters suggests a role in Zn-excess and Fe-deficiency up-regulation of ZIFL transcripts. Moreover, this is the first description of the ZIFL gene family in plants and the basis for functional studies on this family, which may play important roles in Zn and Fe homeostasis in plants. PMID:21266036

2011-01-01

183

Characterization and measurement of the plasma alpha- and beta-sex hormone-binding globulin paralogs in salmon.  

PubMed

When the biochemical characteristics of coho salmon SHBG (csSHBG) plasma were examined, two different steroid-binding profiles were obtained corresponding to recombinant csSHBG-alpha and csSHBG-beta. These SHBG paralogs share only 24% sequence identity, and this explains their unique steroid-binding properties. Both proteins bind testosterone, but csSHBG-alpha also binds androstenedione (Kd = 2.8 nm) and ethinylestradiol with high affinity, whereas csSHBG-beta binds estradiol (Kd = 0.8 nm) preferentially. When analyzed by gel filtration, csSHBG-alpha displays the properties of a 153-kDa homodimer, whereas csSHBG-beta elutes as a 68-kDa monomer. The unique steroid-binding properties of csSHBG-alpha and csSHBG-beta allowed us to develop an assay for their measurements in immature (pre-smolt) and mature coho salmon blood. Plasma csSHBG-alpha levels were 3- to 4-fold higher than those of csSHBG-beta irrespective of developmental stage or sex and correlate with each other. The major site of csSHBG-alpha expression in pre-smolts and mature fish is the liver, but low levels of csSHBG-alpha mRNA are present in stomach/intestine of mature fish. In pre-smolts, high levels of csSHBG-beta mRNA are present in gills and ovary, whereas csSHBG-beta mRNA is most abundant in muscle and stomach/intestine of mature fish. Based on the differences in csSHBG-alpha and csSHBG-beta plasma levels and their tissue expression profiles, we conclude that gills and/or muscle contribute mainly to plasma SHBG-beta in coho salmon. The assays we have developed will enable studies of how SHBG-alpha/SHBG-beta biosynthesis is regulated throughout the salmonid life cycle and how they influence steroid hormone action in these fish. PMID:18703621

Miguel-Queralt, Solange; Underhill, Caroline; Devlin, Robert H; Hammond, Geoffrey L

2009-01-01

184

X-linked mental retardation  

Microsoft Academic Search

A survey of the mentally retarded children with an IQ between 30 and 55 born in a 10-year period (1955-64) and now of school age was carried out in New South Wales. The number of propositi who had a similarly affected sib of the same sex was ascertained; 58 boys had a similarly affected brother(s) and 22 girls had a

Gillian Turner; Brian Turner

1974-01-01

185

Nuclear ribosomal its functional paralogs resolve the phylogenetic relationships of a late-miocene radiation cycad cycas (cycadaceae).  

PubMed

Cycas is the most widespread and diverse genus among the ancient cycads, but the extant species could be the product of late Miocene rapid radiations. Taxonomic treatments to date for this genus are quite controversial, which makes it difficult to elucidate its evolutionary history. We cloned 161 genomic ITS sequences from 31 species representing all sections of Cycas. The divergent ITS paralogs were examined within each species and identified as putative pseudogenes, recombinants and functional paralogs. Functional paralogs were used to reconstruct phylogenetic relationships with pseudogene sequences as molecular outgroups, since an unambiguous ITS sequence alignment with their closest relatives, the Zamiaceae, is unachievable. A fully resolved and highly supported tree topology was obtained at the section level, with two major clades including six minor clades. The results fully supported the classification scheme proposed by Hill (2004) at the section level, with the minor clades representing his six sections. The two major clades could be recognised as two subgenera. The obtained pattern of phylogenetic relationships, combined with the different seed dispersal capabilities and paleogeography, allowed us to propose a late Miocene rapid radiation of Cycas that might have been promoted by vicariant events associated with the complex topography and orogeny of South China and adjacent regions. In contrast, transoceanic dispersals might have played an important role in the rapid diversification of sect. Cycas, whose members have evolved a spongy layer in their seeds aiding water dispersals. PMID:25635842

Xiao, Long-Qian; Möller, Michael

2015-01-01

186

Trypanosoma brucei harbors a divergent XPB helicase paralog that is specialized in nucleotide excision repair and conserved among kinetoplastid organisms  

PubMed Central

Summary Conserved from yeast to humans, TFIIH is essential for RNA polymerase II transcription and nucleotide excision repair (NER). TFIIH consists of a core that includes the DNA helicase Xeroderma pigmentosum B (XPB) and a kinase subcomplex. Trypanosoma brucei TFIIH harbors all core complex components and is indispensable for RNA polymerase II transcription of spliced leader RNA genes (SLRNAs). Kinetoplastid organisms, however, possess two highly divergent XPB paralogs with only the larger being identified as a TFIIH subunit in T. brucei. Here we show that a knockout of the gene for the smaller paralog, termed XPB-R (R for repair) resulted in viable cultured trypanosomes that grew slower than normal. XPB-R depletion did not affect transcription in vivo or in vitro and XPB-R was not found to occupy the SLRNA promoter which assembles a RNA polymerase II transcription pre-initiation complex including TFIIH. However, XPB-R?/? cells were much less tolerant than wild-type cells to UV light- and cisplatin-induced DNAdamage, which require NER. Since XPB-R?/? cells were not impaired in DNA base excision repair, XPB-R appears to function specifically in NER. Interestingly, several other protists possess highly divergent XPB paralogs suggesting that XPBs specialized in transcription or NER exist beyond the Kinetoplastida. PMID:24134817

Badjatia, Nitika; Nguyen, Tu N; Lee, Ju Huck; Günzl, Arthur

2013-01-01

187

Nuclear Ribosomal ITS Functional Paralogs Resolve the Phylogenetic Relationships of a Late-Miocene Radiation Cycad Cycas (Cycadaceae)  

PubMed Central

Cycas is the most widespread and diverse genus among the ancient cycads, but the extant species could be the product of late Miocene rapid radiations. Taxonomic treatments to date for this genus are quite controversial, which makes it difficult to elucidate its evolutionary history. We cloned 161 genomic ITS sequences from 31 species representing all sections of Cycas. The divergent ITS paralogs were examined within each species and identified as putative pseudogenes, recombinants and functional paralogs. Functional paralogs were used to reconstruct phylogenetic relationships with pseudogene sequences as molecular outgroups, since an unambiguous ITS sequence alignment with their closest relatives, the Zamiaceae, is unachievable. A fully resolved and highly supported tree topology was obtained at the section level, with two major clades including six minor clades. The results fully supported the classification scheme proposed by Hill (2004) at the section level, with the minor clades representing his six sections. The two major clades could be recognised as two subgenera. The obtained pattern of phylogenetic relationships, combined with the different seed dispersal capabilities and paleogeography, allowed us to propose a late Miocene rapid radiation of Cycas that might have been promoted by vicariant events associated with the complex topography and orogeny of South China and adjacent regions. In contrast, transoceanic dispersals might have played an important role in the rapid diversification of sect. Cycas, whose members have evolved a spongy layer in their seeds aiding water dispersals. PMID:25635842

Xiao, Long-Qian; Möller, Michael

2015-01-01

188

Recombineering-based dissection of flanking and paralogous Hox gene functions in mouse reproductive tracts  

PubMed Central

Hox genes are key regulators of development. In mammals, the study of these genes is greatly confounded by their large number, overlapping functions and interspersed shared enhancers. Here, we describe the use of a novel recombineering strategy to introduce simultaneous frameshift mutations into the flanking Hoxa9, Hoxa10 and Hoxa11 genes, as well as their paralogs on the HoxD cluster. The resulting Hoxa9,10,11 mutant mice displayed dramatic synergistic homeotic transformations of the reproductive tracts, with the uterus anteriorized towards oviduct and the vas deferens anteriorized towards epididymis. The Hoxa9,10,11 mutant mice also provided a genetic setting that allowed the discovery of Hoxd9,10,11 redundant reproductive tract patterning function. Both shared and distinct Hox functions were defined. Hoxd9,10,11 play a crucial role in the regulation of uterine immune function. Non-coding non-polyadenylated RNAs were among the key Hox targets, with dramatic downregulation in mutants. We observed Hox cross-regulation of transcription and splicing. In addition, we observed a surprising anti-dogmatic apparent posteriorization of the uterine epithelium. In caudal regions of the uterus, the normal simple columnar epithelium flanking the lumen was replaced by a pseudostratified transitional epithelium, normally found near the more posterior cervix. These results identify novel molecular functions of Hox genes in the development of the male and female reproductive tracts. PMID:23760953

Raines, Anna M.; Adam, Mike; Magella, Bliss; Meyer, Sara E.; Grimes, H. Leighton; Dey, Sudhansu K.; Potter, S. Steven

2013-01-01

189

Paralog re-emergence: a novel, historically contingent mechanism in the evolution of antimicrobial resistance.  

PubMed

Evolution of resistance to drugs and pesticides poses a serious threat to human health and agricultural production. CYP51 encodes the target site of azole fungicides, widely used clinically and in agriculture. Azole resistance can evolve due to point mutations or overexpression of CYP51, and previous studies have shown that fungicide-resistant alleles have arisen by de novo mutation. Paralogs CYP51A and CYP51B are found in filamentous ascomycetes, but CYP51A has been lost from multiple lineages. Here, we show that in the barley pathogen Rhynchosporium commune, re-emergence of CYP51A constitutes a novel mechanism for the evolution of resistance to azoles. Pyrosequencing analysis of historical barley leaf samples from a unique long-term experiment from 1892 to 2008 indicates that the majority of the R. commune population lacked CYP51A until 1985, after which the frequency of CYP51A rapidly increased. Functional analysis demonstrates that CYP51A retains the same substrate as CYP51B, but with different transcriptional regulation. Phylogenetic analyses show that the origin of CYP51A far predates azole use, and newly sequenced Rhynchosporium genomes show CYP51A persisting in the R. commune lineage rather than being regained by horizontal gene transfer; therefore, CYP51A re-emergence provides an example of adaptation to novel compounds by selection from standing genetic variation. PMID:24732957

Hawkins, Nichola J; Cools, Hans J; Sierotzki, Helge; Shaw, Michael W; Knogge, Wolfgang; Kelly, Steven L; Kelly, Diane E; Fraaije, Bart A

2014-07-01

190

Paralog Re-Emergence: A Novel, Historically Contingent Mechanism in the Evolution of Antimicrobial Resistance  

PubMed Central

Evolution of resistance to drugs and pesticides poses a serious threat to human health and agricultural production. CYP51 encodes the target site of azole fungicides, widely used clinically and in agriculture. Azole resistance can evolve due to point mutations or overexpression of CYP51, and previous studies have shown that fungicide-resistant alleles have arisen by de novo mutation. Paralogs CYP51A and CYP51B are found in filamentous ascomycetes, but CYP51A has been lost from multiple lineages. Here, we show that in the barley pathogen Rhynchosporium commune, re-emergence of CYP51A constitutes a novel mechanism for the evolution of resistance to azoles. Pyrosequencing analysis of historical barley leaf samples from a unique long-term experiment from 1892 to 2008 indicates that the majority of the R. commune population lacked CYP51A until 1985, after which the frequency of CYP51A rapidly increased. Functional analysis demonstrates that CYP51A retains the same substrate as CYP51B, but with different transcriptional regulation. Phylogenetic analyses show that the origin of CYP51A far predates azole use, and newly sequenced Rhynchosporium genomes show CYP51A persisting in the R. commune lineage rather than being regained by horizontal gene transfer; therefore, CYP51A re-emergence provides an example of adaptation to novel compounds by selection from standing genetic variation. PMID:24732957

Hawkins, Nichola J.; Cools, Hans J.; Sierotzki, Helge; Shaw, Michael W.; Knogge, Wolfgang; Kelly, Steven L.; Kelly, Diane E.; Fraaije, Bart A.

2014-01-01

191

Experimental method to characterize the retardance function of optical variable retarders  

NASA Astrophysics Data System (ADS)

In this work, we present an experimental method to characterize variable optical retarders, which can have linear or non-linear behavior of the retardance variation. A theoretical analysis of such is presented using a combination of Stokes vectors and Mueller matrixes for three different optical retarders. A straightforward method for phase unwrapping, or reconstructing the original phase from the measured retardance, is proposed that yields high-accuracy results. This work can be used in an undergraduate optics lab to help students understand the concepts of retardance and its control and also how variable retardance devices work.

López-Téllez, Juan M.; Bruce, Neil C.; Delgado-Aguillón, Jesús; Garduño-Mejía, Jesús; Avendaño-Alejo, Maximino

2015-02-01

192

Rad51/Dmc1 paralogs and mediators oppose DNA helicases to limit hybrid DNA formation and promote crossovers during meiotic recombination  

PubMed Central

During meiosis programmed DNA double-strand breaks (DSBs) are repaired by homologous recombination using the sister chromatid or the homologous chromosome (homolog) as a template. This repair results in crossover (CO) and non-crossover (NCO) recombinants. Only CO formation between homologs provides the physical linkages guiding correct chromosome segregation, which are essential to produce healthy gametes. The factors that determine the CO/NCO decision are still poorly understood. Using Schizosaccharomyces pombe as a model we show that the Rad51/Dmc1-paralog complexes Rad55-Rad57 and Rdl1-Rlp1-Sws1 together with Swi5-Sfr1 play a major role in antagonizing both the FANCM-family DNA helicase/translocase Fml1 and the RecQ-type DNA helicase Rqh1 to limit hybrid DNA formation and promote Mus81-Eme1-dependent COs. A common attribute of these protein complexes is an ability to stabilize the Rad51/Dmc1 nucleoprotein filament, and we propose that it is this property that imposes constraints on which enzymes gain access to the recombination intermediate, thereby controlling the manner in which it is processed and resolved. PMID:25414342

Lorenz, Alexander; Mehats, Alizée; Osman, Fekret; Whitby, Matthew C.

2014-01-01

193

Rad51/Dmc1 paralogs and mediators oppose DNA helicases to limit hybrid DNA formation and promote crossovers during meiotic recombination.  

PubMed

During meiosis programmed DNA double-strand breaks (DSBs) are repaired by homologous recombination using the sister chromatid or the homologous chromosome (homolog) as a template. This repair results in crossover (CO) and non-crossover (NCO) recombinants. Only CO formation between homologs provides the physical linkages guiding correct chromosome segregation, which are essential to produce healthy gametes. The factors that determine the CO/NCO decision are still poorly understood. Using Schizosaccharomyces pombe as a model we show that the Rad51/Dmc1-paralog complexes Rad55-Rad57 and Rdl1-Rlp1-Sws1 together with Swi5-Sfr1 play a major role in antagonizing both the FANCM-family DNA helicase/translocase Fml1 and the RecQ-type DNA helicase Rqh1 to limit hybrid DNA formation and promote Mus81-Eme1-dependent COs. A common attribute of these protein complexes is an ability to stabilize the Rad51/Dmc1 nucleoprotein filament, and we propose that it is this property that imposes constraints on which enzymes gain access to the recombination intermediate, thereby controlling the manner in which it is processed and resolved. PMID:25414342

Lorenz, Alexander; Mehats, Alizée; Osman, Fekret; Whitby, Matthew C

2014-12-16

194

Brominated flame retardants in laboratory air  

Microsoft Academic Search

During the development of a method for determination of brominated flame retardants in human plasma and serum using solid-phase extraction, several brominated flame retardants were found in the procedural blanks. The contaminants originated most probably from the laboratory air. The brominated flame retardants were found to be adsorbed on glass surfaces and to be acquired using solid-phase sampling. 2,4,6-Tribromophenol, 2,2?,4,4?-tetrabromodiphenyl

C Thomsen; H Leknes; E Lundanes; G Becher

2001-01-01

195

A review of flame retardant polypropylene fibres  

Microsoft Academic Search

Flame retardants for polypropylene (PP) and their potential suitability for use in fibre applications are reviewed. Five principal types of generic flame retardant systems for inclusion in polypropylene fibres have been identified as phosphorus-containing, halogen-containing, silicon-containing, metal hydrate and oxide and the more recently developed nanocomposite flame retardant formulations.The most effective to date comprise halogen–antimony and phosphorus–bromine combinations, which while

Sheng Zhang; A. Richard Horrocks

2003-01-01

196

A RT I C L E S Protein complexes containing CYFIP/Sra/PIR121  

E-print Network

CYFIP (cytoplasmic fragile-X mental retardation interacting protein; Sra, PIR121), a clathrin heavy chain binding protein associated with mental retardation. The Rac1 GTPase and its exchange factor -PIX-X mental retardation protein21 . This protein complex regulates Rac1-dependent WAVE2 function at cellular

Kirchhausen, Tomas

197

Tetrahymena pot2 is a developmentally regulated paralog of pot1 that localizes to chromosome breakage sites but not to telomeres.  

PubMed

Tetrahymena telomeres are protected by a protein complex composed of Pot1, Tpt1, Pat1, and Pat2. Pot1 binds the 3' overhang and serves multiple roles in telomere maintenance. Here we describe Pot2, a paralog of Pot1 which has evolved a novel function during Tetrahymena sexual reproduction. Pot2 is unnecessary for telomere maintenance during vegetative growth, as the telomere structure is unaffected by POT2 macronuclear gene disruption. Pot2 is expressed only in mated cells, where it accumulates in developing macronuclei around the time of two chromosome processing events: internal eliminated sequence (IES) excision and chromosome breakage. Chromatin immunoprecipitation (ChIP) demonstrated Pot2 localization to regions of chromosome breakage but not to telomeres or IESs. Pot2 association with chromosome breakage sites (CBSs) occurs slightly before chromosome breakage. Pot2 did not bind CBSs or telomeric DNA in vitro, suggesting that it is recruited to CBSs by another factor. The telomere proteins Pot1, Pat1, and Tpt1 and the IES binding factor Pdd1 fail to colocalize with Pot2. Thus, Pot2 is the first protein found to associate specifically with CBSs. The selective association of Pot2 versus Pdd1 with CBSs or IESs indicates a mechanistic difference between the chromosome processing events at these two sites. Moreover, ChIP revealed that histone marks characteristic of IES processing, H3K9me3 and H3K27me3, are absent from CBSs. Thus, the mechanisms of chromosome breakage and IES excision must be fundamentally different. Our results lead to a model where Pot2 directs chromosome breakage by recruiting telomerase and/or the endonuclease responsible for DNA cleavage to CBSs. PMID:25303953

Cranert, Stacey; Heyse, Serena; Linger, Benjamin R; Lescasse, Rachel; Price, Carolyn

2014-12-01

198

Alpha thalassaemia-mental retardation, X linked  

PubMed Central

X-linked alpha thalassaemia mental retardation (ATR-X) syndrome in males is associated with profound developmental delay, facial dysmorphism, genital abnormalities and alpha thalassaemia. Female carriers are usually physically and intellectually normal. So far, 168 patients have been reported. Language is usually very limited. Seizures occur in about one third of the cases. While many patients are affectionate with their caregivers, some exhibit autistic-like behaviour. Patients present with facial hypotonia and a characteristic mouth. Genital abnormalities are observed in 80% of children and range from undescended testes to ambiguous genitalia. Alpha-thalassaemia is not always present. This syndrome is X-linked recessive and results from mutations in the ATRX gene. This gene encodes the widely expressed ATRX protein. ATRX mutations cause diverse changes in the pattern of DNA methylation at heterochromatic loci but it is not yet known whether this is responsible for the clinical phenotype. The diagnosis can be established by detection of alpha thalassaemia, identification of ATRX gene mutations, ATRX protein studies and X-inactivation studies. Genetic counselling can be offered to families. Management is multidisciplinary: young children must be carefully monitored for gastro-oesophageal reflux as it may cause death. A number of individuals with ATR-X are fit and well in their 30s and 40s. PMID:16722615

Gibbons, Richard

2006-01-01

199

The consequence of an additional NADH dehydrogenase paralog on the growth of Gluconobacter oxydans DSM3504.  

PubMed

Acetic acid bacteria such as Gluconobacter oxydans are used in several biotechnological processes due to their ability to perform rapid incomplete regio- and stereo-selective oxidations of a great variety of carbohydrates, alcohols, and related compounds by their membrane-bound dehydrogenases. In order to understand the growth physiology of industrial strains such as G. oxydans ATCC 621H that has high substrate oxidation rates but poor growth yields, we compared its genome sequence to the genome sequence of strain DSM 3504 that reaches an almost three times higher optical density. Although the genome sequences are very similar, DSM 3504 has additional copies of genes that are absent from ATCC 621H. Most importantly, strain DSM 3504 contains an additional type II NADH dehydrogenase (ndh) gene and an additional triosephosphate isomerase (tpi) gene. We deleted these additional paralogs from DSM 3504, overexpressed NADH dehydrogenase in ATCC 621H, and monitored biomass and the concentration of the representative cell components as well as O2 and CO2 transfer rates in growth experiments on mannitol. The data revealed a clear competition of membrane-bound dehydrogenases and NADH dehydrogenase for channeling electrons in the electron transport chain of Gluconobacter and an important role of the additional NADH dehydrogenase for increased growth yields. The less active the NADH dehydrogenase is, the more active is the membrane-bound polyol dehydrogenase. These results were confirmed by introducing additional ndh genes via plasmid pAJ78 in strain ATCC 621H, which leads to a marked increase of the growth rate. PMID:25267158

Kostner, D; Luchterhand, B; Junker, A; Volland, S; Daniel, R; Büchs, J; Liebl, W; Ehrenreich, A

2015-01-01

200

Improving fire retardancy of fast growing wood by coating with fire retardant and surface densification  

Microsoft Academic Search

Fire retardant fast-growing wood product was developed by coating with fire retardant and densifying the surface of wood. Trimethylol melamineformaldehyde resin mixed with phosphoric acid was coated on the wood surface, preheated and followed by hot pressing. E?ects of the amount of coating, preheating temperature, and densifying ratio on the fire retardancy of sugi (Cryptomeria japonica D. Don) wood, and

Subyakto; Takeshi Kajimoto; Toshimitsu Hata; Shigehisa Ishihara; Shuichi Kawai; Hideo Getto

1998-01-01

201

314 American Association on Mental Retardation American Journal on Mental Retardation, 2001, Vol. 106, No. 4, 314326  

E-print Network

314 American Association on Mental Retardation American Journal on Mental Retardation, 2001, Vol. 106, No. 4, 314­326 Enhancing Free-Recall Rates of Individuals With Mental Retardation Michael T retardation (Soraci et al., 1994, 1999). The present extension to individuals with mental retardation involved

Dennis, Nancy

202

Political Philosophy and the Mentally Retarded.  

ERIC Educational Resources Information Center

The effects of Social Darwinism, eugenics, and contemporary political conservatism on the status of advocacy efforts for the mentally retarded are reviewed. Provided are historical sketches of Social Darwinism, which viewed the retarded as members of an inferior race, and eugenics, which argued for sterilization of the "genetically unfit". The…

Stanovich, Keith E.

203

Problems of Psychology of Mentally Retarded Children.  

ERIC Educational Resources Information Center

Presented are 18 papers on problems in the psychology of mentally retarded children. Seven of the papers are in English, two in French, and nine in Russian. The English papers are concerned with the following topics: peculiarities of psychic functions in oligophrenic (retarded) children with pronounced underdevelopment of frontal lobes of cerebral…

Academy of Pedagogical Sciences of the USSR, Moscow. Inst. of Defectology.

204

Flame retardant cotton based highloft nonwovens  

Technology Transfer Automated Retrieval System (TEKTRAN)

Flame retardancy has been a serious bottleneck to develop cotton blended very high specific volume bulky High loft fabrics. Alternately, newer approach to produce flame retardant cotton blended High loft fabrics must be employed that retain soft feel characteristics desirable of furnishings. Hence, ...

205

Discrimination Learning in Profoundly Retarded Children.  

ERIC Educational Resources Information Center

A study investigating the discrimination abilities of two crib-bound, cerebral palsied, profoundly retarded females demonstrates the importance of individual differences among such children and suggests that discriminative responding may be demonstrated by at least some profoundly retarded children, particularly if distributed practice is employed…

Suib, Michael R.; And Others

1980-01-01

206

Body Awareness in Children with Mental Retardation  

ERIC Educational Resources Information Center

The body awareness of 124 toddlers with mental retardation and of 124 children developing normally matched to them on age and gender was examined. Twenty-nine of the children with mental retardation were diagnosed as Down syndrome (DS). The "Pointing and Naming" Test of Berges and Lezine [Berges, J., & Lezine, I. (1978). "Test d'imitation de…

Simons, Johan; Dedroog, Inge

2009-01-01

207

Assessment of Terms to Describe Mental Retardation  

ERIC Educational Resources Information Center

There is currently debate among professionals in the area of mental retardation/developmental disabilities regarding the use of, and a possible replacement for, the term mental retardation. Using the semantic differential technique, 284 participants drawn from various Midwestern populations completed assessments of several terms used to describe…

Panek, Paul E.; Smith, Jessi L.

2005-01-01

208

Thermal stability and flame retardancy of polyurethanes  

Microsoft Academic Search

The thermal stability and flame retardancy of polyurethanes is reviewed. Polyurethanes (PUs) are an important class of polymers that have wide application in a number of different industrial sectors. More than 70% of the literature that deals with PUs evaluates their thermal stability or flame retardancy and attempts to provide a structure–property correlation. The importance of studying thermal degradation, understanding

D. K. Chattopadhyay; Dean C. Webster

2009-01-01

209

UNDERSTANDING AND HELPING THE RETARDED READER.  

ERIC Educational Resources Information Center

THE PROCEEDINGS OF A 1962 STATEWIDE ARIZONA CONFERENCE ON READING DEVELOPMENT AND READING DIFFICULTIES INCLUDE 15 PAPERS. ARTICLES ON THE ABLE RETARDED READER ARE "UNDERSTANDING THE ABLE RETARDED READER" BY HELEN M. ROBINSON, AND "CLASSROOM PROCEDURES" BY ROSEMARY YOAKUM. PAPERS ON EMOTIONALLY DISTURBED CHILDREN ARE "IDENTIFICATION OF EMOTIONAL…

STRANG, RUTH, ED.

210

Purdue extension Growth Retardants: A Promising  

E-print Network

on a large scale was the formulation in the late 1970s of the cell elongation inhibitors, paclobutrazol of arborists about two years ago. Today, only one growth retardant for use on trees remains, paclobutrazol. Satisfactory performance of paclobutrazol as a growth retardant, as well as several benefits to tree health

211

Identifying Depression in Students with Mental Retardation.  

ERIC Educational Resources Information Center

Offers guidelines to teachers for identifying depression in students with mental retardation. Discusses prevalence and symptoms of depression, causes of depression, difficulty of diagnosis in students with mental retardation, detecting symptoms in the classroom, treatment of depression, and psychological services. Inserts list ideas for helping…

Stough, Laura M.; Baker, Lynn

1999-01-01

212

Mental retardation general intelligence and modularity  

Microsoft Academic Search

This article presents a case for distinguishing between mental retardation as a general deficit of thinking and mental retardation that might result from the global effects of a specific deficit in a cognitive module. Using Anderson's (1992a) theory of the minimal cognitive architecture of intelligence and developmental, I show how this distinction can explain the pattern of intellectual strengths and

Mike Anderson

1998-01-01

213

A 5-formyltetrahydrofolate cycloligase paralog from all domains of life: comparative genomic and experimental evidence for a cryptic role in thiamin metabolism.  

PubMed

A paralog (here termed COG0212) of the ATP-dependent folate salvage enzyme 5-formyltetrahydrofolate cycloligase (5-FCL) occurs in all domains of life and, although typically annotated as 5-FCL in pro- and eukaryotic genomes, is of unknown function. COG0212 is similar in overall structure to 5-FCL, particularly in the substrate binding region, and has distant similarity to other kinases. The Arabidopsis thaliana COG0212 protein was shown to be targeted to chloroplasts and to be required for embryo viability. Comparative genomic analysis revealed that a high proportion (19%) of archaeal and bacterial COG0212 genes are clustered on the chromosome with various genes implicated in thiamin metabolism or transport but showed no such association between COG0212 and folate metabolism. Consistent with the bioinformatic evidence for a role in thiamin metabolism, ablating COG0212 in the archaeon Haloferax volcanii caused accumulation of thiamin monophosphate. Biochemical and functional complementation tests of several known and hypothetical thiamin-related activities (involving thiamin, its breakdown products, and their phosphates) were, however, negative. Also consistent with the bioinformatic evidence, the COG0212 proteins from A. thaliana and prokaryote sources lacked 5-FCL activity in vitro and did not complement the growth defect or the characteristic 5-formyltetrahydrofolate accumulation of a 5-FCL-deficient (?ygfA) Escherichia coli strain. We therefore propose (a) that COG0212 has an unrecognized yet sometimes crucial role in thiamin metabolism, most probably in salvage or detoxification, and (b) that is not a 5-FCL and should no longer be so annotated. PMID:21538139

Pribat, Anne; Blaby, Ian K; Lara-Núñez, Aurora; Jeanguenin, Linda; Fouquet, Romain; Frelin, Océane; Gregory, Jesse F; Philmus, Benjamin; Begley, Tadhg P; de Crécy-Lagard, Valérie; Hanson, Andrew D

2011-09-01

214

Expression of the mouse MHC class Ib H2-T11 gene product, a paralog of H2-T23 (Qa-1) with shared peptide-binding specificity.  

PubMed

The mouse MHC class Ib gene H2-T11 is 95% identical at the DNA level to H2-T23, which encodes Qa-1, one of the most studied MHC class Ib molecules. H2-T11 mRNA was observed to be expressed widely in tissues of C57BL/6 mice, with the highest levels in thymus. To circumvent the availability of a specific mAb, cells were transduced with cDNA encoding T11 with a substituted ?3 domain. Hybrid T11D3 protein was expressed at high levels similar to control T23D3 molecules on the surface of both TAP(+) and TAP(-) cells. Soluble T11D3 was generated by folding in vitro with Qa-1 determinant modifier, the dominant peptide presented by Qa-1. The circular dichroism spectrum of this protein was similar to that of other MHC class I molecules, and it was observed to bind labeled Qa-1 determinant modifier peptide with rapid kinetics. By contrast to the Qa-1 control, T11 tetramers did not react with cells expressing CD94/NKG2A, supporting the conclusion that T11 cannot replace Qa-1 as a ligand for NK cell inhibitory receptors. T11 also failed to substitute for Qa-1 in the presentation of insulin to a Qa-1-restricted T cell hybridoma. Despite divergent function, T11 was observed to share peptide-loading specificity with Qa-1. Direct analysis by tandem mass spectrometry of peptides eluted from T11D3 and T23D3 isolated from Hela cells demonstrated a diversity of peptides with a clear motif that was shared between the two molecules. Thus, T11 is a paralog of T23 encoding an MHC class Ib molecule that shares peptide-binding specificity with Qa-1 but differs in function. PMID:24958902

Chen, Lili; Reyes-Vargas, Eduardo; Dai, Hu; Escobar, Hernando; Rudd, Brant; Fairbanks, Jared; Ho, Alexander; Cusick, Mathew F; Kumánovics, Attila; Delgado, Julio; He, Xiao; Jensen, Peter E

2014-08-01

215

Evolution of the vertebrate genome as reflected in paralogous chromosomal regions in man and the house mouse  

SciTech Connect

Gene constellations on several human chromosomes are interpreted as indications of large regional duplications that took place during evolution of the vertebrate genome. Four groups of paralogous chromosomal regions in man and the house mouse are suggested and are believed to be conserved remnants of the two or three rounds of tetraploidization that are likely to have occurred during evolution of the vertebrates. The phenomenon of differential silencing of genes is described. The importance of conservation of linkage of particular genes is discussed in relation to genetic regulation and cell differentiation. 120 refs., 5 tabs.

Lundin, L.G. (Univ. of Uppsala (Sweden))

1993-04-01

216

Social development of children with mental retardation  

PubMed Central

Background: Social development of children with mental retardation has implications for prognosis. The present study evaluated whether the social maturity scale alone can reflect on the social maturity, intellectual level and consequent adjustment in family and society of children with mental retardation. Materials and Methods: Thirty-five mentally retarded children were administered Vineland Social Maturity Scale and Stanford Binet Intelligence Scale. Results: It was found that there was significant relationship between the measures of social maturity scale and the IQ of the subjects. Further it was found that with increasing severity of retardation, social development also decreases and age does not have any effect on social development. Conclusion: Social quotient increases from profound to mild level of retardation. PMID:21234165

Kumar, Indrabhushan; Singh, Amool R.; Akhtar, S.

2009-01-01

217

Attitudes Toward Mentally Retarded Persons: Effects of Attitude Referent Specificity  

ERIC Educational Resources Information Center

In a study involving 75 female undergraduate education majors, attitudes toward a "mentally retarded person" referent were compared with attitudes toward mentally retarded referents who were described in more specific terms (retardation severity and chronological age). (Author/CL)

Gottlieb, Jay; Siperstein, Gary N.

1976-01-01

218

38 CFR 4.127 - Mental retardation and personality disorders.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Mental retardation and personality disorders. 4.127...Ratings Mental Disorders § 4.127 Mental retardation and personality disorders. Mental retardation and personality disorders are...

2014-07-01

219

38 CFR 4.127 - Mental retardation and personality disorders.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Mental retardation and personality disorders. 4.127...Ratings Mental Disorders § 4.127 Mental retardation and personality disorders. Mental retardation and personality disorders are...

2011-07-01

220

38 CFR 4.127 - Mental retardation and personality disorders.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Mental retardation and personality disorders. 4.127...Ratings Mental Disorders § 4.127 Mental retardation and personality disorders. Mental retardation and personality disorders are...

2013-07-01

221

38 CFR 4.127 - Mental retardation and personality disorders.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Mental retardation and personality disorders. 4.127...Ratings Mental Disorders § 4.127 Mental retardation and personality disorders. Mental retardation and personality disorders are...

2012-07-01

222

38 CFR 4.127 - Mental retardation and personality disorders.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Mental retardation and personality disorders. 4.127...Ratings Mental Disorders § 4.127 Mental retardation and personality disorders. Mental retardation and personality disorders are...

2010-07-01

223

Noncoding RNAs in mental retardation  

PubMed Central

Recent genome-wide interrogations of transcribed RNA have yielded compelling evidence for pervasive and complex transcription throughout a large majority of the human genome. Tens of thousands of noncoding RNA transcripts have been identified, most of which have yet to be functionally characterized. Along with the revelation that noncoding RNAs in the human genome are surprisingly abundant, there has been a surge in molecular and genetic data showing important and diverse regulatory roles for noncoding RNA. In this report, we summarize the potential roles that noncoding RNAs may play in the molecular pathogenesis of different mental retardation disorders. We suspect that these findings are just the tip of the iceberg, with noncoding RNAs possibly being involved in disease pathogenesis at different levels and through multiple distinct mechanisms. PMID:19159391

Szulwach, KE; Jin, P; Alisch, RS

2012-01-01

224

Aetiology of mild mental retardation.  

PubMed Central

A clinical and family study was carried out in 169 children attending schools for the mildly mentally retarded in Southampton to assess the prevalence of recognised medical risk factors; 71 children (42%) had such risk factors. These were prenatal in 22, perinatal in 41, and postnatal in eight. Risk factors of possible, but less certain, significance were found in a further 63 children (37%). In 86 families (51%) there was a history of serious educational problems in both parents. The prevalence of both types of risk factor was higher in the children whose parents had no educational problems. There were, however, 25 children (15%) whose parents had no history of educational problems and in whom medical risk factors were either absent or minimal. PMID:3178264

Lamont, M A; Dennis, N R

1988-01-01

225

High-density linkage mapping and evolution of paralogs and orthologs in Salix and Populus  

PubMed Central

Background Salix (willow) and Populus (poplar) are members of the Salicaceae family and they share many ecological as well as genetic and genomic characteristics. The interest of using willow for biomass production is growing, which has resulted in increased pressure on breeding of high yielding and resistant clones adapted to different environments. The main purpose of this work was to develop dense genetic linkage maps for mapping of traits related to yield and resistance in willow. We used the Populus trichocarpa genome to extract evenly spaced markers and mapped the orthologous loci in the willow genome. The marker positions in the two genomes were used to study genome evolution since the divergence of the two lineages some 45 mya. Results We constructed two linkage maps covering the 19 linkage groups in willow. The most detailed consensus map, S1, contains 495 markers with a total genetic distance of 2477 cM and an average distance of 5.0 cM between the markers. The S3 consensus map contains 221 markers and has a total genetic distance of 1793 cM and an average distance of 8.1 cM between the markers. We found high degree of synteny and gene order conservation between willow and poplar. There is however evidence for two major interchromosomal rearrangements involving poplar LG I and XVI and willow LG Ib, suggesting a fission or a fusion in one of the lineages, as well as five intrachromosomal inversions. The number of silent substitutions were three times lower (median: 0.12) between orthologs than between paralogs (median: 0.37 - 0.41). Conclusions The relatively slow rates of genomic change between willow and poplar mean that the genomic resources in poplar will be most useful in genomic research in willow, such as identifying genes underlying QTLs of important traits. Our data suggest that the whole-genome duplication occurred long before the divergence of the two genera, events which have until now been regarded as contemporary. Estimated silent substitution rates were 1.28 × 10-9 and 1.68 × 10-9 per site and year, which are close to rates found in other perennials but much lower than rates in annuals. PMID:20178595

2010-01-01

226

Public health implications of components of plastics manufacture. Flame retardants.  

PubMed Central

The four processes involved in the flammability of materials are described and related to the various flame retardance mechanisms that may operate. Following this the four practical approaches used in improving flame retardance of materials are described. Each approach is illustrated with a number of typical examples of flame retardants or synthetic procedures used. This overview of flammability, flame retardance, and flame retardants used is followed by a more detailed examination of most of the plastics manufactured in the United States during 1973, their consumption patterns, and the primary types of flame retardants used in the flame retardance of the most used plastics. The main types of flame retardants are illustrated with a number of typical commercial examples. Statistical data on flame retardant market size, flame retardant growth in plastics, and price ranges of common flame retardants are presented. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 4. PMID:1175568

Pearce, E M; Liepins, R

1975-01-01

227

A polymeric flame retardant additive for rubbers  

SciTech Connect

Synthesis of a polyphosphonate by the interfacial polymerization of bisphenol-A (BPA) and dichloro-phenyl phosphine oxide (DCPO) using cetyltrimethyl ammonium chloride (TMAC) as phase transfer catalyst (PTC) was reported. The polyphosphonate was characterized by elemental analysis, IR, TGA, DSC and 1H-NMR spectroscopy. The flame retardancy of the polymer was done by OI study. The polymer was used as a fire retardant additive to rubbers such as natural rubber (NR), styrene-butadiene rubber(SBR), nitrile rubber (NBR) and chloroprene rubber (CR). The efficiency of the fire retardant property of this additive was determined by LOI measurements of the various rubber samples.

Ghosh, S.N.; Maiti, S. [Indian Institute of Technology, Kharagpur (India)

1993-12-31

228

Engineering Flame Retardant Biodegradable Nanocomposites  

NASA Astrophysics Data System (ADS)

Cellulose-based PLA/PBAT polymer blends can potentially be a promising class of biodegradable nanocomposites. Adding cellulose fiber reinforcement can improve mechanical properties of biodegradable plastics, but homogeneously dispersing hydrophilic cellulose in the hydrophobic polymer matrix poses a significant challenge. We here show that resorcinol diphenyl phosphates (RDP) can be used to modify the surface energy, not only reducing phase separation between two polymer kinds but also allowing the cellulose particles and the Halloysite clay to be easily dispersed within polymer matrices to achieve synergy effect using melt blending. Here in this study we describe the use of cellulose fiber and Halloysite clay, coated with RDP surfactant, in producing the flame retardant polymer blends of PBAT(Ecoflex) and PLA which can pass the stringent UL-94 V0 test. We also utilized FTIR, SEM and AFM nanoindentation to elucidate the role RDP plays in improving the compatibility of biodegradable polymers, and to determine structure property of chars that resulted in composites that could have optimized mechanical and thermal properties.

He, Shan; Yang, Kai; Guo, Yichen; Zhang, Linxi; Pack, Seongchan; Davis, Rachel; Lewin, Menahem; Ade, Harald; Korach, Chad; Kashiwagi, Takashi; Rafailovich, Miriam

2013-03-01

229

Retardation analytical model to extend service life  

NASA Technical Reports Server (NTRS)

A fatigue crack growth model that incorporates crack growth retardation effects and is applicable to the materials characteristics and service environments of high performance LH2/LO2 engine systems was developed and tested.

Matejczyk, D.

1984-01-01

230

Sterilization of Persons with Mental Retardation.  

ERIC Educational Resources Information Center

This article examines the historical, legal, and ethical concerns regarding sterilization for persons with mental retardation and offers guidelines to help counsel individuals with disabilities or their families regarding decision making about sterilization. (DB)

Elkins, Thomas E.; Andersen, H. Frank

1992-01-01

231

Brominated Flame Retardants and Perfluorinated Chemicals  

EPA Science Inventory

Brominated flame retardants (BFRs) and perfluorinated chemicals (PFCs) belong to a large class of chemicals known as organohalogens. It is believed that both BFRs and PFCs saved lives by reducing flammability of materials commonly used and bactericidal (biocidal) properties. Thes...

232

PCBs, PBBs and Brominated Flame Retardants  

EPA Science Inventory

This chapter introduces selected organohalogen chemicals such as polychlorinated biphenyls (PCB5), polychiorinated biphenyls (PBBs), and brominated flame retardants (BFRs) with emphasis on the background, physicochemical properties, environmental levels, health effects and possib...

233

Identifying depression in students with mental retardation  

E-print Network

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Identifying depression in students with mental retardation Stough, Laura M;Baker, Lynn Teaching Exceptional Children; Mar/Apr 1999; 31, 4; Pro...

Stough, Laura

2003-01-01

234

Identifying depression in students with mental retardation  

E-print Network

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Identifying depression in students with mental retardation Stough, Laura M;Baker, Lynn Teaching Exceptional Children; Mar/Apr 1999; 31, 4; Pro...

Stough, Laura

1999-01-01

235

Lagrangian formalism and retarded classical electrodynamics  

Microsoft Academic Search

Unlike the 1\\/c2 approximation, where classical electrodynamics is described by the Darwin Lagrangian, here there is no Lagrangian to describe retarded (resp., advanced) classical electrodynamics up to 1\\/c3 for two-point charges with different masses.

X. Jaen; J. Llosa; A. Molina

1989-01-01

236

HEALTH EFFECTS OF BROMINATED FLAME RETARDANTS (BFRS)  

EPA Science Inventory

Abstract Brominated flame retardant use has increased dramatically in order to provide fire safety to consumers. However, there is growing concern about widespread environmental contamination and potential health risks from some of these products. The most used products...

237

X-linked mental retardation 2  

SciTech Connect

This book contains papers on X-linked mental retardation. Chapters include clinical aspects; cytogenetic aspects; DNA and lineage; genetics and segregation; epidemiology and genetics; cytogenetics and fragile site expression.

Opitz, J.M.; Reynolds, J.F.; Spano, L.M. (Shodair Children's Hospital, Helena, MT (US))

1986-01-01

238

Retardation Measurements of Infrared PVA Wave plate  

NASA Astrophysics Data System (ADS)

The wave plate made of Polyvinyl Alcohol PVA plastic film has several advantages such as its lower cost and insensitivity to temperature and incidence angle so it has been used in the Solar Multi-Channel Telescope SMCT in China But the important parameter retardations of PVA wave plates in the near infrared wavelength have never been provided In this paper a convenient and high precise instrument to get the retardations of discrete wavelengths or a continuous function of wavelength in near infrared is developed In this method the retardations of wave plates have been determined through calculating the maximum and minimum of light intensity The instrument error has been shown Additionally we can get the continuous direction of wavelength retardations in the ultraviolet visible or infrared spectral in another way

Sun, Y.; Z, H.; W, D.; D, Y.; Z, Z.; S, J.

239

Diagnosis and Management of Intrauterine Growth Retardation  

Microsoft Academic Search

Intrauterine growth retardation (IUGR) is associated with significant perinatal morbidity and mortality. This condition can be a sign of genetic disorders, fetal infection, uteroplacental insufficiency, or constitutionally small fetuses. Correct determination of gestational age is the first step in prenatal screening of growth-retarded fetuses. The discovery of a small-for-gestational age fetus necessitates fetal assessment for the evaluation of the etiology

J. Lepercq; D. Mahieu-Caputo

1998-01-01

240

Gitelman's syndrome: Rare presentation with growth retardation  

PubMed Central

Gitelman's syndrome is an autosomal recessive disorder characterized by hypokalemic metabolic alkalosis, hypokalemia, hypomagnesaemia, hypocalciuria, hyperreninemia and without hypertension. Gitelman's syndrome is caused by mutations of the SLC12A3 gene, which encodes the Na/Cl co-transporter (NCCT) in the distal convoluted tubule. Majority of cases manifest during adolescence or adulthood and growth retardation is not the common feature. We report a rare presentation of Gitelman's syndrome in a four-year-old boy with growth retardation. PMID:24574637

Gaur, A.; Ambey, R.; Gaur, B. K.

2014-01-01

241

Experimental intrauterine growth retardation alters renal development  

Microsoft Academic Search

Vascular placental insufficiency is considered a common pathogenic factor in human intrauterine growth retardation (IUGR),\\u000a resulting in small-for-gestational-age, asymmetric newborns. IUGR neonates experience higher morbidity and mortality rates,\\u000a as well as a possible contribution towards late sequelae, such as hypertension, and cardiovascular disease in adulthood. To\\u000a simulate vascular placental insufficiency, an experimental rabbit IUGR model was used. Intrauterine growth retardation

Haim Bassan; Leonor Leider Trejo; Naam Kariv; Merav Bassan; Esther Berger; Aviva Fattal; Illana Gozes; Shaul Harel

2000-01-01

242

Intrauterine radiation exposures and mental retardation  

Microsoft Academic Search

Small head size and mental retardation have been known as effects of intrauterine exposure to ionizing radiation since the 1920s. In the 1950s, studies of Japanese atomic-bomb survivors revealed that at 4-17 wk of gestation, the greater the dose, the smaller the brain (and head size), and that beginning at 0.5 Gy (50 rad) in Hiroshima, mental retardation increased in

R. W. Miller

1988-01-01

243

Environmentally Benign Flame Retardant Nanocoatings for Fabric  

E-print Network

of the most natural textile fibers used to produce apparel, home furnishings, and industrial products, but this cellulosic material has a low limiting oxygen index (LOI) and combustion temperature (360 ? 425 ?C) that makes it highly flammable.44 Cotton...-containing flame retardants include elemental red phosphorus,57 inorganic phosphates,58 and organophosphates.59 It is believed these flame retardants are significantly more effective in oxygen-containing polymers (e.g., cellulose and rigid polyurethane foam).60...

Li, Yu-Chin

2012-07-16

244

Thermally Stable and Flame Retardant Elastomeric Nanocomposites  

Microsoft Academic Search

\\u000a This chapter is dedicated to thermally stable and flame retardant elastomeric composites. Two approaches are considered: the\\u000a synthesis of elastomeric nanocomposites, where the nanoparticles are dispersed at the nanoscale, and the incorporation of\\u000a nanofillers at high loadings where agglomerate of nanoparticles are observed in the elastomeric matrix. The chapter is mainly\\u000a focused on the key parameter influencing the flame retardancy,

O. Cerin; G. Fontaine; S. Duquesne; S. Bourbigot

245

Including Children with Mental Retardation in the Religious Community.  

ERIC Educational Resources Information Center

This article describes practical strategies for promoting inclusion in religious programs. Strategies are provided for including children with mental disabilities, mild mental retardation, moderate mental retardation, and severe to profound mental retardation, and older students with mental retardation. Strategies are also provided for preparing…

Collins, Belva C.; Epstein, Ann; Reiss, Toni; Lowe, Verna

2001-01-01

246

Interactions of the G quartet forming semaphorin 3F RNA with the RGG box domain of the fragile X protein family  

PubMed Central

Fragile X syndrome, the most common cause of inherited mental retardation, is caused by the transcriptional silencing of the fmr1 gene due to an unstable expansion of a CGG trinucleotide repeat and its subsequent hypermethylation in its 5? UTR. This gene encodes for the fragile X mental retardation protein (FMRP), an RNA-binding protein that has been shown to use its RGG box domain to bind to G quartet-forming RNA. In this study, we performed a detailed analysis of the interactions between the FMRP RGG box domain and one of its proposed RNA targets, human semaphorin 3F (S3F) RNA by using biophysical methods such as fluorescence, UV and circular dichroism spectroscopy. We show that this RNA forms a G quartet-containing structure, which is recognized with high affinity and specificity by the FMRP RGG box. In addition, we analyzed the interactions of human S3F RNA with the RGG box and RG cluster of the two FMRP autosomal paralogs, the FXR1P and FXR2P. We found that this RNA is bound with high affinity and specificity only by the FXR1P RGG box, but not by the FXR2P RG cluster. Both FMRP and FXR1P RGG box are able to unwind the G quartet structure of S3F RNA, however, the peptide concentrations required in this process are very different: a ratio of 1:6 RNA:FMRP RGG box versus 1:2 RNA:FXR1P RGG box. PMID:17693432

Menon, Lakshmi; Mihailescu, Mihaela-Rita

2007-01-01

247

Current researches on fire retardant materials in Japan  

NASA Astrophysics Data System (ADS)

The use of fire retardant materials is a very effective way to decrease human loss in the event of building fires. However, smoke and toxicity in a fire, which is the collateral phenomena due to fire retardant were paid more attention than the fire retardant materials themselves. This is because much damage is brought about by smoke and toxicity in a fire. Research papers on fire retardant materials are largely concerned with pyrolysis and combustion products. Twenty-eight papers are reviewed and classified into the following three categories: flame retarding mechanism and evaluation of flammability, pyrolysis and gaseous products of flame retardant materials, and development of flame retardant materials.

Akita, K.

248

Haploinsufficiency of the GPD2 gene in a patient with nonsyndromic mental retardation.  

PubMed

We have investigated the chromosome abnormalities in a female patient exhibiting mild nonsyndromic mental retardation. The patient carries a de novo balanced reciprocal translocation 46,XX,t(2;7)(q24.1;q36.1). Physical mapping of the breakpoints by fluorescent in situ hybridization experiments revealed the disruption of the GPD2 gene at the 2q24.1 region. This gene encodes the mitochondrial glycerophosphate dehydrogenase (mGPDH), which is located on the outer surface of the inner mitochondrial membrane, and catalyzes the unidirectional conversion of glycerol-3-phosphate (G3P) to dihydroxyacetone phosphate with concomitant reduction of the enzyme-bound FAD. Molecular and functional studies showed approximately a twofold decrease of GPD2 transcript level as well as decreased activity of the coded mGPDH protein in lymphoblastoid cell lines of the patient compared to controls. Bioinformatics analysis allowed us to confirm the existence of a novel transcript of the GPD2 gene, designated GPD2c, which is directly disrupted by the 2q breakpoint. To validate GPD2 as a new candidate gene for mental retardation, we performed mutation screening of the GPD2 gene in 100 mentally retarded patients; however, no mutations have been identified. Nevertheless, our results propose that a functional defect of the mGPDH protein could be associated with mental retardation, suggesting that GPD2 gene could be involved in mental retardation in some cases. PMID:19011903

Daoud, Hussein; Gruchy, Nicolas; Constans, Jean-Marc; Moussaoui, Edgar; Saumureau, Simone; Bayou, Nadia; Amy, Maïté; Védrine, Sylviane; Vu, Phi Yen; Rötig, Agnès; Laumonnier, Frédéric; Vourc'h, Patrick; Andres, Christian R; Leporrier, Nathalie; Briault, Sylvain

2009-01-01

249

Interplay of the Serine/Threonine-Kinase StkP and the Paralogs DivIVA and GpsB in Pneumococcal Cell Elongation and Division  

PubMed Central

Despite years of intensive research, much remains to be discovered to understand the regulatory networks coordinating bacterial cell growth and division. The mechanisms by which Streptococcus pneumoniae achieves its characteristic ellipsoid-cell shape remain largely unknown. In this study, we analyzed the interplay of the cell division paralogs DivIVA and GpsB with the ser/thr kinase StkP. We observed that the deletion of divIVA hindered cell elongation and resulted in cell shortening and rounding. By contrast, the absence of GpsB resulted in hampered cell division and triggered cell elongation. Remarkably, ?gpsB elongated cells exhibited a helical FtsZ pattern instead of a Z-ring, accompanied by helical patterns for DivIVA and peptidoglycan synthesis. Strikingly, divIVA deletion suppressed the elongated phenotype of ?gpsB cells. These data suggest that DivIVA promotes cell elongation and that GpsB counteracts it. Analysis of protein-protein interactions revealed that GpsB and DivIVA do not interact with FtsZ but with the cell division protein EzrA, which itself interacts with FtsZ. In addition, GpsB interacts directly with DivIVA. These results are consistent with DivIVA and GpsB acting as a molecular switch to orchestrate peripheral and septal PG synthesis and connecting them with the Z-ring via EzrA. The cellular co-localization of the transpeptidases PBP2x and PBP2b as well as the lipid-flippases FtsW and RodA in ?gpsB cells further suggest the existence of a single large PG assembly complex. Finally, we show that GpsB is required for septal localization and kinase activity of StkP, and therefore for StkP-dependent phosphorylation of DivIVA. Altogether, we propose that the StkP/DivIVA/GpsB triad finely tunes the two modes of peptidoglycan (peripheral and septal) synthesis responsible for the pneumococcal ellipsoid cell shape. PMID:24722178

Campo, Nathalie; Cluzel, Caroline; Lavergne, Jean-Pierre; Freton, Céline; Combet, Christophe; Guiral, Sébastien; Soufi, Boumediene; Macek, Boris; Kuru, Erkin; VanNieuwenhze, Michael S.; Brun, Yves V.; Di Guilmi, Anne-Marie; Claverys, Jean-Pierre; Galinier, Anne; Grangeasse, Christophe

2014-01-01

250

American Association on Mental Retardation 237 VOLUME 107, NUMBER 4: 237251 JULY 2002 AMERICAN JOURNAL ON MENTAL RETARDATION  

E-print Network

American Association on Mental Retardation 237 VOLUME 107, NUMBER 4: 237­251 JULY 2002 AMERICAN JOURNAL ON MENTAL RETARDATION Guided Visual Search in Individuals With Mental Retardation Michael T at the University of Massachusetts Medical School Abstract The ability of individuals with mental retardation

Dennis, Nancy

251

Rad51 paralog complexes BCDX2 and CX3 act at different stages in the BRCA1-BRCA2-dependent homologous recombination pathway.  

PubMed

The Rad51 paralogs are required for homologous recombination (HR) and the maintenance of genomic stability. The molecular mechanisms by which the five vertebrate Rad51 paralogs regulate HR and genomic integrity remain unclear. The Rad51 paralogs associate with one another in two distinct complexes: Rad51B-Rad51C-Rad51D-XRCC2 (BCDX2) and Rad51C-XRCC3 (CX3). We find that the BCDX2 and CX3 complexes act at different stages of the HR pathway. In response to DNA damage, the BCDX2 complex acts downstream of BRCA2 recruitment but upstream of Rad51 recruitment. In contrast, the CX3 complex acts downstream of Rad51 recruitment but still has a marked impact on the measured frequency of homologous recombination. Both complexes are epistatic with BRCA2 and synthetically lethal with Rad52. We conclude that human Rad51 paralogs facilitate BRCA2-Rad51-dependent homologous recombination at different stages in the pathway and function independently of Rad52. PMID:23149936

Chun, Jarin; Buechelmaier, Erika S; Powell, Simon N

2013-01-01

252

The black-headed jumping spider, Trite planiceps Simon, 1899 (Araneae: Salticidae): redescription including cytochrome c oxidase subunit 1 and paralogous 28S sequences  

Microsoft Academic Search

Trite planiceps Simon, 1899, the black-headed jumping spider, is redescribed and the distribution and biology of the species is discussed. DNA sequences from the mitochondrial gene cytochrome c oxidase subunit 1 (COI) and the nuclear gene 28S ribosomal RNA are presented. An intraspecific phylogeny based on COI from T. planiceps from throughout New Zealand is presented. Paralogous copies of 28S

CJ Vink; N Dupérré; BN McQuillan

2011-01-01

253

Pseudomonas savastanoi pv. savastanoi Contains Two iaaL Paralogs, One of Which Exhibits a Variable Number of a Trinucleotide (TAC) Tandem Repeat? †  

PubMed Central

In this study, Pseudomonas savastanoi pv. savastanoi isolates were demonstrated to contain two iaaL paralogs, which are both chromosomally located in most strains. Comparative analysis of iaaL nucleotide sequences amplified from these two paralogs revealed that one paralog, iaaLPsn, is 100% identical to iaaL from P. savastanoi pv. nerii, while the other paralog, iaaLPsv, exhibited 93% identity to iaaL from Pseudomonas syringae pv. tomato (iaaLPto). A 3-nucleotide motif (TAC) comprised of 3 to 15 repeats, which remained stable after propagation of the strains in olive plants, was found in iaaLPsv. Based on the observed nucleotide sequence variations, a restriction fragment length polymorphism assay was developed that allowed differentiation among iaaLPsn, iaaLPsv, and iaaLPto. In addition, reverse transcriptase PCR on total RNA from P. savastanoi pv. savastanoi strains demonstrated that both iaaLPsv and iaaLPsn containing 14 or fewer TAC repeats are transcribed. Capillary electrophoresis analysis of PCR-amplified DNA fragments containing the TAC repeats from iaaLPsv allowed the differentiation of P. savastanoi pv. savastanoi isolates. PMID:19098222

Matas, Isabel M.; Pérez-Martínez, Isabel; Quesada, José M.; Rodríguez-Herva, José J.; Penyalver, Ramón; Ramos, Cayo

2009-01-01

254

Defining Mental Retardation and Ensuring Access to the General Curriculum  

E-print Network

Defining Mental Retardation and Ensuring Access to the General Curriculum Michael L. Wehmeyer University of Kansas Abstract: Release of the most recent edition (2002) of the American Association on Mental Retardation’s terminology and classification... manual provides a point in time to consider ways in which mental retardation is understood and how that understanding contributes to educational practices to promote positive outcomes for students with mental retardation. Since release of the previous...

Wehmeyer, Michael L.

2003-01-01

255

Unsolved problems and unanswered questions in flame retardance of polymers  

Microsoft Academic Search

Some of the unsolved problems and unanswered questions in the flame retardance of polymers are reviewed. They include, durable flame-retardant systems for cotton; FR treatment of cotton–PET blends; durable, weatherable, non-water-leachable, FR treatment of lignocellulosic products, especially wood; better understanding of gas phase and condensed phase mechanisms of flame retardance; flame retardance by sulfur derivatives; weatherable flame-retardant coatings; lowering smoke

Menachem Lewin

2005-01-01

256

Loss of WAVE-1 causes sensorimotor retardation and reduced learning and memory in mice  

E-print Network

. Soderling* , Lorene K. Langeberg*, Jacquelyn A. Soderling*, Stephen M. Davee*, Richard Simerly , Jacob Raber with 3p-syndrome mental retardation who are haploinsuf- ficient for WRP MEGAP, a component of the WAVE-1 relay signals to cytoskeletal sites through the Wiskott­Aldrich-syndrome family of scaffolding proteins

Scott, John D.

257

Protein  

MedlinePLUS

... gov . Nutrition for Everyone Nutrition Topics Share Compartir Protein What do you think about when you hear ... How much protein do I need? What is Protein? Proteins are part of every cell, tissue, and ...

258

Mutations in single FT- and TFL1-paralogs of rapeseed (Brassica napus L.) and their impact on flowering time and yield components  

PubMed Central

Rapeseed (Brassica napus L.) is grown in different geographical regions of the world. It is adapted to different environments by modification of flowering time and requirement for cold. A broad variation exists from very early-flowering spring-type to late-flowering winter cultivars which only flower after exposure to an extended cold period. B. napus is an allopolyploid species which resulted from the hybridization between B. rapa and B. oleracea. In Arabidopsis thaliana, the PEBP-domain genes FLOWERING LOCUS-T (FT) and TERMINAL FLOWER-1 (TFL1) are important integrators of different flowering pathways. Six FT and four TFL1 paralogs have been identified in B. napus. However, their role in flowering time control is unknown. We identified EMS mutants of the B. napus winter-type inbreed line Express 617. In total, 103 mutant alleles have been determined for BnC6FTb, BnC6FTa, and BnTFL1-2 paralogs. We chose three non-sense and 15 missense mutant lines (M3) which were grown in the greenhouse. Although only two out of 6 FT paralogs were mutated, 6 out of 8 BnC6FTb mutant lines flowered later as the control, whereas all five BnC6FTa mutant lines started flowering as the non-mutated parent. Mutations within the BnTFL1-2 paralog had no large effects on flowering time but on yield components. F1 hybrids between BnTFL1-2 mutants and non-mutated parents had increased seed number per pod and total seeds per plant suggesting that heterozygous mutations in a TFL1 paralog may impact heterosis in rapeseed. We demonstrate that single point-mutations in BnFT and BnTFL1 paralogs have effects on flowering time despite the redundancy of the rapeseed genome. Moreover, our results suggest pleiotropic effects of BnTFL1 paralogs beyond the regulation of flowering time. PMID:24987398

Guo, Yuan; Hans, Harloff; Christian, Jung; Molina, Carlos

2014-01-01

259

Protein  

NSDL National Science Digital Library

Protein structure: Primary protein structure is a sequence of amino acids. Secondary protein structure occurs when the amino acids in the sequence are linked by hydrogen bonds. Tertiary protein structure occurs when certain attractions are present between alpha helices and pleated sheets. Quaternary protein structure is a protein consisting of more than one amino acid chain.

Darryl Leja (National Human Genome Research Institute REV)

2005-04-04

260

Orthopedia Transcription Factor otpa and otpb Paralogous Genes Function during Dopaminergic and Neuroendocrine Cell Specification in Larval Zebrafish  

PubMed Central

The homeodomain transcription factor Orthopedia (Otp) is an important regulator for specification of defined subsets of neuroendocrine cells and dopaminergic neurons in vertebrates. In zebrafish, two paralogous otp genes, otpa and otpb, are present in the genome. Neither complete loss of Otp activity nor differential contributions of Otpa and Otpb to specification of defined neuronal populations have been analyzed in detail. We characterized zebrafish embryos and early larvae mutant for null alleles of otpa, otpb, or both genes to determine their individual contributions to the specification of th expressing dopaminergic neuronal populations as well as of crh, oxt, avp, trh or sst1.1 expressing neuroendocrine cells. otpa mutant larvae show an almost complete reduction of ventral diencephalic dopaminergic neurons, as reported previously. A small reduction in the number of trh cells in the preoptic region is detectable in otpa mutants, but no significant loss of crh, oxt and avp preoptic neuroendocrine cells. otpb single mutant larvae do not display a reduction in dopaminergic neurons or neuroendocrine cells in the otp expressing regions. In contrast, in otpa and otpb double mutant larvae specific groups of dopaminergic neurons as well as of crh, oxt, avp, trh and sst1.1-expressing neuroendocrine cells are completely lost. These observations suggest that the requirement for otpa and otpb function during development of the larval diencephalon is partially redundant. During evolutionary diversification of the paralogous otp genes, otpa maintained the prominent role in ventral diencephalic dopaminergic and neuroendocrine cell specification and is capable of partially compensating otpb loss of function. In addition, we identified a role of Otp in the development of a domain of somatostatin1-expressing cells in the rostral hindbrain, a region with strong otp expression but so far uncharacterized Otp function. Otp may thus be crucial for defined neuronal cell types also in the hindbrain. PMID:24073233

Fernandes, António M.; Beddows, Erin; Filippi, Alida; Driever, Wolfgang

2013-01-01

261

Orthopedia transcription factor otpa and otpb paralogous genes function during dopaminergic and neuroendocrine cell specification in larval zebrafish.  

PubMed

The homeodomain transcription factor Orthopedia (Otp) is an important regulator for specification of defined subsets of neuroendocrine cells and dopaminergic neurons in vertebrates. In zebrafish, two paralogous otp genes, otpa and otpb, are present in the genome. Neither complete loss of Otp activity nor differential contributions of Otpa and Otpb to specification of defined neuronal populations have been analyzed in detail. We characterized zebrafish embryos and early larvae mutant for null alleles of otpa, otpb, or both genes to determine their individual contributions to the specification of th expressing dopaminergic neuronal populations as well as of crh, oxt, avp, trh or sst1.1 expressing neuroendocrine cells. otpa mutant larvae show an almost complete reduction of ventral diencephalic dopaminergic neurons, as reported previously. A small reduction in the number of trh cells in the preoptic region is detectable in otpa mutants, but no significant loss of crh, oxt and avp preoptic neuroendocrine cells. otpb single mutant larvae do not display a reduction in dopaminergic neurons or neuroendocrine cells in the otp expressing regions. In contrast, in otpa and otpb double mutant larvae specific groups of dopaminergic neurons as well as of crh, oxt, avp, trh and sst1.1-expressing neuroendocrine cells are completely lost. These observations suggest that the requirement for otpa and otpb function during development of the larval diencephalon is partially redundant. During evolutionary diversification of the paralogous otp genes, otpa maintained the prominent role in ventral diencephalic dopaminergic and neuroendocrine cell specification and is capable of partially compensating otpb loss of function. In addition, we identified a role of Otp in the development of a domain of somatostatin1-expressing cells in the rostral hindbrain, a region with strong otp expression but so far uncharacterized Otp function. Otp may thus be crucial for defined neuronal cell types also in the hindbrain. PMID:24073233

Fernandes, António M; Beddows, Erin; Filippi, Alida; Driever, Wolfgang

2013-01-01

262

Functional Modeling Identifies Paralogous Solanesyl-diphosphate Synthases That Assemble the Side Chain of Plastoquinone-9 in Plastids*  

PubMed Central

It is a little known fact that plastoquinone-9, a vital redox cofactor of photosynthesis, doubles as a precursor for the biosynthesis of a vitamin E analog called plastochromanol-8, the physiological significance of which has remained elusive. Gene network reconstruction, GFP fusion experiments, and targeted metabolite profiling of insertion mutants indicated that Arabidopsis possesses two paralogous solanesyl-diphosphate synthases, AtSPS1 (At1g78510) and AtSPS2 (At1g17050), that assemble the side chain of plastoquinone-9 in plastids. Similar paralogous pairs were detected throughout terrestrial plant lineages but were not distinguished in the literature and genomic databases from mitochondrial homologs involved in the biosynthesis of ubiquinone. The leaves of the atsps2 knock-out were devoid of plastochromanol-8 and displayed severe losses of both non-photoactive and photoactive plastoquinone-9, resulting in near complete photoinhibition at high light intensity. Such a photoinhibition was paralleled by significant damage to photosystem II but not to photosystem I. In contrast, in the atsps1 knock-out, a small loss of plastoquinone-9, restricted to the non-photoactive pool, was sufficient to eliminate half of the plastochromanol-8 content of the leaves. Taken together, these results demonstrate that plastochromanol-8 originates from a subfraction of the non-photoactive pool of plastoquinone-9. In contrast to other plastochromanol-8 biosynthetic mutants, neither the single atsps knock-outs nor the atsps1 atsps2 double knock-out displayed any defects in tocopherols accumulation or germination. PMID:23913686

Block, Anna; Fristedt, Rikard; Rogers, Sara; Kumar, Jyothi; Barnes, Brian; Barnes, Joshua; Elowsky, Christian G.; Wamboldt, Yashitola; Mackenzie, Sally A.; Redding, Kevin; Merchant, Sabeeha S.; Basset, Gilles J.

2013-01-01

263

The discovery of Foxl2 paralogs in chondrichthyan, coelacanth and tetrapod genomes reveals an ancient duplication in vertebrates  

PubMed Central

The Foxl2 (forkhead box L2) gene is an important member of the forkhead domain family, primarily responsible for the development of ovaries during female sex differentiation. The evolutionary studies conducted previously considered the presence of paralog Foxl2 copies only in teleosts. However, to search for possible paralog copies in other groups of vertebrates and ensure that all predicted copies were homolog to the Foxl2 gene, a broad evolutionary analysis was performed, based on the forkhead domain family. A total of 2464 sequences for the forkhead domain were recovered, and subsequently, 64 representative sequences for Foxl2 were used in the evolutionary analysis of this gene. The most important contribution of this study was the discovery of a new subgroup of Foxl2 copies (ortholog to Foxl2B) present in the chondrichthyan Callorhinchus milii, in the coelacanth Latimeria chalumnae, in the avian Taeniopygia guttata and in the marsupial Monodelphis domestica. This new scenario indicates a gene duplication event in an ancestor of gnathostomes. Furthermore, based on the analysis of the syntenic regions of both Foxl2 copies, the duplication event was not exclusive to Foxl2. Moreover, the duplicated copy distribution was shown to be complex across vertebrates, especially in tetrapods, and the results strongly support a loss of this copy in eutherian species. Finally, the scenario observed in this study suggests an update for Foxl2 gene nomenclature, extending the actual suggested teleost naming of Foxl2A and Foxl2B to all vertebrate sequences and contributing to the establishment of a new evolutionary context for the Foxl2 gene. PMID:23549337

Geraldo, M T; Valente, G T; Braz, A SK; Martins, C

2013-01-01

264

An evolutionary perspective on Elovl5 fatty acid elongase: comparison of Northern pike and duplicated paralogs from Atlantic salmon  

PubMed Central

Background The ability to produce physiologically critical LC-PUFA from dietary fatty acids differs greatly among teleost species, and is dependent on the possession and expression of fatty acyl desaturase and elongase genes. Atlantic salmon, as a result of a recently duplicated genome, have more of these enzymes than other fish. Recent phylogenetic studies show that Northern pike represents the closest extant relative of the preduplicated ancestral salmonid. Here we characterise a pike fatty acyl elongase, elovl5, and compare it to Atlantic salmon elovl5a and elovl5b duplicates. Results Phylogenetic analyses show that Atlantic salmon paralogs are evolving symmetrically, and they have been retained in the genome by purifying selection. Heterologous expression in yeast showed that Northern pike Elovl5 activity is indistinguishable from that of the salmon paralogs, efficiently elongating C18 and C20 substrates. However, in contrast to salmon, pike elovl5 was predominantly expressed in brain with negligible expression in liver and intestine. Conclusions We suggest that the predominant expression of Elovl5b in salmon liver and Elovl5a in salmon intestine is an adaptation, enabled by genome duplication, to a diet rich in terrestrial invertebrates which are relatively poor in LC-PUFA. Pike have retained an ancestral expression profile which supports the maintenance of PUFA in the brain but, due to a highly piscivorous LC-PUFA-rich diet, is not required in liver and intestine. Thus, the characterisation of elovl5 in Northern pike provides insights into the evolutionary divergence of duplicated genes, and the ecological adaptations of salmonids which have enabled colonisation of nutrient poor freshwaters. PMID:23597093

2013-01-01

265

Dynamics of the evolution of orthologous and paralogous portions of a complex locus region in two genomes of allopolyploid wheat.  

PubMed

Two overlapping bacterial artificial chromosome (BAC) clones from the B genome of the tetraploid wheat Triticum turgidum were identified, each of which contains one of the two high-molecular-weight (HMW) glutenin genes, comprising the complex Glu-B1 locus. The complete sequence (285 506 bp of DNA) of this chromosomal region was determined. The two paralogous x-type ( Glu-1-1 ) and y-type ( Glu-1-2 ) HMW-glutenin genes of the complex Glu-B1 locus were found to be separated by ca. 168 000 bp instead of the 51 000 bp separation previously reported for the orthologous Glu-D1 locus of Aegilops tauschii, the D-genome donor of hexaploid wheat. This difference in intergene spacing is due almost entirely to be the insertion of clusters of nested retrotransposons. Otherwise, the orientation and order of the HMW glutenins and adjacent genes were identical in the two genomes. A comparison of these orthologous regions indicates modes and patterns of sequence divergence, with implications for the overall Triticeae genome structure and evolution. A duplicate globulin gene, found 5' of each HMW-glutenin gene, assists to tentatively define the original duplication event leading to the paralogous x- and y-type HMW-glutenin genes. The intergenic regions of the two loci are composed of different patterns and classes of retrotransposons, indicating that insertion times of these retroelements were after the divergence of the two wheat genomes. In addition, a putative receptor kinase gene near the y-type HMW-glutenin gene at the Glu-B1 locus is likely active as it matches recently reported ESTs from germinating barley endosperm. The presence of four genes represented only in the Triticeae endosperm ESTs suggests an endosperm-specific chromosome domain. PMID:15159634

Kong, Xiu-Ying; Gu, Yong Qiang; You, Frank M; Dubcovsky, Jorge; Anderson, Olin D

2004-01-01

266

Intrauterine radiation exposures and mental retardation  

SciTech Connect

Small head size and mental retardation have been known as effects of intrauterine exposure to ionizing radiation since the 1920s. In the 1950s, studies of Japanese atomic-bomb survivors revealed that at 4-17 wk of gestation, the greater the dose, the smaller the brain (and head size), and that beginning at 0.5 Gy (50 rad) in Hiroshima, mental retardation increased in frequency with increasing dose. No other excess of birth defects was observed. Otake and Schull (1984) pointed out that the period of susceptibility to mental retardation coincided with that for proliferation and migration of neuronal elements from near the cerebral ventricles to the cortex. Mental retardation could be the result of interference with this process. Their analysis indicated that exposures at 8-15 wk to 0.01-0.02 Gy (1-2 rad) doubled the frequency of severe mental retardation. This estimate was based on small numbers of mentally retarded atomic-bomb survivors. Although nuclear accidents have occurred recently, new cases will hopefully be too rare to provide further information about the risk of mental retardation. It may be possible, however, to learn about lesser impairment. New psychometric tests may be helpful in detecting subtle deficits in intelligence or neurodevelopmental function. One such test is PEERAMID, which is being used in schools to identify learning disabilities due, for example, to deficits in attention, short- or long-term memory, or in sequencing information. This and other tests could be applied in evaluating survivors of intrauterine exposure to various doses of ionizing radiation. The results could change our understanding of the safety of low-dose exposures.

Miller, R.W.

1988-08-01

267

Recent Research Progress on the Flame-Retardant Mechanism of Halogen-Free Flame Retardant Polypropylene  

Microsoft Academic Search

Polypropylene (PP) is one of the five kinds of universal polymers that have greatly improved our life qualities. While a pestilent limitation of PP is its flammability. Usually, halogen-containing flame retardants (FRs) are used to improve its flame retard ability. However, the halogen-containing FRs are limited more and more strictly because they would produce environment problems, such as the release

Jianjun Wang; Li Wang; Anguo Xiao

2009-01-01

268

Fire retardancy of vinyl ester nanocomposites: Synergy with phosphorus-based fire retardants  

Microsoft Academic Search

Vinyl ester (PVE) nanocomposites were prepared using both clay and polyhedral oligosilsesquioxanes (POSS) as the nano-dimensional material. From cone calorimetric data, it was shown that both POSS and clay affect the flammability of the nanocomposites to the same extent. To improve on the flame retardancy, the nanocomposites were combined with phosphorous-containing fire retardants (FRs) and the result compared to the

Grace Chigwada; Panchatapa Jash; David D. Jiang; Charles A. Wilkie

2005-01-01

269

Cooperative and Competitive Behavior of Retarded and Non-Retarded Children at Two Ages.  

ERIC Educational Resources Information Center

Cooperative and competitive interaction (interpersonal relationship) between pairs of retarded and nonretarded children of ages 6 to 7 and 11 to 12 were assessed in a situation involving a marble pull apparatus in which competitive interaction was nonadaptive in terms of reward attainment. The retarded group was significantly more cooperative than…

Madsen, Millard C.; Connor, Catherine

270

Retardance and flicker modeling and characterization of electro-optic linear retarders by averaged Stokes polarimetry.  

PubMed

A polarimetric method for the measurement of linear retardance in the presence of phase fluctuations is presented. This can be applied to electro-optic devices behaving as variable linear retarders. The method is based on an extended Mueller matrix model for the linear retarder containing the time-averaged effects of the instabilities. As a result, an averaged Stokes polarimetry technique is proposed to characterize both the retardance and its flicker magnitude. Predictive capability of the approach is experimentally demonstrated, validating the model and the calibration technique. The approach is applied to liquid crystal on silicon displays (LCoS) using a commercial Stokes polarimeter. Both the magnitude of the average retardance and the amplitude of its fluctuation are obtained for each gray level value addressed, thus enabling a complete phase characterization of the LCoS. PMID:24562265

Martínez, Francisco J; Márquez, Andrés; Gallego, Sergi; Francés, Jorge; Pascual, Inmaculada; Beléndez, Augusto

2014-02-15

271

Thermal damping and retardation in karst conduits  

NASA Astrophysics Data System (ADS)

Water temperature is a non-conservative tracer in the environment. Variations in recharge temperature are damped and retarded as water moves through an aquifer due to heat exchange between water and rock. However, within karst aquifers, seasonal and short-term fluctuations in recharge temperature are often transmitted over long distances before they are fully damped. Using analytical solutions and numerical simulations, we develop relationships that describe the effect of flow path properties, flow-through time, recharge characteristics, and water and rock physical properties on the damping and retardation of thermal peaks/troughs in karst conduits. Using these relationships, one can estimate the thermal retardation and damping that would occur under given conditions with a given conduit geometry. Ultimately, these relationships can be used with thermal damping and retardation field data to estimate parameters such as conduit diameter. We also examine sets of numerical simulations where we relax some of the assumptions used to develop these relationships, testing the effects of variable diameter, variable velocity, open channels, and recharge shape on thermal damping and retardation to provide some constraints on uncertainty. Finally, we discuss a multitracer experiment that provides some field confirmation of our relationships. High temporal resolution water temperature data are required to obtain sufficient constraints on the magnitude and timing of thermal peaks and troughs in order to take full advantage of water temperature as a tracer.

Luhmann, A. J.; Covington, M. D.; Myre, J. M.; Perne, M.; Jones, S. W.; Alexander, E. C., Jr.; Saar, M. O.

2015-01-01

272

Neurobiology of Disease Postadolescent Changes in Regional Cerebral Protein  

E-print Network

, Bethesda, Maryland 20892 Methylation-induced transcriptional silencing of the fragile X mental retardation-1 (Fmr1) gene leads to absence of the gene product, fragile X mental retardation protein (FMRPGluRs) is fragile X mental retardation-1 (Fmr1) (Weiler et al., 1997). Silencing of the gene for Fmr1 by a repeat

Baker, Chris I.

273

78 FR 46499 - Change in Terminology: “Mental Retardation” to “Intellectual Disability”  

Federal Register 2010, 2011, 2012, 2013, 2014

...Change in Terminology: ``Mental Retardation'' to ``Intellectual Disability...are replacing the term ``mental retardation'' with ``intellectual disability...proposed replacing the term ``mental retardation'' with ``intellectual...

2013-08-01

274

78 FR 5755 - Change in Terminology: “Mental Retardation” to “Intellectual Disability”  

Federal Register 2010, 2011, 2012, 2013, 2014

...Change in Terminology: ``Mental Retardation'' to ``Intellectual Disability...propose to replace the term ``mental retardation'' with ``intellectual disability...gradually replacing the term ``mental retardation'' nationwide....

2013-01-28

275

Patterned retarder films using reactive mesogen technology  

NASA Astrophysics Data System (ADS)

A range of polymerisable liquid crystals mixtures have been developed (so called, Reactive Mesogen) that are ideally suited for the fabrication of patterned retarder films. Such films, made using a combination of Merck Reactive Mesogen Mixtures coated on a plastic substrate containing a photoalignment layer, are commercially employed to produce 3D displays. Different methods of patterning Reactive Mesogen Mixtures are discussed and the merits of each considered. Although the first commercial products use normal dispersion Reactive Mesogen Materials, the advantages of using the next generation of materials, which have improved wavelength dispersion, are introduced with a focus on their use in 3D patterned retarder films.

Parri, Owain; Smith, Graham; Harding, Richard; Yoon, Hyun-Jin; Gardiner, Iain; Sargent, Joe; Skjonnemand, Karl

2011-03-01

276

Chromosome Instability and Defective Recombinational Repair in Knockout Mutants of the Five Rad51 Paralogs  

Microsoft Academic Search

The Rad51 protein, a eukaryotic homologue of Escherichia coli RecA, plays a central role in both mitotic and meiotic homologous DNA recombination (HR) in Saccharomyces cerevisiae and is essential for the proliferation of vertebrate cells. Five vertebrate genes, RAD51B ,- C, and -D and XRCC2 and -3, are implicated in HR on the basis of their sequence similarity to Rad51

MINORU TAKATA; MASAO S. SASAKI; SEIJI TACHIIRI; TORU FUKUSHIMA; EIICHIRO SONODA; DAVID SCHILD; LARRY H. THOMPSON; SHUNICHI TAKEDA

2001-01-01

277

RAD51 paralogs: Roles in DNA damage signalling, recombinational repair and tumorigenesis  

Microsoft Academic Search

Chromosomal double-strand breaks (DSBs) have the potential to permanently arrest cell cycle progression and endanger cell survival. They must therefore be efficiently repaired to preserve genome integrity and functionality. Homologous recombination (HR) provides an important error-free mechanism for DSB repair in mammalian cells. In addition to RAD51, the central recombinase activity in mammalian cells, a family of proteins known as

Natsuko Suwaki; Kerstin Klare; Madalena Tarsounas

278

Fetal growth retardation associated with maternal administration of immunosuppressive drugs.  

PubMed

Since maternal-fetal immunogenetic disparity facilitates growth of the fetoplacental unit, nonspecific depression of the maternal immune system by immunosuppressive drugs could result in previously unrecognized adverse effects such as fetal growth retardation. To test this hypothesis, groups of 6 to 8 primigravid Fischer female rats mated with DA or Fischer male rats were treated with saline (controls) or either cyclophosphamide (Cytoxan) or azathioprine (Imuran) in doses similar to those used therapeutically in human subjects. It was found that these drugs caused an increased incidence of fetal death and produced fetal and neonatal growth retardation. Smaller placentas and fetuses reflected a decrease in cell number rather than cell size whereas water, fat, and protein content were only minimally affected. Analyses of mean maternal weight gain, spleen weight assays, and changes in the lymph nodes draining the uterus indicate that effects detrimental to the offspring are primarily the result of immunologic and cytotoxic mechanisms. Moreover, a review of the literature suggests that these immunosuppressive agents are also associated with small-for-gestational age infants in human pregnancies. PMID:879225

Scott, J R

1977-07-15

279

The Performance of Cultural-Familial Retardates on Conservation Tasks  

ERIC Educational Resources Information Center

Compared the performance of 29 institutionalized cultural-familial mental retardates on Piagetian conservation tasks. Examined the effects of age, sex, and degree of retardation on conservation performance. (BD)

Lesser, Harvey; And Others

1978-01-01

280

45 CFR 1308.10 - Eligibility criteria: Mental retardation.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Eligibility criteria: Mental retardation. 1308.10 Section...DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION...1308.10 Eligibility criteria: Mental retardation. (a) A...

2012-10-01

281

45 CFR 1308.10 - Eligibility criteria: Mental retardation.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Eligibility criteria: Mental retardation. 1308.10 Section...DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION...1308.10 Eligibility criteria: Mental retardation. (a) A...

2010-10-01

282

45 CFR 1308.10 - Eligibility criteria: Mental retardation.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Eligibility criteria: Mental retardation. 1308.10 Section...DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION...1308.10 Eligibility criteria: Mental retardation. (a) A...

2011-10-01

283

45 CFR 1308.10 - Eligibility criteria: Mental retardation.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Eligibility criteria: Mental retardation. 1308.10 Section...DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION...1308.10 Eligibility criteria: Mental retardation. (a) A...

2013-10-01

284

Rationale of an Education Approach to the Mentally Retarded.  

ERIC Educational Resources Information Center

The importance of an educational approach to the mentally retarded is that it forces professionals to perceive the mentally retarded as those who develop slowly, but could advance more rapidly if everything were appropriate in their environment. (Author/BRR)

Gauthier, Yvon; Benoit, E. Paul

1982-01-01

285

Curriculum Guides for the Mentally Retarded: An Analysis and Recommendations  

ERIC Educational Resources Information Center

The report summarizes the results of an analysis of curriculum guides for the mentally retarded, and sets forth general recommendations related to the development of public school curricula for mentally retarded students. (SBH)

Cegelka, Walter J.

1978-01-01

286

45 CFR 1308.10 - Eligibility criteria: Mental retardation.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Eligibility criteria: Mental retardation. 1308.10 Section 1308.10 Public Welfare...Performance Standards § 1308.10 Eligibility criteria: Mental retardation. (a) A child is classified as...

2014-10-01

287

BROMINATED FLAME RETARDANTS: CAUSE FOR CONCERN?  

EPA Science Inventory

Brominated flame retardants (BFRs) have routinely been added to consumer products for several decades in a successful effort to reduce fire-related injury and property damage. Recently, concern for this emerging class of chemicals has risen due to the occurrence of several class...

288

Mental Illness in Persons with Mental Retardation  

Microsoft Academic Search

What is mental health? Mental health is a goal for all people, including those with mental retardation, not just those having difficulties. Mental health is an essential ingredient in the quality of life. The two main aspects of mental health are emotional well-being and rewarding social and interpersonal relationships. Emotional well-being is an important part of the gift of human

Steven Reiss; Ruth Ryan

289

Mental Retardation and Developmental Disabilities. Second Edition.  

ERIC Educational Resources Information Center

This book presents 19 chapters on life span perspectives and service issues for people with mental retardation and developmental disabilities. The book presents best practices and provides a view of the range of services necessary to work with people who have those disabilities. It is intended to provide a core reference for providers in the…

McLaughlin, Phillip J., Ed.; Wehman, Paul, Ed.

290

Puberty in the Girl Who is Retarded.  

ERIC Educational Resources Information Center

Designed to help mothers of mentally retarded girls deal with the problems and concerns of puberty, the booklet provides information on physical and emotional changes, menstruation, masturbation, heterosexual behavior, contraception, protection against sexual aggression, the possibilities of marriage, and additional sources of information.…

Pattullo, Ann

291

Regulation of Plant Morphology by Growth Retardants  

PubMed Central

The effects of the growth retardants tetcyclacis, a norbornenodiazetine, and LAB 150 978, a dioxanylalkenyl triazole, on seedling growth and endogenous levels of phytohormone-like substances in Glycine max L. cv Maple Arrow were studied. The levels of phytohormone-like substances in the root and in the various shoot tissues were analyzed by immunoassay. After seed treatment with both compounds, shoot growth was reduced more intensively than root growth. Both compounds decreased, on a fresh weight basis, the amount of various immunoreactive gibberellins when compared with the levels in control plants, especially in the shoot tip. Likewise, the growth retardants lowered the levels of abscisic acid-like material, particularly in the primary leaf, the epicotyl and the root. In contrast, the levels of trans-zeatin-riboside and dihydrozeatin-riboside-type cytokinins were considerably elevated by the growth retardants, mainly in the primary leaf, epicotyl, and hypocotyl. On the other hand the level of isopentenyladenosine-like material was less influenced. In general, the immunoreactive 3-indoleacetic acid content in the different plant parts was changed only slightly. It is assumed that besides their effect on gibberellin content both compounds interfere directly or indirectly with the regulation of the endogenous levels of abscisic acid and cytokinins. This might be seen as an additional mode of action of growth retardants explaining some side effects on developmental processes of treated plants, e.g. delayed senescence and enhanced chlorophyll concentration in the leaves. PMID:16665554

Grossmann, Klaus; Kwiatkowski, Jacek; Siebecker, Heinrich; Jung, Johannes

1987-01-01

292

Brominated flame retardants and endocrine disruption  

Microsoft Academic Search

From an environmental point of view, an increasing important group of organohalogen compounds are the brominated flame retardants (BFRs), which are widely used in polymers and textiles and applied in construction materials, furniture, and electronic equipment. BFRs with the highest production volume are the polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBP-A), and hexabromocyclododecane (HBCD). Because of their persistence and low

Joseph G. Vos; Georg Becher; Martin van den Berg; Jacob de Boer; Pim E. G. Leonards

2003-01-01

293

Throwing Patterns of the Mentally Retarded.  

ERIC Educational Resources Information Center

This study explored developmental patterns in the acquisition of the gross motor skill of throwing among 110 educable, mentally retarded 7- to 12-year-olds. Each child was examined through cinematographic procedures to discover: a) variance in throwing patterns, b) elements composing throwing skills, and c) sequential integration of the elements…

Auxter, David

294

BROMINATED FLAME RETARDANTS: WHY DO WE CARE?  

EPA Science Inventory

Brominated flame retardants (BFRs) save lives and property by preventing the spread of fires or delaying the time of flashover, enhancing the time people have to escape. The worldwide production of BFRs exceeded 200,000 metric tons in 2003 placing them in the high production vol...

295

Brominated flame retardants as food contaminants  

Technology Transfer Automated Retrieval System (TEKTRAN)

This book chapter reviews analytical methods for the three major brominated flame retardant (BFR) classes in use today, tetrabromobisphenol-A (TBBP-A), hexabromocyclododecanes (HBCDs), and polybrominated diphenyl ethers (PBDEs), a "legacy" BFR no longer in use, polybrominated biphenyls (PBBs), and a...

296

Polybrominated diphenyl ether (PBDE) flame retardants  

Microsoft Academic Search

Polybrominated diphenyl ether, PBDE, flame retardants are now a world-wide pollution problem reaching even remote areas. They have been found to bioaccumulate and there are concerns over the health effects of exposure to PBDEs, they also have potential endocrine disrupting properties. They are lipophilic compounds so are easily removed from the aqueous environment and are predicted to sorb onto sediments

Frank Rahman; Katherine H Langford; Mark D Scrimshaw; John N Lester

2001-01-01

297

Are brominated flame retardants endocrine disruptors?  

Microsoft Academic Search

Brominated flame retardants (BFRs) are a group of compounds that have received much attention recently due to their similarity with “old” classes of organohalogenated compounds such as polychlorinated biphenyls (PCBs), in terms of their fate, stability in the environment and accumulation in humans and wildlife. Toxic effects, including teratogenicity, carcinogenicity and neurotoxicity, have been observed for some BFR congeners, in

Juliette Legler; Abraham Brouwer

2003-01-01

298

Aging, Mental Retardation and Physical Fitness.  

ERIC Educational Resources Information Center

This fact sheet uses a question-and-answer format to provide an overview of what physical fitness is and how it relates to people with mental retardation. Questions address the following topics: the fitness movement; a definition of physical fitness; the different components of physical fitness (muscle strength and endurance, flexibility, body…

Rimmer, James H.

299

Improving Outcomes for Workers with Mental Retardation  

ERIC Educational Resources Information Center

This research presents an analysis of factors predicting job retention, job satisfaction, and job performance of workers with mental retardation. The findings highlight self-determination as a critical skill in predicting the three important employee outcomes. The study examined a hypothesized job retention model and the outcome of the three…

Fornes, Sandra; Rocco, Tonette S.; Rosenberg, Howard

2008-01-01

300

Preattentive Orienting in Adolescents with Mental Retardation  

ERIC Educational Resources Information Center

Visual attention is preattentively drawn to abrupt onsets of stimuli appearing in a visual array. In this experiment, I examined the speed of attentional capture for persons with and without mental retardation. Participants identified target stimuli that were signaled by a valid location cue (20% of the time), an invalid location cue (60% of the…

Merrill, Edward C.

2005-01-01

301

Mental Retardation and Memory for Spatial Locations.  

ERIC Educational Resources Information Center

Comparison for memory for spatial location of 30 persons with and 30 persons without mental retardation found the control group recalled more intentionally learned than incidentally learned locations. The experimental group performed better after incidental learning than after intentional learning and scored as highly as controls on incidental…

Jones, Robert S. P.; Vaughan, Francis L.; Roberts, Mary

2002-01-01

302

Bibliographic Instruction for Adults with Mental Retardation.  

ERIC Educational Resources Information Center

Conducted as part of a practicum to be completed at the Champaign (Illinois) Public Library and Information Center, this study was designed to view the availability of appropriate bibliographic instruction for adults who are mentally retarded that will enhance both their ability to use library resources and equipment, and their desire to do so.…

Norlin, Dennis A.

303

Euthanasia and Mental Retardation: Suggesting the Unthinkable.  

ERIC Educational Resources Information Center

The article examines current opinions toward euthanasia of persons with mental retardation in light of the history of public and professional attitudes. It also discusses the rejection of euthanasia on moral and religious grounds, and notes the use of lifelong incarceration, based on eugenics principles, to accomplish similar ends. (DB)

Hollander, Russell

1989-01-01

304

HEALTH ASPECTS OF BROMINATED FLAME RETARDANTS (BFRS)  

EPA Science Inventory

In order to reduce the societal costs of fires, flammability standards have been set for consumer products and equipment. Flame retardants containing bromine have constituted the largest share of this market due both to their efficiency and cost. While there are at least 75 dif...

305

Aerobic Fitness for the Moderately Retarded.  

ERIC Educational Resources Information Center

Intended for physical education teachers, the booklet offers ideas for incorporating aerobic conditioning into programs for moderately mentally retarded students. An explanation of aerobic fitness and its benefits is followed by information on initiating a fitness program with evaluation of height, weight, body fat, resting heart rate, and…

Bauer, Dan

1981-01-01

306

Fire retardancy of polypropylene\\/flax blends  

Microsoft Academic Search

A comprehensive characterization of the thermal and the fire behaviour is presented for polypropylene (PP) flax compounds containing ammonium polyphosphate (APP) and expandable graphite as fire retardants. Thermogravimetry coupled with an evolved gas analysis (TG-FTIR) was performed to ensure a significant thermal analysis. The fire response under forced flaming conditions was studied using a cone calorimeter. The external heat flux

B. Schartel; U. Braun; U. Schwarz; S. Reinemann

2003-01-01

307

Involuntary sterilization and the mentally retarded, revisited  

Microsoft Academic Search

Historically, the complexity of the issues that surround the care of mentally retarded individuals has created challenging questions that have confounded public opinions and reactions, the judicial system, and professionals in the medical and scientific community. To further understand the needs and challenges of those who provide services to this group, the basic assumptions and cases relevant to the issue

Janice L. Ricks; Sophia F. Dziegielewski

2000-01-01

308

Flame retardant cotton barrier nonwovens for mattresses  

Technology Transfer Automated Retrieval System (TEKTRAN)

According to regulation CPSC 16 CFR 1633, every new residential mattress sold in the United States since July 2007 must resist ignition by open flame. An environmentally benign “green”, inexpensive way to meet this regulation is to use a low-cost flame retardant (FR) barrier fabric. In this study, a...

309

Educating Students with Mild Mental Retardation.  

ERIC Educational Resources Information Center

This article examines the history of educating students with mild mental retardation and includes discussion of general demographic trends, contextual factors that influenced this process, assessment and instructional practices, and teacher roles and preparation. It then examines these same features currently and offers recommendations for…

Patton, James R.; Polloway, Edward A.; Smith, Tom E. C.

2000-01-01

310

Mental Retardation: Past, Present and Future  

ERIC Educational Resources Information Center

Notes that two developments had major impacts on policies towards the mentally retarded between the 1880s and the 1920s: (1) the swing toward the eugenics-heredity-genetics movement, and (2) the development of individual intelligence testing. (Author/JM)

Crissey, Marie Skodak

1975-01-01

311

Teaching Laundry Skills to Mentally Retarded Students.  

ERIC Educational Resources Information Center

Five moderately and mildly retarded students (19 to 21 years old) were taught to sort garments to be laundered and to use a clothes washer and dryer. Rapid acquisition and maintenance of the laundry skills were obtained through praise and response contingent feedback as a consequence for behavior. (Author/CL)

Cuvo, Anthony J.; And Others

1981-01-01

312

Gravitation is Retarded:Theory and Evidence  

Microsoft Academic Search

Gravitation is Retarded:Theory and Evidence There were more than twenty times of observations about gravity anomalies during the solar eclipses since Maurice Allais's pendulum test during the total solar eclipse of 1954 in Paris. All the theoretical modes are calculated according to Newton's gravitation law. But due to the observation environments and conditions during above observations were not quite well,

K. Tang

2009-01-01

313

Gravitation is Retarded:Theory and Evidence  

NASA Astrophysics Data System (ADS)

Gravitation is Retarded:Theory and Evidence There were more than twenty times of observations about gravity anomalies during the solar eclipses since Maurice Allais’s pendulum test during the total solar eclipse of 1954 in Paris. All the theoretical modes are calculated according to Newton’s gravitation law. But due to the observation environments and conditions during above observations were not quite well, the platform for mounting the gravimeters were quite simple, so that the environment and human’s disturbance were unavoidable, therefore the data obtained from above observation where questionable. It is very hard to give a conclusion to say the gravity anomalies during the eclipses were really existing or not. The more important issue is that none of the suggested external factors could account for the magnitude and timing of observed anomalies, according to Chris Duif of University of Technology of Netherland. Since the total solar eclipse of Mohe, 1997, I have been working on a theory to explain the gravity anomalies. At Mohe, I was watching the image of the eclipse, and led a scientific term to conduct a comprehensive geophysical observation, including the gravity observation. The two kinds of observations were conducted at same location and same time. We noticed that solar light of the eclipse was emitted 500 seconds before the image reached to our eyes and cameras. It was reasonable to have similar idea that the gravitation emitted from the sun is also 500 seconds before our gravimeter received and recorded it; it means that gravitation is retarded. Based on either the Special Relativity or Leinard-Wiechert retarded potential, I have deduced the expressions for retarded gravitation; it is vector modification on Newton’s universal gravitation law. The retarded gravitation is gRT=-GM(R-R?)(1-?2)/R3(1-?r)3 For common cases, bodies move in a weak gravitation field along a quasi-straight light or with a slow speed, such as planets move around the sun or the moon/satellites moves around the earth, I have deduced a very useful expression gRT=gNT[1+(??2-2?r2)/2c2] where,?=v/c,?r=vr/c,??=v?/c, gNT=-GMr/r3. I would like to stress that the approximate solution from the general relativity is only of a scalar modification, as a comparison. The Great Total Soar Eclipse along Yangzi River of July 22 of 2009 provided us a great opportunity to clean up the doubts for last 50 years. Consider that solar gravitation is retarded and the earth’s response is delayed, moon’s retarded factor is negligible, all the theoretical amplitudes and the frequencies for each components of solar tide and moon tide can be calculated, the amplitudes and delay factor of earth tide, the frequencies for each components of solar tide, moon tide and earth tide can been separated and measured from the observation data: Asin?S(t-tS+tE)+Bsin?M(t+tE)=Csin?tot(t+ttot). Taking t=t1 and t=t2, we can get two equations with only two variables, solve the two equations, we can get the retarded factor of the solar gravitation and the delay factor of earth response for each compoenets. The retarded factor obtained will be strong evidence that gravitation is retarded.

Tang, K.

2009-12-01

314

Fire retardancy of a reactively extruded intumescent flame retardant polyethylene system enhanced by metal chelates  

Microsoft Academic Search

A reactive extrusion technology was adopted to synthesize a flame retardant (ER), based on the esterification of melamine phosphate and pentaerythritol. The ER imparts good flame retardancy and non-dripping for polyethylene (PE) when combined with ammonium polyphosphate to yield an intumescent polyethylene (PE–IFR). The performance of this intumescent system has been enhanced by the addition of small amounts (0.2%) chelated

De-Yi Wang; Yun Liu; Yu-Zhong Wang; C. Perdomo Artiles; T. Richard Hull; Dennis Price

2007-01-01

315

Domain duplication, divergence, and loss events in vertebrate Msx paralogs reveal phylogenomically informed disease markers  

PubMed Central

Background Msx originated early in animal evolution and is implicated in human genetic disorders. To reconstruct the functional evolution of Msx and inform the study of human mutations, we analyzed the phylogeny and synteny of 46 metazoan Msx proteins and tracked the duplication, diversification and loss of conserved motifs. Results Vertebrate Msx sequences sort into distinct Msx1, Msx2 and Msx3 clades. The sister-group relationship between MSX1 and MSX2 reflects their derivation from the 4p/5q chromosomal paralogon, a derivative of the original "MetaHox" cluster. We demonstrate physical linkage between Msx and other MetaHox genes (Hmx, NK1, Emx) in a cnidarian. Seven conserved domains, including two Groucho repression domains (N- and C-terminal), were present in the ancestral Msx. In cnidarians, the Groucho domains are highly similar. In vertebrate Msx1, the N-terminal Groucho domain is conserved, while the C-terminal domain diverged substantially, implying a novel function. In vertebrate Msx2 and Msx3, the C-terminal domain was lost. MSX1 mutations associated with ectodermal dysplasia or orofacial clefting disorders map to conserved domains in a non-random fashion. Conclusion Msx originated from a MetaHox ancestor that also gave rise to Tlx, Demox, NK, and possibly EHGbox, Hox and ParaHox genes. Duplication, divergence or loss of domains played a central role in the functional evolution of Msx. Duplicated domains allow pleiotropically expressed proteins to evolve new functions without disrupting existing interaction networks. Human missense sequence variants reside within evolutionarily conserved domains, likely disrupting protein function. This phylogenomic evaluation of candidate disease markers will inform clinical and functional studies. PMID:19154605

Finnerty, John R; Mazza, Maureen E; Jezewski, Peter A

2009-01-01

316

Perceptual Capacities of Retarded and Normal Children. Final Report.  

ERIC Educational Resources Information Center

Eight experiments using as Ss either retarded children, normal children, or normal adults studied the relations of retardation and normal development to the perceptual process of identification. Two experiments were reported on the identification of stimuli varying in either one, two, or three dimensions. Retardates did not perform as well as…

Kaufman, Herbert; Smith, Jerome

317

Cardiovascular Risk Factor Levels in Adults with Mental Retardation.  

ERIC Educational Resources Information Center

Comparison of cardiovascular risk factors (blood lipids, obesity, and smoking) in 329 adults with mental retardation residing in various settings with subjects in the Framingham Offspring Study found that adults with mental retardation had cardiovascular risk profiles similar to those of individuals without mental retardation. (Author/DB)

Rimmer, James H.; And Others

1994-01-01

318

Comparison of Sensorimotor Learning of Mentally Retarded and Normal Adolescents.  

ERIC Educational Resources Information Center

Mildly mentally retarded (N=36), moderately mentally retarded (N=39), and normal (N=37) adolescents were compared on measures of sensorimotor learning ability to determine whether retarded adolescents can learn to perform a vocationally meaningful task as efficiently as normal adolescents. Three measures of sensorimotor learning ability were…

Guay, Roland B.; Andres, Donald L.

319

Detection of Organophosphate Flame Retardants in Furniture Foam  

E-print Network

Detection of Organophosphate Flame Retardants in Furniture Foam and U.S. House Dust H E A T H E R M in the increased use of alternate flame retardant chemicals to meet flammability standards. However in a new flame retardant mixture called Firemaster 550 (4.2% by weight), and one foam sample collected from

320

Mental Retardation Facilities Construction Plan. Second Annual Report.  

ERIC Educational Resources Information Center

Developed in conjunction with the plan for comprehensive state and community action to combat mental retardation, the Maine Mental Retardation Facilities Construction Plan is designed to be integrated with other health facilities and to serve the needs of the mentally retarded. The advisory council and the state agency in charge are described. The…

Maine Committee on Problems of the Mentally Retarded, Augusta.

321

Periventricular heterotopia, mental retardation, and epilepsy associated with  

E-print Network

Periventricular heterotopia, mental retardation, and epilepsy associated with 5q14.3-q15 deletion C features of three unrelated patients with epilepsy, mental retardation, and bilateral PH in the walls), mental retardation, and epilepsy, mapping to chromosome 5q14.3-q15. This observation rein- forces

Cossart, Rosa

322

Generating Models of Mental Retardation from Data with Machine Learning  

E-print Network

Generating Models of Mental Retardation from Data with Machine Learning Subramani Mani 3 Suzanne W domain models of Mental Retardation (MR) from data using Knowledge Discovery and Datamining (KDD) methods of Medicine, Six Richland Medical Park, Columbia SC 29203. We have selected the domain of Mental Retardation

Pazzani, Michael J.

323

Generating Models of Mental Retardation from Data with Machine Learning  

E-print Network

Generating Models of Mental Retardation from Data with Machine Learning Subramani Mani 3 Suzanne W domain models of Mental Retardation (MR) from data using Knowledge Discovery and Datamining (KDD) methods selected the domain of Mental Retardation (MR) for our study due to its complex nature and lack of simple

Pazzani, Michael J.

324

Neuropsychological Profiles of Persons with Mental Retardation and Dementia  

ERIC Educational Resources Information Center

This study examined the use of neuropsychological tests to assist in the differential diagnosis of dementia among persons with mental retardation. The author compared performances of persons with mental retardation and dementia ("n" = 10) to persons with mental retardation without dementia ("n" = 12). Participants were matched by IQ (mild or…

Palmer, Glen A.

2006-01-01

325

Conjunctive Visual Search in Individuals with and without Mental Retardation  

ERIC Educational Resources Information Center

A comprehensive understanding of the basic visual and cognitive abilities of individuals with mental retardation is critical for understanding the basis of mental retardation and for the design of remediation programs. We assessed visual search abilities in individuals with mild mental retardation and in MA- and CA-matched comparison groups. Our…

Carlin, Michael; Chrysler, Christina; Sullivan, Kate

2007-01-01

326

Mental Retardation: The Search for Cures. Research Monograph Number 7.  

ERIC Educational Resources Information Center

The booklet describes the Association for Retarded Citizens' (ARC's) goal of coordinating efforts to seek a cure for mental retardation. Cures are defined as any intervention that would significantly increase intellectual functioning and adaptive behavior beyond the upper level of retardation. It is explained that because of the variety of causes…

Menolascino, Frank J.; Neman, Ronald

327

Stimulus Overselectivity: A Common Feature in Autism and Mental Retardation  

ERIC Educational Resources Information Center

Overselective attention in discrimination between picture cards was investigated with three groups of children with different IQ levels: 10 severely retarded (IQ = 29 - 51, CA = 9.6 - 18 years), 10 moderately retarded (IQ = 56 - 85, CA = 12.8 - 16.3 years), and 10 non-retarded (CA = 10 - 12 years). (Author/IM)

Lovaas, O. Ivar; Wilhelm, Hannelore

1976-01-01

328

The Arabidopsis RAD51 paralogs RAD51B, RAD51D and XRCC2 play partially redundant roles in somatic DNA repair and gene regulation.  

PubMed

The eukaryotic RAD51 gene family has seven ancient paralogs conserved between plants and animals. Among these, RAD51, DMC1, RAD51C and XRCC3 are important for homologous recombination and/or DNA repair, whereas single mutants in RAD51B, RAD51D or XRCC2 show normal meiosis, and the lineages they represent diverged from each other evolutionarily later than the other four paralogs, suggesting possible functional redundancy. The function of Arabidopsis RAD51B, RAD51D and XRCC2 genes in mitotic DNA repair and meiosis was analyzed using molecular genetic, cytological and transcriptomic approaches. The relevant double and triple mutants displayed normal vegetative and reproductive growth. However, the triple mutant showed greater sensitivity than single or double mutants to DNA damage by bleomycin. RNA-Seq transcriptome analysis supported the idea that the triple mutant showed DNA damage similar to that caused by bleomycin. On bleomycin treatment, many genes were altered in the wild-type but not in the triple mutant, suggesting that the RAD51 paralogs have roles in the regulation of gene transcription, providing an explanation for the hypersensitive phenotype of the triple mutant to bleomycin. Our results provide strong evidence that Arabidopsis XRCC2, RAD51B and RAD51D have complex functions in somatic DNA repair and gene regulation, arguing for further studies of these ancient genes that have been maintained in both plants and animals during their long evolutionary history. PMID:24102485

Wang, Yingxiang; Xiao, Rong; Wang, Haifeng; Cheng, Zhihao; Li, Wuxing; Zhu, Genfeng; Wang, Ying; Ma, Hong

2014-01-01

329

Effect of a novel charring–foaming agent on flame retardancy and thermal degradation of intumescent flame retardant polypropylene  

Microsoft Academic Search

A new triazine polymer was synthesized by using cyanuric chloride, ethanolamine and ethylenediamine as raw materials. It is used both as a charring agent and as a foaming agent in intumescent flame retardants, designated as charring–foaming agent (CFA). Effect of CFA on flame retardancy, thermal degradation and mechanical properties of intumescent flame retardant polypropylene (PP) system (IFR–PP system) has been

Bin Li; Miaojun Xu

2006-01-01

330

American Association on Mental Retardation 181 VOLUME 108, NUMBER 3: 181193 MAY 2003 AMERICAN JOURNAL ON MENTAL RETARDATION  

E-print Network

American Association on Mental Retardation 181 VOLUME 108, NUMBER 3: 181­193 MAY 2003 AMERICAN JOURNAL ON MENTAL RETARDATION Detection of Changes in Naturalistic Scenes: Comparisons of Individuals With and Without Mental Retardation Michael T. Carlin, Sal A. Soraci, and Christina P. Strawbridge Shriver Center

Dennis, Nancy

331

American Association on Mental Retardation 149 VOLUME 108, NUMBER 3: 149160 MAY 2003 AMERICAN JOURNAL ON MENTAL RETARDATION  

E-print Network

American Association on Mental Retardation 149 VOLUME 108, NUMBER 3: 149­160 MAY 2003 AMERICAN JOURNAL ON MENTAL RETARDATION Receptive Language Skills of Adolescents and Young Adults With Down and fragile X syndrome are the two most common genetic causes of mental retardation (Dykens, Hodapp

Nguyen, Danh

332

American Association on Mental Retardation 231 VOLUME 109, NUMBER 3: 231236 MAY 2004 AMERICAN JOURNAL ON MENTAL RETARDATION  

E-print Network

American Association on Mental Retardation 231 VOLUME 109, NUMBER 3: 231­236 MAY 2004 AMERICAN JOURNAL ON MENTAL RETARDATION The Relationship Between Age and IQ in Adults With Williams Syndrome Yvonne with autism and no mental retardation show evidence of verbal intellectual skills that improve through

Bellugi, Ursula

333

American Association on Mental Retardation 445 VOLUME 107, NUMBER 6: 445454 NOVEMBER 2002 AMERICAN JOURNAL ON MENTAL RETARDATION  

E-print Network

American Association on Mental Retardation 445 VOLUME 107, NUMBER 6: 445­454 NOVEMBER 2002 AMERICAN JOURNAL ON MENTAL RETARDATION Guiding Visual Attention During Acquisition of Matching-to-Sample Harry A- formances in young children and individuals with mental retardation was demonstrated here through

Dennis, Nancy

334

Overexpression of the chimeric plasmin-resistant VEGF165/VEGF183 (132-158) protein in murine breast cancer induces distinct vascular patterning adjacent to tumors and retarded tumor growth.  

PubMed

A chimeric plasmin?resistant vascular endothelial growth factor (VEGF)165/VEGF192 (132-158) protein, named as VEGF192 (according to the nomenclature of VEGF), designed by a previous study, was demonstrated to have an enhanced affinity for the extracellular matrix (ECM) amongst other bioactivities. However, it is now accepted that mutant VEGFs frequently demonstrate different angiogenic activities and produce different vascular patterning from the parental molecule. The present study hypothesized that VEGF192, due to its enhanced binding affinity to the ECM, would exhibit a different angiogenic activity and produce a different vascular patterning compared to those of VEGF165. Murine breast cancer EMT?6 cells were manipulated to stably overexpress VEGF165 or VEGF192. These cells were then inoculated intradermally into BALB/c mice in order to monitor the formation of vascular patterning in skin proximal to tumors. In vivo angiogenesis experiments revealed that overexpression of VEGF192 in murine breast cancer cells resulted in irregular, disorganized and dense vascular patterning as well as induced a significant inhibition of tumor growth compared with that of VEGF165. In addition, allograft tumor immunochemical assays of VEGF192?overexpressing tumors demonstrated significantly lower vascular densities than those of VEGF165?overexpressing tumors; however, VEGF192 tumors had a significantly enlarged vascular caliber. Conversely, cell wound healing experiments revealed that VEGF192?overexpressing EMT?6 cells had significantly decreased migration rates compared with those of VEGF165?overexpressing EMT?6 cells. In conclusion, the results of the present study supported the hypothesis that the altered ECM affinity of VEGF induced structural alterations to vasculature. In addition, these results provided a novel insight into VEGF design and indirect evidence for the function of exon 8 in VEGF. PMID:25373557

Zhang, Hui-Yong; Fan, Bing-Lin; Wu, Xin-Sheng; Mu, Ling-Min; Wang, Wen-Feng; Zhu, Wu-Ling

2015-02-01

335

Vertebrate Paralogous CRMPs in Nervous System: Evolutionary, Structural, and Functional Interplay.  

PubMed

Collapsin response mediator proteins (CRMPs) family predominantly expressed in the developing nervous system as key molecular components in shaping neural networks. However, knowledge of the evolution of CRMPs is limited. To gain further insight into nervous system evolution in vertebrates, we have performed a comprehensive bioinformatics analysis of CRMPs, including phylogenetic analysis, an examination of positively selected sites and putative biological significance and protein structure analysis. Sequence similarity searches have been performed in genome data to identify homologues of CRMPs in vertebrates. Phylogenetic relationships were constructed to trace the family evolutionary history. Five CRMP members might form through gene duplication. The inferred evolutionary transitions that separate members which belong to different gene clusters correlated with changes in functional properties. To determine the mode of evolution in vertebrates, we used several complementary methods, including site-specific models, branch-specific models and branch-site models to estimated molecular substitution rates and determined the selective force operating at each CRMPs gene cluster. Nineteen positive selection sites and the functional areas were detected in this process. This research gives us a first look at the phylogeny and evolutionary selection pressure of the CRMP family in vertebrates. Additionally, we identified a number of critical amino acid residues likely relevant for the distinct functional properties of the paralogues. In conclusion, the results of this study contribute novel detailed information about the molecular evolution of CRMPs, reveal CRMPs' roles in the pathogenesis of nervous system diseases and provide a new thought of the targeted therapy from the molecular evolution angle. PMID:24894590

Tang, Yanyan; Ye, Ziming; Wei, Yunfei; Lin, Cuiting; Wang, Yongbo; Qin, Chao

2015-02-01

336

Ras1 Acts through Duplicated Cdc42 and Rac Proteins to Regulate Morphogenesis and Pathogenesis in the Human Fungal Pathogen Cryptococcus neoformans  

PubMed Central

Proliferation and morphogenesis in eukaryotic cells depend on the concerted activity of Rho-type GTPases, including Ras, Cdc42, and Rac. The sexually dimorphic fungus Cryptococcus neoformans, which encodes paralogous, non-essential copies of all three, provides a unique model in which to examine the interactions of these conserved proteins. Previously, we demonstrated that RAS1 mediates C. neoformans virulence by acting as a central regulator of both thermotolerance and mating. We report here that ras1? mutants accumulate defects in polarized growth, cytokinesis, and cell cycle progression. We demonstrate that the ras1? defects in thermotolerance and mating can be largely explained by the compromised activity of four downstream Rho-GTPases: the Cdc42 paralogs, Cdc42 and Cdc420; and the Rac paralogs, Rac1 and Rac2. Further, we demonstrate that the separate GTPase classes play distinct Ras-dependent roles in C. neoformans morphogenesis and pathogenesis. Cdc42 paralogs primarily control septin localization and cytokinesis, while Rac paralogs play a primary role in polarized cell growth. Together, these duplicate, related signaling proteins provide a robust system to allow microbial proliferation in the presence of host-derived cell stresses. PMID:23950731

Ballou, Elizabeth Ripley; Kozubowski, Lukasz; Nichols, Connie B.; Alspaugh, J. Andrew

2013-01-01

337

Brominated flame retardants: cause for concern?  

PubMed Central

Brominated flame retardants (BFRs) have routinely been added to consumer products for several decades in a successful effort to reduce fire-related injury and property damage. Recently, concern for this emerging class of chemicals has risen because of the occurrence of several classes of BFRs in the environment and in human biota. The widespread production and use of BFRs; strong evidence of increasing contamination of the environment, wildlife, and people; and limited knowledge of potential effects heighten the importance of identifying emerging issues associated with the use of BFRs. In this article, we briefly review scientific issues associated with the use of tetrabromobisphenol A, hexabromocyclododecane, and three commercial mixtures of polybrominated diphenyl ethers and discuss data gaps. Overall, the toxicology database is very limited; the current literature is incomplete and often conflicting. Available data, however, raise concern over the use of certain classes of brominated flame retardants. PMID:14698924

Birnbaum, Linda S; Staskal, Daniele F

2004-01-01

338

Prepartially crosslinked gel for retarding fluid flow  

SciTech Connect

This patent describes a subterranean formation having channels which have a high permeability to the flow of fluids. A process for retarding fluid flow in the channels comprises: providing a gel-forming composition which when substantially completely gelled in the high permeability channels is operable for retarding fluid flow therein. The gel-forming composition comprises: an aqueous solution comprising a first substance selected from the group consisting of polyvinyl alcohol, a polyvinyl alcohol copolymer, and mixtures thereof, and an effective amount of a second substance selected from the group consisting of aldehydes, aldehyde generating substances, acetals, acetal generating substances, and mixtures thereof capable of crosslinking with the first substance through the formation of acetal crosslinkages. The second substance is operable for forming a gel with the aqueous solution when the gel-forming composition is acidic.

Sandiford, B.B.; Chiou, C.S.

1987-05-19

339

Diagnostic Genome Profiling in Mental Retardation  

Microsoft Academic Search

Mental retardation (MR) occurs in 2%-3% of the general population. Conventional karyotyping has a resolution of 5-10 million bases and detects chromosomal alterations in approximately 5% of individuals with unexplained MR. The frequency of smaller submicroscopic chromosomal alterations in these patients is unknown. Novel molecular karyotyping methods, such as array-based comparative genomic hybridization (array CGH), can detect submicroscopic chromosome alterations

Bert B. A. de Vries; Rolph Pfundt; Martijn Leisink; David A. Koolen; Lisenka E. L. M. Vissers; Irene M. Janssen; Simon van Reijmersdal; Willy M. Nillesen; Erik H. L. P. G. Huys; Nicole de Leeuw; Dominique Smeets; Erik A. Sistermans; Ton Feuth; Conny M. A. van Ravenswaaij-Arts; Eric F. P. M. Schoenmakers; Han G. Brunner; Joris A. Veltman

2005-01-01

340

Walking Habits of Adults with Mental Retardation  

ERIC Educational Resources Information Center

The walking activity of men and women with mental retardation residing in community settings was described. Participants were 38 women (M age = 0.7, SD = 9.5) and 65 men (M age = 35.9, SD = 11.2). They wore pedometers for 7 days. A 2 ? 2 factorial ANOVA indicated no significant gender differences in total step counts or between participants with…

Stanish, Heidi I.; Draheim, Christopher C.

2005-01-01

341

Combustion toxicity of fire retarded EVA  

Microsoft Academic Search

A Purser furnace has been used to investigate the combustion toxicity of ethylene-vinyl acetate copolymer (EVA) with and without fire retardants, under different fire conditions. Steady state flaming combustion has been studied at equivalence ratios ? varying from 0.5 to 1.5 by driving the materials through the furnace at 750 °C. Yields of CO and CO2 for EVA containing 27% vinyl

T. Richard Hull; Rita E Quinn; Irene G Areri; David A Purser

2002-01-01

342

Functional Analysis of Paralogous Thiol-disulfide Oxidoreductases in Streptococcus gordonii*  

PubMed Central

Disulfide bonds are important for the stability of many extracellular proteins, including bacterial virulence factors. Formation of these bonds is catalyzed by thiol-disulfide oxidoreductases (TDORs). Little is known about their formation in Gram-positive bacteria, particularly among facultative anaerobic Firmicutes, such as streptococci. To investigate disulfide bond formation in Streptococcus gordonii, we identified five putative TDORs from the sequenced genome. Each of the putative TDOR genes was insertionally inactivated with an erythromycin resistance cassette, and the mutants were analyzed for autolysis, extracellular DNA release, biofilm formation, bacteriocin production, and genetic competence. This analysis revealed a single TDOR, SdbA, which exhibited a pleiotropic mutant phenotype. Using an in silico analysis approach, we identified the major autolysin AtlS as a natural substrate of SdbA and showed that SdbA is critical to the formation of a disulfide bond that is required for autolytic activity. Analysis by BLAST search revealed homologs to SdbA in other Gram-positive species. This study provides the first in vivo evidence of an oxidoreductase, SdbA, that affects multiple phenotypes in a Gram-positive bacterium. SdbA shows low sequence homology to previously identified oxidoreductases, suggesting that it may belong to a different class of enzymes. Our results demonstrate that SdbA is required for disulfide bond formation in S. gordonii and indicate that this enzyme may represent a novel type of oxidoreductase in Gram-positive bacteria. PMID:23615907

Davey, Lauren; Ng, Crystal K. W.; Halperin, Scott A.; Lee, Song F.

2013-01-01

343

Functional analysis of paralogous thiol-disulfide oxidoreductases in Streptococcus gordonii.  

PubMed

Disulfide bonds are important for the stability of many extracellular proteins, including bacterial virulence factors. Formation of these bonds is catalyzed by thiol-disulfide oxidoreductases (TDORs). Little is known about their formation in Gram-positive bacteria, particularly among facultative anaerobic Firmicutes, such as streptococci. To investigate disulfide bond formation in Streptococcus gordonii, we identified five putative TDORs from the sequenced genome. Each of the putative TDOR genes was insertionally inactivated with an erythromycin resistance cassette, and the mutants were analyzed for autolysis, extracellular DNA release, biofilm formation, bacteriocin production, and genetic competence. This analysis revealed a single TDOR, SdbA, which exhibited a pleiotropic mutant phenotype. Using an in silico analysis approach, we identified the major autolysin AtlS as a natural substrate of SdbA and showed that SdbA is critical to the formation of a disulfide bond that is required for autolytic activity. Analysis by BLAST search revealed homologs to SdbA in other Gram-positive species. This study provides the first in vivo evidence of an oxidoreductase, SdbA, that affects multiple phenotypes in a Gram-positive bacterium. SdbA shows low sequence homology to previously identified oxidoreductases, suggesting that it may belong to a different class of enzymes. Our results demonstrate that SdbA is required for disulfide bond formation in S. gordonii and indicate that this enzyme may represent a novel type of oxidoreductase in Gram-positive bacteria. PMID:23615907

Davey, Lauren; Ng, Crystal K W; Halperin, Scott A; Lee, Song F

2013-06-01

344

Loss of WAVE-1 causes sensorimotor retardation and reduced learning and memory in mice  

PubMed Central

The Scar/WAVE family of scaffolding proteins organize molecular networks that relay signals from the GTPase Rac to the actin cytoskeleton. The WAVE-1 isoform is a brain-specific protein expressed in variety of areas including the regions of the hippocampus and the Purkinje cells of the cerebellum. Targeted disruption of the WAVE-1 gene generated mice with reduced anxiety, sensorimotor retardation, and deficits in hippocampal-dependent learning and memory. These sensorimotor and cognitive deficits are analogous to the symptoms of patients with 3p-syndrome mental retardation who are haploinsufficient for WRP/MEGAP, a component of the WAVE-1 signaling network. Thus WAVE-1 is required for normal neural functioning. PMID:12578964

Soderling, Scott H.; Langeberg, Lorene K.; Soderling, Jacquelyn A.; Davee, Stephen M.; Simerly, Richard; Raber, Jacob; Scott, John D.

2003-01-01

345

The mGluR theory of fragile X mental retardation  

Microsoft Academic Search

Many of the diverse functional consequences of activating group 1 metabotropic glutamate receptors require translation of pre-existing mRNA near synapses. One of these consequences is long-term depression (LTD) of transmission at hippocampal synapses. Loss of fragile X mental retardation protein (FMRP), the defect responsible for fragile X syndrome in humans, increases LTD in mouse hippocampus. This finding is consistent with

Mark F. Bear; Kimberly M. Huber; Stephen T. Warren

2004-01-01

346

The evolutionary history of carbamoyltransferases: A complex set of paralogous genes was already present in the last universal common ancestor.  

PubMed

Forty-four sequences of ornithine carbamoyltransferases (OTCases) and 33 sequences of aspartate carbamoyltransferases (ATCases) representing the three domains of life were multiply aligned and a phylogenetic tree was inferred from this multiple alignment. The global topology of the composite rooted tree (each enzyme family being used as an outgroup to root the other one) suggests that present-day genes are derived from paralogous ancestral genes which were already of the same size and argues against a mechanism of fusion of independent modules. A closer observation of the detailed topology shows that this tree could not be used to assess the actual order of organismal descent. Indeed, this tree displays a complex topology for many prokaryotic sequences, with polyphyly for Bacteria in both enzyme trees and for the Archaea in the OTCase tree. Moreover, representatives of the two prokaryotic Domains are found to be interspersed in various combinations in both enzyme trees. This complexity may be explained by assuming the occurrence of two subfamilies in the OTCase tree (OTC alpha and OTC beta) and two other ones in the ATCase tree (ATC I and ATC II). These subfamilies could have arisen from duplication and selective losses of some differentiated copies during the successive speciations. We suggest that Archaea and Eukaryotes share a common ancestor in which the ancestral copies giving the present-day ATC II/OTC beta combinations were present, whereas Bacteria comprise two classes: one containing the ATC II/OTC alpha combination and the other harboring the ATC I/OTC beta combination. Moreover, multiple horizontal gene transfers could have occurred rather recently amongst prokaryotes. Whichever the actual history of carbamoyltransferases, our data suggest that the last common ancestor to all extant life possessed differentiated copies of genes coding for both carbamoyltransferases, indicating it as a rather sophisticated organism. PMID:10486004

Labedan, B; Boyen, A; Baetens, M; Charlier, D; Chen, P; Cunin, R; Durbeco, V; Glansdorff, N; Herve, G; Legrain, C; Liang, Z; Purcarea, C; Roovers, M; Sanchez, R; Toong, T L; Van de Casteele, M; van Vliet, F; Xu, Y; Zhang, Y F

1999-10-01

347

Divergent nuclear 18S rDNA paralogs in a turkey coccidium, Eimeria meleagrimitis, complicate molecular systematics and identification.  

PubMed

Multiple 18S rDNA sequences were obtained from two single-oocyst-derived lines of each of Eimeria meleagrimitis and Eimeria adenoeides. After analysing the 15 new 18S rDNA sequences from two lines of E. meleagrimitis and 17 new sequences from two lines of E. adenoeides, there were clear indications that divergent, paralogous 18S rDNA copies existed within the nuclear genome of E. meleagrimitis. In contrast, mitochondrial cytochrome c oxidase subunit I (COI) partial sequences from all lines of a particular Eimeria sp. were identical and, in phylogenetic analyses, COI sequences clustered unambiguously in monophyletic and highly-supported clades specific to individual Eimeria sp. Phylogenetic analysis of the new 18S rDNA sequences from E. meleagrimitis showed that they formed two distinct clades: Type A with four new sequences; and Type B with nine new sequences; both Types A and B sequences were obtained from each of the single-oocyst-derived lines of E. meleagrimitis. Together these rDNA types formed a well-supported E. meleagrimitis clade. Types A and B 18S rDNA sequences from E. meleagrimitis had a mean sequence identity of only 97.4% whereas mean sequence identity within types was 99.1-99.3%. The observed intraspecific sequence divergence among E. meleagrimitis 18S rDNA sequence types was even higher (approximately 2.6%) than the interspecific sequence divergence present between some well-recognized species such as Eimeria tenella and Eimeria necatrix (1.1%). Our observations suggest that, unlike COI sequences, 18S rDNA sequences are not reliable molecular markers to be used alone for species identification with coccidia, although 18S rDNA sequences have clear utility for phylogenetic reconstruction of apicomplexan parasites at the genus and higher taxonomic ranks. PMID:23639264

El-Sherry, Shiem; Ogedengbe, Mosun E; Hafeez, Mian A; Barta, John R

2013-07-01

348

On the Use of Gene Ontology Annotations to Assess Functional Similarity among Orthologs and Paralogs: A Short Report  

PubMed Central

A recent paper (Nehrt et al., PLoS Comput. Biol. 7:e1002073, 2011) has proposed a metric for the “functional similarity” between two genes that uses only the Gene Ontology (GO) annotations directly derived from published experimental results. Applying this metric, the authors concluded that paralogous genes within the mouse genome or the human genome are more functionally similar on average than orthologous genes between these genomes, an unexpected result with broad implications if true. We suggest, based on both theoretical and empirical considerations, that this proposed metric should not be interpreted as a functional similarity, and therefore cannot be used to support any conclusions about the “ortholog conjecture” (or, more properly, the “ortholog functional conservation hypothesis”). First, we reexamine the case studies presented by Nehrt et al. as examples of orthologs with divergent functions, and come to a very different conclusion: they actually exemplify how GO annotations for orthologous genes provide complementary information about conserved biological functions. We then show that there is a global ascertainment bias in the experiment-based GO annotations for human and mouse genes: particular types of experiments tend to be performed in different model organisms. We conclude that the reported statistical differences in annotations between pairs of orthologous genes do not reflect differences in biological function, but rather complementarity in experimental approaches. Our results underscore two general considerations for researchers proposing novel types of analysis based on the GO: 1) that GO annotations are often incomplete, potentially in a biased manner, and subject to an “open world assumption” (absence of an annotation does not imply absence of a function), and 2) that conclusions drawn from a novel, large-scale GO analysis should whenever possible be supported by careful, in-depth examination of examples, to help ensure the conclusions have a justifiable biological basis. PMID:22359495

Thomas, Paul D.; Wood, Valerie; Mungall, Christopher J.; Lewis, Suzanna E.; Blake, Judith A.

2012-01-01

349

Transcription factor SOX3 is involved in X-linked mental retardation with growth hormone deficiency.  

PubMed

Physical mapping of the breakpoints of a pericentric inversion of the X chromosome (46,X,inv[X][p21q27]) in a female patient with mild mental retardation revealed localization of the Xp breakpoint in the IL1RAPL gene at Xp21.3 and the Xq breakpoint near the SOX3 gene (SRY [sex determining region Y]-box 3) (GenBank accession number NM_005634) at Xq26.3. Because carrier females with microdeletion in the IL1RAPL gene do not present any abnormal phenotype, we focused on the Xq breakpoint. However, we were unable to confirm the involvement of SOX3 in the mental retardation in this female patient. To validate SOX3 as an X-linked mental retardation (XLMR) gene, we performed mutation analyses in families with XLMR whose causative gene mapped to Xq26-q27. We show here that the SOX3 gene is involved in a large family in which affected individuals have mental retardation and growth hormone deficiency. The mutation results in an in-frame duplication of 33 bp encoding for 11 alanines in a polyalanine tract of the SOX3 gene. The expression pattern during neural and pituitary development suggests that dysfunction of the SOX3 protein caused by the polyalanine expansion might disturb transcription pathways and the regulation of genes involved in cellular processes and functions required for cognitive and pituitary development. PMID:12428212

Laumonnier, Frédéric; Ronce, Nathalie; Hamel, Ben C J; Thomas, Paul; Lespinasse, James; Raynaud, Martine; Paringaux, Christine; Van Bokhoven, Hans; Kalscheuer, Vera; Fryns, Jean-Pierre; Chelly, Jamel; Moraine, Claude; Briault, Sylvain

2002-12-01

350

Transcription Factor SOX3 Is Involved in X-Linked Mental Retardation with Growth Hormone Deficiency  

PubMed Central

Physical mapping of the breakpoints of a pericentric inversion of the X chromosome (46,X,inv[X][p21q27]) in a female patient with mild mental retardation revealed localization of the Xp breakpoint in the IL1RAPL gene at Xp21.3 and the Xq breakpoint near the SOX3 gene (SRY [sex determining region Y]–box 3) (GenBank accession number NM_005634) at Xq26.3. Because carrier females with microdeletion in the IL1RAPL gene do not present any abnormal phenotype, we focused on the Xq breakpoint. However, we were unable to confirm the involvement of SOX3 in the mental retardation in this female patient. To validate SOX3 as an X-linked mental retardation (XLMR) gene, we performed mutation analyses in families with XLMR whose causative gene mapped to Xq26-q27. We show here that the SOX3 gene is involved in a large family in which affected individuals have mental retardation and growth hormone deficiency. The mutation results in an in-frame duplication of 33 bp encoding for 11 alanines in a polyalanine tract of the SOX3 gene. The expression pattern during neural and pituitary development suggests that dysfunction of the SOX3 protein caused by the polyalanine expansion might disturb transcription pathways and the regulation of genes involved in cellular processes and functions required for cognitive and pituitary development. PMID:12428212

Laumonnier, Frédéric; Ronce, Nathalie; Hamel, Ben C. J.; Thomas, Paul; Lespinasse, James; Raynaud, Martine; Paringaux, Christine; van Bokhoven, Hans; Kalscheuer, Vera; Fryns, Jean-Pierre; Chelly, Jamel; Moraine, Claude; Briault, Sylvain

2002-01-01

351

Tunneling versus quantum interference effect: Role of advanced-advanced and retarded-retarded transmission modes  

NASA Astrophysics Data System (ADS)

Following our previous work [S. Duhot, R. Mélin, Phys. Rev. B 76 (2007) 184503] on the interpretation of an experiment [Latyshev, et al., Phys. Rev. Lett. 78 (1997) 919] on magnetic oscillations of a film of charge density wave pierced by nanoholes, the cross-over between positive and negative magneto-transmission is investigated here within microscopic Green's functions for a simple insulating one dimensional ring having a radius of order of the decay length of evanescent states. Advanced-advanced or retarded-retarded transmission modes lead to negative magneto-transmission at low field and to h/2e oscillations in the flux dependence of the transmission coefficients.

Mélin, R.

2009-03-01

352

Clinical Features: Features of patients with SLC9A6 mutations include mental retardation, microcephaly, truncal ataxia, grand mal  

E-print Network

6/11 Clinical Features: Features of patients with SLC9A6 mutations include mental retardationA6 gene. Molecular and Biochemical Genetics: Mutations of the SLC9A6 [OMIM #300231] gene have been-rich tissues such as brain and skeletal muscle [3]. It is thought that the SLC9A6 protein product, the Na

Ober, Carole

353

Clinical Features: Features of patients with SLC9A6 mutations include mental retardation, microcephaly, truncal ataxia, grand mal  

E-print Network

1/13 Clinical Features: Features of patients with SLC9A6 mutations include mental retardationA6 gene. Molecular and Biochemical Genetics: Mutations of the SLC9A6 [OMIM #300231] gene have been-rich tissues such as brain and skeletal muscle [3]. It is thought that the SLC9A6 protein product, the Na

Ober, Carole

354

Clinical Features: Features of patients with SLC9A6 mutations include mental retardation, microcephaly, truncal ataxia, grand mal  

E-print Network

1/13 Clinical Features: Features of patients with SLC9A6 mutations include mental retardationA6 gene. Molecular and Biochemical Genetics: Mutations of the SLC9A6 [OMIM #300231] gene have been-rich tissues such as brain and skeletal muscle (3). It is thought that the SLC9A6 protein product, the Na

Das, Soma

355

Proteins  

NSDL National Science Digital Library

Paul Anderson explains the structure and importance of proteins. He describes how proteins are created from amino acids connected by dehydration synthesis. He shows the importance of chemical properties in the R-groups of individual amino acids in the polypeptide.

Paul Anderson

2013-03-12

356

Proteins.  

ERIC Educational Resources Information Center

Examines proteins which give rise to structure and, by virtue of selective binding to other molecules, make genes. Binding sites, amino acids, protein evolution, and molecular paleontology are discussed. Work with encoding segments of deoxyribonucleic acid (exons) and noncoding stretches (introns) provides new information for hypotheses. (DH)

Doolittle, Russell F.

1985-01-01

357

Fire-retardant decorative inks for aircraft interiors  

NASA Technical Reports Server (NTRS)

Commercial and experimental fire retardants were screened as potential fire retardants for acrylic printing inks used on aircraft interior sandwich panels. The fire retardants are selected according to their physical properties and their thermostabilities. A criterion for selecting a more stable fire retardant is established. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are used to determine thermostabilities. Results show that the fire retardant formulations are more thermally stable than the acrylic ink control. It is determined that an ink formulation containing a brominated phenol and carboxy-terminated butadiene acrylonitrile which has been modified with a brominated polymeric additive (BPA), yields the highest limiting oxygen index (LOI) of all the compounds tested. All of the fire-retardant formulations have a higher oxygen index than the baseline acrylic ink.

Kourtides, D. A.; Nir, Z.; Mikroyannidis, J. A.

1985-01-01

358

Electrode contamination effects of retarding potential analyzer.  

PubMed

The electrode contamination in electrostatic analyzers such as Langmuir probes and retarding potential analyzers (RPA) is a serious problem for space measurements. The contamination layer acts as extra capacitance and resistance and leads to distortion in the measured I-V curve, which leads to erroneous measurement results. There are two main effects of the contamination layer: one is the impedance effect and the other is the charge attachment and accumulation due to the capacitance. The impedance effect can be reduced or eliminated by choosing the proper sweeping frequency. However, for RPA the charge accumulation effect becomes serious because the capacitance of the contamination layer is much larger than that of the Langmuir probe of similar dimension. The charge accumulation on the retarding potential grid causes the effective potential, that ions experience, to be changed from the applied voltage. Then, the number of ions that can pass through the retarding potential grid to reach the collector and, thus, the measured ion current are changed. This effect causes the measured ion drift velocity and ion temperature to be changed from the actual values. The error caused by the RPA electrode contamination is expected to be significant for sounding rocket measurements with low rocket velocity (1-2 km/s) and low ion temperature of 200-300 K in the height range of 100-300 km. In this paper we discuss the effects associated with the RPA contaminated electrodes based on theoretical analysis and experiments performed in a space plasma operation chamber. Finally, the development of a contamination-free RPA for sounding rocket missions is presented. PMID:24517809

Fang, H K; Oyama, K-I; Cheng, C Z

2014-01-01

359

Nanotechnology finding its way into flame retardancy  

SciTech Connect

Nanotechnology is one of the key technologies of the 21{sup st} century. The exploitation of 'new' effects that arise from materials structured on the nano-scale has also been proposed successfully for flame retardancy of polymers since the end of the 90s. Of all of the approaches these include, at this time the use of nanocomposites offers the best potential for industrial application, also some other ideas are sketched, such as using electrospun nanofibers mats or layer-by-layer deposits as protection coatings, as well as sub-micrometer multilayer coatings as effective IR-mirrors. The general phenomena, inducing a flow limit in the pyrolysing melt and changing the fire residue, are identified in nanocomposites. Key experiments are performed such as quasi online investigation of the protection layer formation to understand what is going on in detail. The flame retardancy mechanisms are discussed and their impact on fire behaviour quantified. With the latter, the presentation pushes forward the state of the art. For instance, the heat shielding is experimentally quantified for a layered silicate epoxy resin nanocomposite proving that it is the only import mechanism controlling the reduction in peak heat release rate in the investigated system for different irradiations. The flame retardancy performance is assessed comprehensively illuminating not only the strengths but also the weak points of the concepts. Guidelines for materials development are deduced and discussed. Apart from inorganic fillers (layered silicate, boehmite, etc.) not only carbon nanoobjects such as multiwall carbon nanotubes, multilayer graphene and graphene are investigated, but also nanoparticles that are more reactive and harbor the potential for more beneficial interactions with the polymer matrix.

Schartel, Bernhard, E-mail: bernhard.schartel@bam.de [BAM Federal Institute for Materials Research and Testing, Unter den Eichen 87, 12205 Berlin (Germany)

2014-05-15

360

Nanotechnology finding its way into flame retardancy  

NASA Astrophysics Data System (ADS)

Nanotechnology is one of the key technologies of the 21st century. The exploitation of "new" effects that arise from materials structured on the nano-scale has also been proposed successfully for flame retardancy of polymers since the end of the 90s. Of all of the approaches these include, at this time the use of nanocomposites offers the best potential for industrial application, also some other ideas are sketched, such as using electrospun nanofibers mats or layer-by-layer deposits as protection coatings, as well as sub-micrometer multilayer coatings as effective IR-mirrors. The general phenomena, inducing a flow limit in the pyrolysing melt and changing the fire residue, are identified in nanocomposites. Key experiments are performed such as quasi online investigation of the protection layer formation to understand what is going on in detail. The flame retardancy mechanisms are discussed and their impact on fire behaviour quantified. With the latter, the presentation pushes forward the state of the art. For instance, the heat shielding is experimentally quantified for a layered silicate epoxy resin nanocomposite proving that it is the only import mechanism controlling the reduction in peak heat release rate in the investigated system for different irradiations. The flame retardancy performance is assessed comprehensively illuminating not only the strengths but also the weak points of the concepts. Guidelines for materials development are deduced and discussed. Apart from inorganic fillers (layered silicate, boehmite, etc.) not only carbon nanoobjects such as multiwall carbon nanotubes, multilayer graphene and graphene are investigated, but also nanoparticles that are more reactive and harbor the potential for more beneficial interactions with the polymer matrix.

Schartel, Bernhard

2014-05-01

361

Electrode contamination effects of retarding potential analyzer  

NASA Astrophysics Data System (ADS)

The electrode contamination in electrostatic analyzers such as Langmuir probes and retarding potential analyzers (RPA) is a serious problem for space measurements. The contamination layer acts as extra capacitance and resistance and leads to distortion in the measured I-V curve, which leads to erroneous measurement results. There are two main effects of the contamination layer: one is the impedance effect and the other is the charge attachment and accumulation due to the capacitance. The impedance effect can be reduced or eliminated by choosing the proper sweeping frequency. However, for RPA the charge accumulation effect becomes serious because the capacitance of the contamination layer is much larger than that of the Langmuir probe of similar dimension. The charge accumulation on the retarding potential grid causes the effective potential, that ions experience, to be changed from the applied voltage. Then, the number of ions that can pass through the retarding potential grid to reach the collector and, thus, the measured ion current are changed. This effect causes the measured ion drift velocity and ion temperature to be changed from the actual values. The error caused by the RPA electrode contamination is expected to be significant for sounding rocket measurements with low rocket velocity (1-2 km/s) and low ion temperature of 200-300 K in the height range of 100-300 km. In this paper we discuss the effects associated with the RPA contaminated electrodes based on theoretical analysis and experiments performed in a space plasma operation chamber. Finally, the development of a contamination-free RPA for sounding rocket missions is presented.

Fang, H. K.; Oyama, K.-I.; Cheng, C. Z.

2014-01-01

362

New hybrid halogen-free flame retardants  

NASA Astrophysics Data System (ADS)

The main objective of this work were researches concerning the methods of the in-situ modification of silicate layer-tubular mineral (SL-TM) halloysite, using the salts of melamine, i.e. melamine cyanurate. The modified mineral was used as flame retardant to thermoplastic polymers. In the case of the application of halloysite modified by melamine cyanurate to polyamide 6 (PA6) the highest parameters of vertical and horizontal flammability were achieved. The mechanical properties of filled polyamide 6 have been improved.

Kijowska, Dorota; Jankowski, Piotr

2014-05-01

363

Retardation of nanoparticles growth by doping  

PubMed Central

The process of doping of CdS nanoparticles with Mn during colloidal synthesis is analyzed by EPR and optical studies. Analysis of EPR results demonstrated that Mn2+ ions are successfully incorporated into the nanoparticles and occupy the crystal sites both in the bulk of a NP and near the surface of a NP. Optical absorption measurements revealed the retardation of absorption edge shift during the growth for Mn-doped CdS NPs as compared to the undoped CdS NPs. It was concluded that the presence of Mn in the solution leads to the inhibition of NPs growth. PMID:25593561

2014-01-01

364

A new protein superfamily: TPPP-like proteins.  

PubMed

The introduction of the term 'Tubulin Polymerization Promoting Protein (TPPP)-like proteins' is suggested. They constitute a eukaryotic protein superfamily, characterized by the presence of the p25alpha domain (Pfam05517, IPR008907), and named after the first identified member, TPPP/p25, exhibiting microtubule stabilizing function. TPPP-like proteins can be grouped on the basis of two characteristics: the length of their p25alpha domain, which can be long, short, truncated or partial, and the presence or absence of additional domain(s). TPPPs, in the strict sense, contain no other domains but one long or short p25alpha one (long- and short-type TPPPs, respectively). Proteins possessing truncated p25alpha domain are first described in this paper. They evolved from the long-type TPPPs and can be considered as arthropod-specific paralogs of long-type TPPPs. Phylogenetic analysis shows that the two groups (long-type and truncated TPPPs) split in the common ancestor of arthropods. Incomplete p25alpha domains can be found in multidomain TPPP-like proteins as well. The various subfamilies occur with a characteristic phyletic distribution: e. g., animal genomes/proteomes contain almost without exception long-type TPPPs; the multidomain apicortins occur almost exclusively in apicomplexan parasites. There are no data about the physiological function of these proteins except two human long-type TPPP paralogs which are involved in developmental processes of the brain and the musculoskeletal system, respectively. I predict that the superfamily members containing long or partial p25alpha domain are often intrinsically disordered proteins, while those with short or truncated domain(s) are structurally ordered. Interestingly, members of this superfamily connected or maybe connected to diseases are intrinsically disordered proteins. PMID:23166627

Orosz, Ferenc

2012-01-01

365

A New Protein Superfamily: TPPP-Like Proteins  

PubMed Central

The introduction of the term ‘Tubulin Polymerization Promoting Protein (TPPP)-like proteins’ is suggested. They constitute a eukaryotic protein superfamily, characterized by the presence of the p25alpha domain (Pfam05517, IPR008907), and named after the first identified member, TPPP/p25, exhibiting microtubule stabilizing function. TPPP-like proteins can be grouped on the basis of two characteristics: the length of their p25alpha domain, which can be long, short, truncated or partial, and the presence or absence of additional domain(s). TPPPs, in the strict sense, contain no other domains but one long or short p25alpha one (long- and short-type TPPPs, respectively). Proteins possessing truncated p25alpha domain are first described in this paper. They evolved from the long-type TPPPs and can be considered as arthropod-specific paralogs of long-type TPPPs. Phylogenetic analysis shows that the two groups (long-type and truncated TPPPs) split in the common ancestor of arthropods. Incomplete p25alpha domains can be found in multidomain TPPP-like proteins as well. The various subfamilies occur with a characteristic phyletic distribution: e. g., animal genomes/proteomes contain almost without exception long-type TPPPs; the multidomain apicortins occur almost exclusively in apicomplexan parasites. There are no data about the physiological function of these proteins except two human long-type TPPP paralogs which are involved in developmental processes of the brain and the musculoskeletal system, respectively. I predict that the superfamily members containing long or partial p25alpha domain are often intrinsically disordered proteins, while those with short or truncated domain(s) are structurally ordered. Interestingly, members of this superfamily connected or maybe connected to diseases are intrinsically disordered proteins. PMID:23166627

Orosz, Ferenc

2012-01-01

366

Growth and sexual maturity pattern of girls with mental retardation  

PubMed Central

Background: Growth of mentally retarded children differs from that of normal children. However, the adolescent growth and development of Indian mentally retarded children has not been studied. Aim: This study was conducted to evaluate the physical growth and sexual development of adolescent mentally retarded girls in North Indian population and to compare it with that of normal girls of same age group. Materials and Methods: One hundred mentally retarded (intelligence quotient (IQ) less than 70) and 100 normal girls between 10 and 20 years of age were categorized into 1-year age groups. Their height was measured and the sexual development was assessed based on breast development (BD) and pubic hair growth (PH) stages 1-5 on the basis of Tanner scale. The data was then compared between the two groups using Student's t-test. The mean age of menarche was calculated by applying Probit analysis. Results: The mean height of mentally retarded girls was significantly retarded as compared to normal girls at all ages; however, the mean height gain during 11-20 years was same in both the groups. The mentally retarded girls also showed significant retardation in PH growth at 15-17 years and in BD at 15-16 years of age. Conclusions: The physical growth and sexual development of adolescent mentally retarded girls was retarded as compared to the normal girls. The physical growth retardation occurred during early childhood (before 11 years), however the retardation in sexual maturity occurred during middle adolescence, between 15-17 years of age. PMID:24600577

Baidwan, Sukhinder; Paul, Molly M; Chhatwal, Jugesh; Deswal, RS

2014-01-01

367

Evolution of the paralogous hap and iga genes in Haemophilus influenzae: evidence for a conserved hap pseudogene associated with microcolony formation in the recently diverged Haemophilus aegyptius and H. influenzae biogroup aegyptius.  

PubMed

Certain non-capsulate strains belonging to the Haemophilus influenzae/Haemophilus aegyptius complex show unusually high pathogenicity, but the evolutionary origin of these virulent phenotypes, termed H. influenzae biogroup aegyptius, is as yet unknown. The aim of the present study was to elucidate the mechanisms of evolution of two paralogous genes, hap and iga, which encode the adhesion and penetration Hap protein and the IgA1 protease respectively. Partial sequencing of hap and iga genes in a comprehensive collection of strains belonging to the H. influenzae/H. aegyptius complex revealed considerable genetic polymorphism and pronounced mosaic-like patterns in both genes, but no evidence of intrastrain recombination between the two genes. A conserved hap pseudogene was present in all strains of H. aegyptius and H. influenzae biogroup aegyptius, each of which constituted distinct subpopulations as revealed by phylogenetic analysis. There was no evidence for a second, functional copy of the hap gene in these strains. The perturbed expression of the Hap serine protease appears to be associated with the formation of elongated bacterial cells growing in chains and a distinct colonization pattern on conjunctival cells, previously termed microcolony formation. The fact that individual hap pseudogenes differed from the ancestral sequence by zero to two positions within a 1.5 kb stretch suggests that the silencing event happened approximately 2000-11,000 years ago. Divergence of H. aegyptius and H. influenzae biogroup aegyptius occurred subsequent to this genetic event. The loss of Hap protein expression may be one of the genetic events that facilitated exploitation of the conjunctivae as a new niche. PMID:12453222

Kilian, Mogens; Poulsen, Knud; Lomholt, Hans

2002-12-01

368

Differential responses of the promoters from nearly identical paralogs of loblolly pine ( Pinus taeda L.) ACC oxidase to biotic and abiotic stresses in transgenic Arabidopsis thaliana  

Microsoft Academic Search

Promoters from an ACC oxidase gene (PtACO1) and its nearly identical paralog (NIP) (PtACO2) of loblolly pine (Pinus taeda L.) were recovered from genomic DNA using PCR amplification. Transgenic Arabidopsis plants harboring genetic constructs from which ?-glucuronidase (GUS) expression was driven by the full-length (pACO1:GUS, pACO2:GUS) or truncated (pACO1-1.2:GUS, pACO2-1.2:GUS) loblolly pine ACC oxidase gene promoters displayed distinctive patterns of

Shenghua Yuan; Jeffrey F. D. Dean

2010-01-01

369

Evaluation of Still Picture Telephone for Mentally Retarded Persons. Telematics and Mental Retardation.  

ERIC Educational Resources Information Center

This study examined the benefit of using a visual telecommunication system for Sweden's children and adults with mild to moderate mental retardation and speech difficulties. The Panasonic Image Communication Unit connects to standard modular telephones and includes a camera and monitor for the transfer of pictures. Units were placed in eight…

Brodin, Jane; Bjorck-Akesson, Eva

370

Sexual Knowledge and Attitudes of Institutionalized and Noninstitutionalized Retarded Adolescents  

ERIC Educational Resources Information Center

Sixty-one noninstitutionalized and 61 institutionalized educable mentally retarded adolescents were psychometrically assessed on three measures: sexual knowledge, sexual attitudes, and self-concept. (Author)

Hall, Judy E.; Morris, Helen L.

1976-01-01

371

Rotatable broadband retarders for far infrared spectroscopic ellipsometry  

SciTech Connect

Rotatable retarders have been developed for applications in spectroscopic, full Mueller Matrix ellipsometry in the far-IR spectral range. Several materials, such as silicon, KRS-5, and a commercial polymer plastic (TOPAS) have been utilized to achieve a fully adjustable retardation between 0{sup o} and 90{sup o}. Experimental characteristics of the rotatable retarders that utilize three- and four-bounce designs are compared with calculations. We discuss the effect of light focusing on the performance of these rotatable retarders. Broadband optical retarders are required for spectroscopic ellipsometry in its full Mueller matrix (MM) realization. Performance of the MM ellipsometer depends on the capability to produce substantially linearly-independent Stokes vectors for the light incident onto the sample. As has been shown, the errors in the measuredMMof the sample are proportional to the condition number of the 4 x 4 matrix composed of the Stokes vectors of four polarization states incident at the sample. It can be proven that it is impossible to cover the Poincare sphere with linearly-independent Stokes vectors by only changing the linear polarization at the input surface of a stationary retarder. As we will illustrate further in this paper, total coverage of the Poincare sphere is possible by rotating a tandem of a linear polarizer and a retarder with a retardation of 90{sup o}. It is this goal that we are trying to achieve in the retarder designs described in this paper.

Kang, T.D.; Carr, G.; Zhou, T.; Kotelyanskii, M.; Sirenko, A.A.

2010-12-09

372

Fire-retardant decorative inks for aircraft interiors  

NASA Technical Reports Server (NTRS)

Commercial and experimental fire retardants were screened for possible use wiith acrylic printing inks on aircraft interior sandwich panels. The fire retardants were selected according to their physical properties and thermostabilities. Thermostabilities were determined by thermogravimetric analysis and differential scanning calorimetry. A criterion was then established for selecting the more stable agent. Results show that some of the bromine-containing fire retardants are more thermostable than the acrylic ink, alone, used as a control. Also, the bromine-containing fire retardants yield even better limiting oxygen index values when tested after adding carboxy-terminated butadiene acrylonitrile (CTBN) rubber.

Nir, Z.; Mikroyannidis, J. A.; Kourtides, D. A.

1984-01-01

373

Psychomotor retardation in depression: Biological underpinnings, measurement, and treatment  

PubMed Central

Psychomotor retardation is a long established component of depression that can have significant clinical and therapeutic implications for treatment. Due to its negative impact on overall function in depressed patients, we review its biological correlates, optimal methods of measurement, and relevance in the context of therapeutic interventions. The aim of the paper is to provide a synthesis of the literature on psychomotor retardation in depression with the goal of enhanced awareness for clinicians and researchers. Increased knowledge and understanding of psychomotor retardation in major depressive disorder may lead to further research and better informed diagnosis in regards to psychomotor retardation. Manifestations of psychomotor retardation include slowed speech, decreased movement, and impaired cognitive function. It is common in patients with melancholic depression and those with psychotic features. Biological correlates may include abnormalities in the basal ganglia and dopaminergic pathways. Neurophysiologic tools such as neuroimaging and transcranial magnetic stimulation may play a role in the study of this symptom in the future. At present, there are three objective scales to evaluate psychomotor retardation severity. Studies examining the impact of psychomotor retardation on clinical outcome have found differential results. However, available evidence suggests that depressed patients with psychomotor retardation may respond well to electroconvulsive therapy (ECT). Current literature regarding antidepressants is inconclusive, though tricyclic antidepressants may be considered for treatment of patients with psychomotor retardation. Future work examining this objective aspect of major depressive disorder (MDD) is essential. This could further elucidate the biological underpinnings of depression and optimize its treatment. PMID:21044654

Buyukdura, Jeylan S.; McClintock, Shawn M.; Croarkin, Paul E.

2013-01-01

374

Protein  

MedlinePLUS

... juvenile or insulin-dependent diabetes), proteins found in cow’s milk have been implicated in the development of ... O., et al., Removal of Bovine Insulin From Cow’s Milk Formula and Early Initiation of Beta-Cell ...

375

Calcium-sensing mechanism in TRPC5 channels contributing to retardation of neurite outgrowth.  

PubMed

The calcium- and sodium-permeable transient receptor potential channel TRPC5 has an inhibitory role in neuronal outgrowth but the mechanisms governing its activity are poorly understood. Here we propose a mechanism involving the neuronal calcium sensor-1 (NCS-1) protein. Inhibitory mutants of TRPC5 and NCS-1 enhance neurite outgrowth similarly. Mutant NCS-1 does not inhibit surface-expression of TRPC5 but generally suppresses channel activity, irrespective of whether it is evoked by carbachol, store depletion, lanthanides or elevated intracellular calcium. NCS-1 and TRPC5 are in the same protein complex in rat brain and NCS-1 directly binds to the TRPC5 C-terminus. The data suggest protein-protein interaction between NCS-1 and TRPC5, and involvement of this protein complex in retardation of neurite outgrowth. PMID:16469785

Hui, Hui; McHugh, Damian; Hannan, Meredith; Zeng, Fanning; Xu, Shang-Zhong; Khan, Saeed-Ul-Hassan; Levenson, Robert; Beech, David J; Weiss, Jamie L

2006-04-01

376

Loss of Zona Pellucida Binding Proteins in the Acrosomal Matrix Disrupts Acrosome Biogenesis and Sperm Morphogenesis  

Microsoft Academic Search

Zona pellucida binding protein 1 (ZPBP1), a spermatid and spermatozoon protein that localizes to the acrosome, was originally identified in pigs and named for its binding to the oocyte zona pellucida. In an in silico search for germ cell-specific genes, Zpbp1 and its novel paralog, Zpbp2, were discovered and confirmed to be expressed only in the testes in both mice

Yi-Nan Lin; Angshumoy Roy; Wei Yan; Kathleen H. Burns; Martin M. Matzuk

2007-01-01

377

Nabumetone Induces Less Gastrointestinal Mucosal Changes Than Diclofenac Retard  

Microsoft Academic Search

The aim of the study was to compare the efficacy and the effects on the mucosa of the gastrointestinal tract (GIT) of nabumetone and diclofenac retard in patients with osteoarthritis (OA). An open, multicentre, randomised, comparative, endoscopy-blind parallel group study included 201 patients with nabumetone and 193 patients with diclofenac retard suffering from moderate to severe OA of the knee

R. Be?vá?; Z. Urbanová; V. Vlasáková; J. Vítová; I. Rybár; H. Maldyk; A. Filipowicz-Sosnowska; K. Bernacka; S. Mackiewicz; B. Gömör; B. Rojkovich; B. Siro; J. Bereczki; K. Toth; S. Sukenik; L. Green; M. Ehrenfeld; K. Pavelka

1999-01-01

378

Community Care for People with Mental Retardation in the Netherlands.  

ERIC Educational Resources Information Center

Services for people with mental retardation in the Netherlands are examined, with emphasis on normalization, placement options including group homes and institutionalization, guidance for families through the Social Pedological Service, and the care of mental illness in mentally retarded persons through special diagnostic and treatment centers.…

Dosen, Anton

1988-01-01

379

Third International Conference on Environmentally Friendly Fire-Retardant Systems  

Microsoft Academic Search

The Third International Conference on Fire Retardancy of Polymeric Materials was held in Atlanta, Georgia, USA, on December 7–8, 1993. The conference focused upon the latest developments in zero- and lowhalogen additives and polymers used to minimize flammability, smoke, fume, and toxicity problems. This was an intensive and executive-level meeting for compounders and technical specialists using fire retardants (FR) in

G. E. Zaikov; A. Ya. Polishchuk

1995-01-01

380

Novel phosphonates triazine derivative as economic flame retardant for cotton  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phosphorous-containing flame retardants are widely used in standard and engineering plastics, polyurethane foams, thermosets, coatings, and textiles. Organophosphorous flame retardants have been known to be more effective when used in conjunction with nitrogen-containing systems. Their mixture produ...

381

Schools for the Mentally Retarded in a Labour Market Perspective  

Microsoft Academic Search

This study examines explanations and conceptions among teachers and parents of the mentally retarded as well as supervisors and representatives of the employers at supervised work training places of the fact that only few of the students from vocational schools for the mentally retarded in Sweden can find employment within the ordinary labour market without subsidies from the state. The

Jerry Rosenqvist

1990-01-01

382

Flame retardant antibacterial cotton high-loft nonwoven fabrics  

Technology Transfer Automated Retrieval System (TEKTRAN)

Flame retardant treated gray cotton fibers were blended with antibacterial treated gray cotton fibers and polyester/polyester sheath/core bicomponent fibers to form high-loft fabrics. The high flame retardancy (FR) and antibacterial property of these high lofts were evaluated by limiting oxygen inde...

383

Cone calorimeter evaluation of two flame retardant cotton fabrics  

Technology Transfer Automated Retrieval System (TEKTRAN)

Unbleached (grey) cotton needle punched nonwoven (NW) fabrics with 12.5% polypropylene scrim were treated with two phosphate-nitrogen based fire-retardant (FR) formulations, SRRC-1 and SRRC-2. The SRRC-1 formulation contains diammonium phosphate as the flame retardant chemical along with urea and d...

384

Anaerobic degradation of brominated flame retardants in sewage sludge  

Microsoft Academic Search

Tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), and decabromodiphenyl ether (DecaBDE) are high production volume chemicals used as flame retardants in plastics for products such as electronic equipment, insulation panels, and textiles. The environmental safety of brominated flame retardants, especially their persistence, bioaccumulation, and toxicity is a controversial topic. Here, we studied and compared the degradation of TBBPA, HBCD, and DecaBDE under

Andreas C. Gerecke; Walter Giger; Paul C. Hartmann; Norbert V. Heeb; Hans-Peter E. Kohler; Peter Schmid; Markus Zennegg; Martin Kohler

2006-01-01

385

Mental Retardation. Selected Articles from the Rehabilitation Record.  

ERIC Educational Resources Information Center

Presented are six articles on residential living, vocational education, employment recreation, deinstitutionalization, and workshop experience of mentally retarded children and adults. K. Grunewald discusses the planning of housing for five- to eight person groups of retarded children and adults in varying kinds of residential facilities in Sweden…

Rehabilitation Services Administration (DHEW), Washington, DC.

386

Cursorial spiders retard initial aphid population growth at low densities  

E-print Network

Cursorial spiders retard initial aphid population growth at low densities in winter wheat K technique that revealed species-specific aphid consump- tion rates with a factorial field experiment on aphid population growth. Only cursorial spiders retarded aphid population growth in our cage experiment

Illinois at Chicago, University of

387

Psychiatric Illness in Mentally Retarded Adolescents: Clinical Features.  

ERIC Educational Resources Information Center

Describes the clinical features of the most important psychiatric disorders in mentally retarded adolescents: mood disorders, psychotic disorders, severe behavioral disorders, personality disorders, anxiety disorders, and attention-deficit The impact of mental retardation on personality development is confirmed by the high psychopathological…

Masi, Gabriele

1998-01-01

388

Competence and Adjustment of Siblings of Children with Mental Retardation.  

ERIC Educational Resources Information Center

This study compared the adjustment and competence of 100 children and adolescents, half of whom were siblings of individuals with mental retardation. Although there were no overall differences for internalizing disorders, externalizing disorders, self-esteem, and competence, boys with a mentally retarded sibling had more difficulty in school…

Hannah, Mary E.; Midlarsky, Elizabeth

1999-01-01

389

Some Psychological Dimensions of Mentally Retarded Sex Offenders.  

ERIC Educational Resources Information Center

Compares 22 mentally retarded sex offenders and non-offenders on measures of hostility toward women, general hostility, self esteem, loneliness, and depression. Results indicate that mentally retarded sex offenders possess more hostility toward women than non-offenders. Discusses implications and future research. (MKA)

Gillis, Mary Annette; De Luca, Rayleen V.; Hume, Michelle; Morton, Michael; Rennpferd, Richard

1998-01-01

390

Sex between People with "Mental Retardation": An Ethical Evaluation.  

ERIC Educational Resources Information Center

Discusses the issue of whether sex between mentally retarded individuals is morally permissable, and if so, under what conditions. Argues that mutual consent has unacceptable consequences for the mentally retarded. Specifies conditions where caregivers can grant permission for sexual activity. Describes the implications for future professionals'…

Spiecker, Ben; Steutel, Jan

2002-01-01

391

Dual-polarization lidar using a liquid crystal variable retarder  

E-print Network

Dual-polarization lidar using a liquid crystal variable retarder Nathan L. Seldomridge Joseph A and characterization of a compact dual-polarization lidar that uses a liquid crystal variable retarder LCVR to discriminate between backscattered polarization states on alternate laser pulses at 30 Hz . Measurements

Shaw, Joseph A.

392

TEACHING THE MENTALLY RETARDED, A HANDBOOK FOR WARD PERSONNEL.  

ERIC Educational Resources Information Center

WRITTEN FOR ATTENDANTS, VOLUNTEERS, PROFESSIONAL PEOPLE, AND PARENTS, THIS MANUAL PRESENTS PRINCIPLES AND METHODS FOR TEACHING THE MENTALLY RETARDED TO BE AS INDEPENDENT AS POSSIBLE. THE FIRST SECTION PROVIDES GENERAL INFORMATION ON THE DEVELOPMENTAL CHARACTERISTICS OF NORMAL CHILDREN AND CONTRASTS THESE WITH SOME OF THE NEEDS OF THE RETARDED.…

BENSBERG, GERALD J.

393

New monomers for fire-retardant radiation curable polymers  

SciTech Connect

Novel photosensitive compositions are described which combine excellent UV curability and good flame-retardant properties. These compositions consist of halogenated allyl or methallyl esters, which, in combination with polythiols and photoinitiators and other additives, result in screenable liquids which can be applied to electronic circuit boards and cured with UV light to hard, fire-retardant coatings.

Kang, W.G.; Bush, R.W.; Ketley, A.D.

1983-01-01

394

Flame retardant properties of triazine phosphonates derivative with cotton fabric  

Technology Transfer Automated Retrieval System (TEKTRAN)

The flame retardant behavior of a cotton fabric treated with phosphorus-nitrogen containing triazine compound was evaluated. It was found that cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) is an excellent starting material for the preparation of phosphonates flame retardants that interacts wel...

395

Advantages of flame retardants based on nitrogen compounds  

Microsoft Academic Search

Nitrogen compounds are a small but rapidly growing group of flame retardants (FR) which are in the focus of public interest concerning environmentally friendly flame retardants. Today their main applications are melamine for polyurethane flexible foams, melamine cyanurate in nylons, melamine phosphates in polyolefines, melamine and melamine phosphates or dicyandiamide in intumescent paints, guanidine phosphates for textiles and guanidine sulfamate

H. Horacek; R. Grabner

1996-01-01

396

Services for People with Mental Retardation or Related Disabilities.  

ERIC Educational Resources Information Center

Intended as a reference for chambers of commerce, physicians, public schools, and other agencies, this directory lists services for families of people with mental retardation or related disabilities in South Carolina. First, the South Carolina Department of Mental Retardation is described, including its service system, organization, case…

South Carolina State Dept. of Mental Retardation, Columbia.

397

Reflections on a Lifetime in Human Services and Mental Retardation  

ERIC Educational Resources Information Center

The author, a life member of the American Association on Mental Retardation, has reflected on over 30 years of primary engagement in mental retardation and inventoried what he believes are certain changes for the better and for the worse that have occurred since the 1950s as well as certain things that have not changed. Some action implications…

Wolfensberger, Wolf

2011-01-01

398

Muscle Fatigue during Intermittent Exercise in Individuals with Mental Retardation  

ERIC Educational Resources Information Center

This study examined fatigue profile during intermittent exercise in 10 men with mild to moderate mental retardation (MR) and 10 men without mental retardation (C). They performed 4 x 30 s maximal knee extensions and flexions with 1-min rest on an isokinetic dynamometer. Peak torque of flexors (PTFL) and extensors (PTEX), total work (TW), and…

Zafeiridis, Andreas; Giagazoglou, Paraskevi; Dipla, Konstantina; Salonikidis, Konstantinos; Karra, Chrisanthi; Kellis, Eleftherios

2010-01-01

399

Community Involvement and Socialization among Individuals with Mental Retardation  

ERIC Educational Resources Information Center

Mental retardation, a condition characterized by significantly lower than average intellectual ability and adaptive behavior deficits, currently affects between 2% and 3% of the population. Individuals with mental retardation experience many difficulties throughout their lives, with one such difficulty being that they have few opportunities for…

Kampert, Amy L.; Goreczny, Anthony J.

2007-01-01

400

Family Problem-Solving with Children Who Have Mental Retardation  

ERIC Educational Resources Information Center

Problem-solving discussions were observed within families of children with mental retardation and multiple comparison groups (total N = 162 families). As expected, parents were more persistent and directive with their children who had mental retardation, but they also avoided negative exchanges with these children. These patterns did not spillover…

Floyd, Frank J; Harter, Kristina S. M.; Costigan, Catherine L.

2004-01-01

401

Implicit Learning in Children and Adolescents with Mental Retardation.  

ERIC Educational Resources Information Center

A study compared the implicit learning of 58 children (ages 7-14) with mental retardation and 53 controls (ages 3-8). Individuals with mental retardation modified their behavior after an implicit training procedure similar to the controls. The effect of implicit learning did not vary as a function of IQ or age. (Contains references.) (Author/CR)

Vinter, Annie; Detable, Christelle

2003-01-01

402

Adaptive Behavior Malingering in Legal Claims of Mental Retardation  

ERIC Educational Resources Information Center

In 2002, the Supreme Court ruled that it is unconstitutional to put people with mental retardation to death for capital crimes ("Atkins v. Virginia," 2002). Justice Scalia dissented, suggesting that mental retardation is a condition easy to feign. The current study examined whether participants provided with the definition of mental…

Kadlubek, Renee Marie

2012-01-01

403

Development of the Fear Survey for Adults with Mental Retardation  

ERIC Educational Resources Information Center

This paper describes the development of the fear survey for adults with mental retardation (FSAMR) and provides initial evidence of its psychometric properties. The FSAMR was designed to be sensitive to the assessment needs of individuals with mental retardation. The items were developed through open-ended interviews, a review of existing…

Ramirez, Sylvia Z.; Lukenbill, James F.

2007-01-01

404

Defining Mental Retardation and Ensuring Access to the General Curriculum.  

ERIC Educational Resources Information Center

Discussion of trends in the American Association on Mental Retardation's definition of mental retardation notes a shift toward a support paradigm and a definition stressing the interaction between a person's independent functioning and the various contexts of the person's life. The current definition is seen to promote greater access to the…

Wehmeyer, Michael L.

2003-01-01

405

Public Health Approach to the Study of Mental Retardation  

ERIC Educational Resources Information Center

We applied a public health approach to the study of mental retardation by providing a basic descriptive epidemiological analysis using a large statewide linked birth and public school record database (N = 327,831). Sociodemographic factors played a key role across all levels of mental retardation. Birthweight less than 1000 g was associated with…

Chapman, Derek A.; Scott, Keith G.; Stanton-Chapman, Tina L.

2008-01-01

406

Defining Mental Retardation: A Matter of Life or Death  

ERIC Educational Resources Information Center

Because persons with mental retardation cannot be executed for murder, the diagnosis becomes a life and death matter. The American Association on Mental Retardation (now the American Association on Intellectual and Developmental Disabilities) and other associations agree that IQ alone is an insufficient criterion and adaptive functioning also…

Lichten, William; Simon, Elliot W.

2007-01-01

407

TERMINOLOGY AND CONCEPTS IN APPRAISING THE MENTALLY RETARDED.  

ERIC Educational Resources Information Center

THE OBJECTIVE OF THIS STUDY WAS TO MINIMIZE THE VARIABILITY IN LEGAL AND EDUCATIONAL CLASSIFICATION OF THE MENTALLY RETARDED. A SYSTEMATIC REVIEW WAS MADE OF THE SEMANTIC VARIATIONS IN THE DEFINITION OF THE MENTALLY RETARDED IN TERMS OF FUNCTIONAL ADEQUACY FOR EDUCATION, TRAINING, OR CUSTODIAL CARE. THE METHOD INVOLVED THE REVIEW OF STATUTES AND…

LORGE, IRVING; AND OTHERS

408

Programs for Preventing the Causes of Mental Retardation.  

ERIC Educational Resources Information Center

This monograph, which reports findings from the New Jersey Governor's Council on the Prevention of Mental Retardation, discusses the scope of mental retardation (MR), its causes, identification of people at risk, and prevention methods. The Council cites several cost-effective prevention programs, such as vaccination programs and prenatal care…

Oliphant, Peter S.; And Others

409

Carbamazepine-Induced Hyponatremia in Patients with Mental Retardation.  

ERIC Educational Resources Information Center

This study of 40 patients with mental retardation receiving carbamazepine found hyponatremia in only 5 percent of these patients and found a statistically, but not clinically, significant decrease in serum sodium levels in patients receiving anticonvulsant polytherapy. Results support the use of this drug with patients with mental retardation and…

Kastner, Ted; And Others

1992-01-01

410

Optimization of retardance for a complete Stokes polarimeter  

SciTech Connect

The authors present two figures of merit based on singular value decomposition which can be used to assess the noise immunity of a complete Stokes polarimeter. These are used to optimize a polarimeter consisting of a rotatable retarder and fixed polarizer. A retardance of 132{degree} (approximately three eights wave) and retarder orientation angles of {+-}51.7{degree} and {+-}15.1{degree} are found to be optimal when four measurements are used. Use of this retardance affords a factor of 1.5 improvement in signal-to-noise ratio over systems employing a quarter wave plate. A geometric means of visualizing the optimization process is discussed, and the advantages of the use of additional measurements are investigated. No advantage of using retarder orientation angles spaced uniformly through 360{degree} is found over repeated measurements made at the four angles given previously.

Sabatke, D.S.; Descour, M.R.; Dereniak, E.L.; Sweatt, W.C.; Kemme, S.A.; Phipps, G.S.

2000-01-13

411

Children's Knowledge of Time and Money: Effective Instruction for the Mentally Retarded  

ERIC Educational Resources Information Center

The effectiveness of the Time and Money units (which involve language and vocabulary in teaching time and money concepts to primary level retardates) was investigated with 112 nonretarded, 133 educable mentally retarded, and 115 trainable mentally retarded children. (SBH)

Thurlow, Martha L.; Turnure, James E.

1977-01-01

412

Attitudes of Fast Food Restaurant Managers towards Hiring the Mentally Retarded: A Survey.  

ERIC Educational Resources Information Center

The majority of the managers reported some prior experience with mentally retarded persons, believed that the mentally retarded should be employed competitively, but were undecided whether they personally would employ an adequately prepared mentally retarded worker. (SW)

Gruenhagen, Kathleen A.

1982-01-01

413

White matter tract integrity and intelligence in patients with mental retardation and healthy adults  

E-print Network

White matter tract integrity and intelligence in patients with mental retardation and healthy of brain white matter tracts and intelligence in patients with mental retardation (MR) and healthy adults; Fractional anisotropy; Mental retardation; Intelligence Introduction Researchers have long attempted

Jiang,Tianzi

414

How Artificial Ontogenies Can Retard Evolution  

E-print Network

Recently there has been much interest in the role of indirect genetic encodings as a means to achieve increased evolvability. From this perspective, artificial ontogenies have largely been seen as a vehicle to relate the indirect encodings to complex phenotypes. However, the introduction of a development phase does not come without other consequences. We show that the conjunction of the latent ontogenic stucture and the common practice of only evaluating the final phenotype obtained from development can have a net retarding effect on evolution. Using a formal model of development, we show that this effect arises primarily due to the relation between the ontogenic structure to the fitness function, which in turn impacts the properties being evaluated and selected for during evolution. This effect is empirically demonstrated with a toy search problem using LOGO-turtle based embryogenic processes.

Shivakumar Viswanathan; Jordan Pollack

2005-01-01

415

Cytogenetic findings in mentally retarded Iranian patients.  

PubMed

We conducted a cytogenetic study on 865 individuals with idiopathic mental retardation (MR) who were admitted to the Cytogenetics Department of the Iran Blood Transfusion Organisation (IBTO) Research Centre, Tehran, Iran; these were performed on blood samples using conventional staining methods. Chromosome anomalies were identified in 205 of the patients (23.6%). The majority were Down's syndrome cases (n = 138). In 33 males, a positive fragile X anomaly was found. The remainder (n = 34) had other chromosomal abnormalities including structural chromosome aberrations (n = 23), marker chromosomes with an unknown origin (n = 3), sex chromosome aneuploidy (n = 6) and trisomy 18 (n = 2). The contribution of chromosome aberrations to the cause of MR in this group of patients is discussed. PMID:24052729

Nasiri, F; Mahjoubi, F; Manouchehry, F; Razazian, F; Mortezapour, F; Rahnama, M

2012-12-01

416

Early growth retardation in diabetic pregnancy.  

PubMed Central

Thirty-five insulin-dependent diabetic women with reliable menstrual histories were examined by ultrasonic scanning in the 7th-14th weeks of pregnancy. Judged from crown-to-rump length the fetuses were on average 5.4 days smaller than those in a local normal series. Ten of the fetuses were nine days or more smaller than normal and had a lower mean birth weight than the others, though the mean gestational age was similar. Maternal diabetes was not more severe in this group, but only two of the mothers had attended a special hospital for control of their disease as compared with 19 of the remainder. Although babies of diabetic mothers are often overweight, there appears to be a subgroup of cases in which fetal growth is retarded early in pregnancy, leading to low birth weight and possibly a higher incidence of congenital malformations. PMID:760936

Pedersen, J F; Mølsted-Pedersen, L

1979-01-01

417

Highly accurate spectral retardance characterization of a liquid crystal retarder including Fabry-Perot interference effects  

SciTech Connect

Multiple-beam Fabry-Perot (FP) interferences occur in liquid crystal retarders (LCR) devoid of an antireflective coating. In this work, a highly accurate method to obtain the spectral retardance of such devices is presented. On the basis of a simple model of the LCR that includes FP effects and by using a voltage transfer function, we show how the FP features in the transmission spectrum can be used to accurately retrieve the ordinary and extraordinary spectral phase delays, and the voltage dependence of the latter. As a consequence, the modulation characteristics of the device are fully determined with high accuracy by means of a few off-state physical parameters which are wavelength-dependent, and a single voltage transfer function that is valid within the spectral range of characterization.

Vargas, Asticio [Departamento de Ciencias Físicas, Universidad de La Frontera, Temuco (Chile); Center for Optics and Photonics, Universidad de Concepción, Casilla 4016, Concepción (Chile); Mar Sánchez-López, María del [Instituto de Bioingeniería, Universidad Miguel Hernández, 03202 Elche (Spain); García-Martínez, Pascuala [Departament d'Òptica, Universitat de València, 45100 Burjassot (Spain); Arias, Julia; Moreno, Ignacio [Departamento de Ciencia de Materiales, Óptica y Tecnología Electrónica, Universidad Miguel Hernández, 03202 Elche (Spain)

2014-01-21

418

Multiple Co-Evolutionary Networks Are Supported by the Common Tertiary Scaffold of the LacI/GalR Proteins  

PubMed Central

Protein families might evolve paralogous functions on their common tertiary scaffold in two ways. First, the locations of functionally-important sites might be “hard-wired” into the structure, with novel functions evolved by altering the amino acid (e.g. Ala vs Ser) at these positions. Alternatively, the tertiary scaffold might be adaptable, accommodating a unique set of functionally important sites for each paralogous function. To discriminate between these possibilities, we compared the set of functionally important sites in the six largest paralogous subfamilies of the LacI/GalR transcription repressor family. LacI/GalR paralogs share a common tertiary structure, but have low sequence identity (?30%), and regulate a variety of metabolic processes. Functionally important positions were identified by conservation and co-evolutionary sequence analyses. Results showed that conserved positions use a mixture of the “hard-wired” and “accommodating” scaffold frameworks, but that the co-evolution networks were highly dissimilar between any pair of subfamilies. Therefore, the tertiary structure can accommodate multiple networks of functionally important positions. This possibility should be included when designing and interpreting sequence analyses of other protein families. Software implementing conservation and co-evolution analyses is available at https://sourceforge.net/projects/coevolutils/. PMID:24391951

Parente, Daniel J.; Swint-Kruse, Liskin

2013-01-01

419

Study on preparation and fire-retardant mechanism analysis of intumescent flame-retardant coatings  

Microsoft Academic Search

An intumescent flame-retardant coating was prepared by unsaturated polyester resin and epoxy resin as two-component matrix resins, ammonium polyphosphate (APP) as acid source, melamine (Mel) as the blowing agent and pentaerythritol (PER) as carbon agent, expandable graphite as synergistic agent, adding titanium dioxide (TiO2), solvent and other assistants. Results showed that such a coating had excellent physical–chemical properties. When the

Jun-wei Gu; Guang-cheng Zhang; Shan-lai Dong; Qiu-yu Zhang; Jie Kong

2007-01-01

420

Correlated structural kinetics and retarded solvent dynamics at the metalloprotease active site  

PubMed Central

Solvent dynamics can play a major role in enzyme activity, but obtaining an accurate, quantitative picture of solvent activity during catalysis is quite challenging. Here, we combine terahertz spectroscopy and X-ray absorption analyses to measure changes in the coupled water-protein motions during peptide hydrolysis by a zinc-dependent human metalloprotease. These changes were tightly correlated with rearrangements at the active site during the formation of productive enzyme-substrate intermediates and were different from those in an enzyme–inhibitor complex. Molecular dynamics simulations showed a steep gradient of fast-to-slow coupled protein-water motions around the protein, active site and substrate. Our results show that water retardation occurs before formation of the functional Michaelis complex. We propose that the observed gradient of coupled protein-water motions may assist enzyme-substrate interactions through water-polarizing mechanisms that are remotely mediated by the catalytic metal ion and the enzyme active site. PMID:21926991

Grossman, Moran; Born, Benjamin; Heyden, Matthias; Tworowski, Dmitry; Fields, Gregg B; Sagi, Irit; Havenith, Martina

2012-01-01

421

Analysis of the Criminal Justice Personnels' (Police, Lawyers, Judges) Understanding of Mental Retardation and of the Mentally Retarded Offender.  

ERIC Educational Resources Information Center

The study involving 100 police officers, 75 lawyers, and 35 judges was designed to investigate and analyze the criminal justice system (CJS) personnel's understanding of mental retardation and the mentally retarded (MR) offender. Among findings obtained from responses to questionnaires were the following: 65% of the respondents indicated they…

Schilit, Jeffrey

422

Robo4 vaccines induce antibodies that retard tumor growth.  

PubMed

Tumor endothelial specific expression of Robo4 in adults identifies this plasma membrane protein as an anti-cancer target for immunotherapeutic approaches, such as vaccination. In this report, we describe how vaccination against Robo4 inhibits angiogenesis and tumor growth. To break tolerance to the auto-antigen Robo4, mice were immunised with the extracellular domain of mouse Robo4, fused to the Fc domain of human immunoglobulin within an adjuvant. Vaccinated mice show a strong antibody response to Robo4, with no objectively detectable adverse effects on health. Robo4 vaccinated mice showed impaired fibrovascular invasion and angiogenesis in a rodent sponge implantation assay, as well as a reduced growth of implanted syngeneic Lewis lung carcinoma. The anti-tumor effect of Robo4 vaccination was present in CD8 deficient mice but absent in B cell or IgG1 knockout mice, suggesting antibody dependent cell mediated cytotoxicity as the anti-vascular/anti-tumor mechanism. Finally, we show that an adjuvant free soluble Robo4-carrier conjugate can retard tumor growth in carrier primed mice. These results point to appropriate Robo4 conjugates as potential anti-angiogenic vaccines for cancer patients. PMID:25348086

Zhuang, Xiaodong; Ahmed, Forhad; Zhang, Yang; Ferguson, Henry J; Steele, Jane C; Steven, Neil M; Nagy, Zsuzsanna; Heath, Victoria L; Toellner, Kai-Michael; Bicknell, Roy

2015-01-01

423

[Update on the genetics of X-linked mental retardation].  

PubMed

Mutations in X-linked genes are likely to account for the observation that more males than females are affected with mental retardation. Causative mutations have been identified in both syndromic XLMR and in the genetically heterogeneous non-syndromic forms of XLMR, without a clear clinical phenotype other than cognitive deficit. Progress in genome analysis and the establishment of large collaborations between clinical and molecular research teams, especially the European XLMR consortium, have led to the identification of 20 non-syndromic XLMR genes and 25 syndromic XLMR genes. Given the extensive heterogeneity of non syndromic XLMR, different strategies are used for the identification of new genes: linkage analysis, studies of balanced chromosomal rearrangements (X-autosome translocations, microdeletions) and candidate genes strategies by mutation screening in regions of the X chromosome known to be involved in neuronal development and function. Delineating the monogenic causes of XLMR and their molecular and cellular consequences will provide insight into the mechanisms that are required for normal development of cognitive function in humans. Non syndromic XLMR proteins include 5 distinct classes: transmembrane receptors, small GTPases effectors or regulators, enzymes and translational regulators. PMID:17028563

Bahi-Buisson, N; Chelly, J; des Portes, V

2006-10-01

424

40 CFR 201.26 - Procedures for the measurement on receiving property of retarder and car coupling noise.  

Code of Federal Regulations, 2014 CFR

...measurement on receiving property of retarder and car coupling noise. 201.26 Section 201...measurement on receiving property of retarder and car coupling noise. (a) Retarders ...Ladj ave max ) for retarders. (b) Car coupling impact —(1)...

2014-07-01

425

40 CFR 201.26 - Procedures for the measurement on receiving property of retarder and car coupling noise.  

Code of Federal Regulations, 2013 CFR

...measurement on receiving property of retarder and car coupling noise. 201.26 Section 201...measurement on receiving property of retarder and car coupling noise. (a) Retarders ...Ladj ave max ) for retarders. (b) Car coupling impact —(1)...

2013-07-01

426

40 CFR 201.26 - Procedures for the measurement on receiving property of retarder and car coupling noise.  

Code of Federal Regulations, 2012 CFR

...measurement on receiving property of retarder and car coupling noise. 201.26 Section 201...measurement on receiving property of retarder and car coupling noise. (a) Retarders ...Ladj ave max ) for retarders. (b) Car coupling impact —(1)...

2012-07-01

427

40 CFR 201.26 - Procedures for the measurement on receiving property of retarder and car coupling noise.  

Code of Federal Regulations, 2011 CFR

...measurement on receiving property of retarder and car coupling noise. 201.26 Section 201...measurement on receiving property of retarder and car coupling noise. (a) Retarders ...Ladj ave max ) for retarders. (b) Car coupling impact —(1)...

2011-07-01

428

Flame Retardant Applications in Camping Tents and Potential Exposure  

PubMed Central

Concern has mounted over health effects caused by exposure to flame retardant additives used in consumer products. Significant research efforts have focused particularly on exposure to polybrominated diphenyl ethers (PBDEs) used in furniture and electronic applications. However, little attention has focused on applications in textiles, particularly textiles meeting a flammability standard known as CPAI-84. In this study, we investigated flame retardant applications in camping tents that met CPAI-84 standards by analyzing 11 samples of tent fabrics for chemical flame retardant additives. Furthermore, we investigated potential exposure by collecting paired samples of tent wipes and hand wipes from 27 individuals after tent setup. Of the 11 fabric samples analyzed, 10 contained flame retardant additives, which included tris(1,3-dichloroisopropyl) phosphate (TDCPP), decabromodiphenyl ether (BDE-209), triphenyl phosphate, and tetrabromobisphenol-A. Flame retardant concentrations were discovered to be as high as 37.5 mg/g (3.8% by weight) in the tent fabric samples, and TDCPP and BDE-209 were the most frequently detected in these samples. We also observed a significant association between TDCPP levels in tent wipes and those in paired hand wipes, suggesting that human contact with the tent fabric material leads to the transfer of the flame retardant to the skin surface and human exposure. These results suggest that direct contact with flame retardant-treated textiles may be a source of exposure. Future studies will be needed to better characterize exposure, including via inhalation and dermal sorption from air. PMID:24804279

2015-01-01

429

Flame Retardant Applications in Camping Tents and Potential Exposure.  

PubMed

Concern has mounted over health effects caused by exposure to flame retardant additives used in consumer products. Significant research efforts have focused particularly on exposure to polybrominated diphenyl ethers (PBDEs) used in furniture and electronic applications. However, little attention has focused on applications in textiles, particularly textiles meeting a flammability standard known as CPAI-84. In this study, we investigated flame retardant applications in camping tents that met CPAI-84 standards by analyzing 11 samples of tent fabrics for chemical flame retardant additives. Furthermore, we investigated potential exposure by collecting paired samples of tent wipes and hand wipes from 27 individuals after tent setup. Of the 11 fabric samples analyzed, 10 contained flame retardant additives, which included tris(1,3-dichloroisopropyl) phosphate (TDCPP), decabromodiphenyl ether (BDE-209), triphenyl phosphate, and tetrabromobisphenol-A. Flame retardant concentrations were discovered to be as high as 37.5 mg/g (3.8% by weight) in the tent fabric samples, and TDCPP and BDE-209 were the most frequently detected in these samples. We also observed a significant association between TDCPP levels in tent wipes and those in paired hand wipes, suggesting that human contact with the tent fabric material leads to the transfer of the flame retardant to the skin surface and human exposure. These results suggest that direct contact with flame retardant-treated textiles may be a source of exposure. Future studies will be needed to better characterize exposure, including via inhalation and dermal sorption from air. PMID:24804279

Keller, Alexander S; Raju, Nikhilesh P; Webster, Thomas F; Stapleton, Heather M

2014-02-11

430

Complex Formation by the Human Rad51B and Rad51C DNA Repair Proteins and Their Activities in Vitro*  

E-print Network

Complex Formation by the Human Rad51B and Rad51C DNA Repair Proteins and Their Activities in Vitro. In addition to Rad51 pro- tein, five paralogs have been identified: Rad51B/ Rad51L1, Rad51C/Rad51L2, Rad51D-(His)6, and Rad51C proteins were individually expressed employ- ing the baculovirus system, and each

Kowalczykowski, Stephen C.

431

Contrasting, Species-Dependent Modulation of Copper-Mediated Neurotoxicity by the Alzheimer's Disease Amyloid Precursor Protein  

Microsoft Academic Search

The amyloid precursor protein (APP) of Alzheimer's disease (AD) has a copper binding domain (CuBD) located in the N-terminal cysteine-rich region that can strongly bind copper(II) and reduce it to Cu(I) in vitro. The CuBD sequence is similar among the APP family paralogs (amyloid precursor-like proteins (APLP1 and APLP2)) and its orthologs (including Drosophila melanogaster, Xenopus laevis, and Caenorhabditis elegans),

Anthony R. White; Gerd Multhaup; Denise Galatis; William J. McKinstry; Michael W. Parker; Rudiger Pipkorn; Konrad Beyreuther; Colin L. Masters; Roberto Cappai

2002-01-01

432

Synergistic effect between polyhedral oligomeric silsesquioxane and flame retardants  

NASA Astrophysics Data System (ADS)

Synergistic effect was observed between two types of flame retardant and two types of polyhedral oligomeric silsesquioxanes (POSS). The polymer matrix was represented by low density polyethylene Bralen RB 2-62 (Slovnaft). The polyethylene was mixed with nanofillers OctaIsobutyl POSS and TriSilanolIsobutyl POSS. The flame retardants was represented by ADK STAB® FP 2200 and Exolite® APP 722. The flammability was investigated by UL-94 test. The results showed that the APP/POSS system had important flame retardant and anti-dripping abilities for LDPE.

Safarikova, B.; Kalendova, A.; Habrova, V.; Zatloukalova, S.; Machovsky, M.

2014-05-01

433

Stokes polarimetry using analysis of the nonlinear voltage-retardance relationship for liquid-crystal variable retarders  

NASA Astrophysics Data System (ADS)

We present a method for using liquid-crystal variable retarders (LCVR's) with continually varying voltage to measure the Stokes vector of a light beam. The LCVR's are usually employed with fixed retardance values due to the nonlinear voltage-retardance behavior that they show. The nonlinear voltage-retardance relationship is first measured and then a linear fit of the known retardance terms to the detected signal is performed. We use known waveplates (half-wave and quarter-wave) as devices to provide controlled polarization states to the Stokes polarimeter and we use the measured Stokes parameters as functions of the orientation of the axes of the waveplates as an indication of the quality of the polarimeter. Results are compared to a Fourier analysis method that does not take into account the nonlinear voltage-retardance relationship and also to a Fourier analysis method that uses experimental voltage values to give a linear retardance function with time. Also, we present results of simulations for comparison.

López-Téllez, J. M.; Bruce, N. C.

2014-03-01

434

Stokes polarimetry using analysis of the nonlinear voltage-retardance relationship for liquid-crystal variable retarders  

SciTech Connect

We present a method for using liquid-crystal variable retarders (LCVR’s) with continually varying voltage to measure the Stokes vector of a light beam. The LCVR's are usually employed with fixed retardance values due to the nonlinear voltage-retardance behavior that they show. The nonlinear voltage-retardance relationship is first measured and then a linear fit of the known retardance terms to the detected signal is performed. We use known waveplates (half-wave and quarter-wave) as devices to provide controlled polarization states to the Stokes polarimeter and we use the measured Stokes parameters as functions of the orientation of the axes of the waveplates as an indication of the quality of the polarimeter. Results are compared to a Fourier analysis method that does not take into account the nonlinear voltage-retardance relationship and also to a Fourier analysis method that uses experimental voltage values to give a linear retardance function with time. Also, we present results of simulations for comparison.

López-Téllez, J. M., E-mail: jmlopez@comunidad.unam.mx; Bruce, N. C. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, Apdo. Postal 70-186, México D.F., 04510 (Mexico)] [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, Apdo. Postal 70-186, México D.F., 04510 (Mexico)

2014-03-15

435

Sentra, a database of signal transduction proteins.  

SciTech Connect

Sentra (http://www-wit.mcs.anl.gov/sentra) is a database of signal transduction proteins with the emphasis on microbial signal transduction. The database was updated to include classes of signal transduction systems modulated by either phosphorylation or methylation reactions such as PAS proteins and serine/threonine kinases, as well as the classical two-component histidine kinases and methyl-accepting chemotaxis proteins. Currently, Sentra contains signal transduction proteins from 43 completely sequenced prokaryotic genomes as well as sequences from SWISS-PROT and TrEMBL. Signal transduction proteins are annotated with information describing conserved domains, paralogous and orthologous sequences, and conserved chromosomal gene clusters. The newly developed user interface supports flexible search capabilities and extensive visualization of the data.

Maltsev, N.; Marland, E.; Yu, G. X.; Bhatnagar, S.; Lusk, R.; Mathematics and Computer Science

2002-01-01

436

Brominated flame retardant exposure of aircraft personnel.  

PubMed

The use of brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) in aircraft is the result of high fire safety demands. Personnel working in or with aircraft might therefore be exposed to several BFRs. Previous studies have reported PBDE exposure in flight attendants and in passengers. One other group that may be subjected to significant BFR exposure via inhalation, are the aircraft maintenance workers. Personnel exposure both during flights and maintenance of aircraft, are investigated in the present study. Several BFRs were present in air and dust sampled during both the exposure scenarios; PBDEs, hexabromocyclododecane (HBCDD), decabromodiphenyl ethane (DBDPE) and 1,2-bis (2,4,6-tribromophenoxy) ethane. PBDEs were also analyzed in serum from pilots/cabin crew, maintenance workers and from a control group of individuals without any occupational aircraft exposure. Significantly higher concentrations of PBDEs were found in maintenance workers compared to pilots/cabin crew and control subjects with median total PBDE concentrations of 19, 6.8 and 6.6 pmol g(-1) lipids, respectively. Pilots and cabin crew had similar concentrations of most PBDEs as the control group, except for BDE-153 and BDE-154 which were significantly higher. Results indicate higher concentrations among some of the pilots compared to the cabin crew. It is however, evident that the cabin personnel have lower BFR exposures compared to maintenance workers that are exposed to such a degree that their blood levels are significantly different from the control group. PMID:24745557

Strid, Anna; Smedje, Greta; Athanassiadis, Ioannis; Lindgren, Torsten; Lundgren, Håkan; Jakobsson, Kristina; Bergman, Åke

2014-12-01

437

Psychomotor Retardation in Elderly Untreated Depressed Patients  

PubMed Central

Background: Psychomotor retardation (PR) is one of the core features in depression according to DSM V (1), but also aging in itself causes cognitive and psychomotor slowing. This is the first study investigating PR in relation to cognitive functioning and to the concomitant effect of depression and aging in a geriatric population ruling out contending effects of psychotropic medication. Methods: A group of 28 non-demented depressed elderly is compared to a matched control group of 20 healthy elderly. All participants underwent a test battery containing clinical depression measures, cognitive measures of processing speed, executive function and memory, clinical ratings of PR, and objective computerized fine motor skill-tests. Statistical analysis consisted of a General Linear Method multivariate analysis of variance to compare the clinical, cognitive, and psychomotor outcomes of the two groups. Results: Patients performed worse on all clinical, cognitive, and PR measures. Both groups showed an effect of cognitive load on fine motor function but the influence was significantly larger for patients than for healthy elderly except for the initiation time. Limitations: Due to the restrictive inclusion criteria, only a relatively limited sample size could be obtained. Conclusion: With a medication free sample, an additive effect of depression and aging on cognition and PR in geriatric patients was found. As this effect was independent of demand of effort (by varying the cognitive load), it was apparently not a motivational slowing effect of depression.

Beheydt, Lieve Lia; Schrijvers, Didier; Docx, Lise; Bouckaert, Filip; Hulstijn, Wouter; Sabbe, Bernard

2015-01-01

438

Retarded hydrodynamic properties of fractal clusters.  

PubMed

Fractal clusters are commonly encountered when working with the stability and the aggregation of colloidal suspensions. In spite of the number of studies that have focused on their stationary hydrodynamic properties, no information is currently known on their retarded hydrodynamic properties. The objective of this work is to close this gap. Clusters with a broad range of fractal dimension values, generated via Monte-Carlo simulations have been analyzed. A rigorous model based on multipole expansion of time-dependent Stokes equations has been developed, and then the full cluster resistance matrix as a function of the frequency has been computed. An attempt has been made to extend Basset, Boussinesque and Oseen equations to fractal clusters, but it was found that the corresponding hydrodynamic radius needs to be a function of frequency. In the case of translational motion, the cluster hydrodynamic radius loses any structural information at high frequencies, becoming independent of the fractal dimension, but depending only on its mass. A simplified model, based on an extension of Kirkwood-Rieseman approach has also been developed. This allows one to perform calculations for clusters with arbitrary masses and fractal dimensions, with good accuracy and very low computational time. It is the first time that the frequency dependence of hydrodynamic properties of complex non-spherical objects has been investigated. PMID:24935184

Lattuada, Marco

2014-09-01

439

Fire retardant effects of polymer nanocomposites.  

PubMed

Among the many and varied applications of nanotechnology, the dispersion of nanoscopic fillers to form polymer nanocomposites with improved fire behaviour illustrates the potential and diversity of nanoscience. Different polymers decompose in different ways and fire retardants act to inhibit the decomposition or flaming combustion processes. Polymer nanocomposites form barriers between the fuel and air, reducing the rate of burning, but beyond that there is little consistency in their effects. It is shown that the decomposition products of polypropylene are changed by the presence of nanoclay, although there is only a small influence on the mass loss rate. The rheological properties of molten polymer nanocomposites are radically different from those of virgin polymers, and these will profoundly affect the heat transfer through the material, resulting in a shorter time to ignition and lower peak in the heat release rate, typical of polymer nanocomposites. The dispersion of nanofillers within polymers is generally measured in the cold polymer, but since this does not reflect the condition at the time of ignition, it is proposed that temperature ramped rheological measurements are more appropriate indicators of dispersion. The influence of polymer nanocomposite formation on the yields of toxic products from fire is studied using the ISO 19700 steady state tube furnace, and it is found that under early stages of burning more carbon monoxide and organoirritants are formed, but under the more toxic under-ventilated conditions, less toxic products are formed. PMID:19916477

Hull, T Richard; Stec, Anna A; Nazare, Shonali

2009-07-01

440

Consequences of Lineage-Specific Gene Loss on Functional Evolution of Surviving Paralogs: ALDH1A and Retinoic Acid Signaling in Vertebrate Genomes  

PubMed Central

Genome duplications increase genetic diversity and may facilitate the evolution of gene subfunctions. Little attention, however, has focused on the evolutionary impact of lineage-specific gene loss. Here, we show that identifying lineage-specific gene loss after genome duplication is important for understanding the evolution of gene subfunctions in surviving paralogs and for improving functional connectivity among human and model organism genomes. We examine the general principles of gene loss following duplication, coupled with expression analysis of the retinaldehyde dehydrogenase Aldh1a gene family during retinoic acid signaling in eye development as a case study. Humans have three ALDH1A genes, but teleosts have just one or two. We used comparative genomics and conserved syntenies to identify loss of ohnologs (paralogs derived from genome duplication) and to clarify uncertain phylogenies. Analysis showed that Aldh1a1 and Aldh1a2 form a clade that is sister to Aldh1a3-related genes. Genome comparisons showed secondarily loss of aldh1a1 in teleosts, revealing that Aldh1a1 is not a tetrapod innovation and that aldh1a3 was recently lost in medaka, making it the first known vertebrate with a single aldh1a gene. Interestingly, results revealed asymmetric distribution of surviving ohnologs between co-orthologous teleost chromosome segments, suggesting that local genome architecture can influence ohnolog survival. We propose a model that reconstructs the chromosomal history of the Aldh1a family in the ancestral vertebrate genome, coupled with the evolution of gene functions in surviving Aldh1a ohnologs after R1, R2, and R3 genome duplications. Results provide evidence for early subfunctionalization and late subfunction-partitioning and suggest a mechanistic model based on altered regulation leading to heterochronic gene expression to explain the acquisition or modification of subfunctions by surviving ohnologs that preserve unaltered ancestral developmental programs in the face of gene loss. PMID:19478994

Cañestro, Cristian; Catchen, Julian M.; Rodríguez-Marí, Adriana; Yokoi, Hayato; Postlethwait, John H.

2009-01-01

441

Consequences of lineage-specific gene loss on functional evolution of surviving paralogs: ALDH1A and retinoic acid signaling in vertebrate genomes.  

PubMed

Genome duplications increase genetic diversity and may facilitate the evolution of gene subfunctions. Little attention, however, has focused on the evolutionary impact of lineage-specific gene loss. Here, we show that identifying lineage-specific gene loss after genome duplication is important for understanding the evolution of gene subfunctions in surviving paralogs and for improving functional connectivity among human and model organism genomes. We examine the general principles of gene loss following duplication, coupled with expression analysis of the retinaldehyde dehydrogenase Aldh1a gene family during retinoic acid signaling in eye development as a case study. Humans have three ALDH1A genes, but teleosts have just one or two. We used comparative genomics and conserved syntenies to identify loss of ohnologs (paralogs derived from genome duplication) and to clarify uncertain phylogenies. Analysis showed that Aldh1a1 and Aldh1a2 form a clade that is sister to Aldh1a3-related genes. Genome comparisons showed secondarily loss of aldh1a1 in teleosts, revealing that Aldh1a1 is not a tetrapod innovation and that aldh1a3 was recently lost in medaka, making it the first known vertebrate with a single aldh1a gene. Interestingly, results revealed asymmetric distribution of surviving ohnologs between co-orthologous teleost chromosome segments, suggesting that local genome architecture can influence ohnolog survival. We propose a model that reconstructs the chromosomal history of the Aldh1a family in the ancestral vertebrate genome, coupled with the evolution of gene functions in surviving Aldh1a ohnologs after R1, R2, and R3 genome duplications. Results provide evidence for early subfunctionalization and late subfunction-partitioning and suggest a mechanistic model based on altered regulation leading to heterochronic gene expression to explain the acquisition or modification of subfunctions by surviving ohnologs that preserve unaltered ancestral developmental programs in the face of gene loss. PMID:19478994

Cañestro, Cristian; Catchen, Julian M; Rodríguez-Marí, Adriana; Yokoi, Hayato; Postlethwait, John H

2009-05-01

442

Retardation of senescence in red clover leaf discs by a new antiozonant, N-(2-(2-oxo-2-imidazolidinyl)ethyl)-N'-phenylurea  

SciTech Connect

Dark-induced senescence in leaf discs from O/sub 3/-sensitive red clover trifoliates (Trifolium pratense L. cv. Pennscott) was markedly retarded by treatment with N-(2-(2-oxo-1-imidazolidinyl))-ethyl-N'-phenylurea (EDU). EDU also protects against acute and chronic foliar O/sub 3/ injury when sprayed on intact leaves or supplied to the plants through soil application. Senescence retardation was measured by time-dependent analyses of chlorophyll, protein, and RNA in discs floated on aqueous EDU solutions ranging from 0 to 500 micrograms per milliliter EDU. Chlorophyll degradation, total protein, and nucleic acids were followed over 10-day test periods. EDU at 500 micrograms per milliliter (50 milligrams per pot), a concentration known to provide optimal protection to intact leaves against O/sub 3/ injury, was most effective in preventing chlorosis and in maintaining high concentrations of protein and RNA in the discs. In discs treated with 500 micrograms per milliliter EDU 90% of the chlorophyll was retained after 10 days in the dark. In contrast, lower concentrations (0, 125, and 250 micrograms per milliliter) showed the complete loss of chlorophyll or an intermediate retardation. The intermediate concentrations were similarly less effective in maintaining protein and RNA levels in the dark stressed leaf discs. It is suggested that EDU retards senescence and mitigates O/sub 3/ injury through the induction of specific free radical scavenging enzymes and in sustaining RNA and protein synthesis.

Lee, E.H.; Bennett, J.H.; Heggestad, H.E.

1981-02-01

443

EFFECT OF ORGANOPHOSPHORUS FLAME RETARDANTS ON NEURONAL DEVELOPMENT IN VITRO  

EPA Science Inventory

The increased use of organophosphorus compounds as alternatives to brominated flame retardants (BFRs) has led to widespread human exposure, There is, however, limited information on their potential health effects. This study compared the effects of nii ne organophosphorus flame...

444

Teaching about Older People with Mental Retardation: An Educational Model.  

ERIC Educational Resources Information Center

The University of Georgia model curriculum to prepare students to work with mentally retarded older adults has six units: population overview, physiological issues, mental health issues, social support systems, service delivery networks, and legal/ethical issues. (SK)

Kropf, Nancy P.; And Others

1993-01-01

445

Burning To Learn: An Introduction to Flame Retardants.  

ERIC Educational Resources Information Center

Presents an activity that demonstrates the effectiveness of flame retardants--substances added to combustible materials to slow down or hinder burning--that can be introduced when discussing combustion reactions or during a practical or everyday chemistry unit. (ASK)

Journal of Chemical Education, 2001

2001-01-01

446

Temporal Anticipation of Response Initiation by Mentally Retarded Persons.  

ERIC Educational Resources Information Center

The ability of 24 moderately retarded adults to anticipate a signal to initiate discrete movements of varying complexity was investigated in two experiements. The results revealed an interaction between temporal anticipation and response complexity. (Author)

Newell, K. M.; And Others

1979-01-01

447

X-linked mental retardation associated with macro-orchidism  

Microsoft Academic Search

Two families are described with an X-linked form of mental retardation in whom the affected males were found to have bilateral enlargement of the testes. No conclusive evidence of any endocrinological disturbance was found.

G Turner; C Eastman; J Casey; A McLeay; P Procopis; B Turner

1975-01-01

448

Aerobic Dance and the Mentally Retarded--A Winning Combination.  

ERIC Educational Resources Information Center

The results of a study on an experimental dance program for mentally retarded children show that these children can improve in physical fitness and that success through physical activities can enhance their generally poor self-concept. (JN)

Barton, Bonnie J.

1982-01-01

449

Developing Primitive Signalling Behavior of Students with Profound Mental Retardation.  

ERIC Educational Resources Information Center

Three profoundly retarded students (ages 6, 8, and 12) were taught prelanguage signalling behaviors (grasping the experimenter's finger and tapping the back of one hand with the other) to initiate co-active imitation behaviors with an adult. (JW)

Sternberg, Les; And Others

1987-01-01

450

Horticultural Careers for Persons with Mental Retardation. Expanding Opportunities.  

ERIC Educational Resources Information Center

Horticulture careers provide therapeutic, rewarding employment for persons with mental retardation. Rehabilitation experts should become aware of the potential employment opportunities in horticulture so that individuals with disabilities can receive the training and job placement support they need. (Author)

Dehart-Bennett, Mary E.; Relf, Diane

1990-01-01

451

Fire retardant foams developed to suppress fuel fires  

NASA Technical Reports Server (NTRS)

Heat insulating polyurethane foam retards and suppresses fuel fires. Uniformly dispersed in the foam is a halogenated polymer capable of splitting off hydrogen halide upon heating and charring of the polyurethane.

Fish, R.; Gilwee, W. J.; Parker, J. A.; Riccitiello, S. R.

1968-01-01

452

Flame Retardants May Raise Risk of Preterm Births, Study Finds  

MedlinePLUS

... JavaScript. Flame Retardants May Raise Risk of Preterm Births, Study Finds Women with higher blood levels of ... 1 million of these babies die shortly after birth, making preterm birth the second-leading cause of ...

453

Mutations in PHF8 are associated with X linked mental retardation and cleft lip/cleft palate  

PubMed Central

Truncating mutations were found in the PHF8 gene (encoding the PHD finger protein 8) in two unrelated families with X linked mental retardation (XLMR) associated with cleft lip/palate (MIM 300263). Expression studies showed that this gene is ubiquitously transcribed, with strong expression of the mouse orthologue Phf8 in embryonic and adult brain structures. The coded PHF8 protein harbours two functional domains, a PHD finger and a JmjC (Jumonji-like C terminus) domain, implicating it in transcriptional regulation and chromatin remodelling. The association of XLMR and cleft lip/palate in these patients with mutations in PHF8 suggests an important function of PHF8 in midline formation and in the development of cognitive abilities, and links this gene to XLMR associated with cleft lip/palate. Further studies will explore the specific mechanisms whereby PHF8 alterations lead to mental retardation and midline defects. PMID:16199551

Laumonnier, F; Holbert, S; Ronce, N; Faravelli, F; Lenzner, S; Schwartz, C; Lespinasse, J; Van Esch, H; Lacombe, D; Goizet, C; Phan-Dinh, T; van Bokhoven, H; Fryns, J; Chelly, J; Ropers, H; Moraine, C; Hamel, B; Briault, S

2005-01-01

454

Mutations in PHF8 are associated with X linked mental retardation and cleft lip/cleft palate.  

PubMed

Truncating mutations were found in the PHF8 gene (encoding the PHD finger protein 8) in two unrelated families with X linked mental retardation (XLMR) associated with cleft lip/palate (MIM 300263). Expression studies showed that this gene is ubiquitously transcribed, with strong expression of the mouse orthologue Phf8 in embryonic and adult brain structures. The coded PHF8 protein harbours two functional domains, a PHD finger and a JmjC (Jumonji-like C terminus) domain, implicating it in transcriptional regulation and chromatin remodelling. The association of XLMR and cleft lip/palate in these patients with mutations in PHF8 suggests an important function of PHF8 in midline formation and in the development of cognitive abilities, and links this gene to XLMR associated with cleft lip/palate. Further studies will explore the specific mechanisms whereby PHF8 alterations lead to mental retardation and midline defects. PMID:16199551

Laumonnier, F; Holbert, S; Ronce, N; Faravelli, F; Lenzner, S; Schwartz, C E; Lespinasse, J; Van Esch, H; Lacombe, D; Goizet, C; Phan-Dinh Tuy, F; van Bokhoven, H; Fryns, J-P; Chelly, J; Ropers, H-H; Moraine, C; Hamel, B C J; Briault, S

2005-10-01

455

Analysis of Ah receptor pathway activation by brominated flame retardants  

Microsoft Academic Search

Brominated flame-retardants (BFRs) are used as additives in plastics to decrease the rate of combustion of these materials, leading to greater consumer safety. As the use of plastics has increased, the production and use of flame-retardants has also grown. Many BFRs are persistent and have been detected in environmental samples, raising concerns about the biological\\/toxicological risk associated with their use.

David J. Brown; Ilse Van Overmeire; Leo Goeyens; Michael S. Denison; Michael J. De Vito; George C. Clark

2004-01-01

456

Flame retardancy of paulownia wood and its mechanism  

Microsoft Academic Search

Paulownia wood (Pauloumia tomentosa) is a special kind of wood material in that it has especially excellent flame retardancy.\\u000a Using this property, it has been commonly used to make clothing wardrobes for a long time in Japan. In this research, the\\u000a flame retardancy of paulownia wood has been verified by heating experiments and cone calorimeter testing. The structure and\\u000a tissue

Peng Li; Juhachi Oda

2007-01-01

457

Polarimetry using liquid-crystal variable retarders: theory and calibration  

Microsoft Academic Search

A Mueller-matrix polarimeter in transmission mode using two electronically controlled liquid-crystal variable retarders has been developed. Its design, theory and calibration are described. Although liquid crystals have been proposed earlier, this paper is focused on the process of the calculation of the Mueller matrix by a matrix-inversion method, oriented to static systems and in vitro samples. By driving the retarders

Juan M Bueno

2000-01-01

458

Combustion of brominated flame retardants and behavior of its byproducts  

Microsoft Academic Search

The substance flow rate of PBDDs\\/DFs into flue gas and incineration residues from incineration of three types of waste samples containing brominated flame retardants were examined. The samples used consisted of PBDEs (a typical retardant), used TV casing materials (actual waste materials), and waste printed circuit boards. PBDDs\\/DFs concentrations in the experimental samples of PBDEs\\/PE, waste TV casing materials and

Shin-ichi Sakai; Jun Watanabe; Yoshiharu Honda; Hiroshi Takatsuki; Isamu Aoki; Masayuki Futamatsu; Ken Shiozaki

2001-01-01

459

Further delineation of X-linked mental retardation  

Microsoft Academic Search

Chromosomal, clinical, and psychological data are presented on members of six families with X-linked mental retardation. Affected males in three of these families express the fra(X)(q28) marker, while the retarded males in the other three do not. Similar variable physical and psychological charateristics, such as lop ears, large testes, and perseverative speech, are present in affected males in all six

D. S. Herbst; H. G. Dunn; F. J. Dill; D. K. Kalousek; L. W. Krywaniuk

1981-01-01

460

Fire retardant mechanism in intumescent ethylene vinyl acetate compositions  

Microsoft Academic Search

The thermal and combustion behaviour of an intumescent fire retardant system based on Polyamide 6 (PA6) and Ammonium Polyphosphate (APP), used to improve flame retardant properties of poly(ethylene-co-vinyl acetate) (EVA), loaded with Mg(OH)2 (MH) was examined. The study of the interactions between the additives introduced in EVA was focused in particular on the MH-APP interaction. The evolution of water from

A. Riva; G. Camino; L. Fomperie; P. Amigouët

2003-01-01

461

Mechanical, microscopical and fire retardant studies of ABS polymers  

Microsoft Academic Search

Antimony trioxide (Sb2O3) is a common additive in ABS flame retardant formulations and the effects of adding it, with four commercial brominated materials, to ABS are reported here. The results focus upon mechanical, rheological, microscopical and flame retardant properties, and the effects of four Sb2O3 materials with average particle sizes ranging from 0.5 to 11.8 ?m. Compounds were produced using

S. R. Owen; J. F. Harper

1999-01-01

462

Preparation and characterization of flame retardant ABS\\/montmorillonite nanocomposite  

Microsoft Academic Search

Flame retardant acrylonitrile–butadiene–styrene (ABS)\\/montmorillonite (MMT) nanocomposites were prepared by direct melt intercalation of ABS, organophilic clay and conventional fire retardants (decabromodiphenyl oxide (DB) and antimony oxide (AO)). Morphology and flammability properties were characterized by X-ray power diffractionmeter (XRD), high resolution electron microscopy (HREM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), limiting oxygen index (LOI) test, UL-94 test and cone

Shaofeng Wang; Yuan Hu; Ruowen Zong; Yong Tang; Zuyao Chen; Weicheng Fan

2004-01-01

463

Prevalence of classical phenylketonuria in mentally retarded individuals in Iran  

Microsoft Academic Search

Summary  Using Guthrie Biological Inhibition Assay, 4963 mentally retarded individuals housed in 31 cities and towns across the country\\u000a were screened for PKU. The average prevalence of classical PKU in the study population was 2.1%, which is higher than that\\u000a reported for most mentally retarded populations in other countries prior to the implementation of a nationwide newborn screening\\u000a programme for PKU.

N. M. Ghiasvand; A. Aledavood; R. Ghiasvand; F. Seyedin Borojeny; S. Seyed; W. Miner; G. R. Saeb Taheri

464

Genetic Causes of Mental Retardation. ARC Q&A #101-50.  

ERIC Educational Resources Information Center

This fact sheet uses a question-and-answer format to summarize what is known about the genetic causes of mental retardation. Questions and answers address the following topics: what genetics is; how a person's genes can cause mental retardation; how often mental retardation is inherited (up to 60 percent of severe mental retardation has genetic…

Arc, Arlington, TX.

465

Familial X-linked mental retardation with an X chromosome abnormality  

Microsoft Academic Search

An X-linked pattern of transmission observed in four families with familial mental retardation in several generations was associated with a probable secondary constriction at the distal end of the q arms of the X chromosome. Twenty retarded males and no retarded females were observed. All available live retarded males and most of their normal mothers were found to have the

J Harvey; C Judge; S Wiener

1977-01-01

466

Effects of Fire Retardant on Water Logan A. Norris and Warren L. Webb2  

E-print Network

Effects of Fire Retardant on Water Quality1 Logan A. Norris and Warren L. Webb2 Abstract: Ammonium-based fire retardants are important in managing wildfires, but their use can adversely affect water impacts from the use of fire retardants are suggested. Chemical fire retardants play an important

Standiford, Richard B.

467

[Preliminary analysis of factors causing mental retardation in China].  

PubMed

Analysis of the data collected from national sampling survey of the mental retarded in 1987 showed: (1) prevalence of mental retardation in China was 12.68/1,000, (2) its causes mainly included hereditary diseases, cerebral diseases, malnutrition, pregnant infection and birth trauma for children and senile dementia for the elderly aged 60 or over, (3) severe mental retardation was mainly caused by cerebral diseases and developmental deformity in the country, and (4) the causes for 40.1% of the mental retarded persons remained unknown. Based on the researches at home and abroad, a series of major preventive measures for mental retardation have been put forward, they included: (1) to promote better birth and better rearing, vaccination, proper nutrition for pregnant mothers and infants, and safety education as focuses in primary prevention, (2) to detect early and timely treat cerebral diseases and nutritional deficiency, to strengthen antenatal diagnosis and early screening for inborn metabolic diseases as secondary prevention, and (3) to strengthen education, behavioral training and psychological rehabilitation, and to provide community-based rehabilitation service for the mental retarded as tertiary prevention. PMID:7842893

Li, A L; Li, L M; Qian, Y P

1994-09-01

468

Flame Retardant Exposure among Collegiate U.S. Gymnasts  

PubMed Central

Gymnastics training facilities contain large volumes of polyurethane foam, a material that often contains additive flame retardants such as PentaBDE. While investigations of human exposure to flame retardants have focused on the general population, potentially higher than background exposures may occur in gymnasts and certain occupational groups. Our objectives were to compare PentaBDE body burden among gymnasts to the general U.S. population and characterize flame retardants levels in gym equipment, air and dust. We recruited 11 collegiate female gymnasts (ages 18–22) from one gym in the Eastern U.S. The geometric mean (GM) concentration of BDE-153 in gymnast sera (32.5 ng/g lipid) was 4–6.5 times higher than general U.S. population groups. Median concentrations of PentaBDE, TBB and TBPH in paired handwipe samples were 2–3 times higher after practice compared to before, indicating the gymnasts contacted these flame retardants during practice. GM concentrations of PentaBDE, TBB and TBPH were 1-3 orders of magnitude higher in gym air and dust than in residences. Our findings suggest that these collegiate gymnasts experienced higher exposures to PentaBDE flame retardants compared to the general U.S. population and that gymnasts may also have increased exposure to other additive flame retardants used in polyurethane foam such as TBB and TBPH. PMID:24195753

Carignan, Courtney C.; Heiger-Bernays, Wendy; McClean, Michael D.; Roberts, Simon C.; Stapleton, Heather M.; Sjödin, Andreas; Webster, Thomas F.

2013-01-01

469

Mutations in a putative global transcriptional regulator cause X-linked mental retardation with ?-thalassemia (ATR-X syndrome)  

Microsoft Academic Search

The ATR-X syndrome is an X-linked disorder comprising severe psychomotor retardation, characteristic facial features, genital abnormalities, and a-thalassemia. We have shown that ATR-X results from diverse mutations of XH2, a member of a subgroup of the helicase superfamily that includes proteins involved in a wide range of cellular functions, including DNA recombination and repair (RAD16, RAD54, and ERCC6) and regulation

Richard J Gibbons; David J Picketts; Laurent Villard; Douglas R Higgs

1995-01-01

470

Reproductive rights of mentally retarded persons.  

PubMed

Mental retardation denotes sub-average intellectual functioning, based on IQ, i.e. the inability of normal learning, accompanied by behavioral and developmental disorders. Persons with impairments (cognitive, motor, sensory or psychiatric) have often been, both through human history and today victims of discrimination and deprived of their basic human rights, both in the public and the private life spheres. Since the end of the 20th century, throughout the developed world, many disabled persons can accomplish their dreams and rights. However, the issue of sexuality is still an obstacle in realizing oneself as a whole person, of course in accordance with personal psychophysical abilities. The greatest problem is present in persons with severe disablement, considered not apt enough for information on sexuality and for expressing themselves as persons with their own sexual needs. Thus it is desirable to observe each disabled person individually and flexibly enough in order to establish parameters for the functioning of an intimate affair on the level of understanding and assent. The legal system must protect the most vulnerable and ensure for them the right of choice and consent, as well as the possibility of fulfilling their sexual needs, so that they could love and be loved. Naturally, the system must be built on foundations that satisfy the needs of its users, but also of persons engaged in work with them. Sex education should contain information regarding biological, socio-cultural and spiritual dimensions of sexuality, including cognitive, affective and behavioral domains. Unfortunately, very few educational programs with such aims provide sex education, not only for the disabled young population but also for the healthy. This review article is based on international investigations and Croatian legislative postulates. Its aim is to focus the attention of both professionals and non-professionals on this delicate problem. PMID:22447084

Katalini?, Sanja; Sendula-Jengi?, Vesna; Sendula-Paveli?, Martina; Zudenigo, Slaven

2012-03-01

471

Mental retardation and prenatal methylmercury toxicity  

SciTech Connect

Methylmercury (MeHg) is a developmental neurotoxicant; exposure results principally from consumption of seafood contaminated by mercury (Hg). In this analysis, the burden of mental retardation (MR) associated with methylmercury exposure in the 2000 U.S. birth cohort is estimated, and the portion of this burden attributable to mercury (Hg) emissions from coal-fired power plants is identified. The aggregate loss in cognition associated with MeHg exposure in the 2000 U.S. birth cohort was estimated using two previously published dose-response models that relate increases in cord blood Hg concentrations with decrements in IQ. MeHg exposure was assumed not to be correlated with native cognitive ability. Previously published estimates were used to estimate economic costs of MR caused by MeHg. Downward shifts in IQ resulting from prenatal exposure to MeHg of anthropogenic origin are associated with 1,566 excess cases of MR annually (range: 376-14,293). This represents 3.2% of MR cases in the US (range: 0.8%-29.2