Risks on N-acetyltransferase 2 and bladder cancer: a meta-analysis.

PubMed

Zhu, Zongheng; Zhang, Jinshan; Jiang, Wei; Zhang, Xianjue; Li, Youkong; Xu, Xiaoming

2015-01-01

It is known that bladder cancer disease is closely related to aromatic amine compounds, which could cause cancer by regulating of N-acetylation and N-acetyltransferase 1 and 2 (NAT1 and NAT2). The NAT2 slowed acetylation and would increase the risk of bladder cancer, with tobacco smoke being regarded as a risk factor for this increased risk. However, the relationship between NAT2 slow acetylation and bladder cancer is still debatable at present. This study aims to explore preliminarily correlation of NAT2 slow acetylation and the risk of bladder cancer. The articles were searched from PubMed, Cochran, McGrane English databases, CBM, CNKI, and other databases. The extraction of bladder cancer patients and a control group related with the NAT2 gene were detected by the state, and the referenced articles and publications were also used for data retrieval. Using a random effects model, the model assumes that the studies included in the analysis cases belong to the overall population in the study of random sampling, and considering the variables within and between studies. Data were analyzed using STATA Version 6.0 software, using the META module. According to the inclusion and exclusion criteria of the literature study, 20 independent studies are included in this meta-analysis. The results showed that the individual differences of bladder cancer susceptibility might be part of the metabolism of carcinogens. Slow acetylation status of bladder cancer associated with the pooled odds ratio was 1.31 (95% confidence interval: 1.11-1.55). The status of NAT2 slow N-acetylation is associated with bladder cancer risks, and may increase the risk of bladder cancer.

Evolution of insect arylalkylamine N-acetyltransferases: Structural evidence from the yellow fever mosquito, Aedes aegypti

PubMed Central

Han, Qian; Robinson, Howard; Ding, Haizhen; Christensen, Bruce M.; Li, Jianyong

2012-01-01

Arylalkylamine N-acetyltransferase (aaNAT) catalyzes the transacetylation from acetyl-CoA to arylalkylamines. aaNATs are involved in sclerotization and neurotransmitter inactivation in insects. Phyletic distribution analysis confirms three clusters of aaNAT-like sequences in insects: typical insect aaNAT, polyamine NAT-like aaNAT, and mosquito unique putative aaNAT (paaNAT). Here we studied three proteins: aaNAT2, aaNAT5b, and paaNAT7, each from a different cluster. aaNAT2, a protein from the typical insect aaNAT cluster, uses histamine as a substrate as well as the previously identified arylalkylamines. aaNAT5b, a protein from polyamine NAT -like aaNAT cluster, uses hydrazine and histamine as substrates. The crystal structure of aaNAT2 was determined using single-wavelength anomalous dispersion methods, and that of native aaNAT2, aaNAT5b and paaNAT7 was detected using molecular replacement techniques. All three aaNAT structures have a common fold core of GCN5-related N-acetyltransferase superfamily proteins, along with a unique structural feature: helix/helices between β3 and β4 strands. Our data provide a start toward a more comprehensive understanding of the structure–function relationship and physiology of aaNATs from the mosquito Aedes aegypti and serve as a reference for studying the aaNAT family of proteins from other insect species. The structures of three different types of aaNATs may provide targets for designing insecticides for use in mosquito control. PMID:22753468

Catalytic properties and heat stabilities of novel recombinant human N-acetyltransferase 2 allozymes support existence of genetic heterogeneity within the slow acetylator phenotype.

PubMed

Hein, David W; Doll, Mark A

2017-08-01

Human N-acetyltransferase 2 (NAT2) catalyzes the N-acetylation of numerous aromatic amine drugs such as sulfamethazine (SMZ) and hydrazine drugs such as isoniazid (INH). NAT2 also catalyzes the N-acetylation of aromatic amine carcinogens such as 2-aminofluorene and the O- and N,O-acetylation of aromatic amine and heterocyclic amine metabolites. Genetic polymorphism in NAT2 modifies drug efficacy and toxicity as well as cancer risk. Acetyltransferase catalytic activities and heat stability associated with six novel NAT2 haplotypes (NAT2*6C, NAT2*14C, NAT2*14D, NAT2*14E, NAT2*17, and NAT2*18) were compared with that of the reference NAT2*4 haplotype following recombinant expression in Escherichia coli. N-acetyltransferase activities towards SMZ and INH were significantly (p < 0.0001) lower when catalyzed by the novel recombinant human NAT2 allozymes compared to NAT2 4. SMZ and INH N-acetyltransferase activities catalyzed by NAT2 14C and NAT2 14D were significantly lower (p < 0.001) than catalyzed by NAT2 6C and NAT2 14E. N-Acetylation catalyzed by recombinant human NAT2 17 was over several hundred-fold lower than by recombinant NAT2 4 precluding measurement of its kinetic or heat inactivation constants. Similar results were observed for the O-acetylation of N-hydroxy-2-aminofluorene and N-hydroxy-2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine and the intramolecular N,O-acetylation of N-hydroxy-N-acetyl-2-aminofluorene. The apparent V max of the novel recombinant NAT2 allozymes NAT2 6C, NAT2 14C, NAT2 14D, and NAT2 14E towards AF, 4-aminobiphenyl (ABP), and 3,2'-dimethyl-4-aminobiphenyl (DMABP) were each significantly (p < 0.001) lower while their apparent K m values did not differ significantly (p > 0.05) from recombinant NAT2 4. The apparent V max catalyzed by NAT2 14C and NAT2 14D were significantly lower (p < 0.05) than the apparent V max catalyzed by NAT2 6C and NAT2 14E towards AF, ABP, and DMABP. Heat inactivation rate constants for recombinant human NAT2 14C, 14D, 14E, and 18 were significantly (p < 0.05) higher than NAT2 4. These results provide further evidence of genetic heterogeneity within the NAT2 slow acetylator phenotype.

The expression of xenobiotic-metabolizing enzymes in human prostate and in prostate epithelial cells (PECs) derived from primary cultures.

PubMed

Al-Buheissi, S Z; Cole, K J; Hewer, A; Kumar, V; Bryan, R L; Hudson, D L; Patel, H R; Nathan, S; Miller, R A; Phillips, D H

2006-06-01

Dietary heterocyclic amines (HCAs) are carcinogenic in rodent prostate requiring activation by enzymes such as cytochrome P450 (CYP) and N-acetyltransferase (NAT). We investigated by Western blotting and immunohistochemistry the expression of CYP1A1, CYP1A2, and NAT1 in human prostate and in prostate epithelial cells (PECs) derived from primary cultures and tested their ability to activate the dietary carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and its N-hydroxy metabolite (N-OH-IQ) to DNA-damaging moieties. Western blotting identified CYP1A1, CYP1A2, and NAT1. Immunohistochemistry localized NAT1 to the cytoplasm of PECs. Inter-individual variation was observed in the expression levels of CYP1A1, 1A2, and NAT1 (11, 75, and 35-fold, respectively). PECs expressed CYP1A1 and NAT1 but not CYP1A2. When incubated with IQ or N-OH-IQ, PECs formed DNA adducts indicating their ability to metabolically activate these compounds. Prostate cells possess the capacity to activate dietary carcinogens. PECs may provide a useful model system to study their role in prostate carcinogenesis.

The Hamburg Selection Procedure for Dental Students – Introduction of the HAM-Nat as subject-specific test for study aptitude

PubMed Central

Kothe, Christian; Hissbach, Johanna; Hampe, Wolfgang

2013-01-01

Introduction: The present study examines the question whether the selection of dental students should be based solely on average school-leaving grades (GPA) or whether it could be improved by using a subject-specific aptitude test. Methods: The HAM-Nat Natural Sciences Test was piloted with freshmen during their first study week in 2006 and 2007. In 2009 and 2010 it was used in the dental student selection process. The sample size in the regression models varies between 32 and 55 students. Results: Used as a supplement to the German GPA, the HAM-Nat test explained up to 12% of the variance in preclinical examination performance. We confirmed the prognostic validity of GPA reported in earlier studies in some, but not all of the individual preclinical examination results. Conclusion: The HAM-Nat test is a reliable selection tool for dental students. Use of the HAM-Nat yielded a significant improvement in prediction of preclinical academic success in dentistry. PMID:24282449

Methamphetamine-induced neuronal protein NAT8L is the NAA biosynthetic enzyme: implications for specialized acetyl coenzyme A metabolism in the CNS.

PubMed

Ariyannur, Prasanth S; Moffett, John R; Manickam, Pachiappan; Pattabiraman, Nagarajan; Arun, Peethambaran; Nitta, Atsumi; Nabeshima, Toshitaka; Madhavarao, Chikkathur N; Namboodiri, Aryan M A

2010-06-04

N-acetylaspartate (NAA) is a concentrated, neuron-specific brain metabolite routinely used as a magnetic resonance spectroscopy marker for brain injury and disease. Despite decades of research, the functional roles of NAA remain unclear. Biochemical investigations over several decades have associated NAA with myelin lipid synthesis and energy metabolism. However, studies have been hampered by an inability to identify the gene for the NAA biosynthetic enzyme aspartate N-acetyltransferase (Asp-NAT). A very recent report has identified Nat8l as the gene encoding Asp-NAT and confirmed that the only child diagnosed with a lack of NAA on brain magnetic resonance spectrograms has a 19-bp deletion in this gene. Based on in vitro Nat8l expression studies the researchers concluded that many previous biochemical investigations have been technically flawed and that NAA may not be associated with brain energy or lipid metabolism. In studies done concurrently in our laboratory we have demonstrated via cloning, expression, specificity for acetylation of aspartate, responsiveness to methamphetamine treatment, molecular modeling and comparative immunolocalization that NAT8L is the NAA biosynthetic enzyme Asp-NAT. We conclude that NAA is a major storage and transport form of acetyl coenzyme A specific to the nervous system, thus linking it to both lipid synthesis and energy metabolism. Published by Elsevier B.V.

Homology modeling and prediction of the amino acid residues participating in the transfer of acetyl-CoA to arylalkylamine by the N-acetyltransferase from Chryseobacterium sp.

PubMed

Takenaka, Shinji; Ozeki, Takahiro; Tanaka, Kosei; Yoshida, Ken-Ichi

2017-11-01

To predict the amino acid residues playing important roles in acetyl-CoA and substrate binding and to study the acetyl group transfer mechanism of Chryseobacterium sp. 5-3B N-acetyltransferase (5-3B NatA). A 3-dimensional homology model of 5-3B NatA was constructed to compare the theoretical structure of this compound with the structures of previously reported proteins belonging to the bacterial GCN5 N-acetyltransferase family. Homology modeling of the 5-3B NatA structure and a characterization of the enzyme's kinetic parameters identified the essential amino acid residues involved in binding and acetyl-group transfer. 126 Leu, 132 Leu, and 135 Lys were implicated in the binding of phosphopantothenic acid, and 100 Tyr and 131 Lys in that of adenosyl biphosphate. The data supported the participation of 83 Glu and 133 Tyr in catalyzing acetyl-group transfer to L-2-phenylglycine. 5-3B NatA catalyzes the enantioselective N-acetylation of L-2-phenylglycine via a ternary complex comprising the enzyme, acetyl-CoA, and the substrate.

A mathematical approach to estimate the efficacy of individual-donation and minipool nucleic acid amplification test options in preventing transmission risk by window period and occult hepatitis B virus infections

PubMed Central

Vermeulen, Marion; van Drimmelen, Harry; Coleman, Charl; Mitchel, Josephine; Reddy, Ravi; Lelie, Nico

2016-01-01

BACKGROUND Sensitivity data from a head-to-head comparison study in South Africa were used to compare the efficacy of the Ultrio Plus assay in individual-donation (ID) and minipool (MP)4 and MP8 formats with that of TaqScreen MP6 in preventing hepatitis B virus (HBV) transmission risk. STUDY DESIGN AND METHODS The replicate nucleic acid test (NAT) results on 106 HBV NAT (Ultrio)-yield samples and 29 HBV DNA (Ultrio)-negative, hepatitis B surface antigen (HBsAg)-positive samples were used to determine the viral load in copies/mL against the Eurohep HBV standard by probit analysis. Random viral load distributions were established in 32 pre-HBsAg window period (WP), 15 post-HBsAg WP, and 56 occult HBV infection (OBI) donations. Regression analysis of log viral load and Poisson distribution statistics of infectious HBV particles in blood components was used to predict infectivity and efficacy of NAT options in removing HBV transmission risk. RESULTS For red blood cell transfusions (20 mL of plasma), the modeling predicted an Ultrio Plus ID-NAT efficacy of 68 and 83% in removing WP and (antibody to hepatitis B surface antigen–negative) OBI transmission risk, respectively, compared to 52 and 49% by TaqScreen MP6. For 200 mL of fresh-frozen plasma the estimated efficacy levels by these ID- and MP6-NAT options reduced to 57 and 44% for WP and to 67 and 34% for OBI donations, respectively. CONCLUSION The efficacy of the currently available commercial NAT systems in reducing HBV transmission risk is mainly driven by the pool size and the transfusion plasma volume. The modeled OBI transmission risk and NAT efficacy levels were in line with those recently reported in three lookback studies and give more insight in the incremental safety provided by HBsAg and antibody to hepatitis B core antigen testing of ID-NAT screened blood. PMID:24749834

The MP (Materialization Pattern) Model for Representing Math Educational Standards

NASA Astrophysics Data System (ADS)

Choi, Namyoun; Song, Il-Yeol; An, Yuan

Representing natural languages with UML has been an important research issue for various reasons. Little work has been done for modeling imperative mood sentences which are the sentence structure of math educational standard statements. In this paper, we propose the MP (Materialization Pattern) model that captures the semantics of English sentences used in math educational standards. The MP model is based on the Reed-Kellogg sentence diagrams and creates MP schemas with the UML notation. The MP model explicitly represents the semantics of the sentences by extracting math concepts and the cognitive process of math concepts from math educational standard statements, and simplifies modeling. This MP model is also developed to be used for aligning math educational standard statements via schema matching.

PlantNATsDB: a comprehensive database of plant natural antisense transcripts.

PubMed

Chen, Dijun; Yuan, Chunhui; Zhang, Jian; Zhang, Zhao; Bai, Lin; Meng, Yijun; Chen, Ling-Ling; Chen, Ming

2012-01-01

Natural antisense transcripts (NATs), as one type of regulatory RNAs, occur prevalently in plant genomes and play significant roles in physiological and pathological processes. Although their important biological functions have been reported widely, a comprehensive database is lacking up to now. Consequently, we constructed a plant NAT database (PlantNATsDB) involving approximately 2 million NAT pairs in 69 plant species. GO annotation and high-throughput small RNA sequencing data currently available were integrated to investigate the biological function of NATs. PlantNATsDB provides various user-friendly web interfaces to facilitate the presentation of NATs and an integrated, graphical network browser to display the complex networks formed by different NATs. Moreover, a 'Gene Set Analysis' module based on GO annotation was designed to dig out the statistical significantly overrepresented GO categories from the specific NAT network. PlantNATsDB is currently the most comprehensive resource of NATs in the plant kingdom, which can serve as a reference database to investigate the regulatory function of NATs. The PlantNATsDB is freely available at http://bis.zju.edu.cn/pnatdb/.

Molecular basis of essential amino acid transport from studies of insect nutrient amino acid transporters of the SLC6 family (NAT-SLC6)

PubMed Central

Boudko, Dmitri Y.

2012-01-01

Two protein families that represent major components of essential amino acid transport in insects have been identified. They are annotated as the SLC6 and SLC7 families of transporters according to phylogenetic proximity to characterized amino acid transporters (HUGO nomenclature). Members of these families have been identified as important apical and basolateral parts of transepithelial essential amino acid absorption in the metazoan alimentary canal. Synergistically, they play critical physiological roles as essential substrate providers to diverse metabolic processes, including generic protein synthesis. This review briefly clarifies the requirements for amino acid transport and a variety of amino acid transport mechanisms, including the aforementioned families. Further it focuses on the large group of Nutrient Amino acid Transporters (NATs), which comprise a recently identified subfamily of the Neurotransmitter Sodium Symporter family (NSS or SLC6). The first insect NAT, cloned from the caterpillar gut, has a broad substrate spectrum similar to mammalian B0 transporters. Several new NAT-SLC6 members have been characterized in an effort to explore mechanisms for the essential amino acid absorption in model dipteran insects. The identification and functional characterization of new B0-like and narrow specificity transporters of essential amino acids in fruit fly and mosquitoes leads to a fundamentally important insight: that NATs evolved and act together as the integrated active core of a transport network that mediates active alimentary absorption and systemic distribution of essential amino acids. This role of NATs is projected from the most primitive prokaryotes to the most complex metazoan organisms, and represents an interesting platform for unraveling the molecular evolution of amino acid transport and modeling amino acid transport disorders. The comparative study of NATs elucidates important adaptive differences between essential amino acid transportomes of invertebrate and vertebrate organisms, outlining a new possibility for selective targeting of essential amino acid absorption mechanisms to control medically and economically important arthropods and other invertebrate organisms. PMID:22230793

Dose-related antihyperglycemic and hypolipidemic effects of two novel thiazolidin-4-ones in a rodent model of metabolic syndrome.

PubMed

Karot, Sarine Sebastian; Surenahalli, Vasantharaju Gowdra; Kishore, Anoop; Mudgal, Jayesh; Nandakumar, Krishnadas; Chirayil, Magith Thambi; Mathew, Geetha; Nampurath, Gopalan Kutty

2016-09-01

The replacement of the thiazolidinedione moiety with a thiazolidinone may yield antidiabetic compounds with similar pleiotropic effects. Hence, the aim of the present study was to explore the dose-related antihyperglycemic and hypolipidemic effects of two synthesized novel thiazolidin-4-one derivatives, one with a nicotinamide and the other with a p-chlorophenoxyacetamide substitution at the N3 position of the thiazolidinone ring (NAT1 and PAT1, respectively), in a rodent model of metabolic syndrome (MetS). Metabolic syndrome was induced in Wistar rats by neonatal administration of monosodium glutamate (i.p.) on 4 consecutive days followed by high-sucrose diet feeding for 6 months. The effects of NAT1 (33 and 66 mg/kg) and molar equivalent doses of PAT1 (40 and 80 mg/kg) on relevant biochemical parameters were evaluated. Because MetS is a state of chronic low-grade inflammation, we also evaluated the effects of these compounds on proinflammatory markers, namely interleukin (IL)-6, tumor necrosis factor (TNF)-α, reactive oxygen species (ROS), and nitric oxide (NO). Both NAT1 and PAT1 attenuated hyperglycemia, hypertriglyceridemia, hypoalphalipoproteinemia, and glucose intolerance. PAT1 exhibited superior antihyperglycemic and antihypoalphalipoproteinemic effects than NAT1. However, NAT1 had a better triglyceride-lowering effect. At the lower dose tested, both compounds significantly reduced elevated malondialdehyde levels. In addition, PAT1 (80 mg/kg) restored hepatic superoxide dismutase enzyme levels. There was a tendency for NAT1 and PAT1 to inhibit elevated hepatic IL-6 and TNF-α levels, but the differences did not reach statistical significance. In addition, PAT1 exhibited in vitro anti-inflammatory activity by reducing proinflammatory ROS and NO levels in RAW264.7 macrophages. The novel thiazolidin-4-ones NAT1 and PAT1 could be potential pleiotropic drug candidates targeting MetS. © 2015 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

Arylamine N-acetyltransferases: from drug metabolism and pharmacogenetics to drug discovery

PubMed Central

Sim, E; Abuhammad, A; Ryan, A

2014-01-01

Arylamine N-acetyltransferases (NATs) are polymorphic drug-metabolizing enzymes, acetylating arylamine carcinogens and drugs including hydralazine and sulphonamides. The slow NAT phenotype increases susceptibility to hydralazine and isoniazid toxicity and to occupational bladder cancer. The two polymorphic human NAT loci show linkage disequilibrium. All mammalian Nat genes have an intronless open reading frame and non-coding exons. The human gene products NAT1 and NAT2 have distinct substrate specificities: NAT2 acetylates hydralazine and human NAT1 acetylates p-aminosalicylate (p-AS) and the folate catabolite para-aminobenzoylglutamate (p-abaglu). Human NAT2 is mainly in liver and gut. Human NAT1 and its murine homologue are in many adult tissues and in early embryos. Human NAT1 is strongly expressed in oestrogen receptor-positive breast cancer and may contribute to folate and acetyl CoA homeostasis. NAT enzymes act through a catalytic triad of Cys, His and Asp with the architecture of the active site-modulating specificity. Polymorphisms may cause unfolded protein. The C-terminus helps bind acetyl CoA and differs among NATs including prokaryotic homologues. NAT in Salmonella typhimurium supports carcinogen activation and NAT in mycobacteria metabolizes isoniazid with polymorphism a minor factor in isoniazid resistance. Importantly, nat is in a gene cluster essential for Mycobacterium tuberculosis survival inside macrophages. NAT inhibitors are a starting point for novel anti-tuberculosis drugs. Human NAT1-specific inhibitors may act in biomarker detection in breast cancer and in cancer therapy. NAT inhibitors for co-administration with 5-aminosalicylate (5-AS) in inflammatory bowel disease has prompted ongoing investigations of azoreductases in gut bacteria which release 5-AS from prodrugs including balsalazide. PMID:24467436

Role of N-acetyltransferase 2 acetylation polymorphism in 4, 4'-methylene bis (2-chloroaniline) biotransformation.

PubMed

Hein, David W; Zhang, Xiaoyan; Doll, Mark A

2018-02-01

Arylamine N-acetyltransferase 1 (NAT1) and 2 (NAT2) catalyze the acetylation of arylamine carcinogens. Single nucleotide polymorphisms in the NAT2 coding exon present in NAT2 haplotypes encode allozymes with reduced N-acetyltransferase activity towards the N-acetylation of arylamine carcinogens and the O-acetylation of their N-hydroxylated metabolites. NAT2 acetylator phenotype modifies urinary bladder cancer risk following exposures to arylamine carcinogens such as 4-aminobiphenyl. 4, 4'-methylene bis (2-chloroaniline) (MOCA) is a Group 1 carcinogen for which a role of the NAT2 acetylation polymorphism on cancer risk is unknown. We investigated the role of NAT2 and the genetic acetylation polymorphism on both MOCA N-acetylation and N-hydroxy-MOCA O-acetylation. MOCA N-acetylation exhibited a robust gene dose response in rabbit liver cytosol and in cryopreserved human hepatocytes derived from individuals of rapid, intermediate and slow acetylator NAT2 genotype. MOCA exhibited about 4-fold higher affinity for recombinant human NAT2 than NAT1. Recombinant human NAT2*4 (reference) and 15 variant recombinant human NAT2 allozymes catalyzed both the N-acetylation of MOCA and the O-acetylation of N-hydroxy-MOCA. Human NAT2 5, NAT2 6, NAT2 7 and NAT2 14 allozymes catalyzed MOCA N-acetylation and N-hydroxy-O-acetylation at rates much lower than the reference NAT2 4 allozyme. In conclusion, our results show that NAT2 acetylator genotype has an important role in MOCA metabolism and suggest that risk assessments related to MOCA exposures consider accounting for NAT2 acetylator phenotype in the analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Math anxiety in Thai early adolescents: a cognitive-behavioral perspective.

PubMed

Wangsiriwech, Tawatchai; Pisitsungkagarn, Kullaya; Jarukasemthawee, Somboon

2017-08-29

With its high prevalence and debilitating impact on students, math anxiety is well studied within the educational context. However, the problem has yet to be examined from the psychological perspective, which is necessary in order to produce a more comprehensive perspective and to pave the way for therapeutic intervention. The current study, therefore, was conducted to identify cognitive and behavioral factors relevant to the occurrence and maintenance of math anxiety. Data were collected from 300 grade 9 students (150 females and 150 males) from public and private schools in Bangkok, Thailand. Participants responded to the measures of math anxiety, negative math beliefs, negative math appraisals and math avoidance. Structural equation modeling was conducted. Model fit indices obtained consistently suggested the good fitness of the model to the data [e.g. χ2/df = 0.42, root mean square error of approximation (RMSEA) = 0.00]. Negative math beliefs, negative math appraisals and math avoidance had a significant direct effect on math anxiety. Additionally, the indirect effect of negative math appraisal was observed between negative math beliefs and math anxiety. In summary, the proposed model accounted for 84.5% of the variance in the anxiety. The findings are discussed with particular focus on implications for therapeutic intervention for math anxiety.

Transcriptional regulation of N-acetylaspartate metabolism in the 5xFAD model of Alzheimer's disease: evidence for neuron-glia communication during energetic crisis.

PubMed

Zaroff, Samantha; Leone, Paola; Markov, Vladimir; Francis, Jeremy S

2015-03-01

N-acetylaspartate (NAA) provides a non-invasive clinical index of neuronal metabolic integrity across the entire neurodegenerative spectrum. While NAA function is not comprehensively defined, reductions in the brain are associated with compromised mitochondrial metabolism and are tightly linked to ATP. We have undertaken an analysis of abnormalities in NAA during early stage pathology in the 5xFAD mouse model of familial Alzheimer's disease and show here that dysregulated expression of the gene encoding for the rate-limiting NAA synthetic enzyme (Nat8L) is associated with deficits in mitochondrial oxidative phosphorylation in this model system. Downreguation of Nat8L is particularly pronounced in the 5xFAD hippocampus, and is preceded by a significant upregulation of oligodendrocytic aspartoacylase (aspa), which encodes for the sole known NAA-catabolizing enzyme in the brain. Reductions in 5xFAD NAA and Nat8L cannot be accounted for by discrepancies in either neuron content or activity of the substrate-providing malate-aspartate shuttle, thereby implicating transcriptional regulation in a coordinated response to pathological energetic crisis. A central role for ASPA in this response is supported by a parallel developmental analysis showing highly significant increases in Nat8L expression in an ASPA-null mouse model during a period of early postnatal development normally punctuated by the transcriptional upregulation of aspa. These results provide preliminary evidence of a signaling mechanism in Alzheimer's disease that involves cross talk between neurons and oligodendrocytes, and suggest that ASPA acts to negatively regulate Nat8L expression. This mechanism is proposed to be a fundamental means by which the brain conserves available substrate during energy crises. Copyright © 2015 Elsevier Inc. All rights reserved.

Structural determinants and cellular environment define processed actin as the sole substrate of the N-terminal acetyltransferase NAA80.

PubMed

Goris, Marianne; Magin, Robert S; Foyn, Håvard; Myklebust, Line M; Varland, Sylvia; Ree, Rasmus; Drazic, Adrian; Bhambra, Parminder; Støve, Svein I; Baumann, Markus; Haug, Bengt Erik; Marmorstein, Ronen; Arnesen, Thomas

2018-04-24

N-terminal (Nt) acetylation is a major protein modification catalyzed by N-terminal acetyltransferases (NATs). Methionine acidic N termini, including actin, are cotranslationally Nt acetylated by NatB in all eukaryotes, but animal actins containing acidic N termini, are additionally posttranslationally Nt acetylated by NAA80. Actin Nt acetylation was found to regulate cytoskeletal dynamics and motility, thus making NAA80 a potential target for cell migration regulation. In this work, we developed potent and selective bisubstrate inhibitors for NAA80 and determined the crystal structure of NAA80 in complex with such an inhibitor, revealing that NAA80 adopts a fold similar to other NAT enzymes but with a more open substrate binding region. Furthermore, in contrast to most other NATs, the substrate specificity of NAA80 is mainly derived through interactions between the enzyme and the acidic amino acids at positions 2 and 3 of the actin substrate and not residues 1 and 2. A yeast model revealed that ectopic expression of NAA80 in a strain lacking NatB activity partially restored Nt acetylation of NatB substrates, including yeast actin. Thus, NAA80 holds intrinsic capacity to posttranslationally Nt acetylate NatB-type substrates in vivo. In sum, the presence of a dominant cotranslational NatB in all eukaryotes, the specific posttranslational actin methionine removal in animals, and finally, the unique structural features of NAA80 leave only the processed actins as in vivo substrates of NAA80. Together, this study reveals the molecular and cellular basis of NAA80 Nt acetylation and provides a scaffold for development of inhibitors for the regulation of cytoskeletal properties. Copyright © 2018 the Author(s). Published by PNAS.

A new approach to the characterization of subtle errors in everyday action: implications for mild cognitive impairment.

PubMed

Seligman, Sarah C; Giovannetti, Tania; Sestito, John; Libon, David J

2014-01-01

Mild functional difficulties have been associated with early cognitive decline in older adults and increased risk for conversion to dementia in mild cognitive impairment, but our understanding of this decline has been limited by a dearth of objective methods. This study evaluated the reliability and validity of a new system to code subtle errors on an established performance-based measure of everyday action and described preliminary findings within the context of a theoretical model of action disruption. Here 45 older adults completed the Naturalistic Action Test (NAT) and neuropsychological measures. NAT performance was coded for overt errors, and subtle action difficulties were scored using a novel coding system. An inter-rater reliability coefficient was calculated. Validity of the coding system was assessed using a repeated-measures ANOVA with NAT task (simple versus complex) and error type (overt versus subtle) as within-group factors. Correlation/regression analyses were conducted among overt NAT errors, subtle NAT errors, and neuropsychological variables. The coding of subtle action errors was reliable and valid, and episodic memory breakdown predicted subtle action disruption. Results suggest that the NAT can be useful in objectively assessing subtle functional decline. Treatments targeting episodic memory may be most effective in addressing early functional impairment in older age.

Effect of common NAT2 variant alleles in the acetylation of the major clonazepam metabolite, 7-aminoclonazepam.

PubMed

Olivera, M; Martínez, C; Gervasini, G; Carrillo, J A; Ramos, S; Benítez, J; García-Martin, E; Agúndez, J A G

2007-01-01

We investigated the role of NAT2 on clonazepam acetylation, using transiently expressed human NAT2 alleles. The NAT25*B and the NAT2*6A variant alleles cause a 20 and 22-fold reduction in the Vmax, respectively. We conclude that NAT2 is responsible for 7-aminoclonazepam acetylation and that NAT2 gene polymorphisms impair such metabolic pathway.

The neutron transmission of natFe, 197Au and natW

NASA Astrophysics Data System (ADS)

Beyer, Roland; Junghans, Arnd R.; Schillebeeckx, Peter; Sirakov, Ivan; Song, Tae-Yung; Bemmerer, Daniel; Capote, Roberto; Ferrari, Anna; Hartmann, Andreas; Hannaske, Ronald; Heyse, Jan; Il Kim, Hyeon; Woon Kim, Jong; Kögler, Toni; Woo Lee, Cheol; Lee, Young-Ouk; Massarczyk, Ralph; Müller, Stefan E.; Reinhardt, Tobias P.; Röder, Marko; Schmidt, Konrad; Schwengner, Ronald; Szücs, Tamás; Takács, Marcell P.; Wagner, Andreas; Wagner, Louis; Yang, Sung-Chul

2018-05-01

Neutron total cross sections of natFe, 197Au and natW have been measured at the n ELBE neutron time-of-flight facility in the energy range 0.15-8MeV with an uncertainty due to counting statistics of up to 2% and a total uncertainty due to systematic effects of 1%. The neutrons are produced with the superconducting electron accelerator ELBE using a liquid lead circuit as photo-neutron target. By periodical sample-in-sample-out measurements the transmission of the sample materials has been determined using a low-threshold plastic scintillation detector. The resulting effective total cross sections show good agreement with previously measured data that cover only part of the energy range available at n ELBE. The results have also been compared to evaluated library files and recent calculations based on a dispersive coupled channel optical model potential.

Enjoying mathematics or feeling competent in mathematics? Reciprocal effects on mathematics achievement and perceived math effort expenditure.

PubMed

Pinxten, Maarten; Marsh, Herbert W; De Fraine, Bieke; Van Den Noortgate, Wim; Van Damme, Jan

2014-03-01

The multidimensionality of the academic self-concept in terms of domain specificity has been well established in previous studies, whereas its multidimensionality in terms of motivational functions (the so-called affect-competence separation) needs further examination. This study aims at exploring differential effects of enjoyment and competence beliefs on two external validity criteria in the field of mathematics. Data analysed in this study were part of a large-scale longitudinal research project. Following a five-wave design, math enjoyment, math competence beliefs, math achievement, and perceived math effort expenditure measures were repeatedly collected from a cohort of 4,724 pupils in Grades 3-7. Confirmatory factor analysis (CFA) was used to test the internal factor structure of the math self-concept. Additionally, a series of nested models was tested using structural equation modelling to examine longitudinal reciprocal interrelations between math competence beliefs and math enjoyment on the one hand and math achievement and perceived math effort expenditure on the other. Our results showed that CFA models with separate factors for math enjoyment and math competence beliefs fit the data substantially better than models without it. Furthermore, differential relationships between both constructs and the two educational outcomes were observed. Math competence beliefs had positive effects on math achievement and negative effects on perceived math effort expenditure. Math enjoyment had (mild) positive effects on subsequent perceived effort expenditure and math competence beliefs. This study provides further support for the affect-competence separation. Theoretical issues regarding adequate conceptualization and practical consequences for practitioners are discussed. © 2013 The British Psychological Society.

Role of Increased n-acetylaspartate Levels in Cancer

PubMed Central

Zand, Behrouz; Previs, Rebecca A.; Zacharias, Niki M.; Rupaimoole, Rajesha; Mitamura, Takashi; Nagaraja, Archana Sidalaghatta; Guindani, Michele; Dalton, Heather J.; Yang, Lifeng; Baddour, Joelle; Achreja, Abhinav; Hu, Wei; Pecot, Chad V.; Ivan, Cristina; Wu, Sherry Y.; McCullough, Christopher R.; Gharpure, Kshipra M.; Shoshan, Einav; Pradeep, Sunila; Mangala, Lingegowda S.; Rodriguez-Aguayo, Cristian; Wang, Ying; Nick, Alpa M.; Davies, Michael A.; Armaiz-Pena, Guillermo; Liu, Jinsong; Lutgendorf, Susan K.; Baggerly, Keith A.; Eli, Menashe Bar; Lopez-Berestein, Gabriel; Nagrath, Deepak; Bhattacharya, Pratip K.

2016-01-01

Background: The clinical and biological effects of metabolic alterations in cancer are not fully understood. Methods: In high-grade serous ovarian cancer (HGSOC) samples (n = 101), over 170 metabolites were profiled and compared with normal ovarian tissues (n = 15). To determine NAT8L gene expression across different cancer types, we analyzed the RNA expression of cancer types using RNASeqV2 data available from the open access The Cancer Genome Atlas (TCGA) website (http://www.cbioportal.org/public-portal/). Using NAT8L siRNA, molecular techniques and histological analysis, we determined cancer cell viability, proliferation, apoptosis, and tumor growth in in vitro and in vivo (n = 6–10 mice/group) settings. Data were analyzed with the Student’s t test and Kaplan-Meier analysis. Statistical tests were two-sided. Results: Patients with high levels of tumoral NAA and its biosynthetic enzyme, aspartate N-acetyltransferase (NAT8L), had worse overall survival than patients with low levels of NAA and NAT8L. The overall survival duration of patients with higher-than-median NAA levels (3.6 years) was lower than that of patients with lower-than-median NAA levels (5.1 years, P = .03). High NAT8L gene expression in other cancers (melanoma, renal cell, breast, colon, and uterine cancers) was associated with worse overall survival. NAT8L silencing reduced cancer cell viability (HEYA8: control siRNA 90.61%±2.53, NAT8L siRNA 39.43%±3.00, P < .001; A2780: control siRNA 90.59%±2.53, NAT8L siRNA 7.44%±1.71, P < .001) and proliferation (HEYA8: control siRNA 74.83%±0.92, NAT8L siRNA 55.70%±1.54, P < .001; A2780: control siRNA 50.17%±4.13, NAT8L siRNA 26.52%±3.70, P < .001), which was rescued by addition of NAA. In orthotopic mouse models (ovarian cancer and melanoma), NAT8L silencing reduced tumor growth statistically significantly (A2780: control siRNA 0.52 g±0.15, NAT8L siRNA 0.08 g±0.17, P < .001; HEYA8: control siRNA 0.79 g±0.42, NAT8L siRNA 0.24 g±0.18, P = .008, A375-SM: control siRNA 0.55 g±0.22, NAT8L siRNA 0.21 g±0.17g, P = .001). NAT8L silencing downregulated the anti-apoptotic pathway, which was mediated through FOXM1. Conclusion: These findings indicate that the NAA pathway has a prominent role in promoting tumor growth and represents a valuable target for anticancer therapy. Altered energy metabolism is a hallmark of cancer (1). Proliferating cancer cells have much greater metabolic requirements than nonproliferating differentiated cells (2,3). Moreover, altered cancer metabolism elevates unique metabolic intermediates, which can promote cancer survival and progression (4,5). Furthermore, emerging evidence suggests that proliferating cancer cells exploit alternative metabolic pathways to meet their high demand for energy and to accumulate biomass (6–8). PMID:26819345

Genetic heterogeneity among slow acetylator N-acetyltransferase 2 phenotypes in cryopreserved human hepatocytes.

PubMed

Doll, Mark A; Hein, David W

2017-07-01

Genetic polymorphisms in human N-acetyltransferase 2 (NAT2) modify the metabolism of numerous drugs and carcinogens. These genetic polymorphisms modify both drug efficacy and toxicity and cancer risk associated with carcinogen exposure. Previous studies have suggested phenotypic heterogeneity among different NAT2 slow acetylator genotypes. NAT2 phenotype was investigated in vitro and in situ in samples of human hepatocytes obtained from various NAT2 slow and intermediate NAT2 acetylator genotypes. NAT2 gene dose response (NAT2*5B/*5B > NAT2*5B/*6A > NAT2*6A/*6A) was observed towards the N-acetylation of the NAT2-specific drug sulfamethazine by human hepatocytes both in vitro and in situ. N-acetylation of 4-aminobiphenyl, an arylamine carcinogen substrate for both N-acetyltransferase 1 and NAT2, showed the same trend both in vitro and in situ although the differences were not significant (p > 0.05). The N-acetylation of the N-acetyltransferase 1-specific substrate p-aminobenzoic acid did not follow this trend. In comparisons of NAT2 intermediate acetylator genotypes, differences in N-acetylation between NAT2*4/*5B and NAT2*4/*6B hepatocytes were not observed in vitro or in situ towards any of these substrates. These results further support phenotypic heterogeneity among NAT2 slow acetylator genotypes, consistent with differential risks of drug failure or toxicity and cancer associated with carcinogen exposure.

Acute murine colitis reduces colonic 5-aminosalicylic acid metabolism by regulation of N-acetyltransferase-2

PubMed Central

Ramírez-Alcántara, Verónica

2014-01-01

Pharmacotherapy based on 5-aminosalicylic acid (5-ASA) is a preferred treatment for ulcerative colitis, but variable patient response to this therapy is observed. Inflammation can affect therapeutic outcomes by regulating the expression and activity of drug-metabolizing enzymes; its effect on 5-ASA metabolism by the colonic arylamine N-acetyltransferase (NAT) enzyme isoforms is not firmly established. We examined if inflammation affects the capacity for colonic 5-ASA metabolism and NAT enzyme expression. 5-ASA metabolism by colonic mucosal homogenates was directly measured with a novel fluorimetric rate assay. 5-ASA metabolism reported by the assay was dependent on Ac-CoA, inhibited by alternative NAT substrates (isoniazid, p-aminobenzoylglutamate), and saturable with Km (5-ASA) = 5.8 μM. A mouse model of acute dextran sulfate sodium (DSS) colitis caused pronounced inflammation in central and distal colon, and modest inflammation of proximal colon, defined by myeloperoxidase activity and histology. DSS colitis reduced capacity for 5-ASA metabolism in central and distal colon segments by 52 and 51%, respectively. Use of selective substrates of NAT isoforms to inhibit 5-ASA metabolism suggested that mNAT2 mediated 5-ASA metabolism in normal and colitis conditions. Western blot and real-time RT-PCR identified that proximal and distal mucosa had a decreased mNAT2 protein-to-mRNA ratio after DSS. In conclusion, an acute colonic inflammation impairs the expression and function of mNAT2 enzyme, thereby diminishing the capacity for 5-ASA metabolism by colonic mucosa. PMID:24742986

Arylamine N-acetyltransferase 1 in situ N-acetylation on CD3+ peripheral blood mononuclear cells correlate with NATb mRNA and NAT1 haplotype.

PubMed

Salazar-González, Raúl A; Turiján-Espinoza, Eneida; Hein, David W; Niño-Moreno, Perla C; Romano-Moreno, Silvia; Milán-Segovia, Rosa C; Portales-Pérez, Diana P

2018-02-01

Human arylamine N-acetyltransferase 1 (NAT1) is responsible for the activation and elimination of xenobiotic compounds and carcinogens. Genetic polymorphisms in NAT1 modify both drug efficacy and toxicity. Previous studies have suggested a role for NAT1 in the development of several diseases. The aim of the present study was to evaluate NAT1 protein expression and in situ N-acetylation capacity in peripheral blood mononuclear cells (PBMC), as well as their possible associations with the expression of NAT1 transcript and NAT1 genotype. We report NAT1 protein, mRNA levels, and N-acetylation in situ activity for PBMC obtained from healthy donors. NAT1-specific protein expression was higher in CD3+ cells than other major immune cell subtypes (CD19 or CD56 cells). N-acetylation of pABA varied markedly among the PBMC of participants, but correlated very significantly with levels of NAT1 transcripts. NAT1*4 subjects showed significantly (p = 0.017) higher apparent pABA V max of 71.3 ± 3.7 versus the NAT1*14B subjects apparent V max of 58.5 ± 2.5 nmoles Ac-pABA/24 h/million cells. Levels of pABA N-acetylation activity at each concentration of substrate evaluated also significantly correlated with NAT1 mRNA levels for all samples (p < 0.0001). This highly significant correlation was maintained for samples with the NAT1*4 (p = 0.002) and NAT1*14B haplotypes (p = 0.0106). These results provide the first documentation that NAT1-catalyzed N-acetylation in PBMC is higher in T cell than in other immune cell subtypes and that individual variation in N-acetylation capacity is dependent upon NAT1 mRNA and NAT1 haplotype.

Functional Effects of Genetic Polymorphisms in the N-acetyltransferase 1 Coding and 3′ Untranslated Regions

PubMed Central

Zhu, Yuanqi; States, J. Christopher; Wang, Yang; Hein, David W.

2011-01-01

BACKGROUND The functional effects of N-acetyltransferase 1 (NAT1) polymorphisms and haplotypes are poorly understood, compromising the validity of associations reported with diseases including birth defects and numerous cancers. METHODS We investigated the effects of genetic polymorphisms within the NAT1 coding region and the 3′-untranslated region (3′-UTR) and their associated haplotypes on N- and O-acetyltransferase catalytic activities, and NAT1 mRNA and protein levels following recombinant expression in COS-1 cells. RESULTS 1088T>A (rs1057126; 3′-UTR) and 1095C>A (rs15561; 3′-UTR) each slightly reduced NAT1 catalytic activity and NAT1 mRNA and protein levels. A 9-base pair (TAATAATAA) deletion between nucleotides 1065-1090 (3′-UTR) reduced NAT1 catalytic activity and NAT1 mRNA and protein levels. In contrast, a 445G>A (rs4987076; V149I), 459G>A (rs4986990; T153T), 640T>G (rs4986783; S214A) coding region haplotype present in NAT1*11 increased NAT1 catalytic activity and NAT1 protein, but not NAT1 mRNA levels. A combination of the 9-base pair (TAATAATAA) deletion and the 445G>A, 459G>A, 640T>G coding region haplotypes, both present in NAT1*11, appeared to neutralize the opposing effects on NAT1 protein and catalytic activity, resulting in levels of NAT1 protein and catalytic activity that did not differ significantly from the NAT1*4 reference. CONCLUSIONS Since 1095C>A (3′-UTR) is the sole polymorphism present in NAT1*3, our data suggests that NAT1*3 is not functionally equivalent to the NAT1*4 reference. Furthermore, our findings provide biological support for reported associations of 1088T>A and 1095C>A polymorphisms with birth defects. PMID:21290563

Benchmark of neutron production cross sections with Monte Carlo codes

NASA Astrophysics Data System (ADS)

Tsai, Pi-En; Lai, Bo-Lun; Heilbronn, Lawrence H.; Sheu, Rong-Jiun

2018-02-01

Aiming to provide critical information in the fields of heavy ion therapy, radiation shielding in space, and facility design for heavy-ion research accelerators, the physics models in three Monte Carlo simulation codes - PHITS, FLUKA, and MCNP6, were systematically benchmarked with comparisons to fifteen sets of experimental data for neutron production cross sections, which include various combinations of 12C, 20Ne, 40Ar, 84Kr and 132Xe projectiles and natLi, natC, natAl, natCu, and natPb target nuclides at incident energies between 135 MeV/nucleon and 600 MeV/nucleon. For neutron energies above 60% of the specific projectile energy per nucleon, the LAQGMS03.03 in MCNP6, the JQMD/JQMD-2.0 in PHITS, and the RQMD-2.4 in FLUKA all show a better agreement with data in heavy-projectile systems than with light-projectile systems, suggesting that the collective properties of projectile nuclei and nucleon interactions in the nucleus should be considered for light projectiles. For intermediate-energy neutrons whose energies are below the 60% projectile energy per nucleon and above 20 MeV, FLUKA is likely to overestimate the secondary neutron production, while MCNP6 tends towards underestimation. PHITS with JQMD shows a mild tendency for underestimation, but the JQMD-2.0 model with a modified physics description for central collisions generally improves the agreement between data and calculations. For low-energy neutrons (below 20 MeV), which are dominated by the evaporation mechanism, PHITS (which uses GEM linked with JQMD and JQMD-2.0) and FLUKA both tend to overestimate the production cross section, whereas MCNP6 tends to underestimate more systems than to overestimate. For total neutron production cross sections, the trends of the benchmark results over the entire energy range are similar to the trends seen in the dominate energy region. Also, the comparison of GEM coupled with either JQMD or JQMD-2.0 in the PHITS code indicates that the model used to describe the first stage of a nucleus-nucleus collision also affects the low-energy neutron production. Thus, in this case, a proper combination of two physics models is desired to reproduce the measured results. In addition, code users should be aware that certain models consistently produce secondary neutrons within a constant fraction of another model in certain energy regions, which might be correlated to different physics treatments in different models.

N-Acetyltransferase 2 (NAT2) polymorphism as a risk modifier of susceptibility to pediatric acute lymphoblastic leukemia.

PubMed

Kamel, Azza M; Ebid, Gamal T A; Moussa, Heba S

2015-08-01

N-Acetyltransferases (NAT) have been known to modify the risk to a variety of solid tumors. However, the role of NAT2 polymorphism in risk susceptibility to childhood acute lymphoblastic leukemia (ALL) is still not well known. We performed a case-control study to determine if the common NAT2 polymorphisms play a role in altering susceptibility to pediatric ALL. DNA of 92 pediatric ALL patients and 312 healthy controls was analyzed for the NAT2 polymorphisms using the PCR-RFLP method. The wild-type NAT2*4 was encountered in 8.6 % of patients versus 11.8 % of controls (P = 0.23). The rapid acetylators NAT2*12 803A>G, AG, GG, and AG/GG were overrepresented in controls (P = 0.0001; odds ratio (OR) 0.22, 0.19, and 0.21 respectively). NAT2*5D 341T>C and NAT2*11A 481C>T were of comparable frequencies. For their combination, NAT2*5A, a slow acetylator, both TCTT and CCCT were overrepresented in patients (P < 0.001; OR 15.8 and 17.9 respectively). NAT2*5B (803A>G, 341T>C, 481C>T) was overrepresented in controls (P < 0.001; OR 0.12). Apparently, 803A>G ameliorated the combined effect of 341T>C and 481C>T. A similar effect was obtained with NAT2*5C (341T>A, 803A>G) (P < 0.0001; OR 0.11). For slow acetylator NAT2*7A 857G>A, GA and GA/AA were overrepresented in patients (P = 0.009 and 0.01; OR 2.74 and 2.72 respectively). NAT2*13 282C>T, NAT2*6B 590G>A, and NAT2*14A 191G>A were of comparable frequencies. NAT2 282C>A in combination with NAT2 857G>A (NAT2*7B) showed a synergistic effect in patients versus controls (P < 0.0001; OR 3.51). In conclusion, NAT2 gene polymorphism(s) with slow acetylator phenotype is generally associated with the risk of development of ALL in children.

NAT2 gene diversity and its evolutionary trajectory in the Americas.

PubMed

Bisso-Machado, R; Ramallo, V; Paixão-Côrtes, V R; Acuña-Alonzo, V; Demarchi, D A; Sandoval, J R S; Granara, A A S; Salzano, F M; Hünemeier, T; Bortolini, M C

2016-11-01

N-acetyltransferase 2 (NAT2) is responsible for metabolizing xenobiotics; NAT2 polymorphisms lead to three phenotypes: rapid, intermediate and slow acetylators. We aimed to investigate NAT2 diversity in Native Americans. NAT2 exon 2 was sequenced for 286 individuals from 21 populations (Native American and American Mestizos). Excluding the basal/rapid haplotype NAT2*4, the most frequent haplotypes are NAT2*5B (35.95%) in hunter-gatherers and NAT2*7B (20.61%) and NAT2*5B (19.08%) in agriculturalists that were related to the slow phenotype. A new haplotype was identified in two Amerindians. Data from the ~44 kb region surrounding NAT2 in 819 individuals from Africa, East-Asia, Europe and America were used in additional analyses. No significant differences in the acetylator NAT2 haplotype and phenotype distributions were found between Native American populations practicing farming and/or herding and those practicing hunting and gathering, probably because of the absence or weakness of selection pressures and presence of demographic and random processes preventing detection of any selection signal.

Congenic rats with higher arylamine N-acetyltransferase 2 activity exhibit greater carcinogen-induced mammary tumor susceptibility independent of carcinogen metabolism.

PubMed

Stepp, Marcus W; Doll, Mark A; Samuelson, David J; Sanders, Mary Ann G; States, J Christopher; Hein, David W

2017-03-31

Recent investigations suggest role(s) of human arylamine N-acetyltransferase 1 (NAT1) in breast cancer. Rat NAT2 is orthologous to human NAT1 and the gene products are functional homologs. We conducted in vivo studies using F344.WKY-Nat2 rapid/slow rats, congenic at rat Nat2 for high (rapid) and low (slow) arylamine N-acetyltransferase activity, to assess a possible role for rat NAT2 in mammary tumor susceptibility. Mammary carcinogens, methylnitrosourea (MNU) and 7,12-dimethylbenzanthracene (DMBA) neither of which is metabolized by N-acetyltransferase, were administered to assess mammary tumors. MNU was administered at 3 or 8 weeks of age. DMBA was administered at 8 weeks of age. NAT2 enzymatic activity and endogenous acetyl-coenzyme A (AcCoA) levels were measured in tissue samples and embryonic fibroblasts isolated from the congenic rats. Tumor latency was shorter in rapid NAT2 rats compared to slow NAT2 rats, with statistical significance for MNU administered at 3 and 8 weeks of age (p = 0.009 and 0.050, respectively). Tumor multiplicity and incidence were higher in rapid NAT2 rats compared to slow NAT2 rats administered MNU or DMBA at 8 weeks of age (MNU, p = 0.050 and 0.035; DMBA, p = 0.004 and 0.027, respectively). Recombinant rat rapid-NAT2, as well as tissue samples and embryonic fibroblasts derived from rapid NAT2 rats, catalyzed p-aminobenzoic acid N-acetyl transfer and folate-dependent acetyl-coenzyme A (AcCoA) hydrolysis at higher rates than those derived from rat slow-NAT2. Embryonic fibroblasts isolated from rapid NAT2 rats displayed lower levels of cellular AcCoA than slow NAT2 rats (p < 0.01). A novel role for rat NAT2 in mammary cancer was discovered unrelated to carcinogen metabolism, suggesting a role for human NAT1 in breast cancer.

Arylamine N-acetyltransferase 2 gene polymorphism in an Algerian population.

PubMed

Chelouti, Hiba; Khelil, Malika

2017-09-01

The arylamine N-acetyltransferase 2 (NAT2) is a key enzyme in the biotransformation of xenobiotics. NAT2 gene polymorphisms have been associated with the risk of isoniazid hepatotoxicity and these polymorphisms change among different populations. The objective of this study is to investigate NAT2 polymorphisms in order to predict the prevalence of NAT2 phenotype in an Algerian population. Genotyping of NAT2 was done using a PCR-RFLP method. Haplotype was analysed using the software package PHASE, version 2.0. The major haplotypes were NAT2*5B (23.72%), NAT2*6 A (18.61%), NAT2*4 (14.60%) and NAT2*5 F (10%). The average of the expected slow acetylator phenotype was 53%. Our results suggest that the high frequency of slow acetylator phenotype requires investigation into its possible association with ATDH.

Association Between N-acetyltransferase 2 Polymorphism and Bladder Cancer Risk: Results From Studies of the Past Decade and a Meta-Analysis.

PubMed

Wu, Haoran; Wang, Xugang; Zhang, Liang; Mo, Naixin; Lv, Zhong

2016-04-01

Numerous studies have identified that the slow acetylation status of N-acetyltransferase 2 (NAT2) is associated with an elevated bladder cancer risk. However, the results remain inconclusive. The aim of our study was to evaluate the effect of NAT2 acetylation status in patients with bladder cancer. Electronic databases were searched to retrieve related studies published in the past decade. The pooled odds ratio (OR) with its 95% confidence interval (CI) was used to calculate the strength of this relationship. Overall, a total of 18 studies were selected for the analysis, which included 4473 bladder cancer cases and 7204 matched controls. Our result showed that the NAT2 slow acetylation phenotypes were significantly associated with an increased risk of bladder cancer compared with the rapid phenotypes (OR, 1.56; 95% CI, 1.33-1.82; P < .00001) in a random-effect model. This significant association was also found in a subgroup analysis of ethnicity (P < .05). Furthermore, the NAT2 slow phenotypes also significantly increased the risk of bladder cancer in smokers (OR, 0.75; 95% CI, 0.62-0.90; P = .002). However, no correlation was found between the combined effect of NAT2 slow phenotypes and gender with bladder cancer risk (OR, 0.89; 95% CI, 0.28-2.78; P = .84). In conclusion, our results suggest that the NAT2 slow acetylator, in particular, the NAT2 slow acetylator combined with smoking, are associated with an increased bladder cancer risk. Future well-designed studies with large populations and more ethnicities are needed to clarify this association further. Copyright © 2016 Elsevier Inc. All rights reserved.

An assessment of differences in costs and health benefits of serology and NAT screening of donations for blood transfusion in different Western countries.

PubMed

Janssen, M P; van Hulst, M; Custer, B

2017-08-01

The cost-utility of safety interventions is becoming increasingly important as a driver of implementation decisions. The aim of this study was to compare the cost-utility of different blood screening strategies in various settings, and to analyse the extent and cause of differences in health economic results. For eight Western countries (Australia, Canada, Denmark, Finland, France, The Netherlands, UK and the United States of America), data were collected on donor and recipient populations, blood products, screening tests, and on patient treatment practices and costs. An existing ISBT web-tool model was used to assess the cost-utility of various strategies for HIV, HCV and HBV screening. The cost-utility ratio of serology screening for these eight countries ranges between -11 000 and 92 000 US$ per QALY, and for NAT between -12 000 and 113 000 US$ per QALY when compared to no screening. Combined serology and NAT ranges between 600 and 217 000 US$ per QALY. The incremental cost-utility of NAT after implementation of serology screening ranges from 2 231 000 to 15 778 000 US$ per QALY. There are substantial differences in costs per QALY between countries for various HIV, HBV and HCV screening strategies. These differences are primarily caused by costs of screening tests and infection rates in the donor population. Within each country, similar cost per QALY results for serology and NAT compared to no screening, coupled with evidence of limited value of serology and NAT together prompts the need for further discussion on the acceptability of parallel testing by serology and NAT. © 2017 International Society of Blood Transfusion.

Regulation of an antisense RNA with the transition of neonatal to IIb myosin heavy chain during postnatal development and hypothyroidism in rat skeletal muscle

PubMed Central

Jiang, Weihua; Qin, Anqi X.; Bodell, Paul W.; Baldwin, Kenneth M.; Haddad, Fadia

2012-01-01

Postnatal development of fast skeletal muscle is characterized by a transition in expression of myosin heavy chain (MHC) isoforms, from primarily neonatal MHC at birth to primarily IIb MHC in adults, in a tightly coordinated manner. These isoforms are encoded by distinct genes, which are separated by ∼17 kb on rat chromosome 10. The neonatal-to-IIb MHC transition is inhibited by a hypothyroid state. We examined RNA products [mRNA, pre-mRNA, and natural antisense transcript (NAT)] of developmental and adult-expressed MHC genes (embryonic, neonatal, I, IIa, IIx, and IIb) at 2, 10, 20, and 40 days after birth in normal and thyroid-deficient rat neonates treated with propylthiouracil. We found that a long noncoding antisense-oriented RNA transcript, termed bII NAT, is transcribed from a site within the IIb-Neo intergenic region and across most of the IIb MHC gene. NATs have previously been shown to mediate transcriptional repression of sense-oriented counterparts. The bII NAT is transcriptionally regulated during postnatal development and in response to hypothyroidism. Evidence for a regulatory mechanism is suggested by an inverse relationship between IIb MHC and bII NAT in normal and hypothyroid-treated muscle. Neonatal MHC transcription is coordinately expressed with bII NAT. A comparative phylogenetic analysis also suggests that bII NAT-mediated regulation has been a conserved trait of placental mammals for most of the eutherian evolutionary history. The evidence in support of the regulatory model implicates long noncoding antisense RNA as a mechanism to coordinate the transition between neonatal and IIb MHC during postnatal development. PMID:22262309

Regulation of an antisense RNA with the transition of neonatal to IIb myosin heavy chain during postnatal development and hypothyroidism in rat skeletal muscle.

PubMed

Pandorf, Clay E; Jiang, Weihua; Qin, Anqi X; Bodell, Paul W; Baldwin, Kenneth M; Haddad, Fadia

2012-04-01

Postnatal development of fast skeletal muscle is characterized by a transition in expression of myosin heavy chain (MHC) isoforms, from primarily neonatal MHC at birth to primarily IIb MHC in adults, in a tightly coordinated manner. These isoforms are encoded by distinct genes, which are separated by ∼17 kb on rat chromosome 10. The neonatal-to-IIb MHC transition is inhibited by a hypothyroid state. We examined RNA products [mRNA, pre-mRNA, and natural antisense transcript (NAT)] of developmental and adult-expressed MHC genes (embryonic, neonatal, I, IIa, IIx, and IIb) at 2, 10, 20, and 40 days after birth in normal and thyroid-deficient rat neonates treated with propylthiouracil. We found that a long noncoding antisense-oriented RNA transcript, termed bII NAT, is transcribed from a site within the IIb-Neo intergenic region and across most of the IIb MHC gene. NATs have previously been shown to mediate transcriptional repression of sense-oriented counterparts. The bII NAT is transcriptionally regulated during postnatal development and in response to hypothyroidism. Evidence for a regulatory mechanism is suggested by an inverse relationship between IIb MHC and bII NAT in normal and hypothyroid-treated muscle. Neonatal MHC transcription is coordinately expressed with bII NAT. A comparative phylogenetic analysis also suggests that bII NAT-mediated regulation has been a conserved trait of placental mammals for most of the eutherian evolutionary history. The evidence in support of the regulatory model implicates long noncoding antisense RNA as a mechanism to coordinate the transition between neonatal and IIb MHC during postnatal development.

Identification of N-Acetyltaurine as a Novel Metabolite of Ethanol through Metabolomics-guided Biochemical Analysis*

PubMed Central

Shi, Xiaolei; Yao, Dan; Chen, Chi

2012-01-01

The influence of ethanol on the small molecule metabolome and the role of CYP2E1 in ethanol-induced hepatotoxicity were investigated using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics platform and Cyp2e1-null mouse model. Histological and biochemical examinations of ethanol-exposed mice indicated that the Cyp2e1-null mice were more resistant to ethanol-induced hepatic steatosis and transaminase leakage than the wild-type mice, suggesting CYP2E1 contributes to ethanol-induced toxicity. Metabolomic analysis of urinary metabolites revealed time- and dose-dependent changes in the chemical composition of urine. Along with ethyl glucuronide and ethyl sulfate, N-acetyltaurine (NAT) was identified as a urinary metabolite that is highly responsive to ethanol exposure and is correlated with the presence of CYP2E1. Subsequent stable isotope labeling analysis using deuterated ethanol determined that NAT is a novel metabolite of ethanol. Among three possible substrates of NAT biosynthesis (taurine, acetyl-CoA, and acetate), the level of taurine was significantly reduced, whereas the levels of acetyl-CoA and acetate were dramatically increased after ethanol exposure. In vitro incubation assays suggested that acetate is the main precursor of NAT, which was further confirmed by the stable isotope labeling analysis using deuterated acetate. The incubations of tissues and cellular fractions with taurine and acetate indicated that the kidney has the highest NAT synthase activity among the tested organs, whereas the cytosol is the main site of NAT biosynthesis inside the cell. Overall, the combination of biochemical and metabolomic analysis revealed NAT is a novel metabolite of ethanol and a potential biomarker of hyperacetatemia. PMID:22228769

Red meat intake, NAT2, and risk of colorectal cancer: A pooled analysis of 11 studies

PubMed Central

Ananthakrishnan, Ashwin N.; Du, Mengmeng; Berndt, Sonja I.; Brenner, Hermann; Caan, Bette J.; Casey, Graham; Chang-Claude, Jenny; Duggan, David; Fuchs, Charles S.; Gallinger, Steven; Giovannucci, Edward L.; Harrison, Tabitha A.; Hayes, Richard B.; Hoffmeister, Michael; Hopper, John L.; Hou, Lifang; Hsu, Li; Jenkins, Mark A.; Kraft, Peter; Ma, Jing; Nan, Hongmei; Newcomb, Polly A.; Ogino, Shuji; Potter, John D.; Seminara, Daniela; Slattery, Martha L.; Thornquist, Mark; White, Emily; Wu, Kana; Peters, Ulrike; Chan, Andrew T.

2014-01-01

Background Red meat intake has been associated with risk of colorectal cancer (CRC), potentially mediated through heterocyclic amines. The metabolic efficiency of N-acetyltransferase 2 (NAT2) required for the metabolic activation of such amines is influenced by genetic variation. The interaction between red meat intake, NAT2 genotype, and CRC has been inconsistently reported. Methods We used pooled individual-level data from the Colon Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO). Red meat intake was collected by each study. We inferred NAT2 phenotype based on polymorphism at rs1495741, highly predictive of enzyme activity. Interaction was assessed using multiplicative interaction terms in multivariate-adjusted models. Results From 11 studies, 8,290 CRC cases and 9,115 controls were included. The highest quartile of red meat intake was associated with increased risk of CRC compared to the lowest quartile (OR 1.41, 95%CI 1.29 – 1.55). However, a significant association was observed only for studies with retrospective diet data, not for studies with diet prospectively assessed before cancer diagnosis. Combining all studies, high red meat intake was similarly associated with CRC in those with a rapid/intermediate NAT2 genotype (OR 1.38, 95%CI 1.20 – 1.59) as with a slow genotype (OR 1.43, 95%CI 1.28 – 1.61) (p- interaction=0.9). Conclusion We found that high red meat intake was associated with increased risk of CRC only from retrospective case-control studies and not modified by NAT2 enzyme activity. Impact Our results suggest no interaction between NAT2 genotype and red-meat intake in mediating risk of CRC. PMID:25342387

Induction of neuronal axon outgrowth by Shati/Nat8l by energy metabolism in mice cultured neurons.

PubMed

Sumi, Kazuyuki; Uno, Kyosuke; Matsumura, Shohei; Miyamoto, Yoshiaki; Furukawa-Hibi, Yoko; Muramatsu, Shin-Ichi; Nabeshima, Toshitaka; Nitta, Atsumi

2015-09-09

A novel N-acetyltransferase, Shati/Nat8l, was identified in the nucleus accumbens of mice repeatedly treated with methamphetamine (METH). Shati/Nat8l has been reported to inhibit the pharmacological action induced by METH. Shati/Nat8l produces N-acetylaspartate from aspartate and acetyl-CoA. Previously, we reported that overexpression of Shati/Nat8l in nucleus accumbens attenuates the response to METH by N-acetylaspartylglutamate (which is derived from N-acetylaspartate)-mGluR3 signaling in the mice brain. In the present study, to clarify the type of cells that produce Shati/Nat8l, we carried out in-situ hybridization for the detection of Shati/Nat8l mRNA along with immunohistochemical studies using serial sections of mice brain. Shati/Nat8l mRNA was detected in neuronal cells, but not in astrocytes or microglia cells. Next, we investigated the function of Shati/Nat8l in the neuronal cells in mice brain; then, we used an adeno-associated virus vector containing Shati/Nat8l for transfection and overexpression of Shati/Nat8l protein into the primary cultured neurons to investigate the contribution toward the neuronal activity of Shati/Nat8l. Overexpression of Shati/Nat8l in the mice primary cultured neurons induced axonal growth, but not dendrite elongation at day 1.5 (DIV). This finding indicated that Shati/Nat8l contributes toward neuronal development. LY341495, a selective group II mGluRs antagonist, did not abolish this axonal growth, and N-acetylaspartylglutamate itself did not abolish axon outgrowth in the same cultured system. The cultured neurons overexpressing Shati/Nat8l contained high ATP, suggesting that axon outgrowth is dependent on energy metabolism. This study shows that Shati/Nat8l in the neuron may induce axon outgrowth by ATP synthesis and not through mGluR3 signaling.

Regression Model Optimization for the Analysis of Experimental Data

NASA Technical Reports Server (NTRS)

Ulbrich, N.

2009-01-01

A candidate math model search algorithm was developed at Ames Research Center that determines a recommended math model for the multivariate regression analysis of experimental data. The search algorithm is applicable to classical regression analysis problems as well as wind tunnel strain gage balance calibration analysis applications. The algorithm compares the predictive capability of different regression models using the standard deviation of the PRESS residuals of the responses as a search metric. This search metric is minimized during the search. Singular value decomposition is used during the search to reject math models that lead to a singular solution of the regression analysis problem. Two threshold dependent constraints are also applied. The first constraint rejects math models with insignificant terms. The second constraint rejects math models with near-linear dependencies between terms. The math term hierarchy rule may also be applied as an optional constraint during or after the candidate math model search. The final term selection of the recommended math model depends on the regressor and response values of the data set, the user s function class combination choice, the user s constraint selections, and the result of the search metric minimization. A frequently used regression analysis example from the literature is used to illustrate the application of the search algorithm to experimental data.

Test and analysis procedures for updating math models of Space Shuttle payloads

NASA Technical Reports Server (NTRS)

Craig, Roy R., Jr.

1991-01-01

Over the next decade or more, the Space Shuttle will continue to be the primary transportation system for delivering payloads to Earth orbit. Although a number of payloads have already been successfully carried by the Space Shuttle in the payload bay of the Orbiter vehicle, there continues to be a need for evaluation of the procedures used for verifying and updating the math models of the payloads. The verified payload math models is combined with an Orbiter math model for the coupled-loads analysis, which is required before any payload can fly. Several test procedures were employed for obtaining data for use in verifying payload math models and for carrying out the updating of the payload math models. Research was directed at the evaluation of test/update procedures for use in the verification of Space Shuttle payload math models. The following research tasks are summarized: (1) a study of free-interface test procedures; (2) a literature survey and evaluation of model update procedures; and (3) the design and construction of a laboratory payload simulator.

Wet-Bulb-Globe Temperature Data Report

DTIC Science & Technology

2015-03-01

Hour Min Pressure Dry Nat Wet Globe Dry Nat Wet Globe Dry Nat Wet Globe Wind Cld amt Cld type Obscuration Quest RH Kestrel RH VPSc RH S1 WBGT Q WBGT...Wet Globe Dry Nat Wet Globe Dry Nat Wet Globe Wind Cld amt Cld type Obscuration Quest RH Kestrel RH VPSc RH S1 WBGT Q WBGT K2 WBGT GMT millibars deg F...Dry Nat Wet Globe Dry Nat Wet Globe Wind Cld amt Cld type Obscuration Quest RH Kestrel RH VPSc RH S1 WBGT Q WBGT K2 WBGT GMT millibars deg F deg F deg

Rapid birth-and-death evolution of the xenobiotic metabolizing NAT gene family in vertebrates with evidence of adaptive selection

PubMed Central

2013-01-01

Background The arylamine N-acetyltransferases (NATs) are a unique family of enzymes widely distributed in nature that play a crucial role in the detoxification of aromatic amine xenobiotics. Considering the temporal changes in the levels and toxicity of environmentally available chemicals, the metabolic function of NATs is likely to be under adaptive evolution to broaden or change substrate specificity over time, making NATs a promising subject for evolutionary analyses. In this study, we trace the molecular evolutionary history of the NAT gene family during the last ~450 million years of vertebrate evolution and define the likely role of gene duplication, gene conversion and positive selection in the evolutionary dynamics of this family. Results A phylogenetic analysis of 77 NAT sequences from 38 vertebrate species retrieved from public genomic databases shows that NATs are phylogenetically unstable genes, characterized by frequent gene duplications and losses even among closely related species, and that concerted evolution only played a minor role in the patterns of sequence divergence. Local signals of positive selection are detected in several lineages, probably reflecting response to changes in xenobiotic exposure. We then put a special emphasis on the study of the last ~85 million years of primate NAT evolution by determining the NAT homologous sequences in 13 additional primate species. Our phylogenetic analysis supports the view that the three human NAT genes emerged from a first duplication event in the common ancestor of Simiiformes, yielding NAT1 and an ancestral NAT gene which in turn, duplicated in the common ancestor of Catarrhini, giving rise to NAT2 and the NATP pseudogene. Our analysis suggests a main role of purifying selection in NAT1 protein evolution, whereas NAT2 was predicted to mostly evolve under positive selection to change its amino acid sequence over time. These findings are consistent with a differential role of the two human isoenzymes and support the involvement of NAT1 in endogenous metabolic pathways. Conclusions This study provides unequivocal evidence that the NAT gene family has evolved under a dynamic process of birth-and-death evolution in vertebrates, consistent with previous observations made in fungi. PMID:23497148

Structures and functions of insect arylalkylamine N-acetyltransferase (iaaNAT); a key enzyme for physiological and behavioral switch in arthropods

PubMed Central

Hiragaki, Susumu; Suzuki, Takeshi; Mohamed, Ahmed A. M.; Takeda, Makio

2015-01-01

The evolution of N-acetyltransfeases (NATs) seems complex. Vertebrate arylalkylamine N-acetyltransferase (aaNAT) has been extensively studied since it leads to the synthesis of melatonin, a multifunctional neurohormone prevalent in photoreceptor cells, and is known as a chemical token of the night. Melatonin also serves as a scavenger for reactive oxygen species. This is also true with invertebrates. NAT therefore has distinct functional implications in circadian function, as timezymes (aaNAT), and also xenobiotic reactions (arylamine NAT or simply NAT). NATs belong to a broader enzyme group, the GCN5-related N-acetyltransferase superfamily. Due to low sequence homology and a seemingly fast rate of structural differentiation, the nomenclature for NATs can be confusing. The advent of bioinformatics, however, has helped to classify this group of enzymes; vertebrates have two distinct subgroups, the timezyme type and the xenobiotic type, which has a wider substrate range including imidazolamine, pharmacological drugs, environmental toxicants and even histone. Insect aaNAT (iaaNAT) form their own clade in the phylogeny, distinct from vertebrate aaNATs. Arthropods are unique, since the phylum has exoskeleton in which quinones derived from N-acetylated monoamines function in coupling chitin and arthropodins. Monoamine oxidase (MAO) activity is limited in insects, but NAT-mediated degradation prevails. However, unexpectedly iaaNAT occurs not only among arthropods but also among basal deuterostomia, and is therefore more apomorphic. Our analyses illustrate that iaaNATs has unique physiological roles but at the same time it plays a role in a timezyme function, at least in photoperiodism. Photoperiodism has been considered as a function of circadian system but the detailed molecular mechanism is not well understood. We propose a molecular hypothesis for photoperiodism in Antheraea pernyi based on the transcription regulation of NAT interlocked by the circadian system. Therefore, the enzyme plays both unique and universal roles in insects. The unique role of iaaNATs in physiological regulation urges the targeting of this system for integrated pest management (IPM). We indeed showed a successful example of chemical compound screening with reconstituted enzyme and further attempts seem promising. PMID:25918505

Structures and functions of insect arylalkylamine N-acetyltransferase (iaaNAT); a key enzyme for physiological and behavioral switch in arthropods.

PubMed

Hiragaki, Susumu; Suzuki, Takeshi; Mohamed, Ahmed A M; Takeda, Makio

2015-01-01

The evolution of N-acetyltransfeases (NATs) seems complex. Vertebrate arylalkylamine N-acetyltransferase (aaNAT) has been extensively studied since it leads to the synthesis of melatonin, a multifunctional neurohormone prevalent in photoreceptor cells, and is known as a chemical token of the night. Melatonin also serves as a scavenger for reactive oxygen species. This is also true with invertebrates. NAT therefore has distinct functional implications in circadian function, as timezymes (aaNAT), and also xenobiotic reactions (arylamine NAT or simply NAT). NATs belong to a broader enzyme group, the GCN5-related N-acetyltransferase superfamily. Due to low sequence homology and a seemingly fast rate of structural differentiation, the nomenclature for NATs can be confusing. The advent of bioinformatics, however, has helped to classify this group of enzymes; vertebrates have two distinct subgroups, the timezyme type and the xenobiotic type, which has a wider substrate range including imidazolamine, pharmacological drugs, environmental toxicants and even histone. Insect aaNAT (iaaNAT) form their own clade in the phylogeny, distinct from vertebrate aaNATs. Arthropods are unique, since the phylum has exoskeleton in which quinones derived from N-acetylated monoamines function in coupling chitin and arthropodins. Monoamine oxidase (MAO) activity is limited in insects, but NAT-mediated degradation prevails. However, unexpectedly iaaNAT occurs not only among arthropods but also among basal deuterostomia, and is therefore more apomorphic. Our analyses illustrate that iaaNATs has unique physiological roles but at the same time it plays a role in a timezyme function, at least in photoperiodism. Photoperiodism has been considered as a function of circadian system but the detailed molecular mechanism is not well understood. We propose a molecular hypothesis for photoperiodism in Antheraea pernyi based on the transcription regulation of NAT interlocked by the circadian system. Therefore, the enzyme plays both unique and universal roles in insects. The unique role of iaaNATs in physiological regulation urges the targeting of this system for integrated pest management (IPM). We indeed showed a successful example of chemical compound screening with reconstituted enzyme and further attempts seem promising.

Cost effectiveness of adding nucleic acid testing to hepatitis B, hepatitis C, and human immunodeficiency virus screening of blood donations in Zimbabwe.

PubMed

Mafirakureva, Nyashadzaishe; Mapako, Tonderai; Khoza, Star; Emmanuel, Jean C; Marowa, Lucy; Mvere, David; Postma, Maarten J; van Hulst, Marinus

2016-12-01

The aim of this study was to assess the cost effectiveness of introducing individual-donation nucleic acid testing (ID-NAT), in addition to serologic tests, compared with the exclusive use of serologic tests for the identification of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) I and II among blood donors in Zimbabwe. The costs, health consequences, and cost effectiveness of adding ID-NAT to serologic tests, compared with serologic testing alone, were estimated from a health care perspective using a decision-analytic model. The introduction of ID-NAT in addition to serologic tests would lower the risk of HBV, HCV, and HIV transmission to 46.9, 0.3, and 2.7 per 100,000 donations, respectively. ID-NAT would prevent an estimated 25, 6, and 9 HBV, HCV, and HIV transfusion-transmitted infections per 100,000 donations, respectively. The introduction of this intervention would result in an estimated 212 quality-adjusted life-years (QALYs) gained. The incremental cost-effectiveness ratio is estimated at US$17,774/QALY, a value far more than three times the gross national income per capita for Zimbabwe. Although the introduction of NAT could further improve the safety of the blood supply, current evidence suggests that it cannot be considered cost effective. Reducing the test costs for NAT through efficient donor recruitment, negotiating the price of reagents, and the efficient use of technology will improve cost effectiveness. © 2016 AABB.

N-acetyltransferase polymorphisms are associated with risk of lymphoma subtypes.

PubMed

Cocco, Pierluigi; Zucca, Mariagrazia; Sanna, Sonia; Satta, Giannina; Nonne, Tinucia; Angelucci, Emanuele; Gabbas, Attilio; Rais, Marco; Malpeli, Giorgio; Campagna, Marcello; Scarpa, Aldo; G Ennas, Maria

2016-06-01

Genes encoding for arylamine N-acetyltransferase 1 and 2 (NAT1 and NAT2) have been investigated with alternate findings in relation to risk of non-Hodgkin lymphoma (NHL). We tested functional haplotype-based NAT1 and NAT2 gene polymorphisms in relation to risk of lymphoma overall and its major B cell subtypes, diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL) and chronic lymphocytic leukaemia (CLL). We used allele specific primers and multiplex PCR to detect NAT1 and NAT2 haplotypes in 248 patients with incident lymphoma and 208 population controls. We inferred the NAT1 rapid and slow acetylator and the NAT2 rapid, intermediate or slow acetylator phenotype, based on published functional data on the respective genotypes. Odds ratios and 95% confidence intervals (95% CIs) for lymphoma, B-NHL, DLBCL, FL, CLL, and other B-NHL combined associated with the inferred rapid NAT1 acetylator and with the intermediate and slow NAT2 acetylator phenotypes were estimated with unconditional and polytomous logistic regression analysis, adjusting for age, gender and education. NAT1 rapid acetylators showed a 2.8-fold excess risk (95% CI 1.5-5.2) for lymphoma (all subtypes combined). Risk was highest for CLL and FL, with significant heterogeneity detected across subtypes. Risk also increased with decreasing NAT2 acetylating capacity with no heterogeneity detected across B cell lymphoma subtypes. Risks did not vary by gender. Although poor statistical power was a major limitation in our study, larger studies and pooled analyses are warranted to test whether NAT1 and NAT2 gene polymorphisms might modulate risk of specific lymphoma subtypes through the varying metabolic activity of their products. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Importance of the Evaluation of N-Acetyltransferase Enzyme Activity Prior to 5-Aminosalicylic Acid Medication for Ulcerative Colitis.

PubMed

Matthis, Andrea L; Zhang, Bin; Denson, Lee A; Yacyshyn, Bruce R; Aihara, Eitaro; Montrose, Marshall H

2016-08-01

5-aminosalicylic acid (5-ASA) is a classic anti-inflammatory drug for the treatment of ulcerative colitis. N-acetyltransferase (NAT) enzymes convert 5-ASA to its metabolite N-acetyl-5-ASA, and it is unresolved whether 5-ASA or N-acetyl-5-ASA is the effective therapeutic molecule. We previously demonstrated that colonic production of N-acetyl-5-ASA (NAT activity) is decreased in dextran sulfate sodium-induced colitis. Our hypothesis is that 5-ASA is the therapeutic molecule to improve colitis, with the corollary that altered NAT activity affects drug efficacy. Since varying clinical effectiveness of 5-ASA has been reported, we also ask if NAT activity varies with inflammation in pediatric or adult patients. Acute colonic inflammation was induced in C57BL/6 NAT wild-type (WT) or knockout mice, using 3.5% dextran sulfate sodium (w/v) concurrent with 5-ASA treatment. Adult and pediatric rectosigmoid biopsies were collected from control or patients with ulcerative colitis. Tissue was analyzed for NAT and myeloperoxidase activity. Dextran sulfate sodium-induced colitis was of similar severity in both NAT WT and knockout mice, and NAT activity was significantly decreased in NAT WT mice. In the setting of colitis, 5-ASA significantly restored colon length and decreased myeloperoxidase activity in NAT knockout but not in WT mice. Myeloperoxidase activity negatively correlated with NAT activity in pediatric patients, but correlation was not observed in adult patients. Inflammation decreases NAT activity in the colon of mice and human pediatric patients. Decreased NAT activity enhances the therapeutic effect of 5-ASA in mice. A NAT activity assay could be useful to help predict the efficacy of 5-ASA therapy.

Natural antisense transcripts are significantly involved in regulation of drought stress in maize.

PubMed

Xu, Jie; Wang, Qi; Freeling, Micheal; Zhang, Xuecai; Xu, Yunbi; Mao, Yan; Tang, Xin; Wu, Fengkai; Lan, Hai; Cao, Moju; Rong, Tingzhao; Lisch, Damon; Lu, Yanli

2017-05-19

Natural antisense transcripts (NATs) are a prominent and complex class of regulatory RNAs. Using strand-specific RNA sequencing, we identified 1769 sense and antisense transcript pairs (NAT pairs) in two maize inbreds with different sensitivity to drought, as well as in two derivative recombination inbred lines (RILs). A significantly higher proportion of NATs relative to non-NATs are specifically expressed under water stress (WS). Surprisingly, expression of sense and antisense transcripts produced by NAT pairs is significantly correlated, particularly under WS. We found an unexpected large proportion of NATs with protein coding potential, as estimated by ribosome release scores. Small RNAs significantly accumulate within NAT pairs, with 21 nt smRNA particularly enriched in overlapping regions of these pairs of genes. The abundance of these smRNAs is significantly altered in the leafbladeless1 mutant, suggesting that these genes may be regulated by the tasiRNA pathway. Further, NATs are significantly hypomethylated and include fewer transposable element sequences relative to non-NAT genes. NAT gene regions also exhibit higher levels of H3K36me3, H3K9ac, and H3K4me3, but lower levels of H3K27me3, indicating that NAT gene pairs generally exhibit an open chromatin configuration. Finally, NAT pairs in 368 diverse maize inbreds and 19 segregating populations were specifically enriched for polymorphisms associated with drought tolerance. Taken together, the data highlight the potential impact of that small RNAs and histone modifications have in regulation of NAT expression, and the significance of NATs in response to WS. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Half a decade of mini-pool nucleic acid testing: Cost-effective way for improving blood safety in India

PubMed Central

Chandrashekar, Shivaram

2014-01-01

Background and Objectives: It is well established that Nucleic acid testing (NAT) reduces window phase of transfusion transmissible infections (TTI) and helps improve blood safety. NAT testing can be done individually or in pools. The objectives of this study were to determine the utility, feasibility and cost effectiveness of an in-house minipool-NAT(MP-NAT). Materials and Methods: Blood donors were screened by history, tested by ELISA and sero-negative samples were subjected to an in-house NAT by using reverse transcriptase-polymerase chain reaction (RT-PCR). Testing was done in mini-pools of size eight (8). Positive pools were repeated with individual samples. Results: During the study period of Oct 2005-Sept 2010 (5 years) all blood donors (n=53729) were screened by ELISA. Of which 469 (0.87%) were positive for HIV-1, HBV or HCV. Sero-negative samples (n=53260) were screened by in-house MP-NAT. HIV-NAT yield was 1/53260 (n=1) and HBV NAT yield (n=2) was 1/26630. Conclusion: NAT yield was lower than other India studies possibly due to the lower sero-reactivity amongst our donors. Nevertheless it intercepted 9 lives including the components prepared. The in-house assay met our objective of improving blood safety at nominal cost and showed that it is feasible to set up small molecular biology units in medium-large sized blood banks and deliver blood within 24-48 hours. The utility of NAT (NAT yield) will vary based on the donor population, the type of serological test used, the nature of kit employed and the sensitivity of NAT test used. The limitations of our in-house MP-NAT consisted of stringent sample preparation requirements, with labor and time involved. The benefits of our MP-NAT were that it acted as a second level of check for ELISA tests, was relatively inexpensive compared to ID-NAT and did not need sophisticated equipment. PMID:24678172

A pilot study of the modulation of sirtuins on arylamine N-acetyltransferase 1 and 2 enzymatic activity.

PubMed

Turiján-Espinoza, Eneida; Salazar-González, Rául Alejandro; Uresti-Rivera, Edith Elena; Hernández-Hernández, Gloria Estela; Ortega-Juárez, Montserrat; Milán, Rosa; Portales-Pérez, Diana

2018-03-01

Arylamine N -acetyltransferase (NAT; E.C. 2.3.1.5) enzymes are responsible for the biotransformation of several arylamine and hydrazine drugs by acetylation. In this process, the acetyl group transferred to the acceptor substrate produces NAT deacetylation and, in consequence, it is susceptible of degradation. Sirtuins are protein deacetylases, dependent on nicotine adenine dinucleotide, which perform post-translational modifications on cytosolic proteins. To explore possible sirtuin participation in the enzymatic activity of arylamine NATs, the expression levels of NAT1, NAT2, SIRT1 and SIRT6 in peripheral blood mononuclear cells (PBMC) from healthy subjects were examined by flow cytometry and Western blot. The in situ activity of the sirtuins on NAT enzymatic activity was analyzed by HPLC, in the presence or absence of an agonist (resveratrol) and inhibitor (nicotinamide) of sirtuins. We detected a higher percentage of positive cells for NAT2 in comparison with NAT1, and higher numbers of SIRT1+ cells compared to SIRT6 in lymphocytes. In situ NAT2 activity in the presence of NAM inhibitors was higher than in the presence of its substrate, but not in the presence of resveratrol. In contrast, the activity of NAT1 was not affected by sirtuins. These results showed that NAT2 activity might be modified by sirtuins.

Diagnostic laparoscopy should be performed before definitive resection for pancreatic cancer: a financial argument.

PubMed

Jayakrishnan, Thejus T; Nadeem, Hasan; Groeschl, Ryan T; George, Ben; Thomas, James P; Ritch, Paul S; Christians, Kathleen K; Tsai, Susan; Evans, Douglas B; Pappas, Sam G; Gamblin, T Clark; Turaga, Kiran K

2015-02-01

Laparoscopy is recommended to detect radiographically occult metastases in patients with pancreatic cancer before curative resection. This study was conducted to test the hypothesis that diagnostic laparoscopy (DL) is cost-effective in patients undergoing curative resection with or without neoadjuvant therapy (NAT). Decision tree modelling compared routine DL with exploratory laparotomy (ExLap) at the time of curative resection in resectable cancer treated with surgery first, (SF) and borderline resectable cancer treated with NAT. Costs (US$) from the payer's perspective, quality-adjusted life months (QALMs) and incremental cost-effectiveness ratios (ICERs) were calculated. Base case estimates and multi-way sensitivity analyses were performed. Willingness to pay (WtP) was US$4166/QALM (or US$50,000/quality-adjusted life year). Base case costs were US$34,921 for ExLap and US$33,442 for DL in SF patients, and US$39,633 for ExLap and US$39,713 for DL in NAT patients. Routine DL is the dominant (preferred) strategy in both treatment types: it allows for cost reductions of US$10,695/QALM in SF and US$4158/QALM in NAT patients. The present analysis supports the cost-effectiveness of routine DL before curative resection in pancreatic cancer patients treated with either SF or NAT. © 2014 International Hepato-Pancreato-Biliary Association.

Contribution of different PSC types to Arctic ozone depletion caused by chlorine activation and denitrification

NASA Astrophysics Data System (ADS)

Kirner, Oliver; Khosrawi, Farah; Müller, Rolf; Weimer, Michael; Ruhnke, Roland

2017-04-01

Heterogeneous reactions on the surfaces of PSC particles and denitrification of the stratosphere are the cause for polar ozone depletion in spring. In a former study we investigated the impact of different types of PSCs on Antarctic ozone depletion with the help of the chemistry-climate model ECHAM5/MESSy Atmospheric chemistry (EMAC). In this study, we investigate the impact of PSCs on Arctic ozone loss. One standard and four sensitivity EMAC simulations (nudged with ERA-Interim) have been performed to evaluate the contribution of liquid, NAT and ice particles to ozone depletion in the Arctic winters 2010/2011 and 2015/2016 due to chlorine activation by heterogeneous chemistry on their surfaces and due to denitrification of the stratosphere. In the first three sensitivity simulations, we changed the heterogeneous chemistry on PSC particles by switching on and off the chemistry on liquid, NAT and ice particles. One further sensitivity simulation without NAT formation (only liquid and ice particles) was performed to evaluate the contribution of NAT to Arctic ozone depletion due to denitrification of the stratosphere. With the help of these different EMAC simulations, we will show the significance of liquid, NAT and ice particles to Arctic ozone depletion caused by chlorine activation and denitrification.

Heterogeneous nucleation of nitric acid trihydrate on clay minerals: relevance to type ia polar stratospheric clouds.

PubMed

Hatch, Courtney D; Gough, Raina V; Toon, Owen B; Tolbert, Margaret A

2008-01-17

Although critical to atmospheric modeling of stratospheric ozone depletion, selective heterogeneous nuclei that promote the formation of Type Ia polar stratospheric clouds (PSCs) are largely unknown. While mineral particles are known to be good ice nuclei, it is currently not clear whether they are also good nuclei for PSCs. In the present study, a high-vacuum chamber equipped with transmission Fourier transform infrared spectroscopy and a quadrupole mass spectrometer was used to study heterogeneous nucleation of nitric acid trihydrate (NAT) on two clay minerals-Na-montmorillonite and kaolinite-as analogs of atmospheric terrestrial and extraterrestrial minerals. The minerals are first coated with a 3:1 supercooled H2O/HNO3 solution prior to the observed nucleation of crystalline NAT. At 220 K, NAT formation was observed at low SNAT values of 12 and 7 on kaolinite and montmorillonite clays, respectively. These are the lowest SNAT values reported in the literature on any substrate. However, NAT nucleation exhibited significant temperature dependence. At lower temperatures, representative of typical polar stratospheric conditions, much higher supersaturations were required before nucleation was observed. Our results suggest that NAT nucleation on mineral particles, not previously treated with sulfuric acid, may not be an important nucleation platform for Type Ia PSCs under normal polar stratospheric conditions.

Formation of model polar stratospheric cloud films

NASA Technical Reports Server (NTRS)

Middlebrook, Ann M.; Koehler, Birgit G.; Mcneill, Laurie S.; Tolbert, Margaret A.

1992-01-01

Fourier transform infrared spectroscopy was used to examine the competitive growth of films representative of polar stratospheric clouds. These experiments show that either crystalline nitric acid trihydrate (beta-NAT) or amorphous films with H2O:HNO3 ratios close to 3:1 formed at temperatures 3-7 K warmer than the ice frost point under stratospheric pressure conditions. In addition, with higher HNO3 pressure, we observed nitric acid dihydrate (NAD) formation at temperatures warmer than ice formation. However, our experiments also show that NAD surfaces converted to beta-NAT upon exposure to stratospheric water pressures. Finally, we determined that the net uptake coefficient for HNO3 on beta-NAT is close to unity, whereas the net uptake coefficient for H2O is much less.

Project Shuttle simulation math model coordination catalog, revision 1

NASA Technical Reports Server (NTRS)

1974-01-01

A catalog is presented of subsystem and environment math models used or planned for space shuttle simulations. The purpose is to facilitate sharing of similar math models between shuttle simulations. It provides information on mach model requirements, formulations, schedules, and contact persons for further information.

Deficiency of N-acetyltransferase increases the interactions of isoniazid with endobiotics in mouse liver.

PubMed

Wang, Pengcheng; Shehu, Amina I; Lu, Jie; Joshi, Rujuta H; Venkataramanan, Raman; Sugamori, Kim S; Grant, Denis M; Zhong, Xiao-Bo; Ma, Xiaochao

2017-12-01

Acetylation is the major metabolic pathway of isoniazid (INH) mediated by N-acetyltransferases (NATs). Previous reports suggest that slow acetylators have higher risks of INH hepatotoxicity than rapid acetylators, but the detailed mechanisms remain elusive. The current study used Nat1/2(-/-) mice to mimic NAT slow metabolizers and to investigate INH metabolism in the liver. We found that INH acetylation is abolished in the liver of Nat1/2(-/-) mice, suggesting that INH acetylation is fully dependent on NAT1/2. In addition to the acetylation pathway, INH can be hydrolyzed to form hydrazine (Hz) and isonicotinic acid (INA). We found that INA level was not altered in the liver of Nat1/2(-/-) mice, indicating that deficiency of NAT1/2 has no effect on INH hydrolysis. Because INH acetylation was abolished and INH hydrolysis was not altered in Nat1/2(-/-) mice, we expected an extremely high level of INH in the liver. However, we only observed a modest accumulation of INH in the liver of Nat1/2(-/-) mice, suggesting that there are alternative pathways in INH metabolism in NAT1/2 deficient condition. Our further studies revealed that the conjugated metabolites of INH with endobiotics, including fatty acids and vitamin B6, were significantly increased in the liver of Nat1/2(-/-) mice. In summary, this study illustrated that deficiency of NAT1/2 decreases INH acetylation, but increases the interactions of INH with endobiotics in the liver. These findings can be used to guide future studies on the mechanisms of INH hepatotoxicity in NAT slow metabolizers. Copyright © 2017 Elsevier Inc. All rights reserved.

NATb/NAT1*4 promotes greater arylamine N-acetyltransferase 1 mediated DNA adducts and mutations than NATa/NAT1*4 following exposure to 4-aminobiphenyl

PubMed Central

Millner, Lori M.; Doll, Mark A.; Cai, Jian; States, J. Christopher; Hein, David W.

2011-01-01

N -acetyltransferase 1 (NAT1) is a phase II metabolic enzyme responsible for the biotransformation of aromatic and heterocyclic amine carcinogens such as 4-aminobiphenyl (ABP). NAT1 catalyzes N-acetylation of arylamines as well as the O-acetylation of N-hydroxylated arylamines. O-acetylation leads to the formation of electrophilic intermediates that result in DNA adducts and mutations. NAT1 is transcribed from a major promoter, NATb, and an alternative promoter, NATa, resulting in mRNAs with distinct 5′-untranslated regions (UTR). NATa mRNA is expressed primarily in the kidney, liver, trachea and lung while NATb mRNA has been detected in all tissues studied. To determine if differences in 5′-UTR have functional effect upon NAT1 activity and DNA adducts or mutations following exposure to ABP, pcDNA5/FRT plasmid constructs were prepared for transfection of full length human mRNAs including the 5′-UTR derived from NATa or NATb, the open reading frame, and 888 nucleotides of the 3′-UTR. Following stable transfection of NATb/NAT1*4 or NATa/NAT1*4 into nucleotide excision repair (NER) deficient Chinese hamster ovary cells, N-acetyltransferase activity (in vitro and in situ), mRNA, and protein expression were higher in NATb/NAT1*4 than NATa/NAT1*4 transfected cells (p<0.05). Consistent with NAT1 expression and activity, ABP-induced DNA adducts and hypoxanthine phosphoribosyl transferase mutants were significantly higher (p<0.05) in NATb/NAT1*4 than in NATa/NAT1*4 transfected cells following exposure to ABP. These differences observed between NATa and NATb suggest that the 5′-UTRs are differentially regulated. PMID:21837760

Measurement of math beliefs and their associations with math behaviors in college students.

PubMed

Hendy, Helen M; Schorschinsky, Nancy; Wade, Barbara

2014-12-01

Our purpose in the present study was to expand understanding of math beliefs in college students by developing 3 new psychometrically tested scales as guided by expectancy-value theory, self-efficacy theory, and health belief model. Additionally, we identified which math beliefs (and which theory) best explained variance in math behaviors and performance by college students and which students were most likely to have problematic math beliefs. Study participants included 368 college math students who completed questionnaires to report math behaviors (attending class, doing homework, reading textbooks, asking for help) and used a 5-point rating scale to indicate a variety of math beliefs. For a subset of 84 students, math professors provided final math grades. Factor analyses produced a 10-item Math Value Scale with 2 subscales (Class Devaluation, No Future Value), a 7-item single-dimension Math Confidence Scale, and an 11-item Math Barriers Scale with 2 subscales (Math Anxiety, Discouraging Words). Hierarchical multiple regression revealed that high levels of the newly discovered class devaluation belief (guided by expectancy-value theory) were most consistently associated with poor math behaviors in college students, with high math anxiety (guided by health belief model) and low math confidence (guided by self-efficacy theory) also found to be significant. Analyses of covariance revealed that younger and male students were at increased risk for class devaluation and older students were at increased risk for poor math confidence. (c) 2014 APA, all rights reserved.

N-acetyltransferase 1*10 genotype in bladder cancer patients.

PubMed

Höhne, Svetlana; Gerullis, Holger; Blaszkewicz, Meinolf; Selinski, Silvia; Hengstler, Jan G; Otto, Thomas; Golka, Klaus

2017-01-01

In a large bladder cancer study in the greater Berlin area with 425 cases and 343 controls, the haplotype N-acetyltransferase 1*10 (NAT1*10) was associated with a decreased bladder cancer risk. In a recently published meta-analysis, results of the studies were found to be inconclusive. Therefore, the aim of this study was to investigate the frequency of NAT1*10 in bladder cancer patients and controls recruited in an area without industries reported to be associated with increased bladder cancer risk. Rs1057126 (1088 T > A) and rs15561 (1095 C > A) were determined in 412 bladder cancer patients and 415 controls without a known history of malignancies. With these two single-nucleotide polymorphisms (SNP), it was possible to distinguish between NAT1*4 (wild type), NAT1*3 (1095 C > A), and NAT1*10 (1088 T > A, 1095C > A). The frequencies of the determined NAT1 haplotypes did not differ markedly between cases and controls: NAT1*4: 74%, NAT1*3: 6%, NAT1*10: 20%. Bladder cancer risk was not significantly modulated by NAT1*10/*10 (OR 1.03, 95% CI 0.71-1.48) but was higher for NAT1*3/*3 genotypes (OR 2.05, 95% CI 1.32-3.21). In contrast to the Berlin study from 2001, data in present study demonstrated that NAT1*10 haplotype was not associated with a significantly decreased bladder cancer risk. This may be due to local effects in the greater Berlin area, particularly at the time of investigation. The findings of the present study are in agreement with observations of a recently published meta-analysis which also showed no relevant impact of NAT1*10 haplotype on bladder cancer risk. The impact of the rare NAT1*3/*3 genotype was significant but this may be attributed to rarity without major practical relevance.

Systemic functional expression of N-acetyltransferase polymorphism in the F344 Nat2 congenic rat

PubMed Central

Hein, David W.; Bendaly, Jean; Neale, Jason R.; Doll, Mark A.

2008-01-01

Rat lines congenic for the rat N-acetyltransferase 2 [(RAT)Nat2] gene were constructed and characterized. F344 (homozygous Nat2 rapid) males were mated to WKY (homozygous Nat2 slow) females to produce heterozygous F1. F1 females were then backcrossed to F344 males. Heterozygous acetylator female progeny from this and each successive backcross were identified by rat Nat2 genotyping and mated with F344 rapid acetylator males. Following ten generations of backcross mating, heterozygous acetylator brother/sister progeny were mated to produce the homozgygous rapid and slow acetylator Nat2 congenic rat lines. p-Aminobenzoic acid (selective for rat NAT2) and 4-aminobiphenyl N-acetyltransferase activities were expressed in all tissues examined (liver, lung, esophagus, stomach, small intestine, colon, pancreas, kidney, skin, leukocytes, and urinary bladder in male and female rats and in breast of female and prostate of male rats). NAT2 expression in rat extrahepatic tissues was much higher than in liver. In each tissue, activities were Nat2-genotype dependent, with highest levels in homozygous rapid acetylators, intermediate levels in heterozygous acetylators, and lowest in homozygous slow acetylators. Sulfamethazine (selective for rat NAT1) N-acetyltransferase activities were observed in all tissues examined in both male and female rats except for breast (females), bladder and leukocytes. In each tissue, the activity was Nat2-genotype independent, with similar levels in homozygous rapid, heterozygous, and homozygous slow acetylators. These congenic rat lines are useful to investigate the role of NAT2 genetic polymorphism in susceptibility to cancers related to arylamine carcinogen exposures. PMID:18799801

Insight into cofactor recognition in arylamine N-acetyltransferase enzymes: structure of Mesorhizobium loti arylamine N-acetyltransferase in complex with coenzyme A.

PubMed

Xu, Ximing; Li de la Sierra-Gallay, Inés; Kubiak, Xavier; Duval, Romain; Chaffotte, Alain F; Dupret, Jean Marie; Haouz, Ahmed; Rodrigues-Lima, Fernando

2015-02-01

Arylamine N-acetyltransferases (NATs) are xenobiotic metabolizing enzymes that catalyze the acetyl-CoA-dependent acetylation of arylamines. To better understand the mode of binding of the cofactor by this family of enzymes, the structure of Mesorhizobium loti NAT1 [(RHILO)NAT1] was determined in complex with CoA. The F42W mutant of (RHILO)NAT1 was used as it is well expressed in Escherichia coli and displays enzymatic properties similar to those of the wild type. The apo and holo structures of (RHILO)NAT1 F42W were solved at 1.8 and 2 Å resolution, respectively. As observed in the Mycobacterium marinum NAT1-CoA complex, in (RHILO)NAT1 CoA binding induces slight structural rearrangements that are mostly confined to certain residues of its `P-loop'. Importantly, it was found that the mode of binding of CoA is highly similar to that of M. marinum NAT1 but different from the modes reported for Bacillus anthracis NAT1 and Homo sapiens NAT2. Therefore, in contrast to previous data, this study shows that different orthologous NATs can bind their cofactors in a similar way, suggesting that the mode of binding CoA in this family of enzymes is less diverse than previously thought. Moreover, it supports the notion that the presence of the `mammalian/eukaryotic insertion loop' in certain NAT enzymes impacts the mode of binding CoA by imposing structural constraints.

Arylamine n-acetyltransferases in eukaryotic microorganisms

USDA-ARS?s Scientific Manuscript database

Microorganisms can survive highly toxic environments through numerous xenobiotic metabolizing enzymes, including arylamine N-acetyltransferases (NATs). NAT genes are present in bacteria, archaea, protists and fungi. In lower taxa of fungi, NAT genes are found in chytridiomycetes. In Dikarya, NAT gen...

Studies on N-Acetyltransferase (NAT2) Genotype Relationships in Emiratis: Confirmation of the Existence of Phenotype Variation among Slow Acetylators.

PubMed

Al-Ahmad, Mohammad M; Amir, Naheed; Dhanasekaran, Subramanian; John, Anne; Abdulrazzaq, Yousef M; Ali, Bassam R; Bastaki, Salim

2017-09-01

Individuals with slow N-acetylation phenotype often experience toxicity from drugs such as isoniazid, sulfonamides, procainamide, and hydralazine, whereas rapid acetylators may not respond to these medications. The highly polymorphic N-acetyltransferase 2 enzyme encoded by the NAT2 gene is one of the N-acetylators in humans with a clear impact on the metabolism of a significant number of important drugs. However, there are limited studies on N-acetylation phenotypes and NAT2 genotypes among Emiratis, and thus this study was carried out to fill this gap. Five hundred seventy-six Emirati subjects were asked to consume a soft drink containing caffeine (a nontoxic and reliable probe for predicting the acetylation phenotype) and then provide a buccal swab along with a spot urine sample. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine the genotype of each individual. Phenotyping was carried out by analyzing the caffeine metabolites using high-performance liquid chromatography (HPLC) analysis. We found that 78.5%, 19.1%, and 2.4% of the Emirati subjects were slow, intermediate, and rapid acetylators, respectively. In addition, we found that 77.4% of the subjects were homozygous or heterozygous for two nonreference alleles, whereas 18.4% and 4.2% were heterozygous or homozygous for the reference allele (NAT2*4), respectively. The most common genotypes found were NAT2*5B/*7B, NAT2*5B/*6A, NAT2*7B/*14B, and NAT2*4/*5B, with frequencies of 0.255, 0.135, 0.105, and 0.09, respectively. The degree of phenotype/genotype concordance was 96.2%. The NAT2*6A/*6A, NAT2*6A/*7B, NAT2*7B/*7B, and NAT2*5A/*5B genotypes were found to be associated with the lowest 5-acetylamino-6-formylamino-3-methyluracil/1-methylxanthine (AFMU/1X) ratios. There is a high percentage of slow acetylators among Emiratis, which correlates with the presence of nonreference alleles for the NAT2 gene. Individuals who carried NAT2*6A/*6A, NAT2*6A/*7B, NAT2*7B/*7B, or NAT2*5A/*5B genotypes might be at higher risk of toxicity with some drugs and some diseases compared to others, as these genotypes are associated with the slowest acetylation status. © 2017 John Wiley & Sons Ltd/University College London.

Experimental results and model calculations of excitation functions relevant to the production of specific radioisotopes for metabolic radiotherapy and for pet

NASA Astrophysics Data System (ADS)

Menapace, E.; Birattari, C.; Bonardi, M. L.; Groppi, F.

2004-10-01

First results are given from the comparison of experimental values and model calculations on accelerator-produced high specific activity radionuclides in no-carrier-added (NCA) form. The relevant radioisotopes are: 64Cu, produced by natZn(d, αxn) and natZn(d,2p) reactions, for simultaneous positron/negatron metabolic radiotherapy and PET imaging; 66Ga high-energy positron emitter (4.2 MeV), produced by natZn(d, xn) reactions, for metabolic radiotherapy and for PET; 186gRe, produced by 186W(p,n) and 186W(d,2n) reactions, for negatron (1.1 MeV) metabolic radiotherapy; 211At/ 211Po, produced by 209Bi( α,2n) reaction (with spike of gamma emitter 210At produced by 209Bi( α,3n) reaction) and 225Ac/ 213Bi/ 213Po, produced by 226Ra(p,2n) reaction, both for high-LET radiotherapy.

Recent progress in N-acetyltransferase research: 7th international workshop on N-acetyltransferases (NAT): workshop report.

PubMed

Lichter, Jutta; Golka, Klaus; Sim, Edith; Blömeke, Brunhilde

2017-07-01

The 7th International Workshop on N-Acetyltransferases (NAT), held from 18 to 20 June 2016, was hosted by Brunhilde Blömeke and her team at the Trier University (Germany). The workshop addressed important aspects and latest advancements in the fields of NAT enzymes, endogenous functions of NATs, NAT gene nomenclature, genetic polymorphisms, and their associations with diseases as well as their use in diagnosis. Representatives from the leading teams performing research on NATs presented their excellent work, discussed the latest results, and created new ideas in the field of N-acetyltransferase research.

Environmental Adaptations Improve Everyday Action in Schizophrenia.

PubMed

Kessler, Rachel K; Rhodes, Emma; Giovannetti, Tania

2015-05-01

Cognitive functioning, particularly executive functioning, is a strong predictor of functional outcomes in people with schizophrenia. Cognitive remediation has been shown to improve specific cognitive processes, but adjunctive interventions are required for meaningful gains in adaptive functioning, particularly in people with chronic illness. This study examined whether (and how) environmental adaptations, used without training, may circumvent cognitive difficulties and facilitate everyday task performance in individuals with chronic schizophrenia. Forty-two individuals with chronic schizophrenia/schizoaffective disorder were administered cognitive measures and two versions of the Naturalistic Action Test (NAT)-a standard version (ST-NAT), and a user-centered version (UC-NAT) that incorporated environmental adaptations designed to facilitate task performance. The NAT conditions were counterbalanced across participants. Analyses compared performance between the NAT versions and examined the cognitive correlates of each NAT condition. Individuals with schizophrenia made fewer errors on the UC-NAT as compared to the ST-NAT; this between-group difference was significant for all error types. Compared to the ST-NAT, the UC-NAT performance was not significantly associated with an executive function measure of planning. Environmental adaptations may be implemented without extensive training to improve everyday action in individuals with chronic schizophrenia. Environmental adaptations that reduce planning demands may be most effective in this population.

Singapore Math: Problem-Solving Secrets from the World's Math Leader

ERIC Educational Resources Information Center

Hogan, Bob

2005-01-01

Using this four CD-ROM disc set, teachers can have their very own math problem solving mentor as a leading expert in Singapore Math guides them through a lively presentation, working through math problems and explaining how Singapore has become the world's leading method in math. The expert's explanation of how to use Singapore's model-drawing…

Longitudinal relations among parents' reactions to children's negative emotions, effortful control, and math achievement in early elementary school.

PubMed

Swanson, Jodi; Valiente, Carlos; Lemery-Chalfant, Kathryn; Bradley, Robert H; Eggum-Wilkens, Natalie D

2014-01-01

Panel mediation models and fixed-effects models were used to explore longitudinal relations among parents' reactions to children's displays of negative emotions, children's effortful control (EC), and children's math achievement (N = 291; M age in fall of kindergarten = 5.66 years, SD = .39 year) across kindergarten through second grade. Parents reported their reactions and children's EC. Math achievement was assessed with a standardized achievement test. First-grade EC mediated the relation between parents' reactions at kindergarten and second-grade math achievement, beyond stability in constructs across study years. Panel mediation model results suggested that socialization of EC may be one method of promoting math achievement in early school; however, when all omitted time-invariant covariates of EC and math achievement were controlled, first-grade EC no longer predicted second-grade math achievement. © 2014 The Authors. Child Development © 2014 Society for Research in Child Development, Inc.

Cis-Natural Antisense Transcripts Are Mainly Co-expressed with Their Sense Transcripts and Primarily Related to Energy Metabolic Pathways during Muscle Development.

PubMed

Zhao, Yunxia; Hou, Ye; Zhao, Changzhi; Liu, Fei; Luan, Yu; Jing, Lu; Li, Xinyun; Zhu, Mengjin; Zhao, Shuhong

2016-01-01

Cis-natural antisense transcripts (cis-NATs) are a new class of RNAs identified in various species. However, the biological functions of cis-NATs are largely unknown. In this study, we investigated the transcriptional characteristics and functions of cis-NATs in the muscle tissue of lean Landrace and indigenous fatty Lantang pigs. In total, 3,306 cis-NATs of 2,469 annotated genes were identified in the muscle tissue of pigs. More than 1,300 cis-NATs correlated with their sense genes at the transcriptional level, and approximately 80% of them were co-expressed in the two breeds. Furthermore, over 1,200 differentially expressed cis-NATs were identified during muscle development. Function annotation showed that the cis-NATs participated in muscle development mainly by co-expressing with genes involved in energy metabolic pathways, including citrate cycle (TCA cycle), glycolysis or gluconeogenesis, mitochondrial activation and so on. Moreover, these cis-NATs and their sense genes abruptly increased at the transition from the late fetal stages to the early postnatal stages and then decreased along with muscle development. In conclusion, the cis-NATs in the muscle tissue of pigs were identified and determined to be mainly co-expressed with their sense genes. The co-expressed cis-NATs and their sense gene were primarily related to energy metabolic pathways during muscle development in pigs. Our results offered novel evidence on the roles of cis-NATs during the muscle development of pigs.

Modeling Math Growth Trajectory--An Application of Conventional Growth Curve Model and Growth Mixture Model to ECLS K-5 Data

ERIC Educational Resources Information Center

Lu, Yi

2016-01-01

To model students' math growth trajectory, three conventional growth curve models and three growth mixture models are applied to the Early Childhood Longitudinal Study Kindergarten-Fifth grade (ECLS K-5) dataset in this study. The results of conventional growth curve model show gender differences on math IRT scores. When holding socio-economic…

Interaction of HCl with a beta-NAT Surface: Prediction of the IR Spectrum

NASA Astrophysics Data System (ADS)

Martin-Llorente, B.; Escribano, R. M.; Fernandez-Torre, D.; Galvez, O.; Herrero, V. J.; Mate, B.; Moreno, M. A.

2009-04-01

Heterogeneous reactions that take place over the surface of polar stratospheric cloud (PSC) particles are thought to play an important role on stratospheric ozone depletion. Chlorine reservoir species, such as HCl and ClONO2, adsorbed on those particles, can be converted to reactive chlorine compounds, responsible for the destruction of ozone. The high temperature phase of nitric acid trihydrate (β-NAT) is one of the most important constituents of PSC. We present here a theoretical study of the system formed by HCl and β-NAT, by means of DFT calculations[1]. The adsorption of HCl on the most favourable site of the (001) surface of the β-NAT crystal[2] is simulated with a suitable model for the description of the vibrational properties of the system. Other possible adsorption sites will also be revised. An assignment of the different spectroscopic features, such as a small band at 2150 cm-1 attributed to the stretching of the adsorbed HCl molecule, is performed by comparing the predicted absorption spectrum with the experimental results[3] [1] J. M. Soler, E. Artacho, J. D. Gale, A. Garc

Codominant Expression of N-Acetylation and O-Acetylation Activities Catalyzed by N-Acetyltransferase 2 in Human Hepatocytes

PubMed Central

Doll, Mark A.; Zang, Yu; Moeller, Timothy

2010-01-01

Human populations exhibit genetic polymorphism in N-acetylation capacity, catalyzed by N-acetyltransferase 2 (NAT2). We investigated the relationship between NAT2 acetylator genotype and phenotype in cryopreserved human hepatocytes. NAT2 genotypes determined in 256 human samples were assigned as rapid (two rapid alleles), intermediate (one rapid and one slow allele), or slow (two slow alleles) acetylator phenotypes based on functional characterization of the NAT2 alleles reported previously in recombinant expression systems. A robust and significant relationship was observed between deduced NAT2 phenotype (rapid, intermediate, or slow) and N-acetyltransferase activity toward sulfamethazine (p < 0.0001) and 4-aminobiphenyl (p < 0.0001) and for O-acetyltransferase-catalyzed metabolic activation of N-hydroxy-4-aminobiphenyl (p < 0.0001), N-hydroxy-2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline (p < 0.01), and N-hydroxy-2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (p < 0.0001). NAT2-specific protein levels also significantly associated with the rapid, intermediate, and slow NAT2 acetylator phenotypes (p < 0.0001). As a negative control, p-aminobenzoic acid (an N-acetyltransferase 1-selective substrate) N-acetyltransferase activities from the same samples did not correlate with the three NAT2 acetylator phenotypes (p > 0.05). These results clearly document codominant expression of human NAT2 alleles resulting in rapid, intermediate, and slow acetylator phenotypes. The three phenotypes reflect levels of NAT2 protein catalyzing both N- and O-acetylation. Our results suggest a significant role of NAT2 acetylation polymorphism in arylamine-induced cancers and are consistent with differential cancer risk and/or drug efficacy/toxicity in intermediate compared with rapid or slow NAT2 acetylator phenotypes. PMID:20430842

Arylamine N-Acetyltransferases in Mycobacteria

PubMed Central

Sim, Edith; Sandy, James; Evangelopoulos, Dimitrios; Fullam, Elizabeth; Bhakta, Sanjib; Westwood, Isaac; Krylova, Anna; Lack, Nathan; Noble, Martin

2008-01-01

Polymorphic Human arylamine N-acetyltransferase (NAT2) inactivates the anti-tubercular drug isoniazid by acetyltransfer from acetylCoA. There are active NAT proteins encoded by homologous genes in mycobacteria including M. tuberculosis, M. bovis BCG, M. smegmatis and M. marinum. Crystallographic structures of NATs from M. smegmatis and M. marinum, as native enzymes and with isoniazid bound share a similar fold with the first NAT structure, Salmonella typhimurium NAT. There are three approximately equal domains and an active site essential catalytic triad of cysteine, histidine and aspartate in the first two domains. An acetyl group from acetylCoA is transferred to cysteine and then to the acetyl acceptor e.g. isoniazid. M. marinum NAT binds CoA in a more open mode compared with CoA binding to human NAT2. The structure of mycobacterial NAT may promote its role in synthesis of cell wall lipids, identified through gene deletion studies. NAT protein is essential for survival of M. bovis BCG in macrophage as are the proteins encoded by other genes in the same gene cluster (hsaA-D). HsaA-D degrade cholesterol, essential for mycobacterial survival inside macrophage. Nat expression remains to be fully understood but is co-ordinated with hsaA-D and other stress response genes in mycobacteria. Amide synthase genes in the streptomyces are also nat homologues. The amide synthases are predicted to catalyse intramolecular amide bond formation and creation of cyclic molecules, e.g. geldanamycin. Lack of conservation of the CoA binding cleft residues of M. marinum NAT suggests the amide synthase reaction mechanism does not involve a soluble CoA intermediate during amide formation and ring closure. PMID:18680471

Genetic and small molecule inhibition of arylamine N-acetyltransferase 1 reduces anchorage-independent growth in human breast cancer cell line MDA-MB-231.

PubMed

Stepp, Marcus W; Doll, Mark A; Carlisle, Samantha M; States, J Christopher; Hein, David W

2018-04-01

Arylamine N-acetyltransferase 1 (NAT1) expression is reported to affect proliferation, invasiveness, and growth of cancer cells. MDA-MB-231 breast cancer cells were engineered such that NAT1 expression was elevated or suppressed, or treated with a small molecule inhibitor of NAT1. The MDA-MB-231 human breast cancer cell lines were engineered with a scrambled shRNA, a NAT1 specific shRNA or a NAT1 overexpression cassette stably integrated into a single flippase recognition target (FRT) site facilitating incorporation of these different genetic elements into the same genomic location. NAT1-specific shRNA reduced NAT1 activity in vitro by 39%, increased endogenous acetyl coenzyme A levels by 35%, and reduced anchorage-independent growth (sevenfold) without significant effects on cell morphology, growth rates, anchorage-dependent colony formation, or invasiveness compared to the scrambled shRNA cell line. Despite 12-fold overexpression of NAT1 activity in the NAT1 overexpression cassette transfected MDA-MB-231 cell line, doubling time, anchorage-dependent cell growth, anchorage-independent cell growth, and relative invasiveness were not changed significantly when compared to the scrambled shRNA cell line. A small molecule (5E)-[5-(4-hydroxy-3,5-diiodobenzylidene)-2-thioxo-1,3-thiazolidin-4-one (5-HDST) was 25-fold more selective towards the inhibition of recombinant human NAT1 than N-acetyltransferase 2. Incubation of MDA-MB-231 cell line with 5-HDST resulted in 60% reduction in NAT1 activity and significant decreases in cell growth, anchorage-dependent growth, and anchorage-independent growth. In summary, inhibition of NAT1 activity by either shRNA or 5-HDST reduced anchorage-independent growth in the MDA-MB-231 human breast cancer cell line. These findings suggest that human NAT1 could serve as a target for the prevention and/or treatment of breast cancer. © 2018 Wiley Periodicals, Inc.

Xenobiotic-metabolizing enzymes in Bacillus anthracis: molecular and functional analysis of a truncated arylamine N-acetyltransferase isozyme.

PubMed

Kubiak, Xavier; Duval, Romain; Pluvinage, Benjamin; Chaffotte, Alain F; Dupret, Jean-Marie; Rodrigues-Lima, Fernando

2017-07-01

The arylamine N-acetyltransferases (NATs) are xenobiotic-metabolizing enzymes that play an important role in the detoxification and/or bioactivation of arylamine drugs and xenobiotics. In bacteria, NATs may contribute to the resistance against antibiotics such as isoniazid or sulfamides through their acetylation, which makes this enzyme family a possible drug target. Bacillus anthracis, a bacterial species of clinical significance, expresses three NAT isozymes with distinct structural and enzymatic properties, including an inactive isozyme ((BACAN)NAT3). (BACAN)NAT3 features both a non-canonical Glu residue in its catalytic triad and a truncated C-terminus domain. However, the role these unusual characteristics play in the lack of activity of the (BACAN)NAT3 isozyme remains unclear. Protein engineering, recombinant expression, enzymatic analyses with aromatic amine substrates and phylogenetic analysis approaches were conducted. The deletion of guanine 580 (G580) in the nat3 gene was shown to be responsible for the expression of a truncated (BACAN)NAT3 isozyme. Artificial re-introduction of G580 in the nat3 gene led to a functional enzyme able to acetylate several arylamine drugs displaying structural characteristics comparable with its functional Bacillus cereus homologue ((BACCR)NAT3). Phylogenetic analysis of the nat3 gene in the B. cereus group further indicated that nat3 may constitute a pseudogene of the B. anthracis species. The existence of NATs with distinct properties and evolution in Bacillus species may account for their adaptation to their diverse chemical environments. A better understanding of these isozymes is of importance for their possible use as drug targets. This article is part of a themed section on Drug Metabolism and Antibiotic Resistance in Micro-organisms. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.14/issuetoc. © 2016 The British Pharmacological Society.

A pilot study on screening blood donors with individual-donation nucleic acid testing in China

PubMed Central

Dong, Jie; Wu, Yaling; Zhu, Hong; Li, Gan; Lv, Mengen; Wu, Daxiao; Li, Xiaotao; Zhu, Faming; Lv, Hangjun

2014-01-01

Background Nucleic acid amplification testing (NAT) is not yet obligatory in China for blood donor screening and the risk of enzyme immunoassay (EIA)-negative, NAT-reactive donations in Chinese blood donors has rarely been reported. The aim of this study was to screen a population of Chinese blood donors using a triplex individual-donation (ID)-NAT assay and assess the safety benefits of implementing NAT. Materials and methods Between 1st August, 2010 and 31st December, 2011 all donations at a Chinese blood centre were screened individually using the Procleix® Ultrio® assay, a multiplex NAT assay for the detection of hepatitis B virus (HBV) DNA, hepatitis C virus (HCV) RNA and human immunodeficiency virus-1 (HIV-1) RNA. All donations were also screened for HBsAg, anti-HIV and anti-HCV using two different EIA for each marker. Samples with discordant results between NAT and EIA were further tested with an alternative NAT assay (Cobas® TaqMan®). Potential yield cases (serologically negative/NAT-reactive donors) were further evaluated when possible. Results During the study period a total of 178,447 donations were screened by NAT and EIA, among which 169 HBV NAT yield cases (0.095%) were detected. No N AT yield cases were found for HIV-1 or HCV. For the HBV NAT yield cases, follow-up results showed that 11 (6.51%) were probable or confirmed HBV window period infections, 5 (2.96%) were chronic HBV carriers and 153 (90.53%) were probable or confirmed occult HBV infections. There was a statistically significant difference between the NAT-positive rates for first-time vs repeat donations (0.472% vs 0.146%, respectively; P<0.001). Discussion Our data demonstrate that the potential HBV yield rate was 1:1,056 for blood donations in the Zhejiang province of China. Implementation of NAT will provide a significant increment in safety relative to serological screening alone. PMID:24333061

On the Leaky Math Pipeline: Comparing Implicit Math-Gender Stereotypes and Math Withdrawal in Female and Male Children and Adolescents

ERIC Educational Resources Information Center

Steffens, Melanie C.; Jelenec, Petra; Noack, Peter

2010-01-01

Many models assume that habitual human behavior is guided by spontaneous, automatic, or implicit processes rather than by deliberate, rule-based, or explicit processes. Thus, math-ability self-concepts and math performance could be related to implicit math-gender stereotypes in addition to explicit stereotypes. Two studies assessed at what age…

Diagnostic laparoscopy should be performed before definitive resection for pancreatic cancer: a financial argument

PubMed Central

Jayakrishnan, Thejus T; Nadeem, Hasan; Groeschl, Ryan T; George, Ben; Thomas, James P; Ritch, Paul S; Christians, Kathleen K; Tsai, Susan; Evans, Douglas B; Pappas, Sam G; Gamblin, T Clark; Turaga, Kiran K

2015-01-01

Objectives Laparoscopy is recommended to detect radiographically occult metastases in patients with pancreatic cancer before curative resection. This study was conducted to test the hypothesis that diagnostic laparoscopy (DL) is cost-effective in patients undergoing curative resection with or without neoadjuvant therapy (NAT). Methods Decision tree modelling compared routine DL with exploratory laparotomy (ExLap) at the time of curative resection in resectable cancer treated with surgery first, (SF) and borderline resectable cancer treated with NAT. Costs (US$) from the payer's perspective, quality-adjusted life months (QALMs) and incremental cost-effectiveness ratios (ICERs) were calculated. Base case estimates and multi-way sensitivity analyses were performed. Willingness to pay (WtP) was US$4166/QALM (or US$50 000/quality-adjusted life year). Results Base case costs were US$34 921 for ExLap and US$33 442 for DL in SF patients, and US$39 633 for ExLap and US$39 713 for DL in NAT patients. Routine DL is the dominant (preferred) strategy in both treatment types: it allows for cost reductions of US$10 695/QALM in SF and US$4158/QALM in NAT patients. Conclusions The present analysis supports the cost-effectiveness of routine DL before curative resection in pancreatic cancer patients treated with either SF or NAT. PMID:25123702

Dose Calculations for [131I] Meta-Iodobenzylguanidine-Induced Bystander Effects

PubMed Central

Gow, M. D.; Seymour, C. B.; Boyd, M.; Mairs, R. J.; Prestiwch, W. V.; Mothersill, C. E.

2014-01-01

Targeted radiotherapy is a potentially useful treatment for some cancers and may be potentiated by bystander effects. However, without estimation of absorbed dose, it is difficult to compare the effects with conventional external radiation treatment. Methods: Using the Vynckier – Wambersie dose point kernel, a model for dose rate evaluation was created allowing for calculation of absorbed dose values to two cell lines transfected with the noradrenaline transporter (NAT) gene and treated with [131I]MIBG. Results: The mean doses required to decrease surviving fractions of UVW/NAT and EJ138/NAT cells, which received medium from [131I]MIBG-treated cells, to 25 – 30% were 1.6 and 1.7 Gy respectively. The maximum mean dose rates achieved during [131I]MIBG treatment were 0.09 – 0.75 Gy/h for UVW/NAT and 0.07 – 0.78 Gy/h for EJ138/NAT. These were significantly lower than the external beam gamma radiation dose rate of 15 Gy/h. In the case of control lines which were incapable of [131I]MIBG uptake the mean absorbed doses following radiopharmaceutical were 0.03 – 0.23 Gy for UVW and 0.03 – 0.32 Gy for EJ138. Conclusion: [131I]MIBG treatment for ICCM production elicited a bystander dose-response profile similar to that generated by external beam gamma irradiation but with significantly greater cell death. PMID:24659931

Automated Loads Analysis System (ATLAS)

NASA Technical Reports Server (NTRS)

Gardner, Stephen; Frere, Scot; O’Reilly, Patrick

2013-01-01

ATLAS is a generalized solution that can be used for launch vehicles. ATLAS is used to produce modal transient analysis and quasi-static analysis results (i.e., accelerations, displacements, and forces) for the payload math models on a specific Shuttle Transport System (STS) flight using the shuttle math model and associated forcing functions. This innovation solves the problem of coupling of payload math models into a shuttle math model. It performs a transient loads analysis simulating liftoff, landing, and all flight events between liftoff and landing. ATLAS utilizes efficient and numerically stable algorithms available in MSC/NASTRAN.

N-acetyltransferase 2 activity and folate levels

PubMed Central

Cao, Wen; Strnatka, Diana; McQueen, Charlene A.; Hunter, Robert J.; Erickson, Robert P.

2010-01-01

Aims To determine whether increased N-acetyltransferase (NAT) activity might have a toxic effect during development and an influence on folate levels since previous work has shown that only low levels of exogenous NAT can be achieved in constitutionally transgenic mice (Cao, et al, 2005) Main Methods A human NAT1 tet-inducible construct was used that would not be expressed until the inducer was delivered. Human NAT1 cDNA was cloned into pTRE2 and injected into mouse oocytes. Two transgenic lines were crossed to mouse line TgN(rtTahCMV)4Uh containing the CMV promoted “teton.”Measurements of red blood cell folate levels in inbred strains of mice were performed. Key findings Only low levels of human NAT1 could be achieved in kidney (highly responsive in other studies) whether the inducer, doxycycline, was given by gavage or in drinking water.An inverse correlation of folate levels with Nat2 enzyme activity was found. Significance Since increasing NAT1 activity decrease folate in at least one tissue, the detrimental effect of expression of human NAT1 in combination with endogenous mouse Nat2 may be a consequence of increased catabolism of folate. PMID:19932120

Gene cloning and characterization of arylamine N-acetyltransferase from Bacillus cereus strain 10-L-2.

PubMed

Takenaka, Shinji; Cheng, Minyi; Mulyono; Koshiya, Atsushi; Murakami, Shuichiro; Aoki, Kenji

2009-01-01

Bacillus cereus strain 10-L-2 synthesizes two arylamine N-acetyltransferases (Nat-a and Nat-b) with broad substrate specificities toward aniline and its derivatives. In southern blot analysis using probes encoding the NH2-terminus of Nat-b and a conserved region of N-acetyltransferases, digested total DNA of strain 10-L-2 showed one positive band. We cloned and sequenced the gene encoding Nat-b. The NH2-terminal amino acid sequence predicted from the open reading frame (768 base pairs) corresponded to that of purified Nat-b. The cloned Nat-b gene was expressed in Escherichia coli. The expressed enzyme (BcNAT) from the recombinant strain was partially purified and characterized. Nat-b from strain 10-L-2 and BcNAT from the recombinant strain were slightly different from each others in substrate specificity and thermo-stability. We examined the biotransformations of 2-aminophenols and phenylenediamines by the whole cells of the recombinant strain. The cells converted these compounds into their corresponding acetanilides. Only one amino group of phenylenediamines was acetylated. The cells utilized 4-nitroacetanilide as an acetyl donor instead of acetyl-CoA. 4-Aminoacetanilide was produced and 4-nitroaniline was released almost stoichiometrically.

Proton and deuteron induced reactions on natGa: Experimental and calculated excitation functions

NASA Astrophysics Data System (ADS)

Hermanne, A.; Adam-Rebeles, R.; Tárkányi, F.; Takács, S.; Ditrói, F.

2015-09-01

Cross-sections for reactions on natGa, induced by protons (up to 65 MeV) and deuterons (up to 50 MeV), producing γ-emitting radionuclides with half-lives longer than 1 h were measured in a stacked-foil irradiation using thin Ga-Ni alloy (70-30%) targets electroplated on Cu or Au backings. Excitation functions for generation of 68,69Ge, 66,67,68,72Ga and 65,69mZn on natGa are discussed, relative to the monitor reactions natAl(d,x)24,22Na, natAl(p,x)24,22Na, natCu(p,x)62Zn and natNi(p,x)57Ni. The results are compared to our earlier measurements, the scarce literature values and to the results of the code TALYS 1.6 (online database TENDL-2014).

A national look at carbon capture and storage-National carbon sequestration database and geographical information system (NatCarb)

USGS Publications Warehouse

Carr, T.R.; Iqbal, A.; Callaghan, N.; ,; Look, K.; Saving, S.; Nelson, K.

2009-01-01

The US Department of Energy's Regional Carbon Sequestration Partnerships (RCSPs) are responsible for generating geospatial data for the maps displayed in the Carbon Sequestration Atlas of the United States and Canada. Key geospatial data (carbon sources, potential storage sites, transportation, land use, etc.) are required for the Atlas, and for efficient implementation of carbon sequestration on a national and regional scale. The National Carbon Sequestration Database and Geographical Information System (NatCarb) is a relational database and geographic information system (GIS) that integrates carbon storage data generated and maintained by the RCSPs and various other sources. The purpose of NatCarb is to provide a national view of the carbon capture and storage potential in the U.S. and Canada. The digital spatial database allows users to estimate the amount of CO2 emitted by sources (such as power plants, refineries and other fossil-fuel-consuming industries) in relation to geologic formations that can provide safe, secure storage sites over long periods of time. The NatCarb project is working to provide all stakeholders with improved online tools for the display and analysis of CO2 carbon capture and storage data. NatCarb is organizing and enhancing the critical information about CO2 sources and developing the technology needed to access, query, model, analyze, display, and distribute natural resource data related to carbon management. Data are generated, maintained and enhanced locally at the RCSP level, or at specialized data warehouses, and assembled, accessed, and analyzed in real-time through a single geoportal. NatCarb is a functional demonstration of distributed data-management systems that cross the boundaries between institutions and geographic areas. It forms the first step toward a functioning National Carbon Cyberinfrastructure (NCCI). NatCarb provides access to first-order information to evaluate the costs, economic potential and societal issues of CO2 capture and storage, including public perception and regulatory aspects. NatCarb online access has been modified to address the broad needs of a spectrum of users. NatCarb includes not only GIS and database query tools for high-end user, but simplified display for the general public using readily available web tools such as Google Earth???and Google Maps???. Not only is NatCarb connected to all the RCSPs, but data are also pulled from public servers including the U.S. Geological Survey-EROS Data Center and from the Geography Network. Data for major CO2 sources have been obtained from U.S. Environmental Protection Agency (EPA) databases, and data on major coal basins and coalbed methane wells were obtained from the Energy Information Administration (EIA). ?? 2009 Elsevier Ltd. All rights reserved.

Lack of association between NAT2 polymorphism and prostate cancer risk: a meta-analysis and trial sequential analysis

PubMed Central

Tang, Jingyuan; Xu, Lingyan; Xu, Haoxiang; Li, Ran; Han, Peng; Yang, Haiwei

2017-01-01

Previous studies have investigated the association between NAT2 polymorphism and the risk of prostate cancer (PCa). However, the findings from these studies remained inconsistent. Hence, we performed a meta-analysis to provide a more reliable conclusion about such associations. In the present meta-analysis, 13 independent case-control studies were included with a total of 14,469 PCa patients and 10,689 controls. All relevant studies published were searched in the databates PubMed, EMBASE, and Web of Science, till March 1st, 2017. We used the pooled odds ratios (ORs) with 95% confidence intervals (CIs) to evaluate the strength of the association between NAT2*4 allele and susceptibility to PCa. Subgroup analysis was carried out by ethnicity, source of controls and genotyping method. What's more, we also performed trial sequential analysis (TSA) to reduce the risk of type I error and evaluate whether the evidence of the results was firm. Firstly, our results indicated that NAT2*4 allele was not associated with PCa susceptibility (OR = 1.00, 95% CI= 0.95–1.05; P = 0.100). However, after excluding two studies for its heterogeneity and publication bias, no significant relationship was also detected between NAT2*4 allele and the increased risk of PCa, in fixed-effect model (OR = 0.99, 95% CI= 0.94–1.04; P = 0.451). Meanwhile, no significant increased risk of PCa was found in the subgroup analyses by ethnicity, source of controls and genotyping method. Moreover, TSA demonstrated that such association was confirmed in the present study. Therefore, this meta-analysis suggested that no significant association between NAT2 polymorphism and the risk of PCa was found. PMID:28915684

Comparative investigation of the xenobiotic metabolizing arylamine N-acetyltransferase enzyme family among fungi

USDA-ARS?s Scientific Manuscript database

Arylamine N-acetyltransferases (NATs) are xenobiotic metabolizing enzymes well-characterized in several bacteria and higher eukaryotes. The role of NATs in fungal biology has only recently been investigated. The NAT1 gene of Gibberella moniliformis was the first NAT cloned and characterized from fun...

Phylogenetic and biological investigation of the xenobiotic metabolizing arylamine N-acetyltransferase enzyme family among fungi

USDA-ARS?s Scientific Manuscript database

Arylamine N-acetyltransferases (NATs) are xenobiotic metabolizing enzymes well-characterized in several bacteria and eukaryotic organisms. The role of NATs in fungal biology has only recently been investigated. The NAT1 (FDB2) gene of Fusarium verticillioides was the first NAT cloned and character...

The use of multifractal modelling for targeting resources from soil and stream geochemistry data: the case of the Variscan basement of the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Gonçalves, Mario; Mateus, Antonio

2016-04-01

The safeguarding of access/use of many critical raw materials for Society requires that much of previously dismissed areas for exploration must be re-evaluated with new criteria in which the significance of "anomaly" should not be treated independently of the geochemical signals of the ore-forming processes and how the different chemical elements are interrelated. For much of the previous decade, several multifractal methods were methodically being refined as automatic tools to analyze and detect geochemical anomalies. These included the early concentration-area method (Cheng et al., 1994), singularity mapping (Cheng, 2007), and spectrum-area (Cheng et al., 2000), which has been recently combined with the bi-dimensional empirical mode decomposition (Xu et al., 2016) as a tool to separate different contributing sources of an otherwise complex geochemical pattern. We propose yet another approach, the use of geochemical indexes, which links to the geological and ore-forming processes known to define a given region in order to assess much of these numerical approaches. Therefore, we picked several areas from the Variscan basement in Portugal, with different geologic and metallogentic contexts, some of them previously analyzed with multifractal methods (Gonçalves et al., 2001; Jesus et al., 2013) and a multi-element geochemical campaign on which to test the different multifractal methods combined with the geochemical indexes, as an advantageous alternative to principal component mapping, for example. Some preliminary essays with stochastic models similar to those reported in Gonçalves (2001) and Agterberg (2007), with different overprinted pulses are presented as well. Acknowledgments: This is a contribution from UID/GEO/50019/2013 - Instituto Dom Luiz, supported by FCT. Agterberg, 2007, Math. Geol., 39, 1. Cheng et al, 1994, J. Geochem. Explor., 51, 109. Cheng et al., 2000, Nat. Resour. Res, 9, 43. Cheng, 2007, Ore Geol. Rev., 32, 314. Gonçalves, 2001, Math. Geol., 33, 41. Gonçalves et al., 2001, J. Geochem. Explor., 72, 91. Jesus et al., 2013, J. Geochem. Explor., 126-127, 23. Xu et al., 2016, J. Geochem. Explor., in press

Understanding the Home Math Environment and Its Role in Predicting Parent Report of Children's Math Skills.

PubMed

Hart, Sara A; Ganley, Colleen M; Purpura, David J

2016-01-01

There is a growing literature concerning the role of the home math environment in children's math development. In this study, we examined the relation between these constructs by specifically addressing three goals. The first goal was to identify the measurement structure of the home math environment through a series of confirmatory factor analyses. The second goal was to examine the role of the home math environment in predicting parent report of children's math skills. The third goal was to test a series of potential alternative explanations for the relation between the home math environment and parent report of children's skills, specifically the direct and indirect role of household income, parent math anxiety, and parent math ability as measured by their approximate number system performance. A final sample of 339 parents of children aged 3 through 8 drawn from Mechanical Turk answered a questionnaire online. The best fitting model of the home math environment was a bifactor model with a general factor representing the general home math environment, and three specific factors representing the direct numeracy environment, the indirect numeracy environment, and the spatial environment. When examining the association of the home math environment factors to parent report of child skills, the general home math environment factor and the spatial environment were the only significant predictors. Parents who reported doing more general math activities in the home reported having children with higher math skills, whereas parents who reported doing more spatial activities reported having children with lower math skills.

Understanding the Home Math Environment and Its Role in Predicting Parent Report of Children’s Math Skills

PubMed Central

Ganley, Colleen M.; Purpura, David J.

2016-01-01

There is a growing literature concerning the role of the home math environment in children’s math development. In this study, we examined the relation between these constructs by specifically addressing three goals. The first goal was to identify the measurement structure of the home math environment through a series of confirmatory factor analyses. The second goal was to examine the role of the home math environment in predicting parent report of children’s math skills. The third goal was to test a series of potential alternative explanations for the relation between the home math environment and parent report of children’s skills, specifically the direct and indirect role of household income, parent math anxiety, and parent math ability as measured by their approximate number system performance. A final sample of 339 parents of children aged 3 through 8 drawn from Mechanical Turk answered a questionnaire online. The best fitting model of the home math environment was a bifactor model with a general factor representing the general home math environment, and three specific factors representing the direct numeracy environment, the indirect numeracy environment, and the spatial environment. When examining the association of the home math environment factors to parent report of child skills, the general home math environment factor and the spatial environment were the only significant predictors. Parents who reported doing more general math activities in the home reported having children with higher math skills, whereas parents who reported doing more spatial activities reported having children with lower math skills. PMID:28005925

Trajectories of Self-Perceived Math Ability, Utility Value and Interest across Middle School as Predictors of High School Math Performance

ERIC Educational Resources Information Center

Petersen, Jennifer Lee; Hyde, Janet Shibley

2017-01-01

Although many studies have documented developmental change in mathematics motivation, little is known about how these trends predict math performance. A sample of 288 participants from the United States reported their perceived math ability, math utility value and math interest in 5th, 7th and 9th grades. Latent growth curve models estimated…

Effectiveness of a flow-based device using riboflavin photochemistry in damaging blood-borne viral nucleic acids.

PubMed

Zhu, Liguo; Tong, Hongli; Wang, Shufang; Yu, Yang; Liu, Zhong; Li, Changqing; Wang, Deqing

2018-05-03

Effectiveness of a flow-based treatment device using riboflavin photochemistry was demonstrated by cytopathic effect method using indicator viruses. However, inactivation efficacy against real blood-borne viruses needs to be evaluated, especially at nucleic acid level. Special plasma samples with varying concentrations of blood-borne virus were selected using a strict blood selection procedure and were treated with device treatment (DT). Nucleic acid test (NAT) using polymerase chain reaction fluorescence method was used to detect virus copies. The NAT value of 4325 in plasma with high Hepatitis B Virus (HBV) concentrations decreased to 1330 with DT. After 100-fold dilution, the NAT value was below the NAT detection limits with DT compared with 23.0 that without DT. The NAT value of 61.9 in plasma with medium HBV concentrations decreased to 37.8 with DT, and after 10-fold dilution, the NAT value was below the NAT detection limits with DT compared with below 20 that without DT. The Ct values of plasma with low concentrations of blood-borne viruses were below the NAT detection limits with DT. There was a dose effect with DT which was effective in blood-borne viruses damaging nucleic acids to a level below the NAT detection limits. Copyright © 2018 Elsevier B.V. All rights reserved.

Functional effects of single nucleotide polymorphisms in the coding region of human N-acetyltransferase 1

PubMed Central

Zhu, Yuanqi; Hein, David W.

2007-01-01

Genetic variants of human N-acetyltransferase 1 (NAT1) are associated with cancer and birth defects. N- and O-acetyltransferase catalytic activities, Michaelis-Menten kinetic constants (Km & Vmax), and steady state expression levels of NAT1-specific mRNA and protein were determined for the reference NAT1*4 and variant human NAT1 haplotypes possessing single nucleotide polymorphisms (SNPs) in the open reading frame. Although none of the SNPs caused a significant effect on steady state levels of NAT1-specific mRNA, C97T(R33stop), C190T(R64W), C559T (R187stop) and A752T(D251V) each reduced NAT1 protein level and/or N- and O-acetyltransferase catalytic activities to levels below detection. G560A(R187Q) substantially reduced NAT1 protein level and catalytic activities and increased substrate Km. The G445A(V149I), G459A(synonymous) and T640G(S214A) haplotype present in NAT1*11 significantly (p<0.05) increased NAT1 protein level and catalytic activity. Neither T21G(synonymous), T402C(synonymous), A613G(M205V), T777C(synonymous), G781A(E261K), or A787G(I263V) significantly affected Km, catalytic activity, mRNA or protein level. These results suggest heterogeneity among slow NAT1 acetylator phenotypes. PMID:17909564

4-Aminobiphenyl Downregulation of NAT2 Acetylator Genotype–Dependent N- and O-acetylation of Aromatic and Heterocyclic Amine Carcinogens in Primary Mammary Epithelial Cell Cultures from Rapid and Slow Acetylator Rats

PubMed Central

Jefferson, Felicia A.; Xiao, Gong H.; Hein, David W.

2009-01-01

Aromatic and heterocyclic amine carcinogens present in the diet and in cigarette smoke induce breast tumors in rats. N-acetyltransferase 1 (NAT1) and N-acetyltransferase 2 (NAT2) enzymes have important roles in their metabolic activation and deactivation. Human epidemiological studies suggest that genetic polymorphisms in NAT1 and/or NAT2 modify breast cancer risk in women exposed to these carcinogens. p-Aminobenzoic acid (selective for rat NAT2) and sulfamethazine (SMZ; selective for rat NAT1) N-acetyltransferase catalytic activities were both expressed in primary cultures of rat mammary epithelial cells. PABA, 2-aminofluorene, and 4-aminobiphenyl N-acetyltransferase and N-hydroxy-2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine and N-hydroxy-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline O-acetyltransferase activities were two- to threefold higher in mammary epithelial cell cultures from rapid than slow acetylator rats. In contrast, SMZ (a rat NAT1-selective substrate) N-acetyltransferase activity did not differ between rapid and slow acetylators. Rat mammary cells cultured in the medium supplemented 24 h with 10μM ABP showed downregulation in the N-and O-acetylation of all substrates tested except for the NAT1-selective substrate SMZ. This downregulation was comparable in rapid and slow NAT2 acetylators. These studies clearly show NAT2 acetylator genotype–dependent N- and O-acetylation of aromatic and heterocyclic amine carcinogens in rat mammary epithelial cell cultures to be subject to downregulation by the arylamine carcinogen ABP. PMID:18842621

Growth of nitric acid hydrates on thin sulfuric acid films

NASA Technical Reports Server (NTRS)

Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

1994-01-01

Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1-3 x 10(exp -4) Torr H2O and 1-2.5 x 10(exp -6) Torr HNO3) and subjected to cooling and heating cycles. Fourier Transform Infrared (FTIR) spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

FUNCTIONAL CHARACTERIZATION OF THE A411T (L137F) and G364A (D122N) GENETIC POLYMORPHISMS IN HUMAN N-ACETYLTRANSFERASE 2

PubMed Central

Zang, Yu; Zhao, Shuang; Doll, Mark A.; States, J Christopher; Hein, David W.

2007-01-01

Human N-acetyltransferase 2 (NAT2) genetic polymorphisms may modify drug efficacy and toxicity and individual cancer susceptibility from carcinogen exposure. A411T (L137F) and G364A (D122N) are two single nucleotide polymorphisms (SNPs) that coexist with other SNPs in human NAT2 alleles NAT2*5I and NAT2*12D, respectively. Cloning and expression in COS-1 cells showed that both A411T and G364A reduced NAT2 immunoreactive protein to an undetectable level without causing changes in mRNA level. Missense mutants displayed different effects on sulfamethazine N-acetylation activity for both L137 (wild-type: 70.2±5.2; L137F: 1.34±0.03; L137W: non-detectable; L137I: 34.2±2.0; L137G: 0.52±0.04 nmol/min/mg) and D122 (wildtype: 70.2±5.2; D122R: non-detectable; D122Q: non-detectable; D122E: 1.72±0.24 nmol/min/mg). To further test our hypothesis that A411T (L137F) and G364A (D122N) accelerate protein degradation, various NAT2 alleles were cloned and expressed in E. coli, which does not possess the ubiquitin-mediated degradation pathway. In contrast to the expression in mammalian cells, recombinant NAT2 possessing either of these two SNPs showed no reduction in immunoreactive NAT2 level when expressed in E. coli. These findings suggest that both A411T (L137F) and G364A (D122N) enhance NAT2 degradation, resulting in reduced NAT2 protein and catalytic activity for NAT2 5I and NAT2 12D. PMID:17264801

N-Acetyltransferase-2 Genotypes Among Patients with Rheumatoid Arthritis Attending Jordan University Hospital

PubMed Central

Oqal, Muna K.; Mustafa, Khader N.

2012-01-01

Aim: To determine the frequency of major N-acetyltransferase (NAT2) alleles and genotypes among Jordanian patients with rheumatoid arthritis (RA). Methods: The study was approved by the IRB of the Jordan University Hospital. An informed consent was signed by every patient. DNA samples from 150 healthy volunteers and 108 patients with RA were analyzed by polymerase chain reaction followed by a restriction fragment length polymorphism assay (PCR-RFLP) to determine the frequency of four major alleles: NAT2*4, NAT2*5, NAT2*6, and NAT2*7. Results: The most prevalent genotypes are those that encode the slow acetylation phenotype. About 59.3% of the patients with RA carried the slow, 33.3% the intermediate, and 7.4% the fast-encoding genotypes. The frequency of NAT2 alleles was 0.241 (95% confidence interval [CI] 0.184–0.298) for NAT2*4, 0.449 (95% CI 0.383–0.515) for NAT2*5, 0.273 (95% CI 0.214–0.332) for NAT2*6, and 0.037 (95% CI 0.012–0.062) for NAT2*7 allele. The overall frequency of the slow acetylation genotype in patients with RA is similar to that in healthy Jordanian volunteers. However, the NAT2*5/7 genotype was found in seven patients (6.5%) with RA and was absent in Jordanian volunteers, and the z test revealed that the difference was statistically significant. This genotype constituted 10.9% of the genotypes encoding slow acetylation. Conclusion: The overall acetylator genotype in RA is similar to that in healthy volunteers. The overall slow acetylator genotypes do not seem to be a genetic risk factor for RA among Jordanians. However, the NAT2*5/7 genotype seems to be related to RA. The nature of this relationship needs further clarification. PMID:22731637

The Shift From Sentinel Lymph Node Biopsy Performed Either Before or After Neoadjuvant Systemic Therapy in the Clinical Negative Nodes of Breast Cancer Patients. Results, and the Advantages and Disadvantages of Both Procedures.

PubMed

Fernandez-Gonzalez, Sergi; Falo, Catalina; Pla, Maria Jesus; Pernas, Sonia; Bajen, Maite; Soler, Teresa; Ortega, Raul; Quetglas, Cecilia; Perez-Martin, Xavier; Fernandez Montoli, Maria Eulalia; Campos, Miriam; Varela-Rodriguez, Mar; Ponce, Jordi; Garcia-Tejedor, Amparo

2018-02-01

In patients with breast cancer who are candidates for neoadjuvant therapy (NAT), the timing of when to perform sentinel lymph node biopsy (SLNB) remains under discussion. The aim of this study was to compare the advantages and disadvantages of SLNB performed before and after NAT. One hundred seventy-two patients, T1c to T3 and N0 (clinically and according to ultrasound) candidates for NAT were included. We compared the outcomes of 2 groups: (1) 122 patients of whom SLNB was performed before NAT (pre-NAT) from December 2006 to April 2014; and (2) 50 patients with SLNB performed after NAT (post-NAT) from May 2014 to July 2016. Both groups were homogeneous in baseline patient characteristics. The SLNB was positive in 50 patients [41.7%] (33 macrometastases [66%] and 17 micrometastases [34%]) versus 6 patients [12%] (5 macrometastases [83.3%] and 1 micrometastases [16.7%]) in pre- and post-NAT groups, respectively. The lymphadenectomy was performed in 34 patients [28.3%] versus 4 patients [8%], with an odds ratio of 3.48 (95% confidence interval, 1.3-9.3). The recurrences in the pre-NAT group after a median follow-up of 62 months were 12 systemic, 2 local and systemic, and none axillary. In the post-NAT group were no recurrences after a median follow-up of 16 months. Finally, SLNB after NAT reduces the delay in starting NAT from 24 to 14 days (medians; P < .001) and the identification of the SLNB was in 122 patients [100%] versus 49 patients [98%]. SLNB performed after NAT significantly reduces the rate of lymphadenectomies without any increase in recurrences at early follow-up. Furthermore, it allows systemic treatment to be started earlier without interfering in the SLNB identification rate. Copyright © 2017 Elsevier Inc. All rights reserved.

Minimum-complexity helicopter simulation math model

NASA Technical Reports Server (NTRS)

Heffley, Robert K.; Mnich, Marc A.

1988-01-01

An example of a minimal complexity simulation helicopter math model is presented. Motivating factors are the computational delays, cost, and inflexibility of the very sophisticated math models now in common use. A helicopter model form is given which addresses each of these factors and provides better engineering understanding of the specific handling qualities features which are apparent to the simulator pilot. The technical approach begins with specification of features which are to be modeled, followed by a build up of individual vehicle components and definition of equations. Model matching and estimation procedures are given which enable the modeling of specific helicopters from basic data sources such as flight manuals. Checkout procedures are given which provide for total model validation. A number of possible model extensions and refinement are discussed. Math model computer programs are defined and listed.

Sexual activity and perceived health among Finnish middle-aged women

PubMed Central

Ojanlatva, Ansa; Mäkinen, Juha; Helenius, Hans; Korkeila, Katariina; Sundell, Jari; Rautava, Päivi

2006-01-01

Background An increasing awareness of the need to address sexual and orgasm experiences as part of life quality and an understanding of the great individual differences between women play roles in women's health and medical care across the specialities. Information is lacking as to how negative attitude toward self (NATS) and performance impairment (PI) are associated with sexual activity of middle-aged women. We examined the associations of sexual experience, orgasm experience, and lack of sexual desire with perceived health and potential explanatory variables of NATS and PI. Methods Questionnaire was mailed to 2 population-based random samples of menopausal or soon-to-be menopausal women (n = 5510, 70% response) stratified according to age (42–46 and 52–56 years). In multivariate analyses of the associations with the outcome variables, perceived health, NATS, and PI were used as covariates in 6 models in which exercise, menstrual symptoms, and illness indicators were taken into account as well. Results Sexual activity variables were associated with perceived health. When present, NATS formed associations with sexual and orgasm experiences, whereas strenuous exercise formed associations with orgasm among 42–46-year-old women alone. Strenuous exercise was not associated with orgasm experience among older women. Conclusion NATS and PI are closely tied to orgasm experiences and the meaning of the roles needs to be exposed. Sexual activity deserves to be addressed more actively in patient contact at least with perimenopausal women. PMID:16686959

Structural and functional characterization of an arylamine N-acetyltransferase from the pathogen Mycobacterium abscessus: differences from other mycobacterial isoforms and implications for selective inhibition.

PubMed

Cocaign, Angélique; Kubiak, Xavier; Xu, Ximing; Garnier, Guillaume; Li de la Sierra-Gallay, Inès; Chi-Bui, Linh; Dairou, Julien; Busi, Florent; Abuhammad, Areej; Haouz, Ahmed; Dupret, Jean Marie; Herrmann, Jean Louis; Rodrigues-Lima, Fernando

2014-11-01

Mycobacterium abscessus is the most pathogenic rapid-growing mycobacterium and is one of the most resistant organisms to chemotherapeutic agents. However, structural and functional studies of M. abscessus proteins that could modify/inactivate antibiotics remain nonexistent. Here, the structural and functional characterization of an arylamine N-acetyltransferase (NAT) from M. abscessus [(MYCAB)NAT1] are reported. This novel prokaryotic NAT displays significant N-acetyltransferase activity towards aromatic substrates, including antibiotics such as isoniazid and p-aminosalicylate. The enzyme is endogenously expressed and functional in both the rough and smooth M. abscessus morphotypes. The crystal structure of (MYCAB)NAT1 at 1.8 Å resolution reveals that it is more closely related to Nocardia farcinica NAT than to mycobacterial isoforms. In particular, structural and physicochemical differences from other mycobacterial NATs were found in the active site. Peculiarities of (MYCAB)NAT1 were further supported by kinetic and docking studies showing that the enzyme was poorly inhibited by the piperidinol inhibitor of mycobacterial NATs. This study describes the first structure of an antibiotic-modifying enzyme from M. abscessus and provides bases to better understand the substrate/inhibitor-binding specificities among mycobacterial NATs and to identify/optimize specific inhibitors. These data should also contribute to the understanding of the mechanisms that are responsible for the pathogenicity and extensive chemotherapeutic resistance of M. abscessus.

Preparing Prekindergartners with Math Readiness Skills: The Effect of Children's Talk, Focus, and Engagement on Math Achievement

ERIC Educational Resources Information Center

Cummings, Tracy; Hofer, Kerry G.; Farran, Dale C.; Lipsey, Mark W.; Bilbrey, Carol; Vorhaus, Elizabeth

2009-01-01

The "Building Blocks PreK Math Curriculum" (Clements & Sarama, 2007) was designed to facilitate children's engagement in math and talk about math. Much research investigates the effect of curriculum on classrooms or teacher practices. This study used a mediational model to look at a curriculum's effect on children's achievement gain, operating…

75 FR 22814 - Guidance for Industry: Nucleic Acid Testing (NAT) for Human Immunodeficiency Virus Type 1 (HIV-1...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-30

... Immunodeficiency Virus Type 1 (HIV-1) and Hepatitis C Virus (HCV): Testing, Product Disposition, and Donor Deferral... Industry: Nucleic Acid Testing (NAT) for Human Immunodeficiency Virus Type 1 (HIV-1) and Hepatitis C Virus... Acid Test (NAT) and Hepatitis C Virus (HCV) NAT, on testing individual samples or pooled samples from...

Analysis of protein function in clinical C. albicans isolates

PubMed Central

Gerami-Nejad, Maryam; Forche, Anja; McClellan, Mark; Berman, Judith

2012-01-01

Clinical isolates are prototrophic and hence are not amenable to genetic manipulation using nutritional markers. Here we describe a new set of plasmids carrying the NAT1 (nourseothricin) drug resistance marker (Shen et al., 2005) that can be used both in clinical isolates and in laboratory strains. We constructed novel plasmids containing HA-NAT1 or MYC-NAT1 cassettes to facilitate PCR-mediated construction of strains with C-terminal epitope-tagged proteins and a NAT1-pMet3-GFP plasmid to enable conditional expression of proteins with or without the green fluorescent protein fused at the N-terminus. Furthermore, for proteins that require both the endogenous N- and C-termini for function, we have constructed a GF-NAT1-FP cassette carrying truncated alleles that facilitate insertion of an intact, single copy of GFP internal to the coding sequence. In addition, GFP-NAT1, RFP-NAT1, and M-Cherry-NAT1 plasmids were constructed expressing two differently labeled gene products for the study of protein co-expression and co-localization in vivo. Together, these vectors provide a useful set of genetic tools for studying diverse aspects of gene function in C. albicans clinical as well as laboratory strains. PMID:22777821

Crystal Structure of the Golgi-Associated Human Nα-Acetyltransferase 60 Reveals the Molecular Determinants for Substrate-Specific Acetylation.

PubMed

Støve, Svein Isungset; Magin, Robert S; Foyn, Håvard; Haug, Bengt Erik; Marmorstein, Ronen; Arnesen, Thomas

2016-07-06

N-Terminal acetylation is a common and important protein modification catalyzed by N-terminal acetyltransferases (NATs). Six human NATs (NatA-NatF) contain one catalytic subunit each, Naa10 to Naa60, respectively. In contrast to the ribosome-associated NatA to NatE, NatF/Naa60 specifically associates with Golgi membranes and acetylates transmembrane proteins. To gain insight into the molecular basis for the function of Naa60, we developed an Naa60 bisubstrate CoA-peptide conjugate inhibitor, determined its X-ray structure when bound to CoA and inhibitor, and carried out biochemical experiments. We show that Naa60 adapts an overall fold similar to that of the catalytic subunits of ribosome-associated NATs, but with the addition of two novel elongated loops that play important roles in substrate-specific binding. One of these loops mediates a dimer to monomer transition upon substrate-specific binding. Naa60 employs a catalytic mechanism most similar to Naa50. Collectively, these data reveal the molecular basis for Naa60-specific acetyltransferase activity with implications for its Golgi-specific functions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Paper-based sample-to-answer molecular diagnostic platform for point-of-care diagnostics.

PubMed

Choi, Jane Ru; Tang, Ruihua; Wang, ShuQi; Wan Abas, Wan Abu Bakar; Pingguan-Murphy, Belinda; Xu, Feng

2015-12-15

Nucleic acid testing (NAT), as a molecular diagnostic technique, including nucleic acid extraction, amplification and detection, plays a fundamental role in medical diagnosis for timely medical treatment. However, current NAT technologies require relatively high-end instrumentation, skilled personnel, and are time-consuming. These drawbacks mean conventional NAT becomes impractical in many resource-limited disease-endemic settings, leading to an urgent need to develop a fast and portable NAT diagnostic tool. Paper-based devices are typically robust, cost-effective and user-friendly, holding a great potential for NAT at the point of care. In view of the escalating demand for the low cost diagnostic devices, we highlight the beneficial use of paper as a platform for NAT, the current state of its development, and the existing challenges preventing its widespread use. We suggest a strategy involving integrating all three steps of NAT into one single paper-based sample-to-answer diagnostic device for rapid medical diagnostics in the near future. Copyright © 2015 Elsevier B.V. All rights reserved.

Preventing disease transmission by deceased tissue donors by testing blood for viral nucleic acid.

PubMed

Strong, D Michael; Nelson, Karen; Pierce, Marge; Stramer, Susan L

2005-01-01

Nucleic acid testing (NAT) has reduced the risk of transmitting infectious disease through blood transfusion. Currently NAT for HIV-1 and HCV are FDA licensed and performed by nearly all blood collection facilities, but HBV NAT is performed under an investigational study protocol. Residual risk estimates indicate that NAT could potentially reduce disease transmission through transplanted tissue. However, tissue donor samples obtained post-mortem have the potential to produce an invalid NAT result due to inhibition of amplification reactions by hemolysis and other factors. The studies reported here summarize the development of protocols to allow NAT of deceased donor samples with reduced rates of invalid results. Using these protocols, inventories from two tissue centers were tested with greater than 99% of samples producing a valid test result.

The role of social support in students' perceived abilities and attitudes toward math and science.

PubMed

Rice, Lindsay; Barth, Joan M; Guadagno, Rosanna E; Smith, Gabrielle P A; McCallum, Debra M

2013-07-01

Social cognitive models examining academic and career outcomes emphasize constructs such as attitude, interest, and self-efficacy as key factors affecting students' pursuit of STEM (science, technology, engineering and math) courses and careers. The current research examines another under-researched component of social cognitive models: social support, and the relationship between this component and attitude and self-efficacy in math and science. A large cross-sectional design was used gathering data from 1,552 participants in four adolescent school settings from 5th grade to early college (41 % female, 80 % white). Students completed measures of perceived social support from parents, teachers and friends as well as their perceived ability and attitudes toward math and science. Fifth grade and college students reported higher levels of support from teachers and friends when compared to students at other grade levels. In addition, students who perceived greater social support for math and science from parents, teachers, and friends reported better attitudes and had higher perceptions of their abilities in math and science. Lastly, structural equation modeling revealed that social support had both a direct effect on math and science perceived abilities and an indirect effect mediated through math and science attitudes. Findings suggest that students who perceive greater social support for math and science from parents, teachers, and friends have more positive attitudes toward math and science and a higher sense of their own competence in these subjects.

Comparison of receptor affinity of natSc-DOTA-TATE versus natGa-DOTA-TATE.

PubMed

Koumarianou, Eftychia; Pawlak, Dariusz; Korsak, Agnieszka; Mikolajczak, Renata

2011-01-01

44Sc as a positron emitter can be an interesting alternative to 68Ga (T½=67.71 min) due to its longer half-life (T½=3.97 h). Moreover, the b-emitter 47Sc can be used for therapy when attached to the same biomolecule vectors. DOTA as a chelating agent has been proven suitable for the radiolabelling of peptides recognising tumour cell receptors in vivo with M3+ radiometals. DOTA-derivatized peptides have been successfully labelled with 90Y and 177Lu for therapy, and with 68Ga for PET imaging. However, published data on 44Sc-labelled DOTA-biomolecules as potential PET radiotracers are still very limited. The aim of this study was to compare the affinity of natGa- and natSc-labelled DOTA-TATE to somatostatin receptors subtype 2 expressed in rat pancreatic cancer cell line AR42J. The cold complexes of DOTA-TATE with natGa and natSc were synthesized and identified by HPLC and MS analysis and evaluated in vitro for competitive binding to cancer cell line AR42J expressing somatostatin receptors subtype 2 (sstr2). The IC50 values calculated from the displacement curve of {125I-Tyr11}-SST-14 were: 0.20±0.18, 0.70±0.20, 0.64±0.22 and 0.67±0.12 for natGa-DOTA-TATE, natSc-DOTA-TATE, DOTA-TATE, and {Tyr11}-SST-14 complexes, respectively, with the affinity lowering in the decreasing order: natGa-DOTA-TATE>DOTA-TATE>Tyr11-SST-14>natSc-DOTA-TATE. The binding affinity of natGa-DOTA-TATE appeared higher than that of natSc-DOTA-TATE. Further in vitro and in vivo studies are needed to verify the influence of the chelated metal on the affinity and uptake of the respective radiolabelled compounds. This information might be crucial when the in vivo applications of peptides labelled with 68Ga and 44Sc for PET, as well as the use of 47Sc for radiotherapy are considered.

Applying Computerized Adaptive Testing to the Negative Acts Questionnaire-Revised: Rasch Analysis of Workplace Bullying

PubMed Central

Ma, Shu-Ching; Li, Yu-Chi; Yui, Mei-Shu

2014-01-01

Background Workplace bullying is a prevalent problem in contemporary work places that has adverse effects on both the victims of bullying and organizations. With the rapid development of computer technology in recent years, there is an urgent need to prove whether item response theory–based computerized adaptive testing (CAT) can be applied to measure exposure to workplace bullying. Objective The purpose of this study was to evaluate the relative efficiency and measurement precision of a CAT-based test for hospital nurses compared to traditional nonadaptive testing (NAT). Under the preliminary conditions of a single domain derived from the scale, a CAT module bullying scale model with polytomously scored items is provided as an example for evaluation purposes. Methods A total of 300 nurses were recruited and responded to the 22-item Negative Acts Questionnaire-Revised (NAQ-R). All NAT (or CAT-selected) items were calibrated with the Rasch rating scale model and all respondents were randomly selected for a comparison of the advantages of CAT and NAT in efficiency and precision by paired t tests and the area under the receiver operating characteristic curve (AUROC). Results The NAQ-R is a unidimensional construct that can be applied to measure exposure to workplace bullying through CAT-based administration. Nursing measures derived from both tests (CAT and NAT) were highly correlated (r=.97) and their measurement precisions were not statistically different (P=.49) as expected. CAT required fewer items than NAT (an efficiency gain of 32%), suggesting a reduced burden for respondents. There were significant differences in work tenure between the 2 groups (bullied and nonbullied) at a cutoff point of 6 years at 1 worksite. An AUROC of 0.75 (95% CI 0.68-0.79) with logits greater than –4.2 (or >30 in summation) was defined as being highly likely bullied in a workplace. Conclusions With CAT-based administration of the NAQ-R for nurses, their burden was substantially reduced without compromising measurement precision. PMID:24534113

Mathematical learning instruction and teacher motivation factors affecting science technology engineering and math (STEM) major choices in 4-year colleges and universities: Multilevel structural equation modeling

NASA Astrophysics Data System (ADS)

Lee, Ahlam

2011-12-01

Using the Educational Longitudinal Study of 2002/06, this study examined the effects of the selected mathematical learning and teacher motivation factors on graduates' science, technology, engineering, and math (STEM) related major choices in 4-year colleges and universities, as mediated by math performance and math self-efficacy. Using multilevel structural equation modeling, I analyzed: (1) the association between mathematical learning instruction factors (i.e., computer, individual, and lecture-based learning activities in mathematics) and students' STEM major choices in 4-year colleges and universities as mediated by math performance and math self-efficacy and (2) the association between school factor, teacher motivation and students' STEM major choices in 4-year colleges and universities via mediators of math performance and math self-efficacy. The results revealed that among the selected learning experience factors, computer-based learning activities in math classrooms yielded the most positive effects on math self-efficacy, which significantly predicted the increase in the proportion of students' STEM major choice as mediated by math self-efficacy. Further, when controlling for base-year math Item Response Theory (IRT) scores, a positive relationship between individual-based learning activities in math classrooms and the first follow-up math IRT scores emerged, which related to the high proportion of students' STEM major choices. The results also indicated that individual and lecture-based learning activities in math yielded positive effects on math self-efficacy, which related to STEM major choice. Concerning between-school levels, teacher motivation yielded positive effects on the first follow up math IRT score, when controlling for base year IRT score. The results from this study inform educators, parents, and policy makers on how mathematics instruction can improve student math performance and encourage more students to prepare for STEM careers. Students should receive all possible opportunities to use computers to enhance their math self-efficacy, be encouraged to review math materials, and concentrate on listening to math teachers' lectures. While all selected math-learning activities should be embraced in math instruction, computer and individual-based learning activities, which reflect student-driven learning, should be emphasized in the high school instruction. Likewise, students should be encouraged to frequently engage in individual-based learning activities to improve their math performance.

Accuracy of various human NAT2 SNP genotyping panels to infer rapid, intermediate and slow acetylator phenotypes

PubMed Central

Hein, David W; Doll, Mark A

2012-01-01

Aim Humans exhibit genetic polymorphism in NAT2 resulting in rapid, intermediate and slow acetylator phenotypes. Over 65 NAT2 variants possessing one or more SNPs in the 870-bp NAT2 coding region have been reported. The seven most frequent SNPs are rs1801279 (191G>A), rs1041983 (282C>T), rs1801280 (341T>C), rs1799929 (481C>T), rs1799930 (590G>A), rs1208 (803A>G) and rs1799931 (857G>A). The majority of studies investigate the NAT2 genotype assay for three SNPs: 481C>T, 590G>A and 857G>A. A tag-SNP (rs1495741) recently identified in a genome-wide association study has also been proposed as a biomarker for the NAT2 phenotype. Materials & methods Sulfamethazine N-acetyltransferase catalytic activities were measured in cryopreserved human hepatocytes from a convenience sample of individuals in the USA with an ethnic frequency similar to the 2010 US population census. These activities were segregated by the tag-SNP rs1495741 and each of the seven SNPs described above. We assessed the accuracy of the tag-SNP and various two-, three-, four- and seven-SNP genotyping panels for their ability to accurately infer NAT2 phenotype. Results The accuracy of the various NAT2 SNP genotype panels to infer NAT2 phenotype were as follows: seven-SNP: 98.4%; tag-SNP: 77.7%; two-SNP: 96.1%; three-SNP: 92.2%; and four-SNP: 98.4%. Conclusion A NAT2 four-SNP genotype panel of rs1801279 (191G>A), rs1801280 (341T>C), rs1799930 (590G>A) and rs1799931 (857G>A) infers NAT2 acetylator phenotype with high accuracy, and is recommended over the tag-, two-, three- and (for economy of scale) the seven-SNP genotyping panels, particularly in populations of non-European ancestry. PMID:22092036

Nat1 promotes translation of specific proteins that induce differentiation of mouse embryonic stem cells.

PubMed

Sugiyama, Hayami; Takahashi, Kazutoshi; Yamamoto, Takuya; Iwasaki, Mio; Narita, Megumi; Nakamura, Masahiro; Rand, Tim A; Nakagawa, Masato; Watanabe, Akira; Yamanaka, Shinya

2017-01-10

Novel APOBEC1 target 1 (Nat1) (also known as "p97," "Dap5," and "Eif4g2") is a ubiquitously expressed cytoplasmic protein that is homologous to the C-terminal two thirds of eukaryotic translation initiation factor 4G (Eif4g1). We previously showed that Nat1-null mouse embryonic stem cells (mES cells) are resistant to differentiation. In the current study, we found that NAT1 and eIF4G1 share many binding proteins, such as the eukaryotic translation initiation factors eIF3 and eIF4A and ribosomal proteins. However, NAT1 did not bind to eIF4E or poly(A)-binding proteins, which are critical for cap-dependent translation initiation. In contrast, compared with eIF4G1, NAT1 preferentially interacted with eIF2, fragile X mental retardation proteins (FMR), and related proteins and especially with members of the proline-rich and coiled-coil-containing protein 2 (PRRC2) family. We also found that Nat1-null mES cells possess a transcriptional profile similar, although not identical, to the ground state, which is established in wild-type mES cells when treated with inhibitors of the ERK and glycogen synthase kinase 3 (GSK3) signaling pathways. In Nat1-null mES cells, the ERK pathway is suppressed even without inhibitors. Ribosome profiling revealed that translation of mitogen-activated protein kinase kinase kinase 3 (Map3k3) and son of sevenless homolog 1 (Sos1) is suppressed in the absence of Nat1 Forced expression of Map3k3 induced differentiation of Nat1-null mES cells. These data collectively show that Nat1 is involved in the translation of proteins that are required for cell differentiation.

Piperidinols That Show Anti-Tubercular Activity as Inhibitors of Arylamine N-Acetyltransferase: An Essential Enzyme for Mycobacterial Survival Inside Macrophages

PubMed Central

Abuhammad, Areej; Fullam, Elizabeth; Lowe, Edward D.; Staunton, David; Kawamura, Akane; Westwood, Isaac M.; Bhakta, Sanjib; Garner, Alun Christopher; Wilson, David L.; Seden, Peter T.; Davies, Stephen G.; Russell, Angela J.; Garman, Elspeth F.; Sim, Edith

2012-01-01

Latent M. tuberculosis infection presents one of the major obstacles in the global eradication of tuberculosis (TB). Cholesterol plays a critical role in the persistence of M. tuberculosis within the macrophage during latent infection. Catabolism of cholesterol contributes to the pool of propionyl-CoA, a precursor that is incorporated into cell-wall lipids. Arylamine N-acetyltransferase (NAT) is encoded within a gene cluster that is involved in the cholesterol sterol-ring degradation and is essential for intracellular survival. The ability of the NAT from M. tuberculosis (TBNAT) to utilise propionyl-CoA links it to the cholesterol-catabolism pathway. Deleting the nat gene or inhibiting the NAT enzyme prevents intracellular survival and results in depletion of cell-wall lipids. TBNAT has been investigated as a potential target for TB therapies. From a previous high-throughput screen, 3-benzoyl-4-phenyl-1-methylpiperidinol was identified as a selective inhibitor of prokaryotic NAT that exhibited antimycobacterial activity. The compound resulted in time-dependent irreversible inhibition of the NAT activity when tested against NAT from M. marinum (MMNAT). To further evaluate the antimycobacterial activity and the NAT inhibition of this compound, four piperidinol analogues were tested. All five compounds exert potent antimycobacterial activity against M. tuberculosis with MIC values of 2.3–16.9 µM. Treatment of the MMNAT enzyme with this set of inhibitors resulted in an irreversible time-dependent inhibition of NAT activity. Here we investigate the mechanism of NAT inhibition by studying protein-ligand interactions using mass spectrometry in combination with enzyme analysis and structure determination. We propose a covalent mechanism of NAT inhibition that involves the formation of a reactive intermediate and selective cysteine residue modification. These piperidinols present a unique class of antimycobacterial compounds that have a novel mode of action different from known anti-tubercular drugs. PMID:23285185

N-acetyltransferase (nat) is a critical conjunct of photoperiodism between the circadian system and endocrine axis in Antheraea pernyi.

PubMed

Mohamed, Ahmed A M; Wang, Qiushi; Bembenek, Jadwiga; Ichihara, Naoyuki; Hiragaki, Susumu; Suzuki, Takeshi; Takeda, Makio

2014-01-01

Since its discovery in 1923, the biology of photoperiodism remains a mystery in many ways. We sought the link connecting the circadian system to an endocrine switch, using Antheraea pernyi. PER-, CLK- and CYC-ir were co-expressed in two pairs of dorsolateral neurons of the protocerebrum, suggesting that these are the circadian neurons that also express melatonin-, NAT- and HIOMT-ir. The results suggest that a melatonin pathway is present in the circadian neurons. Melatonin receptor (MT2 or MEL-1B-R)-ir in PTTH-ir neurons juxtaposing clock neurons suggests that melatonin gates PTTH release. RIA showed a melatonin rhythm with a peak four hours after lights off in adult brain both under LD16:8 (LD) and LD12:12 (SD), and both the peak and the baseline levels were higher under LD than SD, suggesting a photoperiodic influence. When pupae in diapause were exposed to 10 cycles of LD, or stored at 4 °C for 4 months under constant darkness, an increase of NAT activity was observed when PTTH released ecdysone. DNA sequence upstream of nat contained E-boxes to which CYC/CLK could bind, and nat transcription was turned off by clk or cyc dsRNA. dsRNA(NAT) caused dysfunction of photoperiodism. dsRNA(PER) upregulated nat transcription as anticipated, based on findings in the Drosophila melanogaster circadian system. Transcription of nat, cyc and clk peaked at ZT12. RIA showed that dsRNA(NAT) decreased melatonin while dsRNA(PER) increased melatonin. Thus nat, a clock controlled gene, is the critical link between the circadian clock and endocrine switch. MT-binding may release PTTH, resulting in termination of diapause. This study thus examined all of the basic functional units from the clock: a photoperiodic counter as an accumulator of mRNA(NAT), to endocrine switch for photoperiodism in A. pernyi showing this system is self-complete without additional device especially for photoperiodism.

A Comparison of Two Balance Calibration Model Building Methods

NASA Technical Reports Server (NTRS)

DeLoach, Richard; Ulbrich, Norbert

2007-01-01

Simulated strain-gage balance calibration data is used to compare the accuracy of two balance calibration model building methods for different noise environments and calibration experiment designs. The first building method obtains a math model for the analysis of balance calibration data after applying a candidate math model search algorithm to the calibration data set. The second building method uses stepwise regression analysis in order to construct a model for the analysis. Four balance calibration data sets were simulated in order to compare the accuracy of the two math model building methods. The simulated data sets were prepared using the traditional One Factor At a Time (OFAT) technique and the Modern Design of Experiments (MDOE) approach. Random and systematic errors were introduced in the simulated calibration data sets in order to study their influence on the math model building methods. Residuals of the fitted calibration responses and other statistical metrics were compared in order to evaluate the calibration models developed with different combinations of noise environment, experiment design, and model building method. Overall, predicted math models and residuals of both math model building methods show very good agreement. Significant differences in model quality were attributable to noise environment, experiment design, and their interaction. Generally, the addition of systematic error significantly degraded the quality of calibration models developed from OFAT data by either method, but MDOE experiment designs were more robust with respect to the introduction of a systematic component of the unexplained variance.

Completing the Remedial Sequence and College-Level Credit-Bearing Math: Comparing Binary, Cumulative, and Continuation Ratio Logistic Regression Models

ERIC Educational Resources Information Center

Davidson, J. Cody

2016-01-01

Mathematics is the most common subject area of remedial need and the majority of remedial math students never pass a college-level credit-bearing math class. The majorities of studies that investigate this phenomenon are conducted at community colleges and use some type of regression model; however, none have used a continuation ratio model. The…

STS-2: SAIL non-avionics subsystems math model requirements

NASA Technical Reports Server (NTRS)

Bennett, W. P.; Herold, R. W.

1980-01-01

Simulation of the STS-2 Shuttle nonavionics subsystems in the shuttle avionics integration laboratory (SAIL) is necessary for verification of the integrated shuttle avionics system. The math model (simulation) requirements for each of the nonavionics subsystems that interfaces with the Shuttle avionics system is documented and a single source document for controlling approved changes (by the SAIL change control panel) to the math models is provided.

N-Acetyltransferase 2 (NAT2) genetic variation and the susceptibility to noncardiac gastric adenocarcinoma in Taiwan.

PubMed

Chang, Chih-Hao; Huang, Yi-Shin; Perng, Chin-Lin; Lin, Han-Chieh

2016-03-01

N-Acetyltransferase (NAT) is an important enzyme with the capacity to metabolize carcinogenic aromatic amines. However, it remains controversial whether the encoded functional NAT2 genetic polymorphism is related to the risk of gastric adenocarcinoma (GA). The aim of this study was to evaluate the association between NAT2 genetic variation and gastric adenocarcinoma (GA), with special reference to the gastric noncardiac adenocarcinoma (GNA). Peripheral white blood cell DNA from 368 GA patients and 368 age- and sex-matched controls were genotyped for NAT2 by a polymerase chain reaction method. The lifestyle habits of the participants were assessed using a semiquantitative food-frequency questionnaire. NAT2 genotype, interaction with lifestyle habits, and the risk of GA and GNA were analyzed by logistic regression. GA patients were more likely to have a smoking habit, ate more salted foods, and consumed more well-done meat than the controls. There was no association between the NAT2 genotypes and susceptibility to GA. However, if patients with gastric cardiac adenocarcinoma (GCA; n = 42) were excluded, the NAT2 slow acetylators (without rapid acetylator allele) had a higher risk of GA than intermediate and rapid acetylators (odds ratio = 1.53; 95% confidence interval, 1.05-2.23, p = 0.027). In addition, there was a synergic effect of NAT2 slow acetylator and well-done meat intake to the development of GNA (odds ratio = 3.83; 95% confidence interval, 1.68-8.76, p = 0.001). NAT2 slow acetylators have a higher risk of GNA than intermediate and rapid acetylators have in a Taiwanese population. The intake of well-done meat, an additive to the acetylator status, may contribute to the incidence of gastric carcinogenesis. Copyright © 2015. Published by Elsevier Taiwan LLC.

Cost projections for implementation of safety interventions to prevent transfusion-transmitted Zika virus infection in the United States

PubMed Central

Ellingson, Katherine D.; Sapiano, Mathew R.P.; Haass, Kathryn A.; Savinkina, Alexandra A.; Baker, Misha L.; Henry, Richard A.; Berger, James J.; Kuehnert, Matthew J.; Basavaraju, Sridhar V.

2017-01-01

BACKGROUND In August 2016, the Food and Drug Administration advised US blood centers to screen all whole blood and apheresis donations for Zika virus (ZIKV) with an individual-donor nucleic acid test (ID-NAT) or to use approved pathogen reduction technology (PRT). The cost of implementing this guidance nationally has not been assessed. STUDY DESIGN AND METHODS Scenarios were constructed to characterize approaches to ZIKV screening, including universal ID-NAT, risk-based seasonal allowance of minipool (MP) NAT by state, and universal MP-NAT. Data from the 2015 National Blood Collection and Utilization Survey (NBCUS) were used to characterize the number of donations nationally and by state. For each scenario, the estimated cost per donor ($3–$9 for MP-NAT, $7–$13 for ID-NAT) was multiplied by the estimated number of relevant donations from the NBCUS. Cost of PRT was calculated by multiplying the cost per unit ($50–$125) by the number of units approved for PRT. Prediction intervals for costs were generated using Monte Carlo simulation methods. RESULTS Screening all donations in the 50 states and DC for ZIKV by ID-NAT would cost $137 million (95% confidence interval [CI], $109–$167) annually. Allowing seasonal MP-NAT in states with lower ZIKV risk could reduce NAT screening costs by 18% to 25%. Application of PRT to all platelet (PLT) and plasma units would cost $213 million (95% CI, $156–$304). CONCLUSION Universal ID-NAT screening for ZIKV will cost US blood centers more than $100 million annually. The high cost of PRT for apheresis PLTs and plasma could be mitigated if, once validated, testing for transfusion transmissible pathogens could be eliminated. PMID:28591470

Rapid and sensitive approach to simultaneous detection of genomes of hepatitis A, B, C, D and E viruses.

PubMed

Kodani, Maja; Mixson-Hayden, Tonya; Drobeniuc, Jan; Kamili, Saleem

2014-10-01

Five viruses have been etiologically associated with viral hepatitis. Nucleic acid testing (NAT) remains the gold standard for diagnosis of viremic stages of infection. NAT methodologies have been developed for all hepatitis viruses; however, a NAT-based assay that can simultaneously detect all five viruses is not available. We designed TaqMan card-based assays for detection of HAV RNA, HBV DNA, HCV RNA, HDV RNA and HEV RNA. The performances of individual assays were evaluated on TaqMan Array Cards (TAC) for detecting five viral genomes simultaneously. Sensitivity and specificity were determined by testing 329 NAT-tested clinical specimens. All NAT-positive samples for HCV (n = 32), HDV (n = 28) and HEV (n = 14) were also found positive in TAC (sensitivity, 100%). Forty-three of 46 HAV-NAT positive samples were also positive in TAC (sensitivity, 94%), while 36 of 39 HBV-NAT positive samples were positive (sensitivity, 92%). No false-positives were detected for HBV (n = 32), HCV (n = 36), HDV (n = 30), and HEV (n = 31) NAT-negative samples (specificity 100%), while 38 of 41 HAV-NAT negative samples were negative by TAC (specificity 93%). TAC assay was concordant with corresponding individual NATs for hepatitis A-E viral genomes and can be used for their detection simultaneously. The TAC assay has potential for use in hepatitis surveillance, for screening of donor specimens and in outbreak situations. Wider availability of TAC-ready assays may allow for customized assays, for improving acute jaundice surveillance and for other purposes for which there is need to identify multiple pathogens rapidly. Published by Elsevier B.V.

Interaction between Red Meat Intake and NAT2 Genotype in Increasing the Risk of Colorectal Cancer in Japanese and African Americans

PubMed Central

Wang, Hansong; Iwasaki, Motoki; Haiman, Christopher A.; Kono, Suminori; Wilkens, Lynne R.; Keku, Temitope O.; Berndt, Sonja I.; Tsugane, Shoichiro; Le Marchand, Loïc

2015-01-01

Heterocyclic aromatic amines formed in cooked meat may be an underlying mechanism for the red meat-colorectal cancer (CRC) association. These compounds require bioactivaction by N-acetyltransferase 2 (NAT2). An interaction effect between red meat consumption and NAT2 in increasing CRC risk has been inconsistently reported in whites. We investigated this interaction in two populations in which the high-activity rapid NAT2 phenotype is 10- and 2-fold more common than in whites. We meta-analyzed four studies of Japanese (2,217 cases, 3,788 controls) and three studies of African Americans (527 cases, 4,527 controls). NAT2 phenotype was inferred from an optimized seven-SNP genotyping panel. Processed and total red meat intakes were associated with an increased CRC risk in Japanese and in both ethnic groups combined (P’s ≤ 0.002). We observed an interaction between processed meat intake and NAT2 in Japanese (P = 0.04), African Americans (P = 0.02), and in both groups combined (P = 0.006). The association of processed meat with CRC was strongest among individuals with the rapid NAT2 phenotype (combined analysis, OR for highest vs. lowest quartile: 1.62, 95% CI: 1.28–2.05; Ptrend = 8.0×10−5), intermediate among those with the intermediate NAT2 phenotype (1.29, 95% CI: 1.05–1.59; Ptrend = 0.05) and null among those with the slow phenotype (Ptrend = 0.45). A similar interaction was found for NAT2 and total red meat (Pinteraction = 0.03). Our findings support a role for NAT2 in modifying the association between red meat consumption and CRC in Japanese and African Americans. PMID:26683305

The Menu for Every Young Mathematician's Appetite

ERIC Educational Resources Information Center

Legnard, Danielle S.; Austin, Susan L.

2012-01-01

Math Workshop offers differentiated instruction to foster a deep understanding of rich, rigorous mathematics that is attainable by all learners. The inquiry-based model provides a menu of multilevel math tasks, within the daily math block, that focus on similar mathematical content. Math Workshop promotes a culture of engagement and…

NAT10, a nucleolar protein, localizes to the midbody and regulates cytokinesis and acetylation of microtubules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Qi; Zheng, Xingzheng; McNutt, Michael A.

2009-06-10

The midbody is a structural organelle formed in late phase mitosis which is responsible for completion of cytokinesis. Although various kinds of proteins have been found to distribute or immigrate to this organelle, their functions have still not been completely worked out. In this study, we demonstrated that NAT10 (N-acetyltransferase 10, NAT10) is not only predominantly distributed in the nucleolus in interphase, but is also concentrated in the mitotic midbody during telophase. The domain in N-terminal residues 549-834 of NAT10 specifically mediated its subcellular localization. Treatment with genotoxic agents or irradiation increased concentration of NAT10 in both the nucleolus andmore » midbody. Moreover, DNA damage induced increase of NAT10 in the midbody apparently accompanied by in situ elevation of the level of acetylated {alpha}-tubulin, suggesting that it plays a role in maintaining or enhancing stability of {alpha}-tubulin. The depletion of NAT10 induced defects in nucleolar assembly, cytokinesis and decreased acetylated {alpha}-tubulin, leading to G2/M cell cycle arrest or delay of mitotic exit. In addition, over-expression of NAT10 was found in a variety of soft tissue sarcomas, and correlated with tumor histological grading. These results indicate that NAT10 may play an important role in cell division through facilitating reformation of the nucleolus and midbody in the late phase of cell mitosis, and stabilization of microtubules.« less

Identification and validation of N-acetyltransferase 2 as an insulin sensitivity gene.

PubMed

Knowles, Joshua W; Xie, Weijia; Zhang, Zhongyang; Chennamsetty, Indumathi; Chennemsetty, Indumathi; Assimes, Themistocles L; Paananen, Jussi; Hansson, Ola; Pankow, James; Goodarzi, Mark O; Carcamo-Orive, Ivan; Morris, Andrew P; Chen, Yii-Der I; Mäkinen, Ville-Petteri; Ganna, Andrea; Mahajan, Anubha; Guo, Xiuqing; Abbasi, Fahim; Greenawalt, Danielle M; Lum, Pek; Molony, Cliona; Lind, Lars; Lindgren, Cecilia; Raffel, Leslie J; Tsao, Philip S; Schadt, Eric E; Rotter, Jerome I; Sinaiko, Alan; Reaven, Gerald; Yang, Xia; Hsiung, Chao A; Groop, Leif; Cordell, Heather J; Laakso, Markku; Hao, Ke; Ingelsson, Erik; Frayling, Timothy M; Weedon, Michael N; Walker, Mark; Quertermous, Thomas

2015-04-01

Decreased insulin sensitivity, also referred to as insulin resistance (IR), is a fundamental abnormality in patients with type 2 diabetes and a risk factor for cardiovascular disease. While IR predisposition is heritable, the genetic basis remains largely unknown. The GENEticS of Insulin Sensitivity consortium conducted a genome-wide association study (GWAS) for direct measures of insulin sensitivity, such as euglycemic clamp or insulin suppression test, in 2,764 European individuals, with replication in an additional 2,860 individuals. The presence of a nonsynonymous variant of N-acetyltransferase 2 (NAT2) [rs1208 (803A>G, K268R)] was strongly associated with decreased insulin sensitivity that was independent of BMI. The rs1208 "A" allele was nominally associated with IR-related traits, including increased fasting glucose, hemoglobin A1C, total and LDL cholesterol, triglycerides, and coronary artery disease. NAT2 acetylates arylamine and hydrazine drugs and carcinogens, but predicted acetylator NAT2 phenotypes were not associated with insulin sensitivity. In a murine adipocyte cell line, silencing of NAT2 ortholog Nat1 decreased insulin-mediated glucose uptake, increased basal and isoproterenol-stimulated lipolysis, and decreased adipocyte differentiation, while Nat1 overexpression produced opposite effects. Nat1-deficient mice had elevations in fasting blood glucose, insulin, and triglycerides and decreased insulin sensitivity, as measured by glucose and insulin tolerance tests, with intermediate effects in Nat1 heterozygote mice. Our results support a role for NAT2 in insulin sensitivity.

Nucleic Acid Amplification Test For Detection Of West Nile Virus Infection In Pakistani Blood Donors.

PubMed

Niazi, Saifullah Khan; Alam, Maqbool; Yazdani, Muhammad Sajid; Ghani, Eijaz; Rathore, Muhammad Ali

2017-01-01

The study was planned to determine the presence of West Nile Virus (WNV) infection in Pakistani blood donors, using Nucleic Acid Amplification Test (NAT). The blood donors for study were selected on the basis of the standard questionnaire and routine screening results. Six donors were pooled using an automated pipettor and NAT for WNV was performed on Roche Cobas s 201 NAT system. The reactive pools were resolved in Individual Donation-NAT (ID-NAT) format and a sample from FFP bags of reactive donations was retrieved. NAT was again performed on retrieved plasma bag (RPB) sample to confirm the reactive donations. The donors were also recalled and interviewed about history of illness related to recent WNV infection. After serological screening of 1929 donors during the study period, 1860 donors were selected for NAT test for WNV detection. The mean age of the donors was 28±8.77 (range: 18-57 years). 1847 (99.3%) donors were male and 13 (0.7%) were female. NAT for WNV identified six initially reactive pools (0.32%). On follow-up testing with RPB samples, 4 donors (0.21%) were found confirmed reactive for WNV RNA (NAT yield of 1 in 465 blood donors). WNV is a threat to safety of blood products in Pakistan. A screening strategy can be implemented after a large-scale study and financial considerations. One of the reduced cost screening strategies is seasonal screening of blood donors for WNV, with pooling of samples.

Collision risk model for NAT region.

DOT National Transportation Integrated Search

1971-05-01

The paper reviews and summarizes the essential features of the collision risk model used to analyze the effects of separation standards on safety for the parallel tracking system employed in the North Atlantic. The derivation of the model is traced f...

How preschool executive functioning predicts several aspects of math achievement in Grades 1 and 3: A longitudinal study.

PubMed

Viterbori, Paola; Usai, M Carmen; Traverso, Laura; De Franchis, Valentina

2015-12-01

This longitudinal study analyzes whether selected components of executive function (EF) measured during the preschool period predict several indices of math achievement in primary school. Six EF measures were assessed in a sample of 5-year-old children (N = 175). The math achievement of the same children was then tested in Grades 1 and 3 using both a composite math score and three single indices of written calculation, arithmetical facts, and problem solving. Using previous results obtained from the same sample of children, a confirmatory factor analysis examining the latent EF structure in kindergarten indicated that a two-factor model provided the best fit for the data. In this model, inhibition and working memory (WM)-flexibility were separate dimensions. A full structural equation model was then used to test the hypothesis that math achievement (the composite math score and single math scores) in Grades 1 and 3 could be explained by the two EF components comprising the kindergarten model. The results indicate that the WM-flexibility component measured during the preschool period substantially predicts mathematical achievement, especially in Grade 3. The math composite scores were predicted by the WM-flexibility factor at both grade levels. In Grade 3, both problem solving and arithmetical facts were predicted by the WM-flexibility component. The results empirically support interventions that target EF as an important component of early childhood mathematics education. Copyright © 2015 Elsevier Inc. All rights reserved.

Early Math Interest and the Development of Math Skills

ERIC Educational Resources Information Center

Fisher, Paige H.; Dobbs-Oates, Jennifer; Doctoroff, Greta L.; Arnold, David H.

2012-01-01

Prior models suggest that math attitudes and ability might strengthen each other over time in a reciprocal fashion (Ma, 1997). The current study investigated the relationship between math interest and skill both concurrently and over time in a preschool sample. Analyses of concurrent relationships indicated that high levels of interest were…

Estimating Skin Cancer Risk: Evaluating Mobile Computer-Adaptive Testing.

PubMed

Djaja, Ngadiman; Janda, Monika; Olsen, Catherine M; Whiteman, David C; Chien, Tsair-Wei

2016-01-22

Response burden is a major detriment to questionnaire completion rates. Computer adaptive testing may offer advantages over non-adaptive testing, including reduction of numbers of items required for precise measurement. Our aim was to compare the efficiency of non-adaptive (NAT) and computer adaptive testing (CAT) facilitated by Partial Credit Model (PCM)-derived calibration to estimate skin cancer risk. We used a random sample from a population-based Australian cohort study of skin cancer risk (N=43,794). All 30 items of the skin cancer risk scale were calibrated with the Rasch PCM. A total of 1000 cases generated following a normal distribution (mean [SD] 0 [1]) were simulated using three Rasch models with three fixed-item (dichotomous, rating scale, and partial credit) scenarios, respectively. We calculated the comparative efficiency and precision of CAT and NAT (shortening of questionnaire length and the count difference number ratio less than 5% using independent t tests). We found that use of CAT led to smaller person standard error of the estimated measure than NAT, with substantially higher efficiency but no loss of precision, reducing response burden by 48%, 66%, and 66% for dichotomous, Rating Scale Model, and PCM models, respectively. CAT-based administrations of the skin cancer risk scale could substantially reduce participant burden without compromising measurement precision. A mobile computer adaptive test was developed to help people efficiently assess their skin cancer risk.

In vitro effects of 5-hydroxytryptophan, indoleamines and leptin on arylalkylamine N-acetyltransferase (AA-NAT) activity in pineal organ of the fish, Clarias gariepinus (Burchell, 1822) during different phases of the breeding cycle.

PubMed

Gupta, B B P; Yanthan, L; Singh, Ksh Manisana

2010-08-01

Arylalkylamine N-acetyltransferase (AA-NAT) is the rate-limiting enzyme of melatonin biosynthetic pathway. In vitro effects of 5-hydroxytryptophan (5-HTP) and indoleamines (serotonin, N-acetylserotonin and melatonin) were studied on AA-NAT activity in the pineal organ of the fish, C. gariepinus during different phases of its annual breeding cycle. Further, in vitro effects of leptin on AA-NAT activity in the pineal organ were studied in fed and fasted fishes during summer and winter seasons. Treatments with 5-HTP and indoleamines invariably stimulated pineal AA-NAT activity in a dose-dependent manner during all the phases. However, leptin increased AA-NAT activity in a dose-dependent manner only in the pineal organ of the fed fishes, but not of the fasted fishes irrespective of the seasons.

When approximate number acuity predicts math performance: The moderating role of math anxiety

PubMed Central

Libertus, Melissa E.

2018-01-01

Separate lines of research suggest that people who are better at estimating numerical quantities using the approximate number system (ANS) have better math performance, and that people with high levels of math anxiety have worse math performance. Only a handful of studies have examined both ANS acuity and math anxiety in the same participants and those studies report contradictory results. To address these inconsistencies, in the current study 87 undergraduate students completed assessments of ANS acuity, math anxiety, and three different measures of math. We considered moderation models to examine the interplay of ANS acuity and math anxiety on different aspects of math performance. Math anxiety and ANS acuity were both unique significant predictors of the ability to automatically recall basic number facts. ANS acuity was also a unique significant predictor of the ability to solve applied math problems, and this relation was further qualified by a significant interaction with math anxiety: the positive association between ANS acuity and applied problem solving was only present in students with high math anxiety. Our findings suggest that ANS acuity and math anxiety are differentially related to various aspects of math and should be considered together when examining their respective influences on math ability. Our findings also raise the possibility that good ANS acuity serves as a protective factor for highly math-anxious students on certain types of math assessments. PMID:29718939

When approximate number acuity predicts math performance: The moderating role of math anxiety.

PubMed

Braham, Emily J; Libertus, Melissa E

2018-01-01

Separate lines of research suggest that people who are better at estimating numerical quantities using the approximate number system (ANS) have better math performance, and that people with high levels of math anxiety have worse math performance. Only a handful of studies have examined both ANS acuity and math anxiety in the same participants and those studies report contradictory results. To address these inconsistencies, in the current study 87 undergraduate students completed assessments of ANS acuity, math anxiety, and three different measures of math. We considered moderation models to examine the interplay of ANS acuity and math anxiety on different aspects of math performance. Math anxiety and ANS acuity were both unique significant predictors of the ability to automatically recall basic number facts. ANS acuity was also a unique significant predictor of the ability to solve applied math problems, and this relation was further qualified by a significant interaction with math anxiety: the positive association between ANS acuity and applied problem solving was only present in students with high math anxiety. Our findings suggest that ANS acuity and math anxiety are differentially related to various aspects of math and should be considered together when examining their respective influences on math ability. Our findings also raise the possibility that good ANS acuity serves as a protective factor for highly math-anxious students on certain types of math assessments.

Association of N-acetyltransferase 1 polymorphism and bladder cancer risk: an updated meta-analysis and trial sequential analysis.

PubMed

Xu, Zicheng; Li, Xiao; Qin, Zhiqiang; Xue, Jianxin; Wang, Jingyuan; Liu, Zhentao; Cai, Hongzhou; Yu, Bin; Xu, Ting; Zou, Qin

2017-07-24

Individual studies of the association between N-acetyltransferase 1 (NAT1)*10 allele and bladder cancer susceptibility have shown inconclusive results. To derive a more precise estimation of any such relationship, we performed this systemic review and updated meta-analysis based on 17 publications. A total of 17 studies were investigated with 4,322 bladder cancer cases and 4,944 controls. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. Subgroup analyses were conducted based on ethnicity, sex, source of controls and detecting methods. Then trial sequential analysis was performed to evaluate whether the evidence of the results was sufficient and reduce the risk of type I error. There was no association between NAT1*10 allele and bladder cancer risk in a random-effects model (OR = 0.96, 95% CI, 0.84-1.10) or in a fixed-effects model (OR = 0.95, 95% CI, 0.87-1.03). In addition, no significantly increased risk of bladder cancer was found in any other subgroup analysis. Then, trial sequential analyses demonstrated that the results of our study need to be further verified. Despite its limitations, the results of the present meta-analysis suggested that there was no association between NAT1*10 allele and bladder cancer risk. More importantly, our findings need to be further validated regarding whether being without the NAT1*10 allele could in the future be shown to be a potential marker for the risk of bladder cancer.

Math Anxiety and Math Ability in Early Primary School Years.

PubMed

Krinzinger, Helga; Kaufmann, Liane; Willmes, Klaus

2009-06-01

Mathematical learning disabilities (MLDs) are often associated with math anxiety, yet until now, very little is known about the causal relations between calculation ability and math anxiety during early primary school years. The main aim of this study was to longitudinally investigate the relationship between calculation ability, self-reported evaluation of mathematics, and math anxiety in 140 primary school children between the end of first grade and the middle of third grade. Structural equation modeling revealed a strong influence of calculation ability and math anxiety on the evaluation of mathematics but no effect of math anxiety on calculation ability or vice versa-contrasting with the frequent clinical reports of math anxiety even in very young MLD children. To summarize, our study is a first step toward a better understanding of the link between math anxiety and math performance in early primary school years performance during typical and atypical courses of development.

Promotive and Corrosive Factors in African American Students' Math Beliefs and Achievement.

PubMed

Diemer, Matthew A; Marchand, Aixa D; McKellar, Sarah E; Malanchuk, Oksana

2016-06-01

Framed by expectancy-value theory (which posits that beliefs about and the subjective valuation of a domain predict achievement and decision-making in that domain), this study examined the relationships among teacher differential treatment and relevant math instruction on African American students' self-concept of math ability, math task value, and math achievement. These questions were examined by applying structural equation modeling to 618 African American youth (45.6 % female) followed from 7th to 11th grade in the Maryland Adolescent Development in Context Study. While controlling for gender and prior math achievement, relevant math instruction promoted and teacher differential treatment corroded students' math beliefs and achievement over time. Further, teacher discrimination undermined students' perceptions of their teachers, a mediating process under-examined in previous inquiry. These findings suggest policy and practice levers to narrow opportunity gaps, as well as foster math achievement and science, technology, engineering and math success.

Math Anxiety and Math Ability in Early Primary School Years

PubMed Central

Krinzinger, Helga; Kaufmann, Liane; Willmes, Klaus

2010-01-01

Mathematical learning disabilities (MLDs) are often associated with math anxiety, yet until now, very little is known about the causal relations between calculation ability and math anxiety during early primary school years. The main aim of this study was to longitudinally investigate the relationship between calculation ability, self-reported evaluation of mathematics, and math anxiety in 140 primary school children between the end of first grade and the middle of third grade. Structural equation modeling revealed a strong influence of calculation ability and math anxiety on the evaluation of mathematics but no effect of math anxiety on calculation ability or vice versa—contrasting with the frequent clinical reports of math anxiety even in very young MLD children. To summarize, our study is a first step toward a better understanding of the link between math anxiety and math performance in early primary school years performance during typical and atypical courses of development. PMID:20401159

Diverse point mutations in the human gene for polymorphic N-acetyltransferase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vatsis, K.P.; Martell, K.J.; Weber, W.W.

1991-07-15

Classification of humans as rapid or slow acetylators is based on hereditary differences in rates of N-acetylation of therapeutic and carcinogenic agents, but N-acetylation of certain arylamine drugs displays no genetic variation. Two highly homologous human genes for N-acetyltransferase NAT1 and NAT2, presumably code for the genetically invariant and variant NAT proteins, respectively. In the present investigation, 1.9-kilobase human genomic EcoRI fragments encoding NAT2 were generated by the polymerase chain reaction with liver and leukocyte DNA from seven subjects phenotyped as homozygous and heterozygous acetylators. Direct sequencing revealed multiple point mutations in the coding region of two distinct NAT2 variants.more » One of these was derived from leukocytes of a slow acetylator and was distinguished by a silent mutation (coden 94) and a separate G {r arrow} A transition (position 590) leading to replacement of Arg-197 by Gln; the mutated guanine was part of a CpG dinucleotide and a Taq I site. The second NAT2 variant originated from liver with low N-acetylation activity. It was characterized by three nucleotide transitions giving rise to a silent mutation (codon 161), accompanied by obliteration of the sole Kpn I site, and two amino acid substitutions. The results show conclusively that the genetically variant NAT is encoded by NAT2.« less

Priority needs and wisdom strategy for blood transfusion safety in developing low-resource countries.

PubMed

Abdelrazik, Abeer Mohamed; Ezzat Ahmed, Ghada M

2016-02-01

To evaluate the implementation of alternative safety measures that reduce the risk of transfusion transmissible infections as an affordable measure in low resource countries. It is still difficult in developing countries with limited resources to mandate nucleic acid testing due to its high cost. Although NAT reduces the window period of infection, the developing countries are still in need of an efficient and effective transfusion programme before implementing the complex high cost NAT. Two thousand eight hundred eighty sero-negative first-time and repeat donations from Fayoum University Hospital blood bank were individually analysed by NAT for HIV, HBV and HCV. Only discriminatory-positive NAT were classified comparing the non-remunerated and family replacement donations. Significant discriminatory-positive differences were observed for HBV NAT results, 2 remunerated donations compared to 0 non-remunerated sero-negative donations. The discriminatory positive differences were also significant for HCV NAT results, 4 remunerated donations compared to 1 non-remunerated sero-negative donation. No sero-negative, discriminatory-positive NAT HIV case was found. Seven out of 8 discriminatory positive cases were from first time donations. In order to ensure blood safety, the recruitment and retention of voluntary, non-remunerated repeat donors should be a major commitment for low resource countries in which NAT implementation is costly and not feasible. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measurement of activation cross sections of alpha particle induced reactions on iridium up to an energy of 50 MeV.

PubMed

Takács, S; Ditrói, F; Szűcs, Z; Aikawa, M; Haba, H; Komori, Y; Saito, M

2018-06-01

Cross sections of alpha particle induced nuclear reactions on iridium were investigated using a 51.2-MeV alpha particle beam. The standard stacked-foil target technique and the activation method were applied. The activity of the reaction products was assessed without chemical separation using high resolution gamma-ray spectrometry. Excitation functions for production of gold, platinum and iridium isotopes ( 196m2 Au, 196m,g Au, 195m,g Au, 194 Au, 193 m,g Au, 192 Au, 191m,g Au, 191 Pt, 195m Pt, 194g Ir, 194m Ir, 192g Ir, 190g Ir and 189 Ir) were determined and compared with available earlier measured experimental data and results of theoretical calculations using TALYS code system. Cross section data were reported for the first time for the nat Ir(α,x) 196m2 Au, nat Ir(α,x) 196m,g Au, nat Ir(α,x) 191 Pt, nat Ir(α,x) 195m Pt, nat Ir(α,x) 194g Ir, nat Ir(α,x) 194m Ir, nat Ir(α,x) 190g Ir and nat Ir(α,x) 189 Ir processes. A possible production route for 195m Pt, the potentially important radionuclide in nuclear medicine, is discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

NAT1/DAP5/p97 and Atypical Translational Control in the Drosophila Circadian Oscillator

PubMed Central

Bradley, Sean; Narayanan, Siddhartha; Rosbash, Michael

2012-01-01

Circadian rhythms are driven by gene expression feedback loops in metazoans. Based on the success of genetic screens for circadian mutants in Drosophila melanogaster, we undertook a targeted RNAi screen to study the impact of translation control genes on circadian locomotor activity rhythms in flies. Knockdown of vital translation factors in timeless protein-positive circadian neurons caused a range of effects including lethality. Knockdown of the atypical translation factor NAT1 had the strongest effect and lengthened circadian period. It also dramatically reduced PER protein levels in pigment dispersing factor (PDF) neurons. BELLE (BEL) protein was also reduced by the NAT1 knockdown, presumably reflecting a role of NAT1 in belle mRNA translation. belle and NAT1 are also targets of the key circadian transcription factor Clock (CLK). Further evidence for a role of NAT1 is that inhibition of the target of rapamycin (TOR) kinase increased oscillator activity in cultured wings, which is absent under conditions of NAT1 knockdown. Moreover, the per 5′- and 3′-UTRs may function together to facilitate cap-independent translation under conditions of TOR inhibition. We suggest that NAT1 and cap-independent translation are important for per mRNA translation, which is also important for the circadian oscillator. A circadian translation program may be especially important in fly pacemaker cells. PMID:22904033

N-acetyltransferase 1 and 2 polymorphisms and risk of diabetes mellitus type 2 in a Saudi population.

PubMed

Al-Shaqha, Waleed M; Alkharfy, Khalid M; Al-Daghri, Nasser M; Mohammed, Abdul Khader

2015-01-01

There have been inconsistent reports on N-acetyltransferase (NAT) gene polymorphism in type 2 diabetes mellitus (T2DM), and data is particularly limited in the Arab population. Therefore, the main objective of this study was to identify whether the genetic polymorphisms of NAT1 and NAT2 play a role in susceptibility to T2DM in the Saudi population. A population-based, prospective genetic association case-control study on a Saudi population. Whole blood, anthropometric measurements and biochemistry data were collected from 369 Saudi individuals (186 T2DM patients and 183 healthy controls). DNA was isolated from the blood. Polymorphism of NAT1 and NAT2 SNPs [NAT2*7B, rs1041983(C > T); NAT2*7, rs1799931(G > A); NAT2*6A, rs1799930(G > A); NAT2*5A, rs1799929(C > T); and NAT1*11A, rs4986988(C > T)] were evaluated by allelic discrimination using real-time PCR. Subjects with T2DM had a significantly increased body mass index (BMI), waist circumference, sys.tolic and diastolic blood pressure, glucose, triglycerides, and LDL-cholesterol compared with healthy controls (P < .05). The rs1799931(G > A) genotype was detected in the control population but not in the T2DM population (P < .001). The wild type (G) allele frequency was higher in T2DM than controls (P=.038). The mutant allele (A) in rs1799931(G > A) had a protective effect for T2DM (OR 0.32, 95% CI 0.16-0.62; P=.001). Regression analysis showed that BMI, systolic BP and triglycerides are potential risk factors for T2DM. The genotypes as well as the individual alleles of rs1799931(G > A) differed significantly be.tween the case and control populations. The variation in the data reported so far suggest that polymorphism of the NAT gene may vary among different geographical areas. Environmental or dietary factors may also contribute to disease manifestation.

ASTP ranging system mathematical model

NASA Technical Reports Server (NTRS)

Ellis, M. R.; Robinson, L. H.

1973-01-01

A mathematical model is presented of the VHF ranging system to analyze the performance of the Apollo-Soyuz test project (ASTP). The system was adapted for use in the ASTP. The ranging system mathematical model is presented in block diagram form, and a brief description of the overall model is also included. A procedure for implementing the math model is presented along with a discussion of the validation of the math model and the overall summary and conclusions of the study effort. Detailed appendices of the five study tasks are presented: early late gate model development, unlock probability development, system error model development, probability of acquisition and model development, and math model validation testing.

Social Cognitive Predictors of Mexican American High School Students' Math/Science Career Goals

ERIC Educational Resources Information Center

Garriott, Patton O.; Raque-Bogdan, Trisha L.; Zoma, Lorrine; Mackie-Hernandez, Dylan; Lavin, Kelly

2017-01-01

This study tested a social cognitive model of math/science career goals in a sample (N = 258) of Mexican American high school students. Familism and proximal family supports for math/science careers were examined as predictors of math/science: performance accomplishments, self-efficacy, interests, and goals. Results showed that the hypothesized…

Beginning School Math Competence: Minority and Majority Comparisons. Report No. 34.

ERIC Educational Resources Information Center

Entwisle, Doris R.; Alexander, Karl L.

This paper uses a structural model with a large random sample of urban children to explain children's competence in math concepts and computation at the time they begin first grade. These two aspects of math ability respond differently to environmental resources, with math concepts much more responsive to family factors before formal schooling…

North Atlantic (NAT) aided inertial navigation system simulation volume I. : technical results

DOT National Transportation Integrated Search

1973-07-01

Current air traffic operations over the North ATlantic (NAT) and the application of hybrid navigation systems to obtain more accurate performance on these NAT routes are reviewed. A digital computer simulation program (NATNAV - North ATlantic NAVigat...

Spectroscopic studies of model polar stratospheric cloud films

NASA Technical Reports Server (NTRS)

Tolbert, Margaret A.; Koehler, Birgit G.; Middlebrook, Ann M.

1993-01-01

Fourier transform infrared (FTIR) spectroscopy has been used to study nitric-acid/ice films representative of type I polar stratospheric clouds (PSCs). These studies reveal that in addition to amorphous nitric acid/ice mixtures, there are three stable stoichiometric hydrates of nitric acid: nitric-acid monohydrate (NAM), dihydrate (NAD), and trihydrate (NAT). We also observe two distinct crystalline forms of the trihydrate, which we denote alpha- and beta-NAT. These two forms appear to differ in their concentration of crystalline defects, but not in their chemical composition. In addition to probing the composition of type I PSCs, we have also used FTIR spectroscopy to study the interaction of HCl with model PSC films. In this work we find that for HCl pressures in the range 10 exp -5 to 10 exp -7 Torr, HCl is taken up by ice at 155 K to form a thin layer of HCl.6H2O. At 193 K, the uptake of HCl by ice was consistent with less than or equal to monolayer coverage. Uptake of HCl by alpha and beta-NAT at 175 K was also consistent with less than or equal to monolayer coverage.

Modifying high-order aeroelastic math model of a jet transport using maximum likelihood estimation

NASA Technical Reports Server (NTRS)

Anissipour, Amir A.; Benson, Russell A.

1989-01-01

The design of control laws to damp flexible structural modes requires accurate math models. Unlike the design of control laws for rigid body motion (e.g., where robust control is used to compensate for modeling inaccuracies), structural mode damping usually employs narrow band notch filters. In order to obtain the required accuracy in the math model, maximum likelihood estimation technique is employed to improve the accuracy of the math model using flight data. Presented here are all phases of this methodology: (1) pre-flight analysis (i.e., optimal input signal design for flight test, sensor location determination, model reduction technique, etc.), (2) data collection and preprocessing, and (3) post-flight analysis (i.e., estimation technique and model verification). In addition, a discussion is presented of the software tools used and the need for future study in this field.

Occult HBV infection in HIV-infected adults and evaluation of pooled NAT for HBV.

PubMed

Dinesha, T R; Boobalan, J; Sivamalar, S; Subashini, D; Solomon, S S; Murugavel, K G; Balakrishnan, P; Smith, D M; Saravanan, S

2018-06-01

The study aimed to determine the prevalence of occult hepatitis B virus infection among HIV-infected persons and to evaluate the use of a pooling strategy to detect occult HBV infection in the setting of HIV infection. Five hundred and two HIV-positive individuals were tested for HBV, occult HBV and hepatitis C and D with serologic and nucleic acid testing (NAT). We also evaluated a pooled NAT strategy for screening occult HBV infection among the HIV-positive individuals. The prevalence of HBV infection among HIV-positive individuals was 32 (6.4%), and occult HBV prevalence was 10%. The pooling HBV NAT had a sensitivity of 66.7% and specificity of 100%, compared to HBV DNA NAT of individual samples. In conclusion, this study found a high prevalence of occult HBV infection among our HIV-infected population. We also demonstrated that pooled HBV NAT is highly specific, moderately sensitive and cost-effective. As conventional HBV viral load assays are expensive in resource-limited settings such as India, pooled HBV DNA NAT might be a good way for detecting occult HBV infection and will reduce HBV-associated complications. © 2018 John Wiley & Sons Ltd.

Effectiveness of Nateglinide on In Vitro Insulin Secretion from Rat Pancreatic Islets Desensitized to Sulfonylureas

PubMed Central

Wang, Shuya; Dunning, Beth E.

2001-01-01

Chronic exposure of pancreatic islets to sulfonylureas (SUs) is known to impair the ability of islets to respond to subsequent acute stimulation by SUs or glucose. Nateglinide (NAT) is a novel insulinotropic agent with a primarily site of action at β-cell KATP channels, which is common to the structurally diverse drugs like repaglinide (REP) and the SUs. Earlier studies on the kinetics, glucosedependence and sensitivity to metabolic inhibitors of the interaction between NAT and KATP channels suggested a distinct signaling pathways with NAT compared to REP, glyburide (GLY) or glimepiride (GLI). To obtain further evidence for this concept, the present study compared the insulin secretion in vitro from rat islets stimulated acutely by NAT, GLY, GLI or REP at equipotent concentrations during 1-hr static incubation following overnight treatment with GLY or tolbutamide (TOL). The islets fully retained the responsiveness to NAT stimulation after prolonged pretreatment with both SUs, while their acute response to REP, GLY, and GLI was markedly attenuated, confirming the desensitization of islets. The insulinotropic efficacy of NAT in islets desensitized to SUs may result from a distinct receptor/effector mechanism, which contributes to the unique pharmacological profile of NAT. PMID:12369729

Boys' and girls' weight status and math performance from kindergarten entry through fifth grade: a mediated analysis.

PubMed

Gable, Sara; Krull, Jennifer L; Chang, Yiting

2012-01-01

This study tests a mediated model of boys' and girls' weight status and math performance with 6,250 children from the Early Childhood Longitudinal Study. Five data points spanning kindergarten entry (mean age=68.46 months) through fifth grade (mean age=134.60 months) were analyzed. Three weight status groups were identified: persistent obesity, later onset obesity, and never obese. Multilevel models tested relations between weight status and math performance, weight status and interpersonal skills and internalizing behaviors, and interpersonal skills and internalizing behaviors and math performance. Interpersonal skills mediated the association between weight status and math performance for girls, and internalizing behaviors mediated the association between weight status and math performance for both sexes, with effects varying by group and time. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.

Early Math Trajectories: Low-Income Children's Mathematics Knowledge From Ages 4 to 11.

PubMed

Rittle-Johnson, Bethany; Fyfe, Emily R; Hofer, Kerry G; Farran, Dale C

2017-09-01

Early mathematics knowledge is a strong predictor of later academic achievement, but children from low-income families enter school with weak mathematics knowledge. An early math trajectories model is proposed and evaluated within a longitudinal study of 517 low-income American children from ages 4 to 11. This model includes a broad range of math topics, as well as potential pathways from preschool to middle grades mathematics achievement. In preschool, nonsymbolic quantity, counting, and patterning knowledge predicted fifth-grade mathematics achievement. By the end of first grade, symbolic mapping, calculation, and patterning knowledge were the important predictors. Furthermore, the first-grade predictors mediated the relation between preschool math knowledge and fifth-grade mathematics achievement. Findings support the early math trajectories model among low-income children. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

Neurocognitive Predictors of Mathematical Processing in School-Aged Children with Spina Bifida and Their Typically Developing Peers: Attention, Working Memory, and Fine Motor Skills

PubMed Central

Raghubar, Kimberly P.; Barnes, Marcia A.; Dennis, Maureen; Cirino, Paul T.; Taylor, Heather; Landry, Susan

2015-01-01

Objective Math and attention are related in neurobiological and behavioral models of mathematical cognition. This study employed model-driven assessments of attention and math in children with spina bifida myelomeningocele (SBM), who have known math difficulties and specific attentional deficits, to more directly examine putative relations between attention and mathematical processing. The relation of other domain general abilities and math was also investigated. Method Participants were 9.5-year-old children with SBM (N = 44) and typically developing children (N = 50). Participants were administered experimental exact and approximate arithmetic tasks, and standardized measures of math fluency and calculation. Cognitive measures included the Attention Network Test (ANT), and standardized measures of fine motor skills, verbal working memory (WM), and visual-spatial WM. Results Children with SBM performed similarly to peers on exact arithmetic but more poorly on approximate and standardized arithmetic measures. On the ANT, children with SBM differed from controls on orienting attention but not alerting and executive attention. Multiple mediation models showed that: fine motor skills and verbal WM mediated the relation of group to approximate arithmetic; fine motor skills and visual-spatial WM mediated the relation of group to math fluency; and verbal and visual-spatial WM mediated the relation of group to math calculation. Attention was not a significant mediator of the effects of group for any aspect of math in this study. Conclusions Results are discussed with reference to models of attention, WM, and mathematical cognition. PMID:26011113

Neurocognitive predictors of mathematical processing in school-aged children with spina bifida and their typically developing peers: Attention, working memory, and fine motor skills.

PubMed

Raghubar, Kimberly P; Barnes, Marcia A; Dennis, Maureen; Cirino, Paul T; Taylor, Heather; Landry, Susan

2015-11-01

Math and attention are related in neurobiological and behavioral models of mathematical cognition. This study employed model-driven assessments of attention and math in children with spina bifida myelomeningocele (SBM), who have known math difficulties and specific attentional deficits, to more directly examine putative relations between attention and mathematical processing. The relation of other domain general abilities and math was also investigated. Participants were 9.5-year-old children with SBM (n = 44) and typically developing children (n = 50). Participants were administered experimental exact and approximate arithmetic tasks, and standardized measures of math fluency and calculation. Cognitive measures included the Attention Network Test (ANT), and standardized measures of fine motor skills, verbal working memory (WM), and visual-spatial WM. Children with SBM performed similarly to peers on exact arithmetic, but more poorly on approximate and standardized arithmetic measures. On the ANT, children with SBM differed from controls on orienting attention, but not on alerting and executive attention. Multiple mediation models showed that fine motor skills and verbal WM mediated the relation of group to approximate arithmetic; fine motor skills and visual-spatial WM mediated the relation of group to math fluency; and verbal and visual-spatial WM mediated the relation of group to math calculation. Attention was not a significant mediator of the effects of group for any aspect of math in this study. Results are discussed with reference to models of attention, WM, and mathematical cognition. (c) 2015 APA, all rights reserved).

Development of 3D and 4D Bridge Models and Plans

DOT National Transportation Integrated Search

2018-05-28

Since 2012, MDOT has been leading national efforts to modernize design development with 3D modeling. Early focus on roadway projects yielded streamlined plan production and digital data for construction. As MDOT pivots to 3D model-centric design, nat...

N-Acetyltransferase Polymorphism and Risk of Colorectal Adenoma and Cancer: A Pooled Analysis of Variations from 59 Studies

PubMed Central

Wang, Xiaoxue; Chen, Yizhi; Li, Rong; Zhang, Ying; Luo, Rongcheng

2012-01-01

Background There have been an increasing number of studies with evidence suggesting that the N-acetyltransferase 1 (NAT1) and N-acetyltransferase 2 (NAT2) genotypes may be implicated in the development of colorectal cancer (CRC) and colorectal adenoma (CRA). So far the published data on this association has remained controversial, however. We performed a meta-analysis of case-cohort and case-control studies using a subset of the published data, with an aim to derive a better understanding of the underlying relationship. Methods/Principal Findings A literature search was performed using Medline database for relevant studies published through October 31, 2011. A total of 39 publications were selected for this meta-analysis, including 11,724 cases and 16,215 controls for CRC, and 3,701 cases and 5,149 controls for CRA. In our pooled analysis of all these studies, the results of our meta-analysis suggested that the NAT1 genotype was not significantly associated with an elevated CRC risk (OR 0.99, 95% CI 0.91–1.07). We also found that individuals with the rapid NAT2 genotype did have an elevated risk of CRC (OR 1.07, 95% CI 1.01–1.13). There was no evidence for an association between the NAT1 and 2 rapid genotype and an elevated CRA risk (NAT1: OR 1.14, 95% CI 0.99–1.29; NAT2: OR 0.94, 95% CI 0.86–1.03). Conclusion This meta-analysis suggests that individuals with NAT2 genotype had an elevated risk of CRC. There was no evidence for the association between NAT1 and 2 rapid genotype and CRA risk. PMID:22905173

In vivo evaluation of a cancer therapy strategy combining HSV1716-mediated oncolysis with gene transfer and targeted radiotherapy.

PubMed

Sorensen, Annette; Mairs, Robert J; Braidwood, Lynne; Joyce, Craig; Conner, Joe; Pimlott, Sally; Brown, Moira; Boyd, Marie

2012-04-01

Oncolytic herpes viruses show promise for cancer treatment. However, it is unlikely that they will fulfill their therapeutic potential when used as monotherapies. An alternative strategy is to use these viruses not only as oncolytic agents but also as a delivery mechanism of therapeutic transgenes to enhance tumor cell killing. The herpes simplex virus 1 deletion mutant HSV1716 is a conditionally replicating oncolytic virus that selectively replicates in and lyses dividing tumor cells. It has a proven safety profile in clinical trials and has demonstrated efficacy as a gene-delivery vehicle. To enhance its therapeutic potential, we have engineered HSV1716 to convey the noradrenaline transporter (NAT) gene (HSV1716/NAT), whose expression endows infected cells with the capacity to accumulate the noradrenaline analog metaiodobenzylguanidine (MIBG). Thus, the NAT gene-infected cells are susceptible to targeted radiotherapy using radiolabeled (131)I-MIBG, a strategy that has already shown promise for combined targeted radiotherapy-gene therapy in cancer cells after plasmid-mediated transfection. We used HSV1716/NAT as a dual cell lysis-gene delivery vehicle for targeting the NAT transgene to human tumor xenografts in vivo. In tumor xenografts that did not express NAT, intratumoral or intravenous injection of HSV1716/NAT induced the capacity for active uptake of (131)I-MIBG. Administration of HSV1716/NAT and (131)I-MIBG resulted in decreased tumor growth and enhanced survival relative to injection of either agent alone. Efficacy was dependent on the scheduling of delivery of the 2 agents. These findings support a role for combination radiotherapy-gene therapy for cancer using HSV1716 expressing the NAT transgene and targeted radionuclide therapy.

Breast cancer, heterocyclic aromatic amines from meat and N-acetyltransferase 2 genotype.

PubMed

Delfino, R J; Sinha, R; Smith, C; West, J; White, E; Lin, H J; Liao, S Y; Gim, J S; Ma, H L; Butler, J; Anton-Culver, H

2000-04-01

Breast cancer risk has been hypothesized to increase with exposure to heterocyclic aromatic amines (HAAs) formed from cooking meat at high temperature. HAAs require enzymatic activation to bind to DNA and initiate carcinogenesis. N-acetyltransferase 2 (NAT2) enzyme activity may play a role, its rate determined by a polymorphic gene. We examined the effect of NAT2 genetic polymorphisms on breast cancer risk from exposure to meat by cooking method, doneness and estimated HAA [2-amino-1-methyl-6-phenylimidazole[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx)] intake. Women were recruited with suspicious breast masses and questionnaire data were collected prior to biopsy to blind subjects and interviewers to diagnoses. For 114 cases with breast cancer and 280 controls with benign breast disease, NAT2 genotype was determined using allele-specific PCR amplification to detect slow acetylator mutations. HAAs were estimated from interview data on meat type, cooking method and doneness, combined with a quantitative HAA database. Logistic regression models controlled for known risk factors, first including all controls, then 108 with no or low risk (normal breast or no hyperplasia) and finally 149 with high risk (hyperplasia, atypical hyperplasia, complex fibroadenomas). Meat effects were examined within NAT2 strata to assess interactions. We found no association between NAT2 and breast cancer. These Californian women ate more white than red meat (control median 46 versus 8 g/day). There were no significant associations of breast cancer with red meat for any doneness. White meat was significantly protective (>67 versus <26 g/day, OR 0.46, 95% CI 0.23-0.94, P for trend = 0.02), as was chicken, including well done, pan fried and barbecued chicken. MeIQx and DiMeIQx were not associated with breast cancer. A protective effect of PhIP was confounded after controlling for well done chicken. Results were unchanged using low or high risk controls or dropping 30 in situ cases. There was no interaction between NAT2 and HAAs. These findings do not support a role for HAAs from meat or NAT2 in the etiology of breast cancer. Further research is needed to explain the white meat association.

Trajectory Studies of Large HNO3-Containing PSC Particles in the Arctic: Evidence for the Role of NAT

NASA Technical Reports Server (NTRS)

McKinney, K. A.; Wennberg, P. O.; Dhaniyala, S.; Fahey, D. W.; Northway, M. J.; Kuenzi, K. F.; Kleinboehl, A.; Sinnhuber, M.; Kuellmann, H.; Bremer, H.;

Rapid identification of the NAT2 genotype in tuberculosis patients by multicolor melting curve analysis.

PubMed

Hu, Yanjie; Chen, Suting; Yu, Xia; Dai, Guangming; Dong, Lingling; Li, Yunxu; Zhao, Liping; Huang, Hairong

2016-07-01

NAT2 genotype is an indicator for isoniazid dosage adjusting for tuberculosis treatment. Multicolor melting curve analysis (MMCA) was evaluated as a potential method for NAT2 genotyping. 352 blood samples were analyzed by MMCA kit (Zeesan Biotech Co., Xiamen, China) targeting NAT2 SNPs at T341C, C481T, G590A and G857A, and direct sequencing was used as control. The sensitivity, specificity and accuracy of the MMCA assay for rapid NAT2 genotype detection were 97.9, 99.6 and 99.1% respectively, whereas for intermediate genotypes the values were 99.5, 98.7 and 99.1%, respectively, and for slow genotypes the values were 100% for the three aspects. The 24 saliva and blood for the control samples were also successfully analyzed using the MMCA assay, both produced uniform outcomes. The MMCA assay described in our study is very promising for the efficient determination of NAT2 genotype, and can facilitate the personalized dosing of isoniazid.

Strategies to identify natural antisense transcripts.

PubMed

Sun, Yulong; Li, Dijie; Zhang, Ru; Peng, Shang; Zhang, Ge; Yang, Tuanmin; Qian, Airong

2017-01-01

Natural antisense transcripts, originally considered as transcriptional noises arising from so-called "junk DNA″, are recently recognized as important modulators for gene regulation. They are prevalent in nearly all realms of life and have been found to modulate gene expression positively or negatively. By affecting almost all stages of gene expression range from pre-transcriptional, transcriptional and post-transcriptional to translation, NATs are fundamentally involved in various biological processes. However, compared to increasing huge data from transcriptional analysis especially high-throughput sequencing technologies (such as RNA-seq), limited functional NATs (around 70) are so far reported, which hinder our advanced comprehensive understanding for this field. Hence, efficient strategies for identifying NATs are urgently desired. In this review, we discussed the current strategies for identifying NATs, with a focus on the advantages, disadvantages, and applications of methods isolating functional NATs. Moreover, publicly available databases for NATs were also discussed. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

High Fidelity Modeling of Field-Reversed Configuration (FRC) Thrusters (Briefing Charts)

DTIC Science & Technology

2017-05-24

Converged Math → Irrelevant Solutions? Validation: Fluids Example Stoke’s Flow MARTIN, SOUSA, TRAN (AFRL/RQRS) DISTRIBUTION A - APPROVED FOR PUBLIC RELEASE...Convergence Tests Converged Math → Irrelevant Solutions? Must be Aware of Valid Assumption Regions Validation: Fluids Example Stoke’s Flow Potential...AND VALIDATION Verification: Asymptotic Models → Analytical Solutions Yields Exact Convergence Tests Converged Math → Irrelevant Solutions? Must be

Arylamine N-acetyltransferase activity in bronchial epithelial cells and its inhibition by cellular oxidants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dairou, Julien; Petit, Emile; Ragunathan, Nilusha

2009-05-01

Bronchial epithelial cells express xenobiotic-metabolizing enzymes (XMEs) that are involved in the biotransformation of inhaled toxic compounds. The activities of these XMEs in the lung may modulate respiratory toxicity and have been linked to several diseases of the airways. Arylamine N-acetyltransferases (NAT) are conjugating XMEs that play a key role in the biotransformation of aromatic amine pollutants such as the tobacco-smoke carcinogens 4-aminobiphenyl (4-ABP) and {beta}-naphthylamine ({beta}-NA). We show here that functional human NAT1 or its murine counterpart Nat2 are present in different lung epithelial cells i.e. Clara cells, type II alveolar cells and bronchial epithelial cells, thus indicating thatmore » inhaled aromatic amines may undergo NAT-dependent biotransformation in lung epithelium. Exposure of these cells to pathophysiologically relevant amounts of oxidants known to contribute to lung dysfunction, such as H{sub 2}O{sub 2} or peroxynitrite, was found to impair the NAT1/Nat2-dependent cellular biotransformation of aromatic amines. Genetic and non genetic impairment of intracellular NAT enzyme activities has been suggested to compromise the important detoxification pathway of aromatic amine N-acetylation and subsequently to contribute to an exacerbation of untoward effects of these pollutants on health. Our study suggests that oxidative/nitroxidative stress in lung epithelial cells, due to air pollution and/or inflammation, could contribute to local and/or systemic dysfunctions through the alteration of the functions of pulmonary NAT enzymes.« less

Homogenous Surface Nucleation of Solid Polar Stratospheric Cloud Particles

NASA Technical Reports Server (NTRS)

Tabazadeh, A.; Hamill, P.; Salcedo, D.; Gore, Warren J. (Technical Monitor)

2002-01-01

A general surface nucleation rate theory is presented for the homogeneous freezing of crystalline germs on the surfaces of aqueous particles. While nucleation rates in a standard classical homogeneous freezing rate theory scale with volume, the rates in a surface-based theory scale with surface area. The theory is used to convert volume-based information on laboratory freezing rates (in units of cu cm, seconds) of nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD) aerosols into surface-based values (in units of sq cm, seconds). We show that a surface-based model is capable of reproducing measured nucleation rates of NAT and NAD aerosols from concentrated aqueous HNO3 solutions in the temperature range of 165 to 205 K. Laboratory measured nucleation rates are used to derive free energies for NAT and NAD germ formation in the stratosphere. NAD germ free energies range from about 23 to 26 kcal mole, allowing for fast and efficient homogeneous NAD particle production in the stratosphere. However, NAT germ formation energies are large (greater than 26 kcal mole) enough to prevent efficient NAT particle production in the stratosphere. We show that the atmospheric NAD particle production rates based on the surface rate theory are roughly 2 orders of magnitude larger than those obtained from a standard volume-based rate theory. Atmospheric volume and surface production of NAD particles will nearly cease in the stratosphere when denitrification in the air exceeds 40 and 78%, respectively. We show that a surface-based (volume-based) homogeneous freezing rate theory gives particle production rates, which are (not) consistent with both laboratory and atmospheric data on the nucleation of solid polar stratospheric cloud particles.

Genetic Variation at the N-acetyltransferase (NAT) Genes in Global Populations

EPA Science Inventory

Functional variability at the N-acetyltransferase (NAT) genes is associated with adverse drug reactions and cancer susceptibility in humans. Previous studies of small sets of ethnic groups have indicated that the NAT genes have high levels of amino acid variation that differ in f...

Atlas Career Path Guidebook: Patterns and Common Practices in Systems Engineers’ Development

DTIC Science & Technology

2018-01-16

Overview of Atlas Proficiency Model .............................................................................. 68 5.1.2. Math /Science/General... Math /Science/General Engineering ................................ 72 Figure 42. Distribution for individuals with highest proficiency self...assessment in Math /Science/General Engineering ..................................................................................... 73 Figure 43

The Relative Value of Growth in Math Fact Skills across Late Elementary and Middle School

ERIC Educational Resources Information Center

Nelson, Peter M.; Parker, David C.; Zaslofsky, Anne F.

2016-01-01

The purpose of the current study was to evaluate the importance of growth in math fact skills within the context of overall math proficiency. Data for 1,493 elementary and middle school students were included for analysis. Regression models were fit to examine the relative value of math fact fluency growth, prior state test performance, and a fall…

77 FR 9681 - Federal Property Suitable as Facilities To Assist the Homeless

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

... Property-Duk Property Olympic Nat'l Park Clallam WA 98326 Landholding Agency: Interior Property Number.../environmental elements Lake Quinault Lapham Olympic Nat'l Park Quinault WA 98575 Landholding Agency: Interior.../environmental elements House 574-Ozettee Ranger Resid Olympic Nat'l Park Clallam WA 98326 Landholding Agency...

Aromatic amine metabolism: immunochemical relationships of N-acetyltransferase and N,O-acyltransferase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Land, S.; Allaben, W.T.; King, C.M.

1986-05-01

Mutagenic and carcinogenic aromatic amines are acetylated in most organisms. Acetyl CoA and arylhydroxamic acids can serve as acetyl donors for N-Acetylation of amines to yield stable amides, or by O-acetylation of hydroxylamine derivatives to produce reactive metabolites that can react covalently with nucleic acid. Polyclonal antibodies against rat arylhydroxamic acid, N,O-acyltransferase (AHAT) have been compared for their abilities to react with this enzyme and the acetyl CoA-dependent N-acetyltransferase (NAT) of the rat, rabbit, hamster, mouse and human. Liver cytosols were treated with increasing quantities of antibodies from immune or control rabbits. Immune complexes were removed by treatment with proteinmore » A-Sepharose before assay of nucleic acid adduct formation by AHAT activation of N-hydroxy-2-acetylaminofluorene and the acetylation of 2-aminofluorene by NAT. Both rat activities, the AHAT of the hamster and the NAT of the mouse and human were removed by this treatment. No decrease in NAT activity of hamster, or of either rabbit cytosol activity was observed. Neither mouse nor human liver has appreciable AHAT activity. These data support the idea that AHAT and NAT of rat, AHAT of hamster and NAT of mouse and human liver are immunochemically related, but that NAT of the hamster is an immunochemically distinct peptide.« less

The Internal/External Frame of Reference of Academic Self-Concept: Extension to a Foreign Language and the Role of Language of Instruction

ERIC Educational Resources Information Center

Xu, Man K.; Marsh, Herbert W.; Hau, Kit-Tai; Ho, Irene T.; Morin, Alexandre J. S.; Abduljabbar, Adel S.

2013-01-01

The internal/external frame of reference (I/E) model (Marsh, 1986) posits that the effects of contrasting math and verbal domains of achievement are positive for matching academic self-concepts (ASCs) but negative for nonmatching ASCs (i.e., math achievement on verbal ASC; verbal achievement on math ASC). We extend the classic I/E model by…

Regularity Results for a Class of Functionals with Non-Standard Growth

NASA Astrophysics Data System (ADS)

Acerbi, Emilio; Mingione, Giuseppe

We consider the integral functional under non-standard growth assumptions that we call p(x) type: namely, we assume that a relevant model case being the functional Under sharp assumptions on the continuous function p(x)>1 we prove regularity of minimizers. Energies exhibiting this growth appear in several models from mathematical physics.

Observational Evidence Against Mountain-Wave Generation of Ice Nuclei as a Prerequisite for the Formation of Three Solid Nitric Acid Polar Stratospheric Clouds Observed in the Arctic in Early December 1999

NASA Technical Reports Server (NTRS)

Pagan, Kathy L.; Tabazadeh, Azadeh; Drdla, Katja; Hervig, Mark E.; Eckermann, Stephen D.; Browell, Edward V.; Legg, Marion J.; Foschi, Patricia G.

2004-01-01

A number of recently published papers suggest that mountain-wave activity in the stratosphere, producing ice particles when temperatures drop below the ice frost point, may be the primary source of large NAT particles. In this paper we use measurements from the Advanced Very High Resolution Radiometer (AVHRR) instruments on board the National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites to map out regions of ice clouds produced by stratospheric mountain-wave activity inside the Arctic vortex. Lidar observations from three DC-8 flights in early December 1999 show the presence of solid nitric acid (Type Ia or NAT) polar stratospheric clouds (PSCs). By using back trajectories and superimposing the position maps on the AVHRR cloud imagery products, we show that these observed NAT clouds could not have originated at locations of high-amplitude mountain-wave activity. We also show that mountain-wave PSC climatology data and Mountain Wave Forecast Model 2.0 (MWFM-2) raw hemispheric ray and grid box averaged hemispheric wave temperature amplitude hindcast data from the same time period are in agreement with the AVHRR data. Our results show that ice cloud formation in mountain waves cannot explain how at least three large scale NAT clouds were formed in the stratosphere in early December 1999.

Structure of Mesorhizobium loti arylamine N-acetyltransferase 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holton, Simon J.; Dairou, Julien; Sandy, James

2005-01-01

The crystal structure of a M. loti arylamine N-acetyltransferase 1 has been determined at 2.0 Å resolution. The arylamine N-acetyltransferase (NAT) enzymes have been found in a broad range of both eukaryotic and prokaryotic organisms. The NAT enzymes catalyse the transfer of an acetyl group from acetyl Co-enzyme A onto the terminal nitrogen of a range of arylamine, hydrazine and arylhydrazine compounds. Recently, several NAT structures have been reported from different prokaryotic sources including Salmonella typhimurium, Mycobacterium smegmatis and Pseudomonas aeruginosa. Bioinformatics analysis of the Mesorhizobium loti genome revealed two NAT paralogues, the first example of multiple NAT isoenzymes inmore » a eubacterial organism. The M. loti NAT 1 enzyme was recombinantly expressed and purified for X-ray crystallographic studies. The purified enzyme was crystallized in 0.5 M Ca(OAc){sub 2}, 16% PEG 3350, 0.1 M Tris–HCl pH 8.5 using the sitting-drop vapour-diffusion method. A data set diffracting to 2.0 Å was collected from a single crystal at 100 K. The crystal belongs to the orthorhombic spacegroup P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 53.2, b = 97.3, c = 114.3 Å. The structure was refined to a final free-R factor of 24.8%. The structure reveals that despite low sequence homology, M. loti NAT1 shares the common fold as reported in previous NAT structures and exhibits the same catalytic triad of residues (Cys-His-Asp) in the active site.« less

Aloha Teachers: Teacher Autonomy Support Promotes Native Hawaiian and Pacific Islander Students' Motivation, School Belonging, Course-Taking and Math Achievement

ERIC Educational Resources Information Center

Froiland, John Mark; Davison, Mark L.; Worrell, Frank C.

2016-01-01

Among 110 Native Hawaiians and Pacific Islanders, teacher autonomy support in 9th grade significantly predicted intrinsic motivation for math in 9th grade as well as math course-taking over the next 2 years, both of which in turn significantly predicted math achievement by 11th grade. In a second model, teacher autonomy support was positively…

The Effect of Cognitively Guided Instruction on Primary Students' Math Achievement, Problem-Solving Abilities and Teacher Questioning

ERIC Educational Resources Information Center

Medrano, Juan

2012-01-01

The purpose of this study is to impact the teaching and learning of math of 2nd through 4th grade math students at Porfirio H. Gonzales Elementary School. The Cognitively Guided Instruction (CGI) model serves as the independent variable for this study. Its intent is to promote math instruction that emphasizes problem-solving to a greater degree…

Cognitive Prediction of Reading, Math, and Attention: Shared and Unique Influences.

PubMed

Peterson, Robin L; Boada, Richard; McGrath, Lauren M; Willcutt, Erik G; Olson, Richard K; Pennington, Bruce F

The current study tested a multiple-cognitive predictor model of word reading, math ability, and attention in a community-based sample of twins ages 8 to 16 years ( N = 636). The objective was to identify cognitive predictors unique to each skill domain as well as cognitive predictors shared among skills that could help explain their overlap and thus help illuminate the basis for comorbidity of related disorders (reading disability, math disability, and attention deficit hyperactivity disorder). Results indicated that processing speed contributes to the overlap between reading and attention as well as math and attention, whereas verbal comprehension contributes to the overlap between reading and math. There was no evidence that executive functioning skills help account for covariation among these skill domains. Instead, specific executive functions differentially related to certain outcomes (i.e., working memory to math and inhibition to attention). We explored whether the model varied in younger versus older children and found only minor differences. Results are interpreted within the context of the multiple deficit framework for neurodevelopmental disorders.

Comparative genomic, phylogenetic, and functional investigation of the xenobiotic metabolizing arylamine N-acetyltransferase enzyme family among fungi

USDA-ARS?s Scientific Manuscript database

Arylamine N-acetyltransferases (NATs) are xenobiotic metabolizing enzymes well-characterized in several bacteria and higher eukaryotes. The role of NATs in fungal biology has only recently been investigated (Glenn and Bacon, 2009; Glenn et al., 2010). The NAT1 gene of Gibberella moniliformis was the...

Comparison of human immunodeficiency virus assays in window phase and elite controller samples: viral load distribution and implications for transmission risk

PubMed Central

Vermeulen, Marion; Coleman, Charl; Mitchel, Josephine; Reddy, Ravi; van Drimmelen, Harry; Fickett, Tracy; Busch, Michael; Lelie, Nico

2016-01-01

BACKGROUND After 3 years of individual-donation nucleic acid test (ID-NAT) screening by the South African National Blood Service (SANBS), a repository of 73 human immunodeficiency virus antibody (anti-HIV)-negative window period (WP)-yield samples and 28 anti-HIV–positive, HIV-RNA–negative elite controllers (ECs) became available for comparison of a p24 antigen (p24 Ag) assay (Innogenetics), two viral load assays (Siemens branch DNA [bDNA] 3.0 and Abbott real-time polymerase chain reaction [RT-PCR]), and three triplex NAT assays (Novartis Diagnostics Ultrio and Ultrio-Plus and Roche TaqScreen) by replicate testing of dilutions. STUDY DESIGN AND METHODS Viral loads were assessed by bDNA and RT-PCR assays and if below 100 copies (cps)/mL, by Ultrio limiting dilution probit analysis. The probability of virus transmission by WP and EC donations was estimated for different levels of the 50% minimum infectious dose (ID50) using Poisson distribution statistics. RESULTS The equal distribution of WP donations plotted by log HIV-RNA levels indicated a random appearance of donors in the ramp-up phase. The HIV p24 Ag assay detected 45% of WP samples and the cutoff crossing point was estimated at 8140 (bDNA)/ 22,710 (RT-PCR) cps/mL. On replicate retesting of 40 HIV p24 Ag–negative ID-NAT WP-yield samples Ultrio minipool (MP)8, Ultrio-Plus MP8, and TaqScreen MP6 detected 79, 81, and 78%, respectively. Modeling with an estimated ID50 of 31.6 virions/RBC indicated that 15% of p24 Ag–negative ID-NAT WP-yield donations would have transmitted HIV if MP6–8 NAT had been used. Only 2% of RBC transfusions from ECs are estimated to be infectious with a worst-case ID50 estimate of 316 virions. CONCLUSION Our analysis of viremia and infectivity of WP and EC donations enables comparison of the efficacy of NAT options in preventing HIV transmission risk. PMID:23445273

Comparison of human immunodeficiency virus assays in window phase and elite controller samples: viral load distribution and implications for transmission risk.

PubMed

Vermeulen, Marion; Coleman, Charl; Mitchel, Josephine; Reddy, Ravi; van Drimmelen, Harry; Fickett, Tracy; Busch, Michael; Lelie, Nico

2013-10-01

After 3 years of individual-donation nucleic acid test (ID-NAT) screening by the South African National Blood Service (SANBS), a repository of 73 human immunodeficiency virus antibody (anti-HIV)-negative window period (WP)-yield samples and 28 anti-HIV-positive, HIV-RNA-negative elite controllers (ECs) became available for comparison of a p24 antigen (p24 Ag) assay (Innogenetics), two viral load assays (Siemens branch DNA [bDNA] 3.0 and Abbott real-time polymerase chain reaction [RT-PCR]), and three triplex NAT assays (Novartis Diagnostics Ultrio and Ultrio-Plus and Roche TaqScreen) by replicate testing of dilutions. Viral loads were assessed by bDNA and RT-PCR assays and if below 100 copies (cps)/mL, by Ultrio limiting dilution probit analysis. The probability of virus transmission by WP and EC donations was estimated for different levels of the 50% minimum infectious dose (ID50 ) using Poisson distribution statistics. The equal distribution of WP donations plotted by log HIV-RNA levels indicated a random appearance of donors in the ramp-up phase. The HIV p24 Ag assay detected 45% of WP samples and the cutoff crossing point was estimated at 8140 (bDNA)/22,710 (RT-PCR) cps/mL. On replicate retesting of 40 HIV p24 Ag-negative ID-NAT WP-yield samples Ultrio minipool (MP)8, Ultrio-Plus MP8, and TaqScreen MP6 detected 79, 81, and 78%, respectively. Modeling with an estimated ID50 of 31.6 virions/RBC indicated that 15% of p24 Ag-negative ID-NAT WP-yield donations would have transmitted HIV if MP6-8 NAT had been used. Only 2% of RBC transfusions from ECs are estimated to be infectious with a worst-case ID50 estimate of 316 virions. Our analysis of viremia and infectivity of WP and EC donations enables comparison of the efficacy of NAT options in preventing HIV transmission risk. © 2013 American Association of Blood Banks.

The human serotonin N-acetyltransferase (EC 2.3.1.87) gene (AANAT): Structure, chromosomal localization, and tissue expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coon, S.L.; Bernard, M.; Roseboom, P.H.

Serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase, AA-NAT, HGMW-approved symbol AANAT;EC 2.3.1.87) is the penultimate enzyme in melatonin synthesis and controls the night/day rhythm in melatonin production in the vertebrate pineal gland. We have found that the human AA-NAT gene spans {approx}2.5 kb, contains four exons, and is located at chromosome 17q25. The open reading frame encodes a 23.2-kDa protein that is {approx}80% identical to sheep and rat AA-NAT. The AA-NAT transcript ({approx}1 kb) is highly abundant in the pineal gland and is expressed at lower levels in the retina and in the Y79 retinoblastoma cell line. AA-NAT mRNA is also detectable atmore » low levels in several brain regions and the pituitary gland, but not in several peripheral tissues examined. Brain and pituitary AA-NAT could modulate serotonin-dependent aspects of human behavior and pituitary function. 31 refs., 5 figs.« less

Asymmetric localization of natural antisense RNA of neuropeptide sensorin in Aplysia sensory neurons during aging and activity.

PubMed

Kadakkuzha, Beena M; Liu, Xin-An; Narvaez, Maria; Kaye, Alexandra; Akhmedov, Komolitdin; Puthanveettil, Sathyanarayanan V

2014-01-01

Despite the advances in our understanding of transcriptome, regulation and function of its non-coding components continue to be poorly understood. Here we searched for natural antisense transcript for sensorin (NAT-SRN), a neuropeptide expressed in the presynaptic sensory neurons of gill-withdrawal reflex of the marine snail Aplysia californica. Sensorin (SRN) has a key role in learning and long-term memory storage in Aplysia. We have now identified NAT-SRN in the central nervous system (CNS) and have confirmed its expression by northern blotting and fluorescent RNA in situ hybridization. Quantitative analysis of NAT-SRN in micro-dissected cell bodies and processes of sensory neurons suggest that NAT-SRN is present in the distal neuronal processes along with sense transcripts. Importantly, aging is associated with reduction in levels of NAT-SRN in sensory neuron processes. Furthermore, we find that forskolin, an activator of CREB signaling, differentially alters the distribution of SRN and NAT-SRN. These studies reveal novel insights into physiological regulation of natural antisense RNAs.

Fluid reasoning predicts future mathematics among children and adolescents

PubMed Central

Green, Chloe T.; Bunge, Silvia A.; Chiongbian, Victoria Briones; Barrow, Maia; Ferrer, Emilio

2017-01-01

The aim of this longitudinal study was to determine whether fluid reasoning (FR) plays a significant role in the acquisition of mathematics skills, above and beyond the effects of other cognitive and numerical abilities. Using a longitudinal cohort sequential design, we examined how FR measured at three assessment occasions, spaced approximately 1.5 years apart, predicted math outcomes for a group of 69 participants between ages 6 and 21 across all three assessment occasions. We used structural equation modeling (SEM) to examine the direct and indirect relations between children's prior cognitive abilities and their future math achievement. A model including age, FR, vocabulary, and spatial skills accounted for 90% of the variance in future math achievement. In this model, FR was the only significant predictor of future math achievement; neither age, vocabulary, nor spatial skills were significant predictors. Thus, FR was the only predictor of future math achievement across a wide age range that spanned primary and secondary school. These findings build on Cattell's conceptualization of FR (Cattell, 1987) as a scaffold for learning, showing that this domain-general ability supports the acquisition of rudimentary math skills as well as the ability to solve more complex mathematical problems. PMID:28152390

A Model for Math Modeling

ERIC Educational Resources Information Center

Lin, Tony; Erfan, Sasan

2016-01-01

Mathematical modeling is an open-ended research subject where no definite answers exist for any problem. Math modeling enables thinking outside the box to connect different fields of studies together including statistics, algebra, calculus, matrices, programming and scientific writing. As an integral part of society, it is the foundation for many…

No doubt about it: when doubtful role models undermine men's and women's math performance under threat.

PubMed

Marx, David M; Monroe, Allyce H; Cole, Chris E; Gilbert, Patricia N

2013-01-01

Past work has shown that female role models are effective buffers against stereotype threat. The present research examines the boundary conditions of this role model effect. Specifically, we argue that female role models should avoid expressing doubt about their math abilities; otherwise they may cease to buffer women from stereotype threat. For men, a non-doubtful male role model should be seen as threatening, thus harming performance. A doubtful male role model, however, should be seen as non-threatening, thus allowing men to perform up to their ability in math. To test this reasoning, men and women were exposed to either an outgroup or ingroup role model who either expressed doubt or did not. Participants then took a math exam under stereotype threat conditions. As expected, doubtful ingroup role models hurt women, but helped men's performance. Outgroup role models' expressed doubt had no differential effect on performance. We also show that expressions of doubt take on a different meaning when expressed by a female rather than a male role model.

Performance analysis for wireless networks: an analytical approach by multifarious Sym Teredo.

PubMed

Punithavathani, D Shalini; Radley, Sheryl

2014-01-01

IPv4-IPv6 transition rolls out numerous challenges to the world of Internet as the Internet is drifting from IPv4 to IPv6. IETF recommends few transition techniques which includes dual stack and translation and tunneling. By means of tunneling the IPv6 packets over IPv4 UDP, Teredo maintains IPv4/IPv6 dual stack node in isolated IPv4 networks behindhand network address translation (NAT). However, the proposed tunneling protocol works with the symmetric and asymmetric NATs. In order to make a Teredo support several symmetric NATs along with several asymmetric NATs, we propose multifarious Sym Teredo (MTS), which is an extension of Teredo with a capability of navigating through several symmetric NATs. The work preserves the Teredo architecture and also offers a backward compatibility with the original Teredo protocol.

Performance Analysis for Wireless Networks: An Analytical Approach by Multifarious Sym Teredo

PubMed Central

Punithavathani, D. Shalini; Radley, Sheryl

2014-01-01

IPv4-IPv6 transition rolls out numerous challenges to the world of Internet as the Internet is drifting from IPv4 to IPv6. IETF recommends few transition techniques which includes dual stack and translation and tunneling. By means of tunneling the IPv6 packets over IPv4 UDP, Teredo maintains IPv4/IPv6 dual stack node in isolated IPv4 networks behindhand network address translation (NAT). However, the proposed tunneling protocol works with the symmetric and asymmetric NATs. In order to make a Teredo support several symmetric NATs along with several asymmetric NATs, we propose multifarious Sym Teredo (MTS), which is an extension of Teredo with a capability of navigating through several symmetric NATs. The work preserves the Teredo architecture and also offers a backward compatibility with the original Teredo protocol. PMID:25506611

Math anxiety and its relationship with basic arithmetic skills among primary school children.

PubMed

Sorvo, Riikka; Koponen, Tuire; Viholainen, Helena; Aro, Tuija; Räikkönen, Eija; Peura, Pilvi; Dowker, Ann; Aro, Mikko

2017-09-01

Children have been found to report and demonstrate math anxiety as early as the first grade. However, previous results concerning the relationship between math anxiety and performance are contradictory, with some studies establishing a correlation between them while others do not. These contradictory results might be related to varying operationalizations of math anxiety. In this study, we aimed to examine the prevalence of math anxiety and its relationship with basic arithmetic skills in primary school children, with explicit focus on two aspects of math anxiety: anxiety about failure in mathematics and anxiety in math-related situations. The participants comprised 1,327 children at grades 2-5. Math anxiety was assessed using six items, and basic arithmetic skills were assessed using three assessment tasks. Around one-third of the participants reported anxiety about being unable to do math, one-fifth about having to answer teachers' questions, and one tenth about having to do math. Confirmatory factor analysis indicated that anxiety about math-related situations and anxiety about failure in mathematics are separable aspects of math anxiety. Structural equation modelling suggested that anxiety about math-related situations was more strongly associated with arithmetic fluency than anxiety about failure. Anxiety about math-related situations was most common among second graders and least common among fifth graders. As math anxiety, particularly about math-related situations, was related to arithmetic fluency even as early as the second grade, children's negative feelings and math anxiety should be identified and addressed from the early primary school years. © 2017 The British Psychological Society.

Searching for the Golden Model of Education: Cross-National Analysis of Math Achievement

PubMed Central

Bodovski, Katerina; Byun, Soo-yong; Chykina, Volha; Chung, Hee Jin

2017-01-01

We utilized four waves of TIMSS data in addition to the information we have collected on countries’ educational systems to examine whether different degrees of standardization, differentiation, proportion of students in private schools and governmental spending on education influence students’ math achievement, its variation and socioeconomic status (SES) gaps in math achievement. Findings: A higher level of standardization of educational systems was associated with higher average math achievement. Greater expenditure on education (as % of total government expenditure) was associated with a lower level of dispersion of math achievement and smaller SES gaps in math achievement. Wealthier countries exhibited higher average math achievement and a narrower variation. Higher income inequality (measured by Gini index) was associated with a lower average math achievement and larger SES gaps. Further, we found that higher level of standardization alleviates the negative effects of differentiation in the systems with more rigid tracking. PMID:29151667

Reliability of a science admission test (HAM-Nat) at Hamburg medical school.

PubMed

Hissbach, Johanna; Klusmann, Dietrich; Hampe, Wolfgang

2011-01-01

The University Hospital in Hamburg (UKE) started to develop a test of knowledge in natural sciences for admission to medical school in 2005 (Hamburger Auswahlverfahren für Medizinische Studiengänge, Naturwissenschaftsteil, HAM-Nat). This study is a step towards establishing the HAM-Nat. We are investigating parallel forms reliability, the effect of a crash course in chemistry on test results, and correlations of HAM-Nat test results with a test of scientific reasoning (similar to a subtest of the "Test for Medical Studies", TMS). 316 first-year students participated in the study in 2007. They completed different versions of the HAM-Nat test which consisted of items that had already been used (HN2006) and new items (HN2007). Four weeks later half of the participants were tested on the HN2007 version of the HAM-Nat again, while the other half completed the test of scientific reasoning. Within this four week interval students were offered a five day chemistry course. Parallel forms reliability for four different test versions ranged from r(tt)=.53 to r(tt)=.67. The retest reliabilities of the HN2007 halves were r(tt)=.54 and r(tt )=.61. Correlations of the two HAM-Nat versions with the test of scientific reasoning were r=.34 und r=.21. The crash course in chemistry had no effect on HAM-Nat scores. The results suggest that further versions of the test of natural sciences will not easily conform to the standards of internal consistency, parallel-forms reliability and retest reliability. Much care has to be taken in order to assemble items which could be used interchangeably for the construction of new test versions. The test of scientific reasoning and the HAM-Nat are tapping different constructs. Participation in a chemistry course did not improve students' achievement, probably because the content of the course was not coordinated with the test and many students lacked of motivation to do well in the second test.

Reliability of a science admission test (HAM-Nat) at Hamburg medical school

PubMed Central

Hissbach, Johanna; Klusmann, Dietrich; Hampe, Wolfgang

2011-01-01

Objective: The University Hospital in Hamburg (UKE) started to develop a test of knowledge in natural sciences for admission to medical school in 2005 (Hamburger Auswahlverfahren für Medizinische Studiengänge, Naturwissenschaftsteil, HAM-Nat). This study is a step towards establishing the HAM-Nat. We are investigating parallel forms reliability, the effect of a crash course in chemistry on test results, and correlations of HAM-Nat test results with a test of scientific reasoning (similar to a subtest of the "Test for Medical Studies", TMS). Methods: 316 first-year students participated in the study in 2007. They completed different versions of the HAM-Nat test which consisted of items that had already been used (HN2006) and new items (HN2007). Four weeks later half of the participants were tested on the HN2007 version of the HAM-Nat again, while the other half completed the test of scientific reasoning. Within this four week interval students were offered a five day chemistry course. Results: Parallel forms reliability for four different test versions ranged from rtt=.53 to rtt=.67. The retest reliabilities of the HN2007 halves were rtt=.54 and rtt =.61. Correlations of the two HAM-Nat versions with the test of scientific reasoning were r=.34 und r=.21. The crash course in chemistry had no effect on HAM-Nat scores. Conclusions: The results suggest that further versions of the test of natural sciences will not easily conform to the standards of internal consistency, parallel-forms reliability and retest reliability. Much care has to be taken in order to assemble items which could be used interchangeably for the construction of new test versions. The test of scientific reasoning and the HAM-Nat are tapping different constructs. Participation in a chemistry course did not improve students’ achievement, probably because the content of the course was not coordinated with the test and many students lacked of motivation to do well in the second test. PMID:21866246

Comparison of CYP1A2 and NAT2 Phenotypes between Black and White Smokers

PubMed Central

Muscat, Joshua E.; Pittman, Brian; Kleinman, Wayne; Lazarus, Philip; Stellman, Steven D.; Richie, John P.

2008-01-01

The lower incidence rate of transitional cell carcinoma of the urinary bladder in blacks than in whites may be due to racial differences in the catalytic activity of enzymes that metabolize carcinogenic arylamines in tobacco smoke. To examine this, we compared cytochrome P4501A2 (CYP1A2) and N-acetyltransferase-2 activities (NAT2) in black and white smokers using urinary caffeine metabolites as a probe for enzyme activity in a community-based study of 165 black and 183 white cigarette smokers. The paraxanthine (1,7-dimethylxanthine, 17X)/caffeine (trimethylxanthine, 137X) ratio or [17X + 1,7-dimethyluric acid (17U)]/137X ratio was used as an indicator of CYP1A2 activity. The 5-acetyl-amino-6-formylamino-3-methyluracil (AFMU)/1-methylxanthine (1X) ratio indicated NAT2 activity. The odds ratio for the slow NAT2 phenotype associated with black race was 0.4; 95% confidence intervals 0.2–0.7. The putative combined low risk phenotype (slow CYP1A2/rapid NAT2) was more common in blacks than in whites (25% vs. 15%, P<0.02). There were no significant racial differences in slow and rapid CYP1A2 phenotypes, and in the combined slow NAT2/rapid CYP1A2 phenotype. Age, education, cigarette smoking amount, body mass index, GSTM1 and GSTM3 genotypes were unrelated to CYP1A2 and NAT2 activity. Intake of cruciferous vegetables (primarily broccoli), red meat, carrots, grapefruit and onions predicted CYP1A2 activity either for all subjects or in race-specific analyses. Carrot and grapefruit consumption was related to NAT2 activity. Collectively, these results indicated that phenotypic differences in NAT2 alone or in combination with CYP1A2 might help explain the higher incidence rates of transitional cell bladder cancer in whites. PMID:18703023

The results of nucleic acid testing in remunerated and non-remunerated blood donors in Lithuania

PubMed Central

Kalibatas, Vytenis; Kalibatienė, Lina

2014-01-01

Background In Lithuania, governmentally covered remuneration for whole blood donations prevails. Donors may choose to accept or reject the remuneration. The purpose of this study was to compare the rate of nucleic acid testing (NAT) discriminatory-positive markers for human immunodeficiency virus-1 (HIV-1), hepatitis B virus (HBV) and hepatitis C virus (HCV) in seronegative, first-time and repeat, remunerated and non-remunerated donations at the National Blood Centre in Lithuania during the period from 2005 to 2010. Materials and methods All seronegative whole blood and blood component donations were individually analysed by NAT for HIV-1, HBV and HCV. Only discriminatory-positive NAT were classified. The prevalence of discriminatory-positive NAT per 100,000 donations in the donor groups and the odds ratios comparing the remunerated and non-remunerated donations were determined. Results Significant differences were observed for HBV NAT results: 47.42 and 26.29 per 100,000 remunerated first-time and repeat donations, respectively, compared to 10.6 and 3.58 per 100,000 non-remunerated first-time and repeat, seronegative donations, respectively. The differences were also significant for HCV NAT results: 47.42 and 51.99 for remunerated first-time and repeat donations, respectively, compared to 2.12 and 0 per 100,000 non-remunerated first-time and repeat, seronegative donations, respectively. No seronegative, discriminatory-positive NAT HIV case was found. The odds of discriminatory HBV and HCV NAT positive results were statistically significantly higher for both first-time and repeat remunerated donations compared to first-time and repeat non-remunerated donations. Discussion First-time and repeat remunerated seronegative donations were associated with a statistically significantly higher prevalence and odds for discriminatory-positive HBV and HCV NAT results compared to first-time and repeat non-remunerated donations at the National Blood Centre in Lithuania. PMID:24120587

Structural Evaluation of 5,5'-Bis(naphth-2-yl)-2,2'-bithiophene in Organic Field-Effect Transistors with n-Octadecyltrichlorosilane Coated SiO2 Gate Dielectric.

PubMed

Lauritzen, Andreas E; Torkkeli, Mika; Bikondoa, Oier; Linnet, Jes; Tavares, Luciana; Kjelstrup-Hansen, Jakob; Knaapila, Matti

2018-05-25

We report on the structure and morphology of 5,5'-bis(naphth-2-yl)-2,2'-bithiophene (NaT2) films in bottom-contact organic field-effect transistors (OFETs) with octadecyltrichlorosilane (OTS) coated SiO 2 gate dielectric, characterized by atomic force microscopy (AFM), grazing-incidence X-ray diffraction (GIXRD), and electrical transport measurements. Three types of devices were investigated with the NaT2 thin-film deposited either on (1) pristine SiO 2 (corresponding to higher surface energy, 47 mJ/m 2 ) or on OTS deposited on SiO 2 under (2) anhydrous or (3) humid conditions (corresponding to lower surface energies, 20-25 mJ/m 2 ). NaT2 films grown on pristine SiO 2 form nearly featureless three-dimensional islands. NaT2 films grown on OTS/SiO 2 deposited under anhydrous conditions form staggered pyramid islands where the interlayer spacing corresponds to the size of the NaT2 unit cell. At the same time, the grain size measured by AFM increases from hundreds of nanometers to micrometers and the crystal size measured by GIXRD from 30 nm to more than 100 nm. NaT2 on OTS/SiO 2 deposited under humid conditions also promotes staggered pyramids but with smaller crystals 30-80 nm. The NaT2 unit cell parameters in OFETs differ 1-2% from those in bulk. Carrier mobilities tend to be higher for NaT2 layers on SiO 2 (2-3 × 10 -4 cm 2 /(V s)) compared to NaT2 on OTS (2 × 10 -5 -1 × 10 -4 cm 2 /(V s)). An applied voltage does not influence the unit cell parameters when probed by GIXRD in operando.

Clinical Outcomes in International Federation of Gynecology and Obstetrics Stage IA Endometrial Cancer With Myometrial Invasion Treated With or Without Postoperative Vaginal Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diavolitsis, V.; Rademaker, A.; Lurain, J.

2012-10-01

Purpose: To assess the clinical outcomes of patients with Stage IA endometrial cancer with myometrial invasion treated with postoperative vaginal brachytherapy (VBT) with those who received no adjuvant therapy (NAT). Methods and Materials: All patients treated with hysterectomy for endometrial cancer at Northwestern Memorial Hospital between 1978 and 2005 were identified. Those patients with Stage IA disease with myometrial invasion who were treated with VBT alone or NAT were identified and included in the present analysis. Results: Of 252 patients with Stage IA endometrial cancer with superficial (<50%) myometrial invasion who met the inclusion criteria, 169 underwent VBT and 83more » received NAT. The median follow-up in the VBT and NAT groups was 103 and 61 months, respectively. In the VBT group, 56.8% had Grade 1, 37.9% had Grade 2, and 5.3% had Grade 3 tumors. In the NAT group, 75.9%, 20.5%, and 3.6% had Grade 1, 2, and 3 tumors, respectively. Lymphatic or vascular space invasion was noted in 12.4% of the VBT patients and 5.6% of the NAT patients. The 5-year overall survival rate was 95.5%. The 5-year recurrence-free survival rate was 92.4% for all patients, 94.4% for the VBT group, and 87.4% for the NAT group (p = NS). Of the 169 VBT patients and 83 NAT patients, 8 (4.7%) and 6 (7.2%) developed recurrent disease. One vaginal recurrence occurred in the VBT group (0.6%) and three in the NAT group (3.8%). Recurrences developed 2-102 months after surgical treatment. Two of the four vaginal recurrences were salvaged. No Grade 3 or higher acute or late radiation toxicity was noted. Conclusions: The use of postoperative VBT in patients with Stage I endometrial cancer with <50% myometrial invasion yielded excellent vaginal disease control and disease-free survival, with minimal toxicity.« less

Evaluation of the Procleix Ultrio Elite Assay and the Panther-System for Individual NAT Screening of Blood, Hematopoietic Stem Cell, Tissue and Organ Donors.

PubMed

Heim, Albert

2016-05-01

The performance of the multiplex Procleix Ultrio Elite assay as individual donor nucleic acid test (ID-NAT) for the detection of HIV-1, HIV-2, HCV, and HBV was evaluated in a retrospective, single center study. ID-NAT results of 21,181 blood donors, 984 tissue donors, 293 hematopoietic stem cell donors and 4 organ donors were reviewed in synopsis with results of serological screening and additional discriminatory and repetitive NAT in case of positive donors. Specificity of the initial Procleix Ultrio Elite assay was 99.98% and after discriminatory testing 100.00%. Initially invalid results were observed in 75 of 21,181 blood donors (0.35%) but 16 of 984 tissue donors (1.62%, p < 0.001) which included non-heart-beating ('cadaveric') donors. All these had valid negative ID-NAT results after repeated testing or testing of 1:5 diluted specimens in case of tissue donors. Occult hepatitis B (defined here as HBV DNAemia without HBsAg detection) was demonstrated by ID-NAT in two anti-HBc-positive tissue donors and suspected in two other tissue donors, where a definite diagnosis was not achieved due to the insufficient sample volumes available. The Procleix Ultrio Elite assay proved to be specific, robust and rapid. Therefore, routine ID-NAT may also be feasible for organ and granulocyte donors.

Number-specific and general cognitive markers of preschoolers' math ability profiles.

PubMed

Gray, Sarah A; Reeve, Robert A

2016-07-01

Different number-specific and general cognitive markers have been claimed to underlie preschoolers' math ability. It is unclear, however, whether similar/different cognitive markers, or combinations of them, are associated with different patterns of emerging math abilities (i.e., different patterns of strength and weakness). To examine this question, 103 preschoolers (40-60 months of age) completed six math tasks (count sequence, object counting, give a number, naming numbers, ordinal relations, and arithmetic), three number-specific markers of math ability (dot enumeration, magnitude comparison, and spontaneous focusing on numerosity), and four general markers (working memory, response inhibition, attention, and vocabulary). A three-step latent profile modeling procedure identified five math ability profiles that differed in their patterns of math strengths and weaknesses; specifically, the profiles were characterized by (a) excellent math ability on all math tasks, (b) good arithmetic ability, (c) good math ability but relatively poor count sequence recitation ability, (d) average ability on all math tasks, and (e) poor ability on all math tasks. After controlling for age, only dot enumeration and spontaneous focusing on numerosity were associated with the math ability profiles, whereas vocabulary was also marginally significant, and these markers were differentially associated with different profiles; that is, different cognitive markers were associated with different patterns of strengths and weaknesses in math abilities. Findings are discussed in terms of their implications for the development of math cognition. Copyright © 2016 Elsevier Inc. All rights reserved.

Proper regulation of a sperm-specific cis-nat-siRNA is essential for double fertilization in Arabidopsis

USDA-ARS?s Scientific Manuscript database

/Cis/-nat-siRNAs are a recently characterized class of small regulatory RNAs that are widespread in eukaryotes. Despite their abundance the importance of their regulatory activity is largely unknown. The only functional role for eukaryotic /cis/-nat-siRNAs that has been described to date is in envir...

7Li-induced reaction on natMo: A study of complete versus incomplete fusion

NASA Astrophysics Data System (ADS)

Kumar, Deepak; Maiti, Moumita; Lahiri, Susanta

2017-07-01

Background: Several investigations on the complete-incomplete fusion (CF-ICF) dynamics of α -cluster well-bound nuclei have been contemplated above the Coulomb barrier (˜4 -7 MeV/nucleon) in recent years. It is therefore expected to observe significant ICF over CF in the reactions induced by a weakly bound α -cluster nucleus at slightly above the barrier. Purpose: Study of the CF-ICF dynamics by measuring the populated residues in the weakly bound 7Li+natMo system at energies slightly above the Coulomb barrier to well above it. Method: In order to investigate CF-ICF in the loosely bound system, 7Li beam was bombarded on the natMo foils, separated by the aluminium (Al) catcher foils alternatively, within ˜3 -6.5 MeV/nucleon. Evaporation residues produced in each foil were identified by the off-line γ -ray spectrometry. Measured cross section data of the residues were compared with the theoretical model calculations based on the equilibrium (EQ) and pre-equilibrium (PEQ) reaction mechanisms. Results: The experimental cross section of Rh 101 m,100 ,99 m,97 ,Ru,9597,Tc 99 m,96 ,95 ,94 ,93 m+g , and 93mMo residues measured at various projectile energies were satisfactorily reproduced by the simplified coupled channel approach in comparison to single barrier penetration model calculation. Significant cross section enhancement in the α -emitting channels was observed compared to EQ and PEQ model calculations throughout observed energy region. The ICF process over CF was analyzed by comparing with EMPIRE. The increment of the incomplete fusion fraction was observed with increasing projectile energies. Conclusions: Theoretical model calculations reveal that the compound reaction mechanism is the major contributor to the production of residues in 7Li+natMo reaction. Theoretical evaluations substantiate the contribution of ICF over the CF in α -emitting channels. EMPIRE estimations shed light on its predictive capability of cross sections of the residues from the heavy-ion induced reactions.

A Physiologically Based Pharmacokinetic Model of Isoniazid and Its Application in Individualizing Tuberculosis Chemotherapy.

PubMed

Cordes, Henrik; Thiel, Christoph; Aschmann, Hélène E; Baier, Vanessa; Blank, Lars M; Kuepfer, Lars

2016-10-01

Due to its high early bactericidal activity, isoniazid (INH) plays an essential role in tuberculosis treatment. Genetic polymorphisms of N-acetyltransferase type 2 (NAT2) cause a trimodal distribution of INH pharmacokinetics in slow, intermediate, and fast acetylators. The success of INH-based chemotherapy is associated with acetylator and patient health status. Still, a standard dose recommended by the FDA is administered regardless of acetylator type or immune status, even though adverse effects occur in 5 to 33% of all patients. Slow acetylators have a higher risk of development of drug-induced toxicity, while fast acetylators and immune-deficient patients face lower treatment success rates. To mechanistically assess the trade-off between toxicity and efficacy, we developed a physiologically based pharmacokinetic (PBPK) model describing the NAT2-dependent pharmacokinetics of INH and its metabolites. We combined the PBPK model with a pharmacodynamic (PD) model of antimycobacterial drug effects in the lungs. The resulting PBPK/PD model allowed the simultaneous simulation of treatment efficacies at the site of infection and exposure to toxic metabolites in off-target organs. Subsequently, we evaluated various INH dosing regimens in NAT2-specific immunocompetent and immune-deficient virtual populations. Our results suggest the need for acetylator-specific dose adjustments for optimal treatment outcomes. A reduced dose for slow acetylators substantially lowers the exposure to toxic metabolites and thereby the risk of adverse events, while it maintains sufficient treatment efficacies. Vice versa, intermediate and fast acetylators benefit from increased INH doses and a switch to a twice-daily administration schedule. Our analysis outlines how PBPK/PD modeling may be used to design and individualize treatment regimens. Copyright © 2016 Cordes et al.

Population Pharmacokinetic Analysis of Isoniazid, Acetylisoniazid, and Isonicotinic Acid in Healthy Volunteers

PubMed Central

Seng, Kok-Yong; Hee, Kim-Hor; Soon, Gaik-Hong; Chew, Nicholas; Khoo, Saye H.

2015-01-01

In this study, we aimed to quantify the effects of the N-acetyltransferase 2 (NAT2) phenotype on isoniazid (INH) metabolism in vivo and identify other sources of pharmacokinetic variability following single-dose administration in healthy Asian adults. The concentrations of INH and its metabolites acetylisoniazid (AcINH) and isonicotinic acid (INA) in plasma were evaluated in 33 healthy Asians who were also given efavirenz and rifampin. The pharmacokinetics of INH, AcINH, and INA were analyzed using nonlinear mixed-effects modeling (NONMEM) to estimate the population pharmacokinetic parameters and evaluate the relationships between the parameters and the elimination status (fast, intermediate, and slow acetylators), demographic status, and measures of renal and hepatic function. A two-compartment model with first-order absorption best described the INH pharmacokinetics. AcINH and INA data were best described by a two- and a one-compartment model, respectively, linked to the INH model. In the final model for INH, the derived metabolic phenotypes for NAT2 were identified as a significant covariate in the INH clearance, reducing its interindividual variability from 86% to 14%. The INH clearance in fast eliminators was 1.9- and 7.7-fold higher than in intermediate and slow eliminators, respectively (65 versus 35 and 8 liters/h). Creatinine clearance was confirmed as a significant covariate for AcINH clearance. Simulations suggested that the current dosing guidelines (200 mg for 30 to 45 kg and 300 mg for >45 kg) may be suboptimal (3 mg/liter ≤ Cmax ≤ 6 mg/liter) irrespective of the acetylator class. The analysis established a model that adequately characterizes INH, AcINH, and INA pharmacokinetics in healthy Asians. Our results refine the NAT2 phenotype-based predictions of the pharmacokinetics for INH. PMID:26282412

Heterogeneous kinetics of H2O, HNO3 and HCl on HNO3 hydrates (α-NAT, β-NAT, NAD) in the range 175-200 K

NASA Astrophysics Data System (ADS)

Iannarelli, Riccardo; Rossi, Michel J.

2016-09-01

Experiments on the title compounds have been performed using a multidiagnostic stirred-flow reactor (SFR) in which the gas phase as well as the condensed phase has been simultaneously investigated under stratospheric temperatures in the range 175-200 K. Wall interactions of the title compounds have been taken into account using Langmuir adsorption isotherms in order to close the mass balance between deposited and desorbed (recovered) compounds. Thin solid films at 1 µm typical thickness have been used as a proxy for atmospheric ice particles and have been deposited on a Si window of the cryostat, with the optical element being the only cold point in the deposition chamber. Fourier transform infrared (FTIR) absorption spectroscopy in transmission as well as partial and total pressure measurement using residual gas mass spectrometry (MS) and sensitive pressure gauges have been employed in order to monitor growth and evaporation processes as a function of temperature using both pulsed and continuous gas admission and monitoring under SFR conditions. Thin solid H2O ice films were used as the starting point throughout, with the initial spontaneous formation of α-NAT (nitric acid trihydrate) followed by the gradual transformation of α- to β-NAT at T > 185 K. Nitric acid dihydrate (NAD) was spontaneously formed at somewhat larger partial pressures of HNO3 deposited on pure H2O ice. In contrast to published reports, the formation of α-NAT proceeded without prior formation of an amorphous HNO3 / H2O layer and always resulted in β-NAT. For α- and β-NAT, the temperature-dependent accommodation coefficient α(H2O) and α(HNO3), the evaporation flux Jev(H2O) and Jev(HNO3) and the resulting saturation vapor pressure Peq(H2O) and Peq(HNO3) were measured and compared to binary phase diagrams of HNO3 / H2O in order to afford a thermochemical check of the kinetic parameters. The resulting kinetic and thermodynamic parameters of activation energies for evaporation (Eev) and standard heats of evaporation ΔHev0 of H2O and HNO3 for α- and β-NAT, respectively, led to an estimate for the relative standard enthalpy difference between α- and β-NAT of -6.0 ± 20 kJ mol-1 in favor of β-NAT, as expected, despite a significantly larger value of Eev for HNO3 in α-NAT. This in turn implies a substantial activation energy for HNO3 accommodation in α- compared to β-NAT where Eacc(HNO3) is essentially zero. The kinetic (α(HCl), Jev(HCl)) and thermodynamic (Peq(HCl)) parameters of HCl-doped α- and β-NAT have been determined under the assumption that HCl adsorption did not significantly affect α(H2O) and α(HNO3) as well as the evaporation flux Jev(H2O). Jev(HCl) and Peq(HCl) on both α- and β-NAT are larger than the corresponding values for HNO3 across the investigated temperature range but significantly smaller than the values for pure H2O ice at T < 200 K.

Increasing Success Rates in Developmental Math: The Complementary Role of Individual and Institutional Characteristics

ERIC Educational Resources Information Center

Fong, Kristen E.; Melguizo, Tatiana; Prather, George

2015-01-01

This study tracks students' progression through developmental math sequences and defines progression as both attempting and passing each level of the sequence. A model of successful progression in developmental education was built utilizing individual-, institutional-, and developmental math-level factors. Employing step-wise logistic regression…

Atlas 1.1: An Update to the Theory of Effective Systems Engineers

DTIC Science & Technology

2018-01-16

Proficiency Model ........................................................................................................... 21 5.1.1 Area 1: Math ... Math /Science/General Engineering: Foundational concepts from mathematics, physical sciences, and general engineering; 2. System’s Domain...Table 5. Atlas Proficiency Areas, Categories, and Topics Area Category Topic 1. Math / Science / General Engineering 1.1. Natural Science

Behavioral Engagement in Learning and Math Achievement over Kindergarten: A Contextual Analysis

ERIC Educational Resources Information Center

Robinson, Keith; Mueller, Anna S.

2014-01-01

Using nationally representative data on 12,462 kindergarten children, this report examines the link between behavioral engagement and math achievement growth during kindergarten. Multilevel models show that students with higher individual engagement tend to experience larger math achievement growth over kindergarten, that classroom engagement…

enVisionMATH. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2013

2013-01-01

"enVisionMATH," published by Pearson Education, Inc., is a core curriculum for students in kindergarten through grade 6. The program seeks to help students develop an understanding of math concepts through problem-based instruction, small-group interaction, and visual learning with a focus on reasoning and modeling. Differentiated…

N-acetyltransferase 2 (NAT2) gene polymorphism as a predisposing factor for phenytoin intoxication in tuberculous meningitis or tuberculoma patients having seizures - A pilot study.

PubMed

Adole, Prashant S; Kharbanda, Parampreet S; Sharma, Sadhna

2016-05-01

Simultaneous administration of phenytoin and isoniazid (INH) in tuberculous meningitis (TBM) or tuberculoma patients with seizures results in higher plasma phenytoin level and thus phenytoin intoxication. N-acetyltransferase 2 (NAT2) enzyme catalyses two acetylation reactions in INH metabolism and NAT2 gene polymorphism leads to slow and rapid acetylators. The present study was aimed to evaluate the effect of allelic variants of N-acetyltransferase 2 (NAT2) gene as a predisposing factor for phenytoin toxicity in patients with TBM or tuberculoma having seizures, and taking INH and phenytoin simultaneously. Sixty patients with TBM or tuberculoma with seizures and taking INH and phenytoin simultaneously for a minimum period of seven days were included in study. Plasma phenytoin was measured by high performance liquid chromatography. NAT2 gene polymorphism was studied using restriction fragment length polymorphism and allele specific PCR. The patients were grouped into those having phenytoin intoxication and those with normal phenytoin level, and also classified as rapid or slow acetylators by NAT2 genotyping. Genotypic analysis showed that of the seven SNPs (single nucleotide polymorphisms) of NAT2 gene studied, six mutations were found to be associated with phenytoin intoxication. For rs1041983 (C282T), rs1799929 (C481T), rs1799931 (G857A), rs1799930 (G590A), rs1208 (A803G) and rs1801280 (T341C) allelic variants, the proportion of homozygous mutant was higher in phenytoin intoxicated group than in phenytoin non-intoxicated group. Homozygous mutant allele of NAT2 gene at 481site may act as a predisposing factor for phenytoin intoxication among TBM or tuberculoma patients having seizures.

Effects of human arylamine N-acetyltransferase I knockdown in triple-negative breast cancer cell lines

PubMed Central

Tiang, Jacky M; Butcher, Neville J; Minchin, Rodney F

2015-01-01

Expression of human arylamine N-acetyltransferase I (NAT1) has been associated with various cancer subtypes and inhibition of this enzyme with small molecule inhibitors or siRNA affects cell growth and survival. Here, we have investigated the role of NAT1 in the invasiveness of breast cancer cells both in vitro and in vivo. We knocked down NAT1 using a lentivirus-based shRNA approach and observed marked changes in cell morphology in the triple-negative breast cancer cell lines MDA-MB-231, MDA-MB-436, and BT-549. Most notable was a reduction in the number and size of the filopodia protrusions on the surface of the cells. The loss of filopodia could be rescued by the reintroduction of NAT1 into the knockdown cells. NAT1 expression was localized to the lamellipodia and extended into the filopodia protrusions. In vitro invasion through Geltrex was significantly inhibited in both the MDA cell lines but not in the BT-549 cells. The expression of Snail increased when NAT1 was knocked down, while other genes associated with mesenchymal to epithelial transition (vimentin, cytokeratin-18, and Twist) did not show any changes. By contrast, both N-cadherin and β-catenin were significantly reduced. When MDA-MB-231 cells expressing shRNA were injected in vivo into BALB/c nu/nu nude mice, a significant reduction in the number of colonies that formed in the lungs was observed. Taken together, the results show that NAT1 can alter the invasion and metastatic properties of some triple-negative breast cancer cells but not all. The study suggests that NAT1 may be a novel therapeutic target in a subset of breast cancers. PMID:25627111

Effects of human arylamine N-acetyltransferase I knockdown in triple-negative breast cancer cell lines.

PubMed

Tiang, Jacky M; Butcher, Neville J; Minchin, Rodney F

2015-04-01

Expression of human arylamine N-acetyltransferase I (NAT1) has been associated with various cancer subtypes and inhibition of this enzyme with small molecule inhibitors or siRNA affects cell growth and survival. Here, we have investigated the role of NAT1 in the invasiveness of breast cancer cells both in vitro and in vivo. We knocked down NAT1 using a lentivirus-based shRNA approach and observed marked changes in cell morphology in the triple-negative breast cancer cell lines MDA-MB-231, MDA-MB-436, and BT-549. Most notable was a reduction in the number and size of the filopodia protrusions on the surface of the cells. The loss of filopodia could be rescued by the reintroduction of NAT1 into the knockdown cells. NAT1 expression was localized to the lamellipodia and extended into the filopodia protrusions. In vitro invasion through Geltrex was significantly inhibited in both the MDA cell lines but not in the BT-549 cells. The expression of Snail increased when NAT1 was knocked down, while other genes associated with mesenchymal to epithelial transition (vimentin, cytokeratin-18, and Twist) did not show any changes. By contrast, both N-cadherin and β-catenin were significantly reduced. When MDA-MB-231 cells expressing shRNA were injected in vivo into BALB/c nu/nu nude mice, a significant reduction in the number of colonies that formed in the lungs was observed. Taken together, the results show that NAT1 can alter the invasion and metastatic properties of some triple-negative breast cancer cells but not all. The study suggests that NAT1 may be a novel therapeutic target in a subset of breast cancers. © 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Brachial artery endothelial function is stable across a menstrual and oral contraceptive pill cycle, but lower in premenopausal women than age-matched men.

PubMed

Shenouda, Ninette; Priest, Stacey E; Rizzuto, Vanessa I; MacDonald, Maureen J

2018-05-04

Sex hormone concentrations differ between men, premenopausal women with natural menstrual cycles (NAT), and premenopausal women using oral contraceptive pills (OCP), as well as across menstrual or OCP phases. This study sought to investigate how differences in sex hormones, particularly estradiol, between men and women and across cycle phases, may influence brachial artery endothelial function. Fifty-three healthy adults (22{plus minus}3 yrs; 20 men, 15 NAT, 18 second, third or fourth generation OCP) underwent assessments of sex hormones and endothelial (flow-mediated dilation test, FMD) and smooth muscle (nitroglycerin test, NTG) function. Men were tested three times at one-week intervals, and women were tested three times throughout a single menstrual or OCP cycle (NAT: menstrual, mid-follicular, luteal; OCP: placebo/no pill, 'early' and 'late' active pill). Endogenous estradiol concentration was comparable between men and women in their NAT menstrual or OCP placebo phase (p=0.36) but increased throughout a NAT cycle (p<0.001). Allometrically scaled FMD did not change across a NAT or OCP cycle but was lower in both groups of women than men (p=0.005), whereas scaled NTG was lower only in NAT women (p=0.001). Changes in estradiol across a NAT cycle were not associated with changes in relative FMD (r2=0.01, p=0.62) or NTG (r2=0.09, p=0.13). Duration of OCP use was negatively associated with the average relative FMD for second generation OCP users only (r=-0.65, p=0.04). Our findings suggest that brachial endothelial function is unaffected by cyclic hormonal changes in premenopausal women but may be negatively impacted by longer term use of second generation OCPs.

Rapid, Fully Automated Digital Immunoassay for p24 Protein with the Sensitivity of Nucleic Acid Amplification for Detecting Acute HIV Infection.

PubMed

Cabrera, Carlos; Chang, Lei; Stone, Mars; Busch, Michael; Wilson, David H

2015-11-01

Nucleic acid testing (NAT) has become the standard for high sensitivity in detecting low levels of virus. However, adoption of NAT can be cost prohibitive in low-resource settings where access to extreme sensitivity could be clinically advantageous for early detection of infection. We report development and preliminary validation of a simple, low-cost, fully automated digital p24 antigen immunoassay with the sensitivity of quantitative NAT viral load (NAT-VL) methods for detection of acute HIV infection. We developed an investigational 69-min immunoassay for p24 capsid protein for use on a novel digital analyzer on the basis of single-molecule-array technology. We evaluated the assay for sensitivity by dilution of standardized preparations of p24, cultured HIV, and preseroconversion samples. We characterized analytical performance and concordance with 2 NAT-VL methods and 2 contemporary p24 Ag/Ab combination immunoassays with dilutions of viral isolates and samples from the earliest stages of HIV infection. Analytical sensitivity was 0.0025 ng/L p24, equivalent to 60 HIV RNA copies/mL. The limit of quantification was 0.0076 ng/L, and imprecision across 10 runs was <10% for samples as low as 0.09 ng/L. Clinical specificity was 95.1%. Sensitivity concordance vs NAT-VL on dilutions of preseroconversion samples and Group M viral isolates was 100%. The digital immunoassay exhibited >4000-fold greater sensitivity than contemporary immunoassays for p24 and sensitivity equivalent to that of NAT methods for early detection of HIV. The data indicate that NAT-level sensitivity for acute HIV infection is possible with a simple, low-cost digital immunoassay. © 2015 American Association for Clinical Chemistry.

Infectivity of HBV DNA positive donations identified in look-back studies in Hyogo-Prefecture, Japan.

PubMed

Bouike, Y; Imoto, S; Mabuchi, O; Kokubunji, A; Kai, S; Okada, M; Taniguchi, R; Momose, S; Uchida, S; Nishio, H

2011-04-01

To clarify transfusion incidence of hepatitis B virus (HBV) infected blood negative for mini pool-nucleic acid amplification testing (MP-NAT). Japanese Red Cross (JRC) blood centres screen donated blood to avoid contamination with HBV. However, a low copy number of HBV may be overlooked. In Hyogo-Prefecture, JRC blood centres screened 787 695 donations for HBV from April 2005 to March 2009. Of these, 685 844 were donations from the repeat donors. To detect the donors with HBV, serological tests, MP-NAT and/or individual donation (ID)-NAT were performed. To detect the recipients with transfusion-transmitted HBV infection (TTHBI), serological analysis and/or ID-NAT were performed. In this study, 265 of the 685 844 repeat donations were serologically and/or MP-NAT positive for HBV. Their repository samples from the previous donation were examined in a look-back study; 13 of the 265 repository samples proved ID-NAT positive. Twelve recipients were transfused with HBV-infected blood components derived from 10 of the 13 HBV-infected donors. Only 1 of the 12 recipients was identified as TTHBI case. Seven of the 12 recipients escaped from our follow-up study and 4 recipients were negative for HBV during the observation period. On the basis of the look-back study among the repeat donors in Hyogo-Prefecture, Japan, donations with HBV-infected blood negative for MP-NAT occurred with a frequency of 13 in 685 844 donations (∼1/53 000 donations). However, more than half of the recipients transfused with HBV-infected blood negative for MP-NAT could not be followed up. It is necessary to establish a more cautious follow-up system. © 2010 The Authors. Transfusion Medicine © 2010 British Blood Transfusion Society.

N-acetyltransferase 2 (NAT2) gene polymorphism as a predisposing factor for phenytoin intoxication in tuberculous meningitis or tuberculoma patients having seizures - A pilot study

PubMed Central

Adole, Prashant S.; Kharbanda, Parampreet S.; Sharma, Sadhna

2016-01-01

Background & objectives: Simultaneous administration of phenytoin and isoniazid (INH) in tuberculous meningitis (TBM) or tuberculoma patients with seizures results in higher plasma phenytoin level and thus phenytoin intoxication. N-acetyltransferase 2 (NAT2) enzyme catalyses two acetylation reactions in INH metabolism and NAT2 gene polymorphism leads to slow and rapid acetylators. The present study was aimed to evaluate the effect of allelic variants of N-acetyltransferase 2 (NAT2) gene as a predisposing factor for phenytoin toxicity in patients with TBM or tuberculoma having seizures, and taking INH and phenytoin simultaneously. Methods: Sixty patients with TBM or tuberculoma with seizures and taking INH and phenytoin simultaneously for a minimum period of seven days were included in study. Plasma phenytoin was measured by high performance liquid chromatography. NAT2 gene polymorphism was studied using restriction fragment length polymorphism and allele specific PCR. Results: The patients were grouped into those having phenytoin intoxication and those with normal phenytoin level, and also classified as rapid or slow acetylators by NAT2 genotyping. Genotypic analysis showed that of the seven SNPs (single nucleotide polymorphisms) of NAT2 gene studied, six mutations were found to be associated with phenytoin intoxication. For rs1041983 (C282T), rs1799929 (C481T), rs1799931 (G857A), rs1799930 (G590A), rs1208 (A803G) and rs1801280 (T341C) allelic variants, the proportion of homozygous mutant was higher in phenytoin intoxicated group than in phenytoin non-intoxicated group. Interpretation & conclusions: Homozygous mutant allele of NAT2 gene at 481site may act as a predisposing factor for phenytoin intoxication among TBM or tuberculoma patients having seizures. PMID:27488001

Designing Tasks for Math Modeling in College Algebra: A Critical Review

ERIC Educational Resources Information Center

Staats, Susan; Robertson, Douglas

2014-01-01

Over the last decade, the pedagogical approach known as mathematical modeling has received increased interest in college algebra classes in the United States. Math modeling assignments ask students to develop their own problem-solving tools to address non-routine, realistic scenarios. The open-ended quality of modeling activities creates dilemmas…

Cosmology with negative absolute temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vieira, J.P.P.; Byrnes, Christian T.; Lewis, Antony, E-mail: J.Pinto-Vieira@sussex.ac.uk, E-mail: ctb22@sussex.ac.uk, E-mail: antony@cosmologist.info

Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion ( w < -1) with no Big Rip, and their contractingmore » counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.« less

Arylamine N-acetyltransferase 2 genotype-dependent N-acetylation of isoniazid in cryopreserved human hepatocytes.

PubMed

Doll, Mark A; Salazar-González, Raúl A; Bodduluri, Srineil; Hein, David W

2017-07-01

Cryopreserved human hepatocytes were used to investigate the role of arylamine N -acetyltransferase 2 (NAT2; EC 2.3.1.5) polymorphism on the N -acetylation of isoniazid (INH). NAT2 genotype was determined by Taqman allelic discrimination assay and INH N -acetylation was measured by high performance liquid chromatography. INH N -acetylation rates in vitro exhibited a robust and highly significant ( P <0.005) NAT2 phenotype-dependent metabolism. N -acetylation rates in situ were INH concentration- and time-dependent. Following incubation for 24 h with 12.5 or 100 µmol/L INH, acetyl-INH concentrations varied significantly ( P = 0.0023 and P = 0.0002) across cryopreserved human hepatocytes samples from rapid, intermediate, and slow acetylators, respectively. The clear association between NAT2 genotype and phenotype supports use of NAT2 genotype to guide INH dosing strategies in the treatment and prevention of tuberculosis.

Excitation functions of nuclear reactions induced by alpha particles up to 42 MeV on natTi for monitoring purposes and TLA

NASA Astrophysics Data System (ADS)

Hermanne, A.; Sonck, M.; Takács, S.; Szelecsényi, F.; Tárkányi, F.

1999-05-01

Excitation functions for the reactions induced by alpha particles on natTi foils and leading to the formation of 44m,44g,46,47,48Sc; 48,51Cr and 48V were determined using the stacked foil technique for energies from the respective reaction thresholds up to 42 MeV. The new experimental values are compared to earlier literature values and generally good accordance is found. It appears that the natTi(α,x) 51Cr reaction is particularly useful for monitoring α-beams in the 10-20 MeV region while for energies above 20 MeV the natTi(α,x) 47Sc reaction or the natTi(α,x) 48V reaction are more suited. The excitation functions established can be used to determine calibration curves for thin layer activation (TLA) as well.

Payload test philosophy. [to provide confidence in Shuttle structural math models

NASA Technical Reports Server (NTRS)

Mayhew, D.

1979-01-01

Shuttle payload test philosophy is discussed with reference to testing to provide confidence in Shuttle structural math models. Particular attention is given the Shuttle quarter-scale program and the Mated Vertical Ground Vibration Test Program.

Young-age gender differences in mathematics mediated by independent control or uncontrollability.

PubMed

Zirk-Sadowski, Jan; Lamptey, Charlotte; Devine, Amy; Haggard, Mark; Szűcs, Dénes

2014-05-01

We studied whether the origins of math anxiety can be related to a biologically supported framework of stress induction: (un)controllability perception, here indicated by self-reported independent efforts in mathematics. Math anxiety was tested in 182 children (8- to 11-year-olds). Latent factor modeling was used to test hypotheses on plausible causal processes and mediations within competing models in quasi-experimental contrasts. Uncontrollability perception in mathematics, or (in)dependence of efforts, best fit the data as an antecedent of math anxiety. In addition, the relationship of math anxiety with gender was fully mediated by adaptive perception of control (i.e. controllability). That is, young boys differ from girls in terms of their experience of control in mathematics learning. These differences influence math anxiety. Our findings are consistent with recent suggestions in clinical literature according to which uncontrollability makes women more susceptible to fear and anxiety disorders. © 2014 John Wiley & Sons Ltd.

Mathematical Modeling: Are Prior Experiences Important?

ERIC Educational Resources Information Center

Czocher, Jennifer A.; Moss, Diana L.

2017-01-01

Why are math modeling problems the source of such frustration for students and teachers? The conceptual understanding that students have when engaging with a math modeling problem varies greatly. They need opportunities to make their own assumptions and design the mathematics to fit these assumptions (CCSSI 2010). Making these assumptions is part…

Designing Networks that are Capable of Self-Healing and Adapting

DTIC Science & Technology

2017-04-01

Undergrad. Res. Fellowship, visiting from Caltech. Undergraduate Eugene Park Math Duke Models of self-healing networks (undergrad. senior thesis...Graduate student Anastasia Deckard Math Duke 3rd/4th year PhD. Wrote software for simulation. Undergraduate Nick Day Math LIMS Summer project at...Harer gave a talk on this DTRA grant to undergraduate math majors at Duke. 11 Q UA D C HA R T Uploaded to the DTRA Basic and Fundamental Research

Excitation functions of the natCr(p,x)44Ti, 56Fe(p,x)44Ti, natNi(p,x)44Ti and 93Nb(p,x)44Ti reactions at energies up to 2.6 GeV

NASA Astrophysics Data System (ADS)

Titarenko, Yu. E.; Batyaev, V. F.; Pavlov, K. V.; Titarenko, A. Yu.; Zhivun, V. M.; Chauzova, M. V.; Balyuk, S. A.; Bebenin, P. V.; Ignatyuk, A. V.; Mashnik, S. G.; Leray, S.; Boudard, A.; David, J. C.; Mancusi, D.; Cugnon, J.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Stankovskiy, A. Yu.

2016-06-01

The paper presents the measured cumulative yields of 44Ti for natCr, 56Fe, natNi and 93Nb samples irradiated by protons at the energy range 0.04-2.6 GeV. The obtained excitation functions are compared with calculations of the well-known codes: ISABEL, Bertini, INCL4.2+ABLA, INCL4.5+ABLA07, PHITS, CASCADE07 and CEM03.02. The predictive power of these codes regarding the studied nuclides is analyzed.

The Neighborhood Auditing Tool: a hybrid interface for auditing the UMLS.

PubMed

Morrey, C Paul; Geller, James; Halper, Michael; Perl, Yehoshua

2009-06-01

The UMLS's integration of more than 100 source vocabularies, not necessarily consistent with one another, causes some inconsistencies. The purpose of auditing the UMLS is to detect such inconsistencies and to suggest how to resolve them while observing the requirement of fully representing the content of each source in the UMLS. A software tool, called the Neighborhood Auditing Tool (NAT), that facilitates UMLS auditing is presented. The NAT supports "neighborhood-based" auditing, where, at any given time, an auditor concentrates on a single-focus concept and one of a variety of neighborhoods of its closely related concepts. Typical diagrammatic displays of concept networks have a number of shortcomings, so the NAT utilizes a hybrid diagram/text interface that features stylized neighborhood views which retain some of the best features of both the diagrammatic layouts and text windows while avoiding the shortcomings. The NAT allows an auditor to display knowledge from both the Metathesaurus (concept) level and the Semantic Network (semantic type) level. Various additional features of the NAT that support the auditing process are described. The usefulness of the NAT is demonstrated through a group of case studies. Its impact is tested with a study involving a select group of auditors.

The Mediating Relation between Symbolic and Nonsymbolic Foundations of Math Competence

PubMed Central

Price, Gavin R.; Fuchs, Lynn S.

2016-01-01

This study investigated the relation between symbolic and nonsymbolic magnitude processing abilities with 2 standardized measures of math competence (WRAT Arithmetic and KeyMath Numeration) in 150 3rd- grade children (mean age 9.01 years). Participants compared sets of dots and pairs of Arabic digits with numerosities 1–9 for relative numerical magnitude. In line with previous studies, performance on both symbolic and nonsymbolic magnitude processing was related to math ability. Performance metrics combining reaction and accuracy, as well as weber fractions, were entered into mediation models with standardized math test scores. Results showed that symbolic magnitude processing ability fully mediates the relation between nonsymbolic magnitude processing and math ability, regardless of the performance metric or standardized test. PMID:26859564

The Mediating Relation between Symbolic and Nonsymbolic Foundations of Math Competence.

PubMed

Price, Gavin R; Fuchs, Lynn S

2016-01-01

This study investigated the relation between symbolic and nonsymbolic magnitude processing abilities with 2 standardized measures of math competence (WRAT Arithmetic and KeyMath Numeration) in 150 3rd-grade children (mean age 9.01 years). Participants compared sets of dots and pairs of Arabic digits with numerosities 1-9 for relative numerical magnitude. In line with previous studies, performance on both symbolic and nonsymbolic magnitude processing was related to math ability. Performance metrics combining reaction and accuracy, as well as weber fractions, were entered into mediation models with standardized math test scores. Results showed that symbolic magnitude processing ability fully mediates the relation between nonsymbolic magnitude processing and math ability, regardless of the performance metric or standardized test.

The decay of hot nuclei formed in La-induced reactions at E/A=45 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Libby, Bruce

1993-01-01

The decay of hot nuclei formed in the reactions 139La + 27Al, 51V, natCu, and 139La were studied by the coincident detection of up to four complex fragments (Z > 3) emitted in these reactions. Fragments were characterized as to their atomic number, energy and in- and out-of-plane angles. The probability of the decay by an event of a given complex fragment multiplicity as a function of excitation energy per nucleon of the source is nearly independent of the system studied. Additionally, there is no large increase in the proportion of multiple fragment events as the excitation energy of themore » source increases past 5 MeV/nucleon. This is at odds with many prompt multifragmentation models of nuclear decay. The reactions 139La + 27Al, 51V, natCu were also studied by combining a dynamical model calculation that simulates the early stages of nuclear reactions with a statistical model calculation for the latter stages of the reactions. For the reaction 139La + 27Al, these calculations reproduced many of the experimental features, but other features were not reproduced. For the reaction 139La + 51V, the calculation failed to reproduce somewhat more of the experimental features. The calculation failed to reproduce any of the experimental features of the reaction 139La + natCu, with the exception of the source velocity distributions.« less

The decay of hot nuclei formed in La-induced reactions at E/A=45 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Libby, B.

1993-01-01

The decay of hot nuclei formed in the reactions [sup 139]La + [sup 27]Al, [sup 51]V, [sup nat]Cu, and [sup 139]La were studied by the coincident detection of up to four complex fragments (Z > 3) emitted in these reactions. Fragments were characterized as to their atomic number, energy and in- and out-of-plane angles. The probability of the decay by an event of a given complex fragment multiplicity as a function of excitation energy per nucleon of the source is nearly independent of the system studied. Additionally, there is no large increase in the proportion of multiple fragment events asmore » the excitation energy of the source increases past 5 MeV/nucleon. This is at odds with many prompt multifragmentation models of nuclear decay. The reactions [sup 139]La + [sup 27]Al, [sup 51]V, [sup nat]Cu were also studied by combining a dynamical model calculation that simulates the early stages of nuclear reactions with a statistical model calculation for the latter stages of the reactions. For the reaction [sup 139]La + [sup 27]Al, these calculations reproduced many of the experimental features, but other features were not reproduced. For the reaction [sup 139]La + [sup 51]V, the calculation failed to reproduce somewhat more of the experimental features. The calculation failed to reproduce any of the experimental features of the reaction [sup 139]La + [sup nat]Cu, with the exception of the source velocity distributions.« less

Measurements of the Total Reaction Cross Sections for 6,8He and 8,9Li Nuclei with Energies of (25-45)A Mev on natAl, natTa and natPb

NASA Astrophysics Data System (ADS)

Erdemchimeg, B.; Artukh, A. G.; Klygin, S. A.; Kononenko, G. A.; Kyslukha, D. A.; Sereda, Yu. M.; Vorontzov, A. N.; Lukyanov, S. M.; Penionzhkevich, Yu. E.; Davaa, S.; Khuukhenkhuu, G.; Borcea, C.; Rotaru, F.; Stanoiu, M.; Martina, L.; Saillant, F.; Raine, B.

2015-06-01

The total nuclear reaction cross sections (σR) measurements have long been of interest since they tell us about the radii and transparency of these nuclei and give clues to understanding of their structure. For studies of unstable nuclei, in particular the physical properties of halo nuclei and the neutron skin thickness, it is valuable to know not only the root-mean-square radii (rms) but it is important to know the details of nucleusnucleus potentials. Our goal was to study total reaction cross sections (σR) by a direct measurement technique (the so-called beam attenuation or transmission method) which allows to extract model independent information. The interaction radii for 6He, 8,9Li were extracted, which are in agreement with the previous measurement at the similar energies (about a few tens of AMeV) Our results show a tendency of increasing radii as function of mass of the secondary targets.

Multivariate Latent Change Modeling of Developmental Decline in Academic Intrinsic Math Motivation and Achievement: Childhood through Adolescence

ERIC Educational Resources Information Center

Gottfried, Adele Eskeles; Marcoulides, George A.; Gottfried, Allen W.; Oliver, Pamella H.; Guerin, Diana Wright

2007-01-01

Research has established that academic intrinsic motivation, enjoyment of school learning without receipt of external rewards, significantly declines across childhood through adolescence. Math intrinsic motivation evidences the most severe decline compared with other subject areas. This study addresses this developmental decline in math intrinsic…

Assessing Impacts of "Math in Focus," a "Singapore Math" Program

ERIC Educational Resources Information Center

Jaciw, Andrew P.; Hegseth, Whitney Michelle; Lin, Li; Toby, Megan; Newman, Denis; Ma, Boya; Zacamy, Jenna

2016-01-01

This study investigates, through a cluster randomized trial, the impact of "Math in Focus," a core mathematics program modeled after instructional approaches used in Singapore, on third- through fifth-grade students' achievement in mathematics. The program is currently being used in more than 400 school districts in the United States.…

Applied Math. Course Materials: Math 111, 112, 113. Seattle Tech Prep Applied Academics Project.

ERIC Educational Resources Information Center

South Seattle Community Coll., Washington.

This publication contains materials for three courses in Applied Math in the Applied Academics program at South Seattle Community College. It begins with the article, "Community College Applied Academics: The State of the Art?" (George B. Neff), which describes the characteristics, model, courses, and coordination activity that make up…

Evaluation of the Procleix Ultrio Elite Assay and the Panther-System for Individual NAT Screening of Blood, Hematopoietic Stem Cell, Tissue and Organ Donors

PubMed Central

Heim, Albert

2016-01-01

Summary Background The performance of the multiplex Procleix Ultrio Elite assay as individual donor nucleic acid test (ID-NAT) for the detection of HIV-1, HIV-2, HCV, and HBV was evaluated in a retrospective, single center study. Methods ID-NAT results of 21,181 blood donors, 984 tissue donors, 293 hematopoietic stem cell donors and 4 organ donors were reviewed in synopsis with results of serological screening and additional discriminatory and repetitive NAT in case of positive donors. Results Specificity of the initial Procleix Ultrio Elite assay was 99.98% and after discriminatory testing 100.00%. Initially invalid results were observed in 75 of 21,181 blood donors (0.35%) but 16 of 984 tissue donors (1.62%, p < 0.001) which included non-heart-beating (‘cadaveric’) donors. All these had valid negative ID-NAT results after repeated testing or testing of 1:5 diluted specimens in case of tissue donors. Occult hepatitis B (defined here as HBV DNAemia without HBsAg detection) was demonstrated by ID-NAT in two anti-HBc-positive tissue donors and suspected in two other tissue donors, where a definite diagnosis was not achieved due to the insufficient sample volumes available. Conclusion The Procleix Ultrio Elite assay proved to be specific, robust and rapid. Therefore, routine ID-NAT may also be feasible for organ and granulocyte donors. PMID:27403089

Role for human arylamine N-acetyltransferase 1 in the methionine salvage pathway.

PubMed

Witham, Katey L; Minchin, Rodney F; Butcher, Neville J

2017-02-01

The Phase II drug metabolizing enzyme arylamine N-acetyltransferase 1 (NAT1) has been implicated in the growth and survival of cancer cells, although the mechanisms that underlies these effects are unknown. Here, a focused metabolomics approach was used to identify changes in folate catabolism as well as the S-adenosylmethionine (SAM) cycle following NAT1 knockdown with shRNA. Although acetylation of the folate catabolite p-aminobenzoylglutamate (pABG) was significantly decreased, there were no changes in intracellular pABG or the various components of the SAM cycle. By contrast, the flux of homocysteine in the medium was different following NAT1 knockdown after the methionine content was exhausted suggesting a need for this metabolite in methionine synthesis. Analysis of the growth of various cancer cells in methylthioadenosine-supplemented medium showed that NAT1 knockdown inhibited the methionine salvage pathway in HT-29 cells but not in HeLa or MDA-MB-436 cells. The cause of this was a low level of expression of the isomerase MRI-1 in the HT-29 cells. Knocking down both NAT1 and MRI-1 in HeLa cells with siRNA further demonstrated a redundancy between these 2 enzymes, although direct isomerase activity by NAT1 could not be demonstrated. The present study has identified a novel endogenous role for human NAT1 that might explain some of its effects in cancer cell growth and survival. Copyright © 2016 Elsevier Inc. All rights reserved.

Solid-state NMR study of various mono- and divalent cation forms of the natural zeolite natrolite.

PubMed

Park, Min Bum; Vicente, Aurélie; Fernandez, Christian; Hong, Suk Bong

2013-05-28

Here we present the one-dimensional (29)Si and (27)Al MAS NMR and two-dimensional (27)Al MQMAS and DQF-STMAS NMR spectra of the monovalent (Na(+), K(+), Rb(+), Cs(+) and NH4(+)) and divalent (Ca(2+), Sr(2+) and Ba(2+)) cation forms of the natural zeolite natrolite (framework type NAT) with complete Si-Al ordering over the crystallographically distinct tetrahedral sites and with the same hydration state (hydrated, partially dehydrated or fully dehydrated). In the case of monovalent cation-exchanged natrolites, the differences in their crystal symmetry evidenced by (29)Si MAS NMR were found to be in good agreement with those determined by crystallographic analyses. However, (27)Al DQF-STMAS NMR spectroscopy shows the presence of two distinct Al sites in dehydrated K-NAT, Rb-NAT and NH4-NAT, suggesting that their actual crystal symmetry is lower than the reported one (i.e., orthorhombic Fdd2). The MAS NMR results also show that the space group of hydrated Ca-NAT is lower than that (monoclinic F1d1) of hydrated scolecite, the natural calcium counterpart of natrolite, which is also the case with hydrated Sr-NAT and Ba-NAT. We believe that the unexpected diversity in the crystal symmetry of natrolite caused by exchange of various mono- and divalent ions, as well as by dehydration, may be inherently due to the high framework flexibility of this natural zeolite.

SP-100 GES/NAT radiation shielding systems design and development testing

NASA Astrophysics Data System (ADS)

Disney, Richard K.; Kulikowski, Henry D.; McGinnis, Cynthia A.; Reese, James C.; Thomas, Kevin; Wiltshire, Frank

1991-01-01

Advanced Energy Systems (AES) of Westinghouse Electric Corporation is under subcontract to the General Electric Company to supply nuclear radiation shielding components for the SP-100 Ground Engineering System (GES) Nuclear Assembly Test to be conducted at Westinghouse Hanford Company at Richland, Washington. The radiation shielding components are integral to the Nuclear Assembly Test (NAT) assembly and include prototypic and non-prototypic radiation shielding components which provide prototypic test conditions for the SP-100 reactor subsystem and reactor control subsystem components during the GES/NAT operations. W-AES is designing three radiation shield components for the NAT assembly; a prototypic Generic Flight System (GFS) shield, the Lower Internal Facility Shield (LIFS), and the Upper Internal Facility Shield (UIFS). This paper describes the design approach and development testing to support the design, fabrication, and assembly of these three shield components for use within the vacuum vessel of the GES/NAT. The GES/NAT shields must be designed to operate in a high vacuum which simulates space operations. The GFS shield and LIFS must provide prototypic radiation/thermal environments and mechanical interfaces for reactor system components. The NAT shields, in combination with the test facility shielding, must provide adequate radiation attenuation for overall test operations. Special design considerations account for the ground test facility effects on the prototypic GFS shield. Validation of the GFS shield design and performance will be based on detailed Monte Carlo analyses and developmental testing of design features. Full scale prototype testing of the shield subsystems is not planned.

West Nile virus blood transfusion-related infection despite nucleic acid testing.

PubMed

Macedo de Oliveira, Alexandre; Beecham, Brady D; Montgomery, Susan P; Lanciotti, Robert S; Linnen, Jeffrey M; Giachetti, Cristina; Pietrelli, Larry A; Stramer, Susan L; Safranek, Thomas J

2004-12-01

A case of West Nile virus (WNV) encephalitis associated with transfusion of blood that did not react when tested for WNV by minipool (MP) nucleic acid testing (NAT) is described. A Nebraska man developed clinical encephalitis 13 days after surgery and transfusion of 26 blood components. Antibody testing confirmed WNV infection. An investigation was initiated to determine the source of this infection. The patient's family members were interviewed to identify risk factors for WNV infection. Residual samples were retested for WNV RNA using transcription-mediated amplification (TMA) assay and two polymerase chain reaction (PCR) assays. Blood donors' follow-up serum samples were collected. All samples were tested for WNV-specific immunoglobulin M antibodies. The patient's family denied recent mosquito exposure. The 20 blood components collected after July 2003 did not react when tested for WNV in a six-member MP-NAT at the time of donation. Retrospective individual testing identified one sample as WNV-reactive by the TMA assay and one of the PCR assays. Seroconversion was demonstrated in the donor associated with this sample. WNV RNA detection by individual donation NAT demonstrates viremic blood escaping MP-NAT and supports transfusion-related WNV transmission. MP-NAT may not detect all WNV-infected blood donors, allowing WNV transmission to continue at low levels. WNV NAT assays might vary in sensitivity and pooling donations could further impact test performance. Understanding MP NAT limitations can improve strategies to maintain safety of the blood supply in the United States.

Predicting first-grade mathematics achievement: the contributions of domain-general cognitive abilities, nonverbal number sense, and early number competence.

PubMed

Hornung, Caroline; Schiltz, Christine; Brunner, Martin; Martin, Romain

2014-01-01

Early number competence, grounded in number-specific and domain-general cognitive abilities, is theorized to lay the foundation for later math achievement. Few longitudinal studies have tested a comprehensive model for early math development. Using structural equation modeling and mediation analyses, the present work examined the influence of kindergarteners' nonverbal number sense and domain-general abilities (i.e., working memory, fluid intelligence, and receptive vocabulary) and their early number competence (i.e., symbolic number skills) on first grade math achievement (i.e., arithmetic, shape and space skills, and number line estimation) assessed 1 year later. Latent regression models revealed that nonverbal number sense and working memory are central building blocks for developing early number competence in kindergarten and that early number competence is key for first grade math achievement. After controlling for early number competence, fluid intelligence significantly predicted arithmetic and number line estimation while receptive vocabulary significantly predicted shape and space skills. In sum we suggest that early math achievement draws on different constellations of number-specific and domain-general mechanisms.

Predicting first-grade mathematics achievement: the contributions of domain-general cognitive abilities, nonverbal number sense, and early number competence

PubMed Central

Hornung, Caroline; Schiltz, Christine; Brunner, Martin; Martin, Romain

2014-01-01

Early number competence, grounded in number-specific and domain-general cognitive abilities, is theorized to lay the foundation for later math achievement. Few longitudinal studies have tested a comprehensive model for early math development. Using structural equation modeling and mediation analyses, the present work examined the influence of kindergarteners' nonverbal number sense and domain-general abilities (i.e., working memory, fluid intelligence, and receptive vocabulary) and their early number competence (i.e., symbolic number skills) on first grade math achievement (i.e., arithmetic, shape and space skills, and number line estimation) assessed 1 year later. Latent regression models revealed that nonverbal number sense and working memory are central building blocks for developing early number competence in kindergarten and that early number competence is key for first grade math achievement. After controlling for early number competence, fluid intelligence significantly predicted arithmetic and number line estimation while receptive vocabulary significantly predicted shape and space skills. In sum we suggest that early math achievement draws on different constellations of number-specific and domain-general mechanisms. PMID:24772098

Motivated Forgetting in Early Mathematics: A Proof-of-Concept Study

PubMed Central

Ramirez, Gerardo

2017-01-01

Educators assume that students are motivated to retain what they are taught. Yet, students commonly report that they forget most of what they learn, especially in mathematics. In the current study I ask whether students may be motivated to forget mathematics because of academic experiences threaten the self-perceptions they are committed to maintaining. Using a large dataset of 1st and 2nd grade children (N = 812), I hypothesize that math anxiety creates negative experiences in the classroom that threaten children’s positive math self-perceptions, which in turn spurs a motivation to forget mathematics. I argue that this motivation to forget is activated during the winter break, which in turn reduces the extent to which children grow in achievement across the school year. Children were assessed for math self-perceptions, math anxiety and math achievement in the fall before going into winter break. During the spring, children’s math achievement was measured once again. A math achievement growth score was devised from a regression model of fall math achievement predicting spring achievement. Results show that children with higher math self-perceptions showed reduced growth in math achievement across the school year as a function of math anxiety. Children with lower math interest self-perceptions did not show this relationship. Results serve as a proof-of-concept for a scientific account of motivated forgetting within the context of education. PMID:29255439

Motivated Forgetting in Early Mathematics: A Proof-of-Concept Study.

PubMed

Ramirez, Gerardo

2017-01-01

Educators assume that students are motivated to retain what they are taught. Yet, students commonly report that they forget most of what they learn, especially in mathematics. In the current study I ask whether students may be motivated to forget mathematics because of academic experiences threaten the self-perceptions they are committed to maintaining. Using a large dataset of 1st and 2nd grade children ( N = 812), I hypothesize that math anxiety creates negative experiences in the classroom that threaten children's positive math self-perceptions, which in turn spurs a motivation to forget mathematics. I argue that this motivation to forget is activated during the winter break, which in turn reduces the extent to which children grow in achievement across the school year. Children were assessed for math self-perceptions, math anxiety and math achievement in the fall before going into winter break. During the spring, children's math achievement was measured once again. A math achievement growth score was devised from a regression model of fall math achievement predicting spring achievement. Results show that children with higher math self-perceptions showed reduced growth in math achievement across the school year as a function of math anxiety. Children with lower math interest self-perceptions did not show this relationship. Results serve as a proof-of-concept for a scientific account of motivated forgetting within the context of education.

Locomotor Stability in a Model Swimmer: Coupling Fluid Dynamics, Neurophysiology and Muscle Mechanics

DTIC Science & Technology

2017-07-05

springs which resist deformation. (C) Inset that shows the position of the muscle segments. Cohen, Holmes, Rand, J. Math Biol. 1982 A representative...numbers are the segment number, labeled from head to tail. Cohen, Holmes, Rand, J. Math Biol. 1982 The signals are periodic. Cohen, Holmes, Rand, J... Math Biol. 1982 From head to tail there is a phase lag on each side. Cohen, Holmes, Rand, J. Math Biol. 1982 On a given segment, the signals are in

Math Model for Naval Ship Handling Trainer.

ERIC Educational Resources Information Center

Golovcsenko, Igor V.

The report describes the math model for an experimental ship handling trainer. The training task is that of a replenishment operation at sea. The model includes equations for ship dynamics of a destroyer, propeller-engine response times, ship separation, interaction effects between supply ship and destroyer, and outputs to a visual display system.…

Space shuttle plume simulation application. Results and math model. [Ames unitary plan wind tunnel test

NASA Technical Reports Server (NTRS)

Boyle, W.; Conine, B.

1978-01-01

Pressure and gauge wind tunnel data from a transonic test of a 0.02 scale model of the space shuttle launch vehicle was analyzed to define the aerodynamic influence of the main propulsion system and solid rocket booster plumes during the transonic portion of ascent flight. Air was used as a simulant gas to develop the model exhaust plumes. A math model of the plume induced aerodynamic characteristics was developed for a range of Mach numbers to match the forebody aerodynamic math model. The base aerodynamic characteristics are presented in terms of forces and moments versus attitude. Total vehicle base and forebody aerodynamic characteristics are presented in terms of aerodynamic coefficients for Mach number from 0.6 to 1.4 Element and component base and forebody aerodynamic characteristics are presented for Mach numbers of 0.6, 1.05, 1.1, 1.25 and 1.4. The forebody data is available at Mach 1.55. Tolerances for all plume induced aerodynamic characteristics are developed in terms of a math model.

Optimal Transport, Convection, Magnetic Relaxation and Generalized Boussinesq Equations

NASA Astrophysics Data System (ADS)

Brenier, Yann

2009-10-01

We establish a connection between optimal transport theory (see Villani in Topics in optimal transportation. Graduate studies in mathematics, vol. 58, AMS, Providence, 2003, for instance) and classical convection theory for geophysical flows (Pedlosky, in Geophysical fluid dynamics, Springer, New York, 1979). Our starting point is the model designed few years ago by Angenent, Haker, and Tannenbaum (SIAM J. Math. Anal. 35:61-97, 2003) to solve some optimal transport problems. This model can be seen as a generalization of the Darcy-Boussinesq equations, which is a degenerate version of the Navier-Stokes-Boussinesq (NSB) equations. In a unified framework, we relate different variants of the NSB equations (in particular what we call the generalized hydrostatic-Boussinesq equations) to various models involving optimal transport (and the related Monge-Ampère equation, Brenier in Commun. Pure Appl. Math. 64:375-417, 1991; Caffarelli in Commun. Pure Appl. Math. 45:1141-1151, 1992). This includes the 2D semi-geostrophic equations (Hoskins in Annual review of fluid mechanics, vol. 14, pp. 131-151, Palo Alto, 1982; Cullen et al. in SIAM J. Appl. Math. 51:20-31, 1991, Arch. Ration. Mech. Anal. 185:341-363, 2007; Benamou and Brenier in SIAM J. Appl. Math. 58:1450-1461, 1998; Loeper in SIAM J. Math. Anal. 38:795-823, 2006) and some fully nonlinear versions of the so-called high-field limit of the Vlasov-Poisson system (Nieto et al. in Arch. Ration. Mech. Anal. 158:29-59, 2001) and of the Keller-Segel for Chemotaxis (Keller and Segel in J. Theor. Biol. 30:225-234, 1971; Jäger and Luckhaus in Trans. Am. Math. Soc. 329:819-824, 1992; Chalub et al. in Mon. Math. 142:123-141, 2004). Mathematically speaking, we establish some existence theorems for local smooth, global smooth or global weak solutions of the different models. We also justify that the inertia terms can be rigorously neglected under appropriate scaling assumptions in the generalized Navier-Stokes-Boussinesq equations. Finally, we show how a “stringy” generalization of the AHT model can be related to the magnetic relaxation model studied by Arnold and Moffatt to obtain stationary solutions of the Euler equations with prescribed topology (see Arnold and Khesin in Topological methods in hydrodynamics. Applied mathematical sciences, vol. 125, Springer, Berlin, 1998; Moffatt in J. Fluid Mech. 159:359-378, 1985, Topological aspects of the dynamics of fluids and plasmas. NATO adv. sci. inst. ser. E, appl. sci., vol. 218, Kluwer, Dordrecht, 1992; Schonbek in Theory of the Navier-Stokes equations, Ser. adv. math. appl. sci., vol. 47, pp. 179-184, World Sci., Singapore, 1998; Vladimirov et al. in J. Fluid Mech. 390:127-150, 1999; Nishiyama in Bull. Inst. Math. Acad. Sin. (N.S.) 2:139-154, 2007).

Novel association between the nonsynonymous A803G polymorphism of the N-acetyltransferase 2 gene and impaired glucose homeostasis in obese children and adolescents.

PubMed

Marzuillo, Pierluigi; Di Sessa, Anna; Umano, Giuseppina Rosaria; Nunziata, Luigia; Cirillo, Grazia; Perrone, Laura; Miraglia Del Giudice, Emanuele; Grandone, Anna

2017-09-01

The N-acetyltransferase 2 ( NAT2 ) A803G polymorphism has been associated with decreased insulin sensitivity in a large adult population with the A allele associated with insulin-resistance-related traits. Evaluate the association of this polymorphism with anthropometric and metabolic parameters in obese children and adolescents. A total of 748 obese children and adolescents were enrolled. Anthropometric and laboratory data were collected. During oral glucose tolerance test, the presence of a possible exaggerated plasma glucose excursion at 1 h (1HPG) or impaired glucose tolerance (IGT) was considered. Homeostasis model assessment, oral disposition index (oDI) and insulinogenic index (IDI) were calculated. Patients were genotyped for the NAT2 A803G polymorphism. The prevalence of both IGT and elevated-1HPG was higher in children carrying the A803 allele (P = .02 and P = .03). Moreover, this allele was associated with both oDI and IGI reduction (P = .01). No differences among the NAT2 A803G genotypes for the other parameters were shown. Children homozygous for the A allele presented an odds ratio (OR), to show IGT of 4.9 (P = .01). Children both homozygous and heterozygous for the A allele had higher risk to show elevated-1HPG (OR of 2.7, P = .005; and OR = 2.3, P = .005) compared with patients homozygous for the NAT2 803G allele. NAT2 A803 allele seems to play a role in worsening the destiny of obese children carrying it, predisposing them to elevated-1HPG and IGT and then to a possible future type 2 diabetes mellitus throughout an impairment of pancreatic β-cellular insulin secretion as suggested by oDI and IGI reduction. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of Single Nucleotide Polymorphisms in Cytochrome P450 Isoenzyme and N-Acetyltransferase 2 Genes on the Metabolism of Artemisinin-Based Combination Therapies in Malaria Patients from Cambodia and Tanzania

PubMed Central

Staehli Hodel, Eva Maria; Csajka, Chantal; Ariey, Frédéric; Guidi, Monia; Kabanywanyi, Abdunoor Mulokozi; Duong, Socheat; Decosterd, Laurent Arthur; Olliaro, Piero; Genton, Blaise

2013-01-01

The pharmacogenetics of antimalarial agents are poorly known, although the application of pharmacogenetics might be critical in optimizing treatment. This population pharmacokinetic-pharmacogenetic study aimed at assessing the effects of single nucleotide polymorphisms (SNPs) in cytochrome P450 isoenzyme genes (CYP, namely, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5) and the N-acetyltransferase 2 gene (NAT2) on the pharmacokinetics of artemisinin-based combination therapies in 150 Tanzanian patients treated with artemether-lumefantrine, 64 Cambodian patients treated with artesunate-mefloquine, and 61 Cambodian patients treated with dihydroartemisinin-piperaquine. The frequency of SNPs varied with the enzyme and the population. Higher frequencies of mutant alleles were found in Cambodians than Tanzanians for CYP2C9*3, CYP2D6*10 (100C→T), CYP3A5*3, NAT2*6, and NAT2*7. In contrast, higher frequencies of mutant alleles were found in Tanzanians for CYP2D6*17 (1023C→T and 2850C→T), CYP3A4*1B, NAT2*5, and NAT2*14. For 8 SNPs, no significant differences in frequencies were observed. In the genetic-based population pharmacokinetic analyses, none of the SNPs improved model fit. This suggests that pharmacogenetic data need not be included in appropriate first-line treatments with the current artemisinin derivatives and quinolines for uncomplicated malaria in specific populations. However, it cannot be ruled out that our results represent isolated findings, and therefore more studies in different populations, ideally with the same artemisinin-based combination therapies, are needed to evaluate the influence of pharmacogenetic factors on the clearance of antimalarials. PMID:23229480

Visitor vehicle emissions study : Yosemite National Park

DOT National Transportation Integrated Search

2005-01-01

The U.S. Department of Transportation, John A. Volpe National Transportation Systems Center (Volpe Center), Environmental Measurement and Modeling Division (Volpe Center), provided technical support to the : National Parks Foundation as part of a Nat...

Visitor vehicle emissions study : Joshua Tree National Park

DOT National Transportation Integrated Search

2005-01-01

The U.S. Department of Transportation, John A. Volpe National Transportation Systems Center (Volpe Center), Environmental Measurement and Modeling Division (Volpe Center), provided technical support to the : National Parks Foundation as part of a Nat...

Visitor vehicle emissions study : Pt. Reyes National Seashore

DOT National Transportation Integrated Search

2005-01-01

The U.S. Department of Transportation, John A. Volpe National Transportation Systems Center (Volpe Center), Environmental Measurement and Modeling Division (Volpe Center), provided technical support to the : National Parks Foundation as part of a Nat...

The influence of math anxiety on symbolic and non-symbolic magnitude processing.

PubMed

Dietrich, Julia F; Huber, Stefan; Moeller, Korbinian; Klein, Elise

2015-01-01

Deficits in basic numerical abilities have been investigated repeatedly as potential risk factors of math anxiety. Previous research suggested that also a deficient approximate number system (ANS), which is discussed as being the foundation for later math abilities, underlies math anxiety. However, these studies examined this hypothesis by investigating ANS acuity using a symbolic number comparison task. Recent evidence questions the view that ANS acuity can be assessed using a symbolic number comparison task. To investigate whether there is an association between math anxiety and ANS acuity, we employed both a symbolic number comparison task and a non-symbolic dot comparison task, which is currently the standard task to assess ANS acuity. We replicated previous findings regarding the association between math anxiety and the symbolic distance effect for response times. High math anxious individuals showed a larger distance effect than less math anxious individuals. However, our results revealed no association between math anxiety and ANS acuity assessed using a non-symbolic dot comparison task. Thus, our results did not provide evidence for the hypothesis that a deficient ANS underlies math anxiety. Therefore, we propose that a deficient ANS does not constitute a risk factor for the development of math anxiety. Moreover, our results suggest that previous interpretations regarding the interaction of math anxiety and the symbolic distance effect have to be updated. We suggest that impaired number comparison processes in high math anxious individuals might account for the results rather than deficient ANS representations. Finally, impaired number comparison processes might constitute a risk factor for the development of math anxiety. Implications for current models regarding the origins of math anxiety are discussed.

The influence of math anxiety on symbolic and non-symbolic magnitude processing

PubMed Central

Dietrich, Julia F.; Huber, Stefan; Moeller, Korbinian; Klein, Elise

2015-01-01

Deficits in basic numerical abilities have been investigated repeatedly as potential risk factors of math anxiety. Previous research suggested that also a deficient approximate number system (ANS), which is discussed as being the foundation for later math abilities, underlies math anxiety. However, these studies examined this hypothesis by investigating ANS acuity using a symbolic number comparison task. Recent evidence questions the view that ANS acuity can be assessed using a symbolic number comparison task. To investigate whether there is an association between math anxiety and ANS acuity, we employed both a symbolic number comparison task and a non-symbolic dot comparison task, which is currently the standard task to assess ANS acuity. We replicated previous findings regarding the association between math anxiety and the symbolic distance effect for response times. High math anxious individuals showed a larger distance effect than less math anxious individuals. However, our results revealed no association between math anxiety and ANS acuity assessed using a non-symbolic dot comparison task. Thus, our results did not provide evidence for the hypothesis that a deficient ANS underlies math anxiety. Therefore, we propose that a deficient ANS does not constitute a risk factor for the development of math anxiety. Moreover, our results suggest that previous interpretations regarding the interaction of math anxiety and the symbolic distance effect have to be updated. We suggest that impaired number comparison processes in high math anxious individuals might account for the results rather than deficient ANS representations. Finally, impaired number comparison processes might constitute a risk factor for the development of math anxiety. Implications for current models regarding the origins of math anxiety are discussed. PMID:26579012

Mission Engineering Competencies Technical Report

DTIC Science & Technology

2018-04-30

generate a mission capability. Note that foundational skills – e.g. math , natural or social sciences, general engineering skills - are not listed in...basic understanding of math , sciences, and the fundamentals of engineering are assumed, the foundational building block for mission...April 30, 2018 69 The Helix model focuses on 6 proficiency areas (Hutchison et al. 2018): 1. Math /Science/General

Increasing Latino/a Representation in Math and Science: An Insider's Look

ERIC Educational Resources Information Center

Aguirre, Jarrad

2009-01-01

Recent Yale alumnus Jarrad Aguirre relates his experience creating MAS Familias, a campus organization that supports Latino/a undergraduates studying math and science. Alarmed by Latino/a students' academic struggles and the lack of Latino/a role models in the fields of math and science--and increasingly aware of the social benefits of a diverse…

Using a Regression Discontinuity Design to Estimate the Impact of Placement Decisions in Developmental Math

ERIC Educational Resources Information Center

Melguizo, Tatiana; Bos, Johannes M.; Ngo, Federick; Mills, Nicholas; Prather, George

2016-01-01

This study evaluates the effectiveness of math placement policies for entering community college students on these students' academic success in math. We estimate the impact of placement decisions by using a discrete-time survival model within a regression discontinuity framework. The primary conclusion that emerges is that initial placement in a…

Effectiveness of the Touch Math Technique in Teaching Basic Addition to Children with Autism

ERIC Educational Resources Information Center

Yikmis, Ahmet

2016-01-01

This study aims to reveal whether the touch math technique is effective in teaching basic addition to children with autism. The dependent variable of this study is the children's skills to solve addition problems correctly, whereas teaching with the touch math technique is the independent variable. Among the single-subject research models, a…

The National Teacher Training Institute for Math, Science and Technology: Exemplary Practice in a Climate of Higher Standards.

ERIC Educational Resources Information Center

Donlevy, James G., Ed.; Donlevy, Tia Rice, Ed.

1999-01-01

Reviews the NTTI (National Teacher Training Institute) for Math, Science and Technology model that trains teachers to use video and Internet resources to enhance math and science instruction. Discusses multimedia methodology; standards-based training; program impact in schools; and lesson plans available on the NTTI Web site. (Author/LRW)

Genetic polymorphisms of N-acetyltransferase 2 & susceptibility to antituberculosis drug-induced hepatotoxicity.

PubMed

Sharma, Surendra K; Jha, Brajesh Kumar; Sharma, Abhishek; Sreenivas, V; Upadhyay, Vishwanath; Jaisinghani, Chandrita; Singla, Rohit; Mishra, Hemant Kumar; Soneja, Manish

2016-12-01

The N-acetyltransferase 2 (NAT2) gene encodes an enzyme which both activates and deactivates arylamine and other drugs and carcinogens. This study was aimed to investigate the role of NAT2 gene polymorphism in anti-tuberculosis drug-induced hepatotoxicity (DIH). In this prospective study, polymerase chain reaction-restriction fragment length polymorphism results for NAT2 gene were compared between 185 tuberculosis patients who did not develop DIH and 105 tuberculosis patients who developed DIH while on anti-tuberculosis drugs. Frequency of slow-acetylator genotype was commonly encountered and was not significantly different between DIH (82.8%) and non-DIH (77.2%) patients. However, the genotypic distribution of variant NAT2FNx015/FNx017 amongst slow-acetylator genotypes was significantly higher in DIH (56%) group as compared to non-DIH (39%) group (odds ratio 2.02; P=0.006). The present study demonstrated no association between NAT2 genotype and DIH in the north Indian patients with tuberculosis.

Measurement of the natHf(d,x)177Ta cross section and impact of erroneous gamma-ray intensities

NASA Astrophysics Data System (ADS)

Simonelli, F.; Abbas, K.; Bulgheroni, A.; Pommé, S.; Altzitzoglou, T.; Suliman, G.

2012-08-01

In this work, excitation functions for deuteron-induced reactions on natural hafnium have been measured in the energy range 7-17 MeV, using the stacked-foil technique. Particular attention has been paid to the reaction natHf(d,x)177Ta, because reported γ-ray intensities have been found to be in disagreement with previously published data. This discrepancy is due to an error in the 2003 ENSDF absolute γ-ray intensities of 177Hf following the decay of 177Ta, which are about a factor of three higher compared to other available data. As a consquence, some peer reviewed papers reporting on natHf(d,x)177Ta, and also on natHf(p,x) 177Ta and natW(p,x) 177Ta, need to be reviewed. An upcoming re-evaluation of the 177Ta decay data shows new significant changes in the absolute γ-ray intensities, which in turn will affect again the 177Ta producing cross sections.

Is the Grass Always Greener? Comparing the Environmental Impact of Conventional, Natural and Grass-Fed Beef Production Systems.

PubMed

Capper, Judith L

2012-04-10

This study compared the environmental impact of conventional, natural and grass-fed beef production systems. A deterministic model based on the metabolism and nutrient requirements of the beef population was used to quantify resource inputs and waste outputs per 1.0 × 10⁸ kg of hot carcass weight beef in conventional (CON), natural (NAT) and grass-fed (GFD) production systems. Production systems were modeled using characteristic management practices, population dynamics and production data from U.S. beef production systems. Increased productivity (slaughter weight and growth rate) in the CON system reduced the cattle population size required to produce 1.0 × 10⁸ kg of beef compared to the NAT or GFD system. The CON system required 56.3% of the animals, 24.8% of the water, 55.3% of the land and 71.4% of the fossil fuel energy required to produce 1.0 × 10⁸ kg of beef compared to the GFD system. The carbon footprint per 1.0 × 10⁸ kg of beef was lowest in the CON system (15,989 × 10³ t), intermediate in the NAT system (18,772 × 10³ t) and highest in the GFD system (26,785 × 10³ t). The challenge to the U.S beef industry is to communicate differences in system environmental impacts to facilitate informed dietary choice.

Toxicokinetics of novel psychoactive substances: characterization of N-acetyltransferase (NAT) isoenzymes involved in the phase II metabolism of 2C designer drugs.

PubMed

Meyer, Markus R; Robert, Anja; Maurer, Hans H

2014-06-05

The 2,5-dimethoxyphenethylamine-derived designer drugs (so-called "2Cs") recently became of great importance on the illicit drug market as stimulating hallucinogens. They are distributed and consumed as "novel psychoactive substances" (NPS) without any safety testing at the forefront. As previous studies have shown, the 2Cs are mainly metabolized by O-demethylation, N-acetylation, or deamination. Therefore, the aim of this study was to elucidate the role of the recombinant human N-acetyltransferase (NAT) isoforms 1 and 2 in the phase II metabolism of 2Cs. For these studies, cDNA-expressed recombinant human NATs were used and formation of metabolites after incubation was measured using GC-MS. NAT2 could be shown to be the only isoform catalyzing the reaction in vitro, hence it should be the only relevant enzyme for in vivo acetylation. In general, all metabolite formation reactions followed classic Michaelis-Menten kinetics and the affinity to human NAT2 was increasing with the volume of the 4-substituent. In consequence, a slow acetylator phenotype or inhibition of NAT2 could lead to decreased N-acetylation and might lead to an increased risk of side effects caused by these novel psychoactive substances. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Crystal structure of bacillus subtilis YdaF protein : a putative ribosomal N-acetyltransferase.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brunzelle, J. S.; Wu, R.; Korolev, S. V.

2004-12-01

Comparative sequence analysis suggests that the ydaF gene encodes a protein (YdaF) that functions as an N-acetyltransferase, more specifically, a ribosomal N-acetyltransferase. Sequence analysis using basic local alignment search tool (BLAST) suggests that YdaF belongs to a large family of proteins (199 proteins found in 88 unique species of bacteria, archaea, and eukaryotes). YdaF also belongs to the COG1670, which includes the Escherichia coli RimL protein that is known to acetylate ribosomal protein L12. N-acetylation (NAT) has been found in all kingdoms. NAT enzymes catalyze the transfer of an acetyl group from acetyl-CoA (AcCoA) to a primary amino group. Formore » example, NATs can acetylate the N-terminal {alpha}-amino group, the {epsilon}-amino group of lysine residues, aminoglycoside antibiotics, spermine/speridine, or arylalkylamines such as serotonin. The crystal structure of the alleged ribosomal NAT protein, YdaF, from Bacillus subtilis presented here was determined as a part of the Midwest Center for Structural Genomics. The structure maintains the conserved tertiary structure of other known NATs and a high sequence similarity in the presumed AcCoA binding pocket in spite of a very low overall level of sequence identity to other NATs of known structure.« less

The Neighborhood Auditing Tool: A Hybrid Interface for Auditing the UMLS

PubMed Central

Morrey, C. Paul; Geller, James; Halper, Michael; Perl, Yehoshua

2009-01-01

The UMLS’s integration of more than 100 source vocabularies, not necessarily consistent with one another, causes some inconsistencies. The purpose of auditing the UMLS is to detect such inconsistencies and to suggest how to resolve them while observing the requirement of fully representing the content of each source in the UMLS. A software tool, called the Neighborhood Auditing Tool (NAT), that facilitates UMLS auditing is presented. The NAT supports “neighborhood-based” auditing, where, at any given time, an auditor concentrates on a single focus concept and one of a variety of neighborhoods of its closely related concepts. Typical diagrammatic displays of concept networks have a number of shortcomings, so the NAT utilizes a hybrid diagram/text interface that features stylized neighborhood views which retain some of the best features of both the diagrammatic layouts and text windows while avoiding the shortcomings. The NAT allows an auditor to display knowledge from both the Metathesaurus (concept) level and the Semantic Network (semantic type) level. Various additional features of the NAT that support the auditing process are described. The usefulness of the NAT is demonstrated through a group of case studies. Its impact is tested with a study involving a select group of auditors. PMID:19475725

The importance of surgeon involvement in the evaluation of non-accidental trauma patients.

PubMed

Larimer, Emily L; Fallon, Sara C; Westfall, Jaimee; Frost, Mary; Wesson, David E; Naik-Mathuria, Bindi J

2013-06-01

Non-Accidental Trauma (NAT) is a significant cause of childhood morbidity and mortality, causing 50% of trauma-related deaths at our institution. Our purpose was to evaluate the necessity of primary surgical evaluation and admission to the trauma service for children presenting with NAT. We reviewed all NAT patients from 2007-2011. Injury types, demographic data, and hospitalization information were collected. Comparisons to accidental trauma (AT) patients were made using Wilcoxon rank sum and Student's t tests. We identified 267 NAT patients presenting with 473 acute injuries. Injuries in NAT patients were more severe than in AT patients, and Injury Severity Scores, ICU admission rates, and mortality were all significantly (p<0.001) higher. The majority suffered from polytrauma. Multiple areas of injury were seen in patients with closed head injuries (72%), extremity fractures (51%), rib fractures (82%), and abdominal/thoracic trauma (80%). Despite these complex injury patterns, only 56% received surgical consults, resulting in potential delays in diagnosis, as 24% of abdominal CT scans were obtained >12 hours after hospitalization. Given the high incidence of polytrauma in NAT patients, prompt surgical evaluation is necessary to determine the scope of injury. Admission to the trauma service and a thorough tertiary survey should be considered for all patients. Copyright © 2013 Elsevier Inc. All rights reserved.

Non-accidental Trauma Injury Patterns and Outcomes: A Single Institutional Experience.

PubMed

Ward, Austin; Iocono, Joseph A; Brown, Samuel; Ashley, Phillip; Draus, John M

2015-09-01

Non-accidental trauma (NAT) victims account for a significant percentage of our pediatric trauma population. We sought to better understand the injury patterns and outcomes of NAT victims who were treated at our level I pediatric trauma center. Trauma registry data were used to identify NAT victims between January 2008 and December 2012. Demographic data, injury severity, hospital course, and outcomes were evaluated. One hundred and eighty-eight cases of suspected NAT were identified. Children were mostly male and white. The median age was 1.1 years; the median Injury Severity Score was 9. Traumatic brain injuries, lower extremity fractures, and skull fractures were the most common injuries. Twenty-seven per cent required medical procedures; most were performed by orthopedic surgery. Twenty-four per cent required admission to the pediatric intensive care unit. The median length of stay was two days. The mortality rate was 9.6 per cent. We generated a hot spot map of our catchment area and identified areas of our state where NAT occurs at increased rates. NAT victims sustain significant morbidity and mortality. Due to the severity of injuries, pediatric trauma surgeons should be involved in the evaluation and management of these children. Much work is needed to prevent the death and disability incurred by victims of child abuse.

SP-100 GES/NAT radiation shielding systems design and development testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Disney, R.K.; Kulikowski, H.D.; McGinnis, C.A.

1991-01-10

Advanced Energy Systems (AES) of Westinghouse Electric Corporation is under subcontract to the General Electric Company to supply nuclear radiation shielding components for the SP-100 Ground Engineering System (GES) Nuclear Assembly Test to be conducted at Westinghouse Hanford Company at Richland, Washington. The radiation shielding components are integral to the Nuclear Assembly Test (NAT) assembly and include prototypic and non-prototypic radiation shielding components which provide prototypic test conditions for the SP-100 reactor subsystem and reactor control subsystem components during the GES/NAT operations. W-AES is designing three radiation shield components for the NAT assembly; a prototypic Generic Flight System (GFS) shield,more » the Lower Internal Facility Shield (LIFS), and the Upper Internal Facility Shield (UIFS). This paper describes the design approach and development testing to support the design, fabrication, and assembly of these three shield components for use within the vacuum vessel of the GES/NAT. The GES/NAT shields must be designed to operate in a high vacuum which simulates space operations. The GFS shield and LIFS must provide prototypic radiation/thermal environments and mechanical interfaces for reactor system components. The NAT shields, in combination with the test facility shielding, must provide adequate radiation attenuation for overall test operations. Special design considerations account for the ground test facility effects on the prototypic GFS shield. Validation of the GFS shield design and performance will be based on detailed Monte Carlo analyses and developmental testing of design features. Full scale prototype testing of the shield subsystems is not planned.« less

Integrating Quantitative Reasoning into STEM Courses Using an Energy and Environment Context

NASA Astrophysics Data System (ADS)

Myers, J. D.; Lyford, M. E.; Mayes, R. L.

2010-12-01

Many secondary and post-secondary science classes do not integrate math into their curriculum, while math classes commonly teach concepts without meaningful context. Consequently, students lack basic quantitative skills and the ability to apply them in real-world contexts. For the past three years, a Wyoming Department of Education funded Math Science Partnership at the University of Wyoming (UW) has brought together middle and high school science and math teachers to model how math and science can be taught together in a meaningful way. The UW QR-STEM project emphasizes the importance of Quantitative Reasoning (QR) to student success in Science, Technology, Engineering and Mathematics (STEM). To provide a social context, QR-STEM has focused on energy and the environment. In particular, the project has examined how QR and STEM concepts play critical roles in many of the current global challenges of energy and environment. During four 3-day workshops each summer and over several virtual and short face-to-face meetings during the academic year, UW and community college science and math faculty work with math and science teachers from middle and high schools across the state to improve QR instruction in math and science classes. During the summer workshops, faculty from chemistry, physics, earth sciences, biology and math lead sessions to: 1) improve the basic science content knowledge of teachers; 2) improve teacher understanding of math and statistical concepts, 3) model how QR can be taught by engaging teachers in sessions that integrate math and science in an energy and environment context; and 4) focus curricula using Understanding by Design to identify enduring understandings on which to center instructional strategies and assessment. In addition to presenting content, faculty work with teachers as they develop classroom lessons and larger units to be implemented during the school year. Teachers form interdisciplinary groups which often consist of math and science teachers from the same school or district. By jointly developing units focused on energy and environment, math and science curricula can be coordinated during the school year. During development, teams present their curricular ideas for peer-review. Throughout the school year, teachers implement their units and collect pre-post data on student learning. Ultimately, science teachers integrate math into their science courses, and math teachers integrate science content in their math courses. Following implementation, participants share their experiences with their peers and faculty. Of central interest during these presentations are: 1) How did the QR-STEM experience change teacher practices in the classroom?; and 2) How did the modification of their teaching practices impact student learning and their ability to successfully master QR? The UW QR-STEM has worked with Wyoming science and math teachers from across the state over the three year grant period.

NAT2 genotype guided regimen reduces isoniazid-induced liver injury and early treatment failure in the 6-month four-drug standard treatment of tuberculosis: a randomized controlled trial for pharmacogenetics-based therapy.

PubMed

Azuma, Junichi; Ohno, Masako; Kubota, Ryuji; Yokota, Soichiro; Nagai, Takayuki; Tsuyuguchi, Kazunari; Okuda, Yasuhisa; Takashima, Tetsuya; Kamimura, Sayaka; Fujio, Yasushi; Kawase, Ichiro

2013-05-01

This study is a pharmacogenetic clinical trial designed to clarify whether the N-acetyltransferase 2 gene (NAT2) genotype-guided dosing of isoniazid improves the tolerability and efficacy of the 6-month four-drug standard regimen for newly diagnosed pulmonary tuberculosis. In a multicenter, parallel, randomized, and controlled trial with a PROBE design, patients were assigned to either conventional standard treatment (STD-treatment: approx. 5 mg/kg of isoniazid for all) or NAT2 genotype-guided treatment (PGx-treatment: approx. 7.5 mg/kg for patients homozygous for NAT2 4: rapid acetylators; 5 mg/kg, patients heterozygous for NAT2 4: intermediate acetylators; 2.5 mg/kg, patients without NAT2 4: slow acetylators). The primary outcome included incidences of 1) isoniazid-related liver injury (INH-DILI) during the first 8 weeks of therapy, and 2) early treatment failure as indicated by a persistent positive culture or no improvement in chest radiographs at the 8th week. One hundred and seventy-two Japanese patients (slow acetylators, 9.3 %; rapid acetylators, 53.5 %) were enrolled in this trial. In the intention-to-treat (ITT) analysis, INH-DILI occurred in 78 % of the slow acetylators in the STD-treatment, while none of the slow acetylators in the PGx-treatment experienced either INH-DILI or early treatment failure. Among the rapid acetylators, early treatment failure was observed with a significantly lower incidence rate in the PGx-treatment than in the STD-treatment (15.0 % vs. 38 %). Thus, the NAT2 genotype-guided regimen resulted in much lower incidences of unfavorable events, INH-DILI or early treatment failure, than the conventional standard regimen. Our results clearly indicate a great potential of the NAT2 genotype-guided dosing stratification of isoniazid in chemotherapy for tuberculosis.

N-acetyltransferase (nat) Is a Critical Conjunct of Photoperiodism between the Circadian System and Endocrine Axis in Antheraea pernyi

PubMed Central

Bembenek, Jadwiga; Hiragaki, Susumu; Suzuki, Takeshi; Takeda, Makio

2014-01-01

Since its discovery in 1923, the biology of photoperiodism remains a mystery in many ways. We sought the link connecting the circadian system to an endocrine switch, using Antheraea pernyi. PER-, CLK- and CYC-ir were co-expressed in two pairs of dorsolateral neurons of the protocerebrum, suggesting that these are the circadian neurons that also express melatonin-, NAT- and HIOMT-ir. The results suggest that a melatonin pathway is present in the circadian neurons. Melatonin receptor (MT2 or MEL-1B-R)-ir in PTTH-ir neurons juxtaposing clock neurons suggests that melatonin gates PTTH release. RIA showed a melatonin rhythm with a peak four hours after lights off in adult brain both under LD16∶8 (LD) and LD12∶12 (SD), and both the peak and the baseline levels were higher under LD than SD, suggesting a photoperiodic influence. When pupae in diapause were exposed to 10 cycles of LD, or stored at 4°C for 4 months under constant darkness, an increase of NAT activity was observed when PTTH released ecdysone. DNA sequence upstream of nat contained E-boxes to which CYC/CLK could bind, and nat transcription was turned off by clk or cyc dsRNA. dsRNANAT caused dysfunction of photoperiodism. dsRNAPER upregulated nat transcription as anticipated, based on findings in the Drosophila melanogaster circadian system. Transcription of nat, cyc and clk peaked at ZT12. RIA showed that dsRNANAT decreased melatonin while dsRNAPER increased melatonin. Thus nat, a clock controlled gene, is the critical link between the circadian clock and endocrine switch. MT-binding may release PTTH, resulting in termination of diapause. This study thus examined all of the basic functional units from the clock: a photoperiodic counter as an accumulator of mRNANAT, to endocrine switch for photoperiodism in A. pernyi showing this system is self-complete without additional device especially for photoperiodism. PMID:24667367

Arylamine N-Acetyltransferase 2 (NAT2) Genetic Diversity and Traditional Subsistence: A Worldwide Population Survey

PubMed Central

Sabbagh, Audrey; Darlu, Pierre; Crouau-Roy, Brigitte; Poloni, Estella S.

2011-01-01

Arylamine N-acetyltransferase 2 (NAT2) is involved in human physiological responses to a variety of xenobiotic compounds, including common therapeutic drugs and exogenous chemicals present in the diet and the environment. Many questions remain about the evolutionary mechanisms that have led to the high prevalence of slow acetylators in the human species. Evidence from recent surveys of NAT2 gene variation suggests that NAT2 slow-causing variants might have become targets of positive selection as a consequence of the shift in modes of subsistence and lifestyle in human populations in the last 10,000 years. We aimed to test more extensively the hypothesis that slow acetylation prevalence in humans is related to the subsistence strategy adopted by the past populations. To this end, published frequency data on the most relevant genetic variants of NAT2 were collected from 128 population samples (14,679 individuals) representing different subsistence modes and dietary habits, allowing a thorough analysis at both a worldwide and continent scale. A significantly higher prevalence of the slow acetylation phenotype was observed in populations practicing farming (45.4%) and herding (48.2%) as compared to populations mostly relying on hunting and gathering (22.4%) (P = 0.0007). This was closely mirrored by the frequency of the slow 590A variant that was found to occur at a three-fold higher frequency in food producers (25%) as compared to hunter-gatherers (8%). These findings are consistent with the hypothesis that the Neolithic transition to subsistence economies based on agricultural and pastoral resources modified the selective regime affecting the NAT2 acetylation pathway. Furthermore, the vast amount of data collected enabled us to provide a comprehensive and up-to-date description of NAT2 worldwide genetic diversity, thus building up a useful resource of frequency data for further studies interested in epidemiological or anthropological research questions involving NAT2. PMID:21494681

Measuring Math Anxiety (in Spanish) with the Rasch Rating Scale Model.

PubMed

Prieto, Gerardo; Delgado, Ana R

2007-01-01

Two successive studies probed the psychometric properties of a Math Anxiety questionnaire (in Spanish) by means of the Rasch Rating Scale Model. Participants were 411 and 216 Spanish adolescents. Convergent validity was examined by correlating the scale with both the Fennema and Sherman Attitude Scale and a math achievement test. The results show that the scores are psychometrically appropriate, and replicate those reported in meta-analyses: medium-sized negative correlations with achievement and with attitudes toward mathematics, as well as moderate sex-related differences (with girls presenting higher anxiety levels than boys).

A structural equation modeling of executive functions, IQ and mathematical skills in primary students: Differential effects on number production, mental calculus and arithmetical problems.

PubMed

Arán Filippetti, Vanessa; Richaud, María Cristina

2017-10-01

Though the relationship between executive functions (EFs) and mathematical skills has been well documented, little is known about how both EFs and IQ differentially support diverse math domains in primary students. Inconsistency of results may be due to the statistical techniques employed, specifically, if the analysis is conducted with observed variables, i.e., regression analysis, or at the latent level, i.e., structural equation modeling (SEM). The current study explores the contribution of both EFs and IQ in mathematics through an SEM approach. A total of 118 8- to 12-year-olds were administered measures of EFs, crystallized (Gc) and fluid (Gf) intelligence, and math abilities (i.e., number production, mental calculus and arithmetical problem-solving). Confirmatory factor analysis (CFA) offered support for the three-factor solution of EFs: (1) working memory (WM), (2) shifting, and (3) inhibition. Regarding the relationship among EFs, IQ and math abilities, the results of the SEM analysis showed that (i) WM and age predict number production and mental calculus, and (ii) shifting and sex predict arithmetical problem-solving. In all of the SEM models, EFs partially or totally mediated the relationship between IQ, age and math achievement. These results suggest that EFs differentially supports math abilities in primary-school children and is a more significant predictor of math achievement than IQ level.

Multi-criteria comparative evaluation of spallation reaction models

NASA Astrophysics Data System (ADS)

Andrianov, Andrey; Andrianova, Olga; Konobeev, Alexandr; Korovin, Yury; Kuptsov, Ilya

2017-09-01

This paper presents an approach to a comparative evaluation of the predictive ability of spallation reaction models based on widely used, well-proven multiple-criteria decision analysis methods (MAVT/MAUT, AHP, TOPSIS, PROMETHEE) and the results of such a comparison for 17 spallation reaction models in the presence of the interaction of high-energy protons with natPb.

“A Reduced-form Model to Estimate Near-road Air Quality for Communities: the Community Line Source modeling system (C-LINE)”

EPA Science Inventory

The paper presents the Community Line Source (C-LINE) modeling system that estimates toxic air pollutant (air toxics) concentration gradients within 500 meters of busy roadways for community-sized areas on the order of 100 km2. C-LINE accesses publicly available datasets with nat...

Avoidance temperament and social-evaluative threat in college students' math performance: a mediation model of math and test anxiety.

PubMed

Liew, Jeffrey; Lench, Heather C; Kao, Grace; Yeh, Yu-Chen; Kwok, Oi-man

2014-01-01

Standardized testing has become a common form of student evaluation with high stakes, and limited research exists on understanding the roles of students' personality traits and social-evaluative threat on their academic performance. This study examined the roles of avoidance temperament (i.e., fear and behavioral inhibition) and evaluative threat (i.e., fear of failure and being viewed as unintelligent) in standardized math test and course grades in college students. Undergraduate students (N=184) from a large public university were assessed on temperamental fear and behavioral inhibition. They were then given 15 minutes to complete a standardized math test. After the test, students provided data on evaluative threat and their math performance (scores on standardized college entrance exam and average grades in college math courses). Results indicate that avoidance temperament was linked to social-evaluative threat and low standardized math test scores. Furthermore, evaluative threat mediated the influence of avoidance temperament on both types of math performance. Results have educational and clinical implications, particularly for students at risk for test anxiety and underperformance. Interventions targeting emotion regulation and stress management skills may help individuals reduce their math and test anxieties.

An explanatory model of maths achievement:Perceived parental involvement and academic motivation.

PubMed

Rodríguez, Susana; Piñeiro, Isabel; Gómez-Taibo, Mª L; Regueiro, Bibiana; Estévez, Iris; Valle, Antonio

2017-05-01

Although numerous studies have tried to explain performance in maths very few have deeply explored the relationship between different variables and how they jointly explain mathematical performance. With a sample of 897 students in 5th and 6th grade in Primary Education and using structural equation modeling (SEM), this study analyzes how the perception of parents’ beliefs is related to children´s beliefs, their involvement in mathematical tasks and their performance. Perceived parental involvement contributes to the motivation of their children in mathematics. Direct supervision of students’ academic work by parents may increase students’ concerns about the image and rating of their children, but not their academic performance. In fact, maths achievement depends directly and positively on the parents’ expectations and children’s maths self-efficacy and negatively on the parents’ help in tasks and performance goal orientation. Perceived parental involvement contributes to children’s motivation in maths essentially conveying confidence in their abilities and showing interest in their progress and schoolwork.

Family Factors Associated with Sixth-Grade Adolescents' Math and Science Career Interests

ERIC Educational Resources Information Center

Turner, Sherri L.; Steward, Jason C.; Lapan, Richard T.

2004-01-01

This study tested a causal model, based on social cognitive career theory (SCCT; R. W. Lent, S. D. Brown, & G. Hackett, 1994, 2000), of math and science career interests among 6th-grade adolescents (N = 318). Consistent with SCCT, it was found that career gender-typing, mother's and father's support for pursuing math and science careers, as well…

Trajectories of Change in Students' Self-Concepts of Ability and Values in Math and College Major Choice

ERIC Educational Resources Information Center

Musu-Gillette, Lauren E.; Wigfield, Allan; Harring, Jeffrey R.; Eccles, Jacquelynne S.

2015-01-01

This study extends previous research on the long-term connections between motivation constructs in expectancy-value theory and achievement outcomes. Using growth mixture modelling, we examined trajectories of change for 421 students from 4th grade through college in their self-concept of ability (SCA) in math, interest in math, and perceived…

Measurement of activation cross-section of long-lived products in deuteron induced nuclear reactions on palladium in the 30-50MeV energy range.

PubMed

Ditrói, F; Tárkányi, F; Takács, S; Hermanne, A; Ignatyuk, A V

2017-10-01

Excitation functions were measured in the 31-49.2MeV energy range for the nat Pd(d,xn) 111,110m,106m,105,104g,103 Ag, nat Pd(d,x) 111m,109,101,100 Pd, nat Pd(d,x), 105,102m,102g,101m,101g,100,99m,99g Rh and nat Pd(d,x) 103,97 Ru nuclear reactions by using the stacked foil irradiation technique. The experimental results are compared with our previous results and with the theoretical predictions calculated with the ALICE-D, EMPIRE-D and TALYS (TENDL libraries) codes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improving Learning for All Students through Equity-Based Inclusive Reform Practices: Effectiveness of a Fully Integrated Schoolwide Model on Student Reading and Math Achievement

ERIC Educational Resources Information Center

Choi, Jeong Hoon; Meisenheimer, Jessica M.; McCart, Amy B.; Sailor, Wayne

2017-01-01

The present investigation examines the schoolwide applications model (SAM) as a potentially effective school reform model for increasing equity-based inclusive education practices while enhancing student reading and math achievement for all students. A 3-year quasi-experimental comparison group analysis using latent growth modeling (LGM) was used…

Growth Texture and Mechanism of Zinc Nanowires Produced by Mechanical Elongation of Nanocontacts.

PubMed

Yamabe, Kammu; Kizuka, Tokushi

2018-01-01

Two zinc nanotips were brought into contact and elongated inside a transmission electron microscope, thereby growing single-crystal nanowires. The growth dynamics was observed in situ via a lattice imaging method. The preferential crystal growth directions were identified as [101-0], [112-0], [101-2-], and [0001]. Of these, the nanowires grown along the [101-0] and [112-0] directions accounted for 75% of the total and were surrounded by low-energy side surfaces, i.e., {0001}, {101-1}, and {101-0}. On the basis of these features, models of the nanowire morphology were proposed. In either growth direction, the tensile force aligned parallel to the direction along which slip events corresponding to the predominant slip system were unlikely to occur. This led to a high tensile stress for extracting atoms from the growth region, i.e., the promotion of nanowire growth.

An integrated model of academic self-concept development: Academic self-concept, grades, test scores, and tracking over 6 years.

PubMed

Marsh, Herbert W; Pekrun, Reinhard; Murayama, Kou; Arens, A Katrin; Parker, Philip D; Guo, Jiesi; Dicke, Theresa

2018-02-01

Our newly proposed integrated academic self-concept model integrates 3 major theories of academic self-concept formation and developmental perspectives into a unified conceptual and methodological framework. Relations among math self-concept (MSC), school grades, test scores, and school-level contextual effects over 6 years, from the end of primary school through the first 5 years of secondary school (a representative sample of 3,370 German students, 42 secondary schools, 50% male, M age at grade 5 = 11.75) support the (1) internal/external frame of reference model: Math school grades had positive effects on MSC, but the effects of German grades were negative; (2) reciprocal effects (longitudinal panel) model: MSC was predictive of and predicted by math test scores and school grades; (3) big-fish-little-pond effect: The effects on MSC were negative for school-average achievement based on 4 indicators (primary school grades in math and German, school-track prior to the start of secondary school, math test scores in the first year of secondary school). Results for all 3 theoretical models were consistent across the 5 secondary school years: This supports the prediction of developmental equilibrium. This integration highlights the robustness of support over the potentially volatile early to middle adolescent period; the interconnectedness and complementarity of 3 ASC models; their counterbalancing strengths and weaknesses; and new theoretical, developmental, and substantive implications at their intersections. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

NREL Model Car Competitions | NREL

Science.gov Websites

skills in both math and science. The goals of the competition include: Generating enthusiasm for science , technology, engineering, and math (STEM) Improving students' understanding of scientific concepts and

The Critical Z-Invariant Ising Model via Dimers: Locality Property

NASA Astrophysics Data System (ADS)

Boutillier, Cédric; de Tilière, Béatrice

2011-01-01

We study a large class of critical two-dimensional Ising models, namely critical Z-invariant Ising models. Fisher (J Math Phys 7:1776-1781, 1966) introduced a correspondence between the Ising model and the dimer model on a decorated graph, thus setting dimer techniques as a powerful tool for understanding the Ising model. In this paper, we give a full description of the dimer model corresponding to the critical Z-invariant Ising model, consisting of explicit expressions which only depend on the local geometry of the underlying isoradial graph. Our main result is an explicit local formula for the inverse Kasteleyn matrix, in the spirit of Kenyon (Invent Math 150(2):409-439, 2002), as a contour integral of the discrete exponential function of Mercat (Discrete period matrices and related topics, 2002) and Kenyon (Invent Math 150(2):409-439, 2002) multiplied by a local function. Using results of Boutillier and de Tilière (Prob Theor Rel Fields 147(3-4):379-413, 2010) and techniques of de Tilière (Prob Th Rel Fields 137(3-4):487-518, 2007) and Kenyon (Invent Math 150(2):409-439, 2002), this yields an explicit local formula for a natural Gibbs measure, and a local formula for the free energy. As a corollary, we recover Baxter's formula for the free energy of the critical Z-invariant Ising model (Baxter, in Exactly solved models in statistical mechanics, Academic Press, London, 1982), and thus a new proof of it. The latter is equal, up to a constant, to the logarithm of the normalized determinant of the Laplacian obtained in Kenyon (Invent Math 150(2):409-439, 2002).

Collaborative Workshops and Student Academic Performance in Introductory College Mathematics Courses: A Study of a Treisman Model Math Excel Program.

ERIC Educational Resources Information Center

Duncan, Hollis; Dick, Thomas

2000-01-01

Describes the Treisman model which involves supplemental workshops in which college students solve problems in collaborative learning groups. Reports on the effectiveness of Math Excel, an implementation of the Treisman model for introductory mathematics courses at Oregon State University over five academic terms. Reveals a significant effect on…

Detection of occult hepatitis B and window period infection among blood donors by individual donation nucleic acid testing in a tertiary care center in South India.

PubMed

Keechilot, Cinzia S; Shenoy, Veena; Kumar, Anil; Biswas, Lalitha; Vijayrajratnam, Sukhithasri; Dinesh, Kavitha; Nair, Prem

With the introduction of highly sensitive hepatitis B surface antigen immunoassay, transfusion associated HBV infection have reduced drastically but they still tend to occur due to blood donors with occult hepatitis B infection (OBI) and window period (WP) infection. Sera from, 24338 healthy voluntary blood donors were screened for HBsAg, HIV and HCV antibody using Vitros Enhanced Chemiluminescent Immunoassay. The median age of the donor population was 30 (range 18-54) with male preponderance (98%). All serologically negative samples were screened by nucleic acid testing (NAT) for viral DNA and RNA. NAT-positive samples were subjected to discriminatory NAT for HBV, HCV, and HIV and all samples positive for HBV DNA were tested for anti-HBc, anti-HBs, HBeAg. Viral load was determined using artus HBV RG PCR Kit. Of the 24,338 donors screened, 99.81% (24292/24338) were HBsAg negative of which NAT was positive for HBV DNA in 0.0205% (5/24292) donors. Four NAT positive donors had viral load of <200 IU/ml making them true cases of OBI. One NAT positive donor was negative for all antibodies making it a case of WP infection. Among OBI donors, 75% (3/4) were immune and all were negative for HBeAg. Precise HBV viral load could not be determined in all (5/5) NAT positive donors due to viral loads below the detection limit of the artus HBV RG PCR Kit. The overall incidence of OBI and WP infections was found to be low at 1 in 6503 and 1 in 24214 donations, respectively. More studies are needed to determine the actual burden of WP infections in Indian blood donors.

Molecular Characterization of a Novel N-Acetyltransferase from Chryseobacterium sp.

PubMed Central

Yoshida, Kenji; Tanaka, Kosei; Yoshida, Ken-ichi

2014-01-01

N-Acetyltransferase from Chryseobacterium sp. strain 5-3B is an acetyl coenzyme A (acetyl-CoA)-dependent enzyme that catalyzes the enantioselective transfer of an acetyl group from acetyl-CoA to the amino group of l-2-phenylglycine to produce (2S)-2-acetylamino-2-phenylacetic acid. We purified the enzyme from strain 5-3B and deduced the N-terminal amino acid sequence. The gene, designated natA, was cloned with two other hypothetical protein genes; the three genes probably form a 2.5-kb operon. The deduced amino acid sequence of NatA showed high levels of identity to sequences of putative N-acetyltransferases of Chryseobacterium spp. but not to other known arylamine and arylalkylamine N-acetyltransferases. Phylogenetic analysis indicated that NatA forms a distinct lineage from known N-acetyltransferases. We heterologously expressed recombinant NatA (rNatA) in Escherichia coli and purified it. rNatA showed high activity for l-2-phenylglycine and its chloro- and hydroxyl-derivatives. The Km and Vmax values for l-2-phenylglycine were 0.145 ± 0.026 mM and 43.6 ± 2.39 μmol · min−1 · mg protein−1, respectively. The enzyme showed low activity for 5-aminosalicylic acid and 5-hydroxytryptamine, which are reported as good substrates of a known arylamine N-acetyltransferase and an arylalkylamine N-acetyltransferase. rNatA had a comparatively broad acyl donor specificity, transferring acyl groups to l-2-phenylglycine and producing the corresponding 2-acetylamino-2-phenylacetic acids (relative activity with acetyl donors acetyl-CoA, propanoyl-CoA, butanoyl-CoA, pentanoyl-CoA, and hexanoyl-CoA, 100:108:122:10:<1). PMID:24375143

A Panel Analysis of Student Mathematics Achievement in the US in the 1990s: Does Increasing the Amount of Time in Learning Activities Affect Math Achievement?

ERIC Educational Resources Information Center

Aksoy, Tevfik; Link, Charles R.

2000-01-01

Uses panel estimation techniques to estimate econometric models of mathematics achievement determinants for a nationally representative sample of high-school students. Extra time spent on math homework increases test scores; an extra hour of TV viewing negatively affects scores. Longer math periods also help. (Contains 56 references.) (MLH)

Mapping Changes in Students' English and Math Self-Concepts: A Latent Growth Model Study

ERIC Educational Resources Information Center

King, Ronnel B.; McInerney, Dennis M.

2014-01-01

The aims of this study were to examine changes in students' English and math self-concepts and to investigate the effects of gender and school ability level on these changes. Self-concept in English and math were measured thrice across three years among a sample of 2618 secondary school students from Hong Kong. Gender and school ability level were…

Training in Influencing Skills from Neuro-Linguistic Programming (Modelled from Hypnosis and Family Therapy), in Combination with Innovative Maths Pedagogy, Raises Maths Attainment in Adult Numeracy Learners

ERIC Educational Resources Information Center

Allan, F.; Bourne, J.; Bouch, D.; Churches, R.; Dennison, J.; Evans, J.; Fowler, J.; Jeffers, A.; Prior, E.; Rhodes, L.

2012-01-01

Case study research suggests that NLP [neuro-linguistic programming] influencing strategies benefit teacher effectiveness. Maths pedagogy involving higher-order questioning, challenge, problem solving and collaborative working may be a way of improving attainment in adult numeracy learning, however, such strategies may be less effective if the…

Enhanced learning of proportional math through music training and spatial-temporal training.

PubMed

Graziano, A B; Peterson, M; Shaw, G L

1999-03-01

It was predicted, based on a mathematical model of the cortex, that early music training would enhance spatial-temporal reasoning. We have demonstrated that preschool children given six months of piano keyboard lessons improved dramatically on spatial-temporal reasoning while children in appropriate control groups did not improve. It was then predicted that the enhanced spatial-temporal reasoning from piano keyboard training could lead to enhanced learning of specific math concepts, in particular proportional math, which is notoriously difficult to teach using the usual language-analytic methods. We report here the development of Spatial-Temporal Math Video Game software designed to teach fractions and proportional math, and its strikingly successful use in a study involving 237 second-grade children (age range six years eight months-eight years five months). Furthermore, as predicted, children given piano keyboard training along with the Math Video Game training scored significantly higher on proportional math and fractions than children given a control training along with the Math Video Game. These results were readily measured using the companion Math Video Game Evaluation Program. The training time necessary for children on the Math Video Game is very short, and they rapidly reach a high level of performance. This suggests that, as predicted, we are tapping into fundamental cortical processes of spatial-temporal reasoning. This spatial-temporal approach is easily generalized to teach other math and science concepts in a complementary manner to traditional language-analytic methods, and at a younger age. The neural mechanisms involved in thinking through fractions and proportional math during training with the Math Video Game might be investigated in EEG coherence studies along with priming by specific music.

Reduced 4-Aminobiphenyl-Induced Liver Tumorigenicity but not DNA Damage in Arylamine N-Acetyltransferase Null Mice

PubMed Central

Sugamori, Kim S.; Brenneman, Debbie; Sanchez, Otto; Doll, Mark A.; Hein, David W.; Pierce, William M.; Grant, Denis M.

2012-01-01

The aromatic amine 4-aminobiphenyl (ABP) is a liver procarcinogen in mice, requiring enzymatic bioactivation to exert its tumorigenic effect. To assess the role of arylamine N-acetyltransferase (NAT)-dependent acetylation capacity in the risk for ABP-induced liver tumors, we compared 1-year liver tumor incidence following the postnatal exposure of wild-type and NAT-deficient Nat1/2(−/−) mice to ABP. At an ABP exposure of 1200 nmoles, male Nat1/2(−/−) mice had a liver tumor incidence of 36% compared to 69% in wild-type males, and at 600 nmoles there was a complete absence of tumors compared to 60% in wild-type mice. Only one female wild-type mouse had a tumor using this exposure protocol. However, levels of N-deoxyguanosin-8-yl-ABP-DNA adducts did not correlate with either the strain or sex differences in tumor incidence. These results suggest that female sex and NAT deficiency reduce risk for ABP-induced liver tumors, but by mechanisms unrelated to differences in DNA-damaging events. PMID:22193722

Math Anxiety Assessment with the Abbreviated Math Anxiety Scale: Applicability and Usefulness: Insights from the Polish Adaptation

PubMed Central

Cipora, Krzysztof; Szczygieł, Monika; Willmes, Klaus; Nuerk, Hans-Christoph

2015-01-01

Math anxiety has an important impact on mathematical development and performance. However, although math anxiety is supposed to be a transcultural trait, assessment instruments are scarce and are validated mainly for Western cultures so far. Therefore, we aimed at examining the transcultural generality of math anxiety by a thorough investigation of the validity of math anxiety assessment in Eastern Europe. We investigated the validity and reliability of a Polish adaptation of the Abbreviated Math Anxiety Scale (AMAS), known to have very good psychometric characteristics in its original, American-English version as well as in its Italian and Iranian adaptations. We also observed high reliability, both for internal consistency and test-retest stability of the AMAS in the Polish sample. The results also show very good construct, convergent and discriminant validity: The factorial structure in Polish adult participants (n = 857) was very similar to the one previously found in other samples; AMAS scores correlated moderately in expected directions with state and trait anxiety, self-assessed math achievement and skill as well temperamental traits of emotional reactivity, briskness, endurance, and perseverance. Average scores obtained by participants as well as gender differences and correlations with external measures were also similar across cultures. Beyond the cultural comparison, we used path model analyses to show that math anxiety relates to math grades and self-competence when controlling for trait anxiety. The current study shows transcultural validity of math anxiety assessment with the AMAS. PMID:26648893

Math Anxiety Assessment with the Abbreviated Math Anxiety Scale: Applicability and Usefulness: Insights from the Polish Adaptation.

PubMed

Cipora, Krzysztof; Szczygieł, Monika; Willmes, Klaus; Nuerk, Hans-Christoph

2015-01-01

Math anxiety has an important impact on mathematical development and performance. However, although math anxiety is supposed to be a transcultural trait, assessment instruments are scarce and are validated mainly for Western cultures so far. Therefore, we aimed at examining the transcultural generality of math anxiety by a thorough investigation of the validity of math anxiety assessment in Eastern Europe. We investigated the validity and reliability of a Polish adaptation of the Abbreviated Math Anxiety Scale (AMAS), known to have very good psychometric characteristics in its original, American-English version as well as in its Italian and Iranian adaptations. We also observed high reliability, both for internal consistency and test-retest stability of the AMAS in the Polish sample. The results also show very good construct, convergent and discriminant validity: The factorial structure in Polish adult participants (n = 857) was very similar to the one previously found in other samples; AMAS scores correlated moderately in expected directions with state and trait anxiety, self-assessed math achievement and skill as well temperamental traits of emotional reactivity, briskness, endurance, and perseverance. Average scores obtained by participants as well as gender differences and correlations with external measures were also similar across cultures. Beyond the cultural comparison, we used path model analyses to show that math anxiety relates to math grades and self-competence when controlling for trait anxiety. The current study shows transcultural validity of math anxiety assessment with the AMAS.

Space shuttle plume/simulation application: Results and math model supersonic data

NASA Technical Reports Server (NTRS)

Boyle, W.; Conine, B.; Bell, G.

1979-01-01

The analysis of pressure and gage wind tunnel data from space shuttle wind tunnel test IA138 was performed to define the aerodynamic influence of the main propulsion system and solid rocket booster plumes on the total vehicles, elements, and components of the space shuttle vehicle during the supersonic portion of ascent flight. A math model of the plume induced aerodynamic characteristics was developed for a range of Mach numbers to match the forebody aerodynamic math model. The base aerodynamic characteristics are presented in terms of forces and moments versus attitude. Total vehicle base and forebody aerodynamic characteristics are presented in terms of aerodynamic coefficients for Mach numbers from 1.55 to 2.5.

Stereotype threat and executive functions: which functions mediate different threat-related outcomes?

PubMed

Rydell, Robert J; Van Loo, Katie J; Boucher, Kathryn L

2014-03-01

Stereotype threat research shows that women's math performance can be reduced by activating gender-based math stereotypes. Models of stereotype threat assert that threat reduces cognitive functioning, thereby accounting for its negative effects. This work provides a more detailed understanding of the cognitive processes through which stereotype threat leads women to underperform at math and to take risks, by examining which basic executive functions (inhibition, shifting, and updating) account for these outcomes. In Experiments 1 and 2, women under threat showed reduced inhibition, reduced updating, and reduced math performance compared with women in a control condition (or men); however, only updating accounted for women's poor math performance under threat. In Experiment 3, only updating accounted for stereotype threat's effect on women's math performance, whereas only inhibition accounted for the effect of threat on risk-taking, suggesting that distinct executive functions can account for different stereotype threat-related outcomes.

Susceptibility of N-acetyltransferase 2 slow acetylators to antituberculosis drug-induced liver injury: a meta-analysis.

PubMed

Shi, Jing; Xie, Min; Wang, Jianmiao; Xu, Yongjian; Liu, Xiansheng

2015-12-01

This study aimed to evaluate the association between N-acetyltransferase 2 (NAT2) gene polymorphisms and the risk of antituberculosis drug-induced liver injury (ATLI). A meta-analysis was performed including 27 studies with 1289 cases and 5462 controls. Odds ratio with 95% CI was used to evaluate the strength of association. Our meta-analysis found that NAT2 slow acetylators were associated with increased risk of ATLI compared with fast and intermediate acetylators when standard dose of isoniazid was administrated (odds ratio: 3.08; 95% CI: 2.29-4.15). Individuals with NAT2 slow acetylators may have increased risk of ATLI when standard dose of isoniazid was used. Detection of NAT2 genotype may benefit to the prevention of ATLI.

Detecting Math Anxiety with a Mixture Partial Credit Model

ERIC Educational Resources Information Center

Ölmez, Ibrahim Burak; Cohen, Allan S.

2017-01-01

The purpose of this study was to investigate a new methodology for detection of differences in middle grades students' math anxiety. A mixture partial credit model analysis revealed two distinct latent classes based on homogeneities in response patterns within each latent class. Students in Class 1 had less anxiety about apprehension of math…

Reciprocal Relationships between Math Self-Concept and Math Anxiety

ERIC Educational Resources Information Center

Ahmed, Wondimu; Minnaert, Alexander; Kuyper, Hans; van der Werf, Greetje

2012-01-01

The present study examined the reciprocal relationships between self-concept and anxiety in mathematics. A sample of 495 grade 7 students (51% girls) completed self-report measures assessing self-concept and anxiety three times in a school year. Structural equation modeling was used to test a cross-lagged panel model of reciprocal effects between…

The Role of Social Support in Students' Perceived Abilities and Attitudes toward Math and Science

ERIC Educational Resources Information Center

Rice, Lindsay; Barth, Joan M.; Guadagno, Rosanna E.; Smith, Gabrielle P. A.; McCallum, Debra M.

2013-01-01

Social cognitive models examining academic and career outcomes emphasize constructs such as attitude, interest, and self-efficacy as key factors affecting students' pursuit of STEM (science, technology, engineering and math) courses and careers. The current research examines another under-researched component of social cognitive models: social…

A descriptive study of high school Latino and Caucasian students' values about math, perceived math achievement and STEM career choice

NASA Astrophysics Data System (ADS)

Rodriguez Flecha, Samuel

The purpose of this study was to examine high school students' math values, perceived math achievement, and STEM career choice. Participants (N=515) were rural high school students from the U.S. Northwest. Data was collected by administering the "To Do or Not to Do:" STEM pilot survey. Most participants (n=294) were Latinos, followed by Caucasians (n=142). Fifty-three percent of the students rated their math achievement as C or below. Of high math students, 57% were male. Females were 53% of low math students. Caucasians (61%) rated themselves as high in math in a greater proportion than Latinos (39%). Latinos (58%) rated themselves as low in math in a greater proportion than Caucasians (39%). Math Values play a significant role in students' perceived math achievement. Internal math values (r =.68, R2 =.46, p =.001) influenced perceived math achievement regardless of gender (males: r =.70, R2 =.49, p =.001; females: r =.65, R2 =.43, p =.001), for Latinos (r =.66, R2 =.44, p =.001), and Caucasians (r =.72, R2 =.51, p =.001). External math values (r =.53, R2 =.28, p =.001) influenced perceived math achievement regardless of gender (males: r =.54, R2 =.30, p =.001; females: r =.49, R2 =.24, p =.001), for Latinos (r =.47, R2 =.22, p =.001), and Caucasians (r =.58, R2 =.33, p =.001). Most high-math students indicated an awareness of being good at math at around 11 years old. Low-math students said that they realized that math was difficult for them at approximately 13 years of age. The influence of parents, teachers, and peers may vary at different academic stages. Approximately half of the participants said there was not a person who had significantly impacted their career choice; only a minority said their parents and teachers were influencing them to a STEM career. Parents and teachers are the most influential relationships in students' career choice. More exposure to STEM role models and in a variety of professions is needed. Possible strategies to impact students' career choice, future directions and recommendations are provided. In sum, positive experiences in STEM can favorably contribute to students' sense of competence and satisfaction.

Verbal and Math Self-Concepts: An Extension of the Internal/External Frame of Reference Model.

ERIC Educational Resources Information Center

Marsh, Herbert W.; Byrne, Barbara M.

The internal/external (I/E) frame of reference model describes relations among Verbal self-concept (VSC), Math self-concept (MSC), and corresponding achievement scores (VACH, MACH). In support of the model Marsh (1986) found that: (1) VSC and MSC were nearly uncorrelated; (2) the effect of VACH on VSC, and of MACH on MSC, were positive; but (3)…

The belief in a negative interdependence of math and verbal abilities as determinant of academic self-concepts.

PubMed

Möller, Jens; Streblow, Lilian; Pohlmann, Britta

2006-03-01

The internal/external frame of reference (I/E) model by Marsh (1986) assumes intra-individual dimensional comparisons in which students compare their own achievements in one subject with their achievements in other subjects. These comparison processes should lead to negative paths from achievement in one subject (e.g. maths) on self-concept in another subject (e.g. verbal domains). Within this study, we investigated the impact of students' belief in a negative interdependence of maths and verbal abilities, that is, whether students think of maths and verbal abilities as negatively correlated or not, on the impact of dimensional comparisons. Maths and German grades, academic self-concepts in maths and German, and a new scale on the beliefs in a negative interdependence of maths and verbal abilities students were assessed (N = 1,443). The importance of the negative interdependence beliefs could be shown: stronger beliefs in a negative interdependence of maths and verbal ability are accompanied by more negative path coefficients from grades in one subject to academic self-concepts in the other subject. Dimensional comparisons seem to be of particular importance for students with negative interdependence beliefs.

HIV Testing

MedlinePlus

... NAT means. Taking pre-exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP) may also reduce the accuracy of NAT if you have HIV. An antigen/antibody test looks for both HIV antibodies and antigens. Antibodies ...

Adjuvant Brachytherapy Removes Survival Disadvantage of Local Disease Extension in Stage IIIC Endometrial Cancer: A SEER Registry Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rossi, Peter J.; Jani, Ashesh B.; Horowitz, Ira R.

2008-01-01

Purpose: To assess the role of radiotherapy (RT) in women with Stage IIIC endometrial cancer. Methods and Materials: The 17-registry Survival, Epidemiology, and End Results (SEER) database was searched for patients with lymph node-positive non-Stage IV epithelial endometrial cancer diagnosed and treated between 1988 and 1998. Two subgroups were identified: those with organ-confined Stage IIIC endometrial cancer and those with Stage IIIC endometrial cancer with direct extension of the primary tumor. RT was coded as external beam RT (EBRT) or brachytherapy (BT). Observed survival (OS) was reported with a minimum of 5 years of follow-up; the survival curves were comparedmore » using the log-rank test. Results: The therapy data revealed 611 women with Stage IIIC endometrial cancer during this period. Of these women, 51% were treated with adjuvant EBRT, 21% with EBRT and BT, and 28% with no additional RT (NAT). Of the 611 patients, 293 had organ-confined Stage IIIC endometrial cancer and 318 patients had Stage IIIC endometrial cancer with direct extension of the primary tumor. The 5-year OS rate for all patients was 40% with NAT, 56% after EBRT, and 64% after EBRT/BT. Adjuvant RT improved survival compared with NAT (p <0.001). In patients with organ-confined Stage IIIC endometrial cancer, the 5-year OS rate was 50% for NAT, 64% for EBRT, and 67% for EBRT/BT. Again, adjuvant RT contributed to improved survival compared with NAT (p = 0.02). In patients with Stage IIIC endometrial cancer and direct tumor extension, the 5-year OS rate was 34% for NAT, 47% for EBRT, and 63% for EBRT/BT. RT improved OS compared with NAT (p <0.001). Also, in this high-risk subgroup, adding BT to EBRT was superior to EBRT alone (p = 0.002). Conclusion: Women with Stage IIIC endometrial cancer receiving adjuvant EBRT and EBRT/BT had improved OS compared with patients receiving NAT. When direct extension of the primary tumor was present, the addition of BT to EBRT was even more beneficial.« less

Adjuvant brachytherapy removes survival disadvantage of local disease extension in stage IIIC endometrial cancer: a SEER registry analysis.

PubMed

Rossi, Peter J; Jani, Ashesh B; Horowitz, Ira R; Johnstone, Peter A S

2008-01-01

To assess the role of radiotherapy (RT) in women with Stage IIIC endometrial cancer. The 17-registry Survival, Epidemiology, and End Results (SEER) database was searched for patients with lymph node-positive non-Stage IV epithelial endometrial cancer diagnosed and treated between 1988 and 1998. Two subgroups were identified: those with organ-confined Stage IIIC endometrial cancer and those with Stage IIIC endometrial cancer with direct extension of the primary tumor. RT was coded as external beam RT (EBRT) or brachytherapy (BT). Observed survival (OS) was reported with a minimum of 5 years of follow-up; the survival curves were compared using the log-rank test. The therapy data revealed 611 women with Stage IIIC endometrial cancer during this period. Of these women, 51% were treated with adjuvant EBRT, 21% with EBRT and BT, and 28% with no additional RT (NAT). Of the 611 patients, 293 had organ-confined Stage IIIC endometrial cancer and 318 patients had Stage IIIC endometrial cancer with direct extension of the primary tumor. The 5-year OS rate for all patients was 40% with NAT, 56% after EBRT, and 64% after EBRT/BT. Adjuvant RT improved survival compared with NAT (p <0.001). In patients with organ-confined Stage IIIC endometrial cancer, the 5-year OS rate was 50% for NAT, 64% for EBRT, and 67% for EBRT/BT. Again, adjuvant RT contributed to improved survival compared with NAT (p = 0.02). In patients with Stage IIIC endometrial cancer and direct tumor extension, the 5-year OS rate was 34% for NAT, 47% for EBRT, and 63% for EBRT/BT. RT improved OS compared with NAT (p <0.001). Also, in this high-risk subgroup, adding BT to EBRT was superior to EBRT alone (p = 0.002). Women with Stage IIIC endometrial cancer receiving adjuvant EBRT and EBRT/BT had improved OS compared with patients receiving NAT. When direct extension of the primary tumor was present, the addition of BT to EBRT was even more beneficial.

Apollo oxygen tank stratification analysis, volume 2

NASA Technical Reports Server (NTRS)

Barton, J. E.; Patterson, H. W.

1972-01-01

An analysis of flight performance of the Apollo 15 cryogenic oxygen tanks was conducted with the variable grid stratification math model developed earlier in the program. Flight conditions investigated were the CMP-EVA and one passive thermal control period which exhibited heater temperature characteristics not previously observed. Heater temperatures for these periods were simulated with the math model using flight acceleration data. Simulation results (heater temperature and tank pressure) compared favorably with the Apollo 15 flight data, and it was concluded that tank performance was nominal. Math model modifications were also made to improve the simulation accuracy. The modifications included the addition of the effects of the tank wall thermal mass and an improved system flow distribution model. The modifications improved the accuracy of simulated pressure response based on comparisons with flight data.

Genetics Home Reference: Williams syndrome

MedlinePlus

... Berman KF. Neural correlates of genetically abnormal social cognition in Williams syndrome. Nat Neurosci. 2005 Aug;8( ... syndrome: a unique window to genetic influences on cognition and behaviour. Nat Rev Neurosci. 2006 May;7( ...

Remediation of Childhood Math Anxiety and Associated Neural Circuits through Cognitive Tutoring

PubMed Central

Iuculano, Teresa; Chen, Lang

2015-01-01

Math anxiety is a negative emotional reaction that is characterized by feelings of stress and anxiety in situations involving mathematical problem solving. High math-anxious individuals tend to avoid situations involving mathematics and are less likely to pursue science, technology, engineering, and math-related careers than those with low math anxiety. Math anxiety during childhood, in particular, has adverse long-term consequences for academic and professional success. Identifying cognitive interventions and brain mechanisms by which math anxiety can be ameliorated in children is therefore critical. Here we investigate whether an intensive 8 week one-to-one cognitive tutoring program designed to improve mathematical skills reduces childhood math anxiety, and we identify the neurobiological mechanisms by which math anxiety can be reduced in affected children. Forty-six children in grade 3, a critical early-onset period for math anxiety, participated in the cognitive tutoring program. High math-anxious children showed a significant reduction in math anxiety after tutoring. Remarkably, tutoring remediated aberrant functional responses and connectivity in emotion-related circuits anchored in the basolateral amygdala. Crucially, children with greater tutoring-induced decreases in amygdala reactivity had larger reductions in math anxiety. Our study demonstrates that sustained exposure to mathematical stimuli can reduce math anxiety and highlights the key role of the amygdala in this process. Our findings are consistent with models of exposure-based therapy for anxiety disorders and have the potential to inform the early treatment of a disability that, if left untreated in childhood, can lead to significant lifelong educational and socioeconomic consequences in affected individuals. SIGNIFICANCE STATEMENT Math anxiety during early childhood has adverse long-term consequences for academic and professional success. It is therefore important to identify ways to alleviate math anxiety in young children. Surprisingly, there have been no studies of cognitive interventions and the underlying neurobiological mechanisms by which math anxiety can be ameliorated in young children. Here, we demonstrate that intensive 8 week one-to-one cognitive tutoring not only reduces math anxiety but also remarkably remediates aberrant functional responses and connectivity in emotion-related circuits anchored in the amygdala. Our findings are likely to propel new ways of thinking about early treatment of a disability that has significant implications for improving each individual's academic and professional chances of success in today's technological society that increasingly demands strong quantitative skills. PMID:26354922

Prediction of lymph node involvement in patients with breast tumors measuring 3-5 cm in a middle-income setting: the role of CancerMath.

PubMed

Pijnappel, E N; Bhoo-Pathy, N; Suniza, J; See, M H; Tan, G H; Yip, C H; Hartman, M; Taib, N A; Verkooijen, H M

2014-12-01

In settings with limited resources, sentinel lymph node biopsy (SNB) is only offered to breast cancer patients with small tumors and a low a priori risk of axillary metastases. We investigated whether CancerMath, a free online prediction tool for axillary lymph node involvement, is able to identify women at low risk of axillary lymph node metastases in Malaysian women with 3-5 cm tumors, with the aim to offer SNB in a targeted, cost-effective way. Women with non-metastatic breast cancers, measuring 3-5 cm were identified within the University Malaya Medical Centre (UMMC) breast cancer registry. We compared CancerMath-predicted probabilities of lymph node involvement between women with versus without lymph node metastases. The discriminative performance of CancerMath was tested using receiver operating characteristic (ROC) analysis. Out of 1,017 patients, 520 (51 %) had axillary involvement. Tumors of women with axillary involvement were more often estrogen-receptor positive, progesterone-receptor positive, and human epidermal growth factor receptor (HER)-2 positive. The mean CancerMath score was higher in women with axillary involvement than in those without (53.5 vs. 51.3, p = 0.001). In terms of discrimination, CancerMath performed poorly, with an area under the ROC curve of 0.553 (95 % confidence interval CI 0.518-0.588). Attempts to optimize the CancerMath model by adding ethnicity and HER2 to the model did not improve discriminatory performance. For Malaysian women with tumors measuring 3-5 cm, CancerMath is unable to accurately predict lymph node involvement and is therefore not helpful in the identification of women at low risk of node-positive disease who could benefit from SNB.

Do student self-efficacy and teacher-student interaction quality contribute to emotional and social engagement in fifth grade math?

PubMed

Martin, Daniel P; Rimm-Kaufman, Sara E

2015-10-01

This study examined (a) the contribution of math self-efficacy to students' perception of their emotional and social engagement in fifth grade math classes, and (b) the extent to which high quality teacher-student interactions compensated for students' low math self-efficacy in contributing to engagement. Teachers (n = 73) were observed three times during the year during math to measure the quality of teacher-student interactions (emotional, organizational, and instructional support). Fifth graders (n = 387) reported on their math self-efficacy at the beginning of the school year and then were surveyed about their feelings of engagement in math class three times during the year immediately after the lessons during which teachers were observed. Results of multi-level models indicated that students initially lower in math self-efficacy reported lower emotional and social engagement during math class than students with higher self-efficacy. However, in classrooms with high levels of teacher emotional support, students reported similar levels of both emotional and social engagement, regardless of their self-efficacy. No comparable findings emerged for organizational and instructional support. The discussion considers the significance of students' own feelings about math in relation to their engagement, as well as the ways in which teacher and classroom supports can compensate for students lack of agency. The work has implications for school psychologists and teachers eager to boost students' engagement in math class. Copyright © 2015 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

The implementation of nucleic acid amplification technology testing for living tissue donors.

PubMed

Westby, J; Lomas, R J; Kearney, J N

2010-05-01

There is a significant requirement within the United Kingdom for tissue grafts from living donors. To ensure safety, blood samples from these donors are tested for pathogens at donation, and at 180 days post donation. Nucleic acid amplification technology (NAT) permits more sensitive detection of pathogens in blood samples than serum antigen testing. NAT testing can be applied to samples from living tissue donors to eliminate the need to re-test these donors 180 days post-donation before grafts can be implanted. This has major financial and operational advantages for a tissue bank, and this manuscript describes how NAT testing was assessed and implemented by NHSBT Tissue Services. When compared to traditional serum antigen testing, NAT testing was more cost effective, more convenient for donors and resulted in a greater proportion of donated grafts being made available for transplant.

Injury patterns of child abuse: Experience of two Level 1 pediatric trauma centers.

PubMed

Yu, Yangyang R; DeMello, Annalyn S; Greeley, Christopher S; Cox, Charles S; Naik-Mathuria, Bindi J; Wesson, David E

2018-05-01

This study examines non-accidental trauma (NAT) fatalities as a percentage of all injury fatalities and identifies injury patterns in NAT admissions to two level 1 pediatric trauma centers. We reviewed all children (<5years old) treated for NAT from 2011 to 2015. Patient demographics, injury sites, and survival were obtained from both institutional trauma registries. Of 4623 trauma admissions, 557 (12%) were due to NAT. However, 43 (46%) of 93 overall trauma fatalities were due to NAT. Head injuries were the most common injuries sustained (60%) and led to the greatest increased risk of death (RR 5.1, 95% CI 2.0-12.7). Less common injuries that increased the risk of death were facial injuries (14%, RR 2.9, 95% CI 1.6-5.3), abdominal injuries (8%, RR 2.8, 95% CI 1.4-5.6), and spinal injuries (3%, RR 3.9, 95% CI 1.8-8.8). Although 76% of head injuries occurred in infants <1year, children ages 1-4years old with head injuries had a significantly higher case fatality rate (27% vs. 6%, p<0.001). Child abuse accounts for a large proportion of trauma fatalities in children under 5years of age. Intracranial injuries are common in child abuse and increase the risk of death substantially. Preventing NAT in infants and young children should be a public health priority. Retrospective Review. II. Copyright © 2018. Published by Elsevier Inc.

Threats and Supports to Female Students' Math Beliefs and Achievement.

PubMed

McKellar, Sarah E; Marchand, Aixa D; Diemer, Matthew A; Malanchuk, Oksana; Eccles, Jacquelynne S

2018-03-23

This study examines how student perceptions of teacher practices contribute to female high school students' math beliefs and achievement. Guided by the expectancy-value framework, we hypothesized that students' motivation beliefs and achievement outcomes in mathematics are fostered by teachers' emphasis on the relevance of mathematics and constrained by gender-based differential treatment. To examine these questions, structural equation modeling was applied to a longitudinal panel of 518 female students from the Maryland Adolescent Development in Context Study. While controlling for prior achievement and race, gendered differential treatment was negatively associated with math beliefs and achievement, whereas relevant math instruction was positively associated with these outcomes. These findings suggest inroads that may foster positive math motivational beliefs and achievement among young women. © 2018 Society for Research on Adolescence.

Earth Observing System (EOS)/Advanced Microwave Sounding Unit-A (AMSU-A) Structural Math Model - A1

NASA Technical Reports Server (NTRS)

Ely, W.

1996-01-01

This report presents the description for the NASTRAN finite element for the AMSU-A1 module. The purpose of this report is to document the NASTRAN bulk data deck, transmitted under separate cover. The structural Math Model is to be used by the spacecraft contractor for dynamic loads analysis.

Educational Investment, Family Context, and Children's Math and Reading Growth from Kindergarten through the Third Grade

ERIC Educational Resources Information Center

Cheadle, Jacob E.

2008-01-01

Drawing on longitudinal data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-1999, this study used IRT modeling to operationalize a measure of parental educational investments based on Lareau's notion of concerted cultivation. It used multilevel piece-wise growth models regressing children's math and reading achievement…

Examining the Relations between Executive Function, Math, and Literacy during the Transition to Kindergarten: A Multi-Analytic Approach

ERIC Educational Resources Information Center

Schmitt, Sara A.; Geldhof, G. John; Purpura, David J.; Duncan, Robert; McClelland, Megan M.

2017-01-01

The present study explored the bidirectional and longitudinal associations between executive function (EF) and early academic skills (math and literacy) across 4 waves of measurement during the transition from preschool to kindergarten using 2 complementary analytical approaches: cross-lagged panel modeling and latent growth curve modeling (LCGM).…

Mysterious quantum Cheshire cat: an illusion

NASA Astrophysics Data System (ADS)

Michielsen, K.; Lippert, Th.; De Raedt, H.

2015-09-01

We provide a mystery-free explanation for the experimentally observed facts in the neutron interferometry quantum Cheshire cat experiment of Denkmayr et al. [Nat. Comm. 5, 4492, 2014] in terms of a discrete-event simulation model, demonstrating that the quantum Cheshire cat is an illusion.

Validation of the use of exogenous gonadotropins (PG600) to increase the efficiency of gilt development programs without affecting lifetime productivity in the breeding herd.

PubMed

Patterson, J; Triemert, E; Gustafson, B; Werner, T; Holden, N; Pinilla, J C; Foxcroft, G

2016-02-01

The objective of this study was to validate the use of exogenous gonadotropin (PG600) treatment for stimulating estrus in noncyclic gilts and to compare lifetime productivity of gilts recorded as having natural (NAT) versus PG600-induced (PG600) first estrus in a commercial setting. Prepubertal Camborough gilts ( = 4,489) were delivered to a gilt development unit (GDU) with the goal of delivering known cyclic breeding-eligible females to the sow farm (SF). A boar exposure area (BEAR) was designed to facilitate stimulation and detection of puberty by providing fence line and direct contact (15 min daily) with mature boars over an intensive 28-d period, starting at approximately d 160 (d 0). At d 14, nonpubertal gilts were mixed in new pen groups. At d 23, noncyclic "opportunity" gilts with no record of vulval development and required to meet breeding targets, were eligible for treatment with PG600 to induce puberty. Overall, 77.6% ( = 3,475) of gilts exhibited standing estrus (NAT = 2,654; PG600 = 821) and were eligible for shipping to the SF at approximately 35 d, and 76.6% of gilts that were administered PG600 exhibited the standing reflex within 13 d of treatment. Ultimately, 72.0% of gilts entering the GDU were delivered to the SF as breeding-eligible females. Considering the gilts delivered, a greater proportion of NAT than PG600 gilts were successfully bred ( < 0.001) and had better farrowing rates to first service, and overall farrowing rates (including gilts that returned to estrus and were rebred) were greater for NAT compared to PG600 gilts ( < 0.001) . Farrowing rates at second and third parity were similar between NAT and PG600 gilts; however, at fourth parity, a greater proportion of NAT gilts farrowed. In comparison, considering only gilts served, there was no difference ( > 0.05) in the proportion of NAT and PG600 gilts farrowing a third litter, but a greater proportion of NAT than PG600 gilts farrowed their fourth litter ( < 0.001). There was no difference between NAT and PG600 gilts for litter size at parity 1 through 4 or total pigs born over 4 parities ( > 0.05). A negative correlation ( < 0.0001) was detected between age at puberty and lifetime growth rate at puberty, and growth rate classification affected age and weight at puberty. However, retention rates and total sow productivity to parity 4 were not affected by growth rate classification at puberty.

Programs for Students and Teachers | NREL

Science.gov Websites

competition that tests the brainpower of middle and high school teams on science and math topics. Model Car 8th grade students. Student teams apply math, science, and creativity to construct solar and battery

It's a Kid's Job: Playing Helps Kids Learn and Grow

MedlinePlus

... and their colleagues found a link between preschoolers’ math skills and their ability to copy models of ... the later study of science, technology, engineering or math. “In a way, a child is becoming a ...

Physics career intentions: The effect of physics identity, math identity, and gender

NASA Astrophysics Data System (ADS)

Lock, Robynne M.; Hazari, Zahra; Potvin, Geoff

2013-01-01

Although nearly half of high school physics students are female, only 21% of physics bachelor's degrees are earned by women. Using data from a national survey of college students in introductory English courses (on science-related experiences, particularly in high school), we examine the influence of students' physics and math identities on their choice to pursue a physics career. Males have higher math and physics identities than females in all three dimensions of our identity framework. These dimensions include: performance/competence (perceptions of ability to perform/understand), recognition (perception of recognition by others), and interest (desire to learn more). A regression model predicting students' intentions to pursue physics careers shows, as expected, that males are significantly more likely to choose physics than females. Surprisingly, however, when physics and math identity are included in the model, females are shown to be equally likely to choose physics careers as compared to males.

Dynamics of two-strain influenza model with cross-immunity and no quarantine class.

PubMed

Chung, K W; Lui, Roger

2016-12-01

The question about whether a periodic solution can exists for a given epidemiological model is a complicated one and has a long history (Hethcote and Levin, Applied math. ecology, biomathematics, vol 18. Springer, Berlin, pp 193-211, 1989). For influenza models, it is well known that a periodic solution can exists for a single-strain model with periodic contact rate (Aron and Schwartz, J Math Biol 110:665-679, 1984; Kuznetsov and Piccardi, J Math Biol 32:109-121, 1994), or a multiple-strain model with cross-immunity and quarantine class or age-structure (Nuño et al., Mathematical epidemiology. Lecture notes in mathematics, vol 1945. Springer, Berlin, 2008, chapter 13). In this paper, we prove the local asymptotic stability of the interior steady-state of a two-strain influenza model with sufficiently close cross-immunity and no quarantine class or age-structure. We also show that if the cross-immunity between two strains are far apart; then it is possible for the interior steady-state to lose its stability and bifurcation of periodic solutions can occur. Our results extend those obtained by Nuño et.al. (SIAM J Appl Math 65:964-982, 2005). This problem is important because understanding the reasons behind periodic outbreaks of seasonal flu is an important issue in public health.

Multilevel Structural Equation Models for Investigating the Effects of Computer-Based Learning in Math Classrooms on Science Technology Engineering and Math (STEM) Major Selection in 4-Year Postsecondary Institutions

ERIC Educational Resources Information Center

Lee, Ahlam

2017-01-01

Background/Context: Because of the growing concern over the decline of bachelor degree recipients in the disciplines of science, technology, engineering, and math (STEM) in the U.S., several studies have been devoted to identifying the factors that affect students' STEM major choices. A majority of these studies have focused on factors relevant to…

Efficient Planning of Wind-Optimal Routes in North Atlantic Oceanic Airspace

NASA Technical Reports Server (NTRS)

Rodionova, Olga; Sridhar, Banavar

2017-01-01

The North Atlantic oceanic airspace (NAT) is crossed daily by more than a thousand flights, which are greatly affected by strong jet stream air currents. Several studies devoted to generating wind-optimal (WO) aircraft trajectories in the NAT demonstrated great efficiency of such an approach for individual flights. However, because of the large separation norms imposed in the NAT, previously proposed WO trajectories induce a large number of potential conflicts. Much work has been done on strategic conflict detection and resolution (CDR) in the NAT. The work presented here extends previous methods and attempts to take advantage of the NAT traffic structure to simplify the problem and improve the results of CDR. Four approaches are studied in this work: 1) subdividing the existing CDR problem into sub-problems of smaller sizes, which are easier to handle; 2) more efficient data reorganization within the considered time period; 3) problem localization, i.e. concentrating the resolution effort in the most conflicted regions; 4) applying CDR to the pre-tactical decision horizon (a couple of hours in advance). Obtained results show that these methods efficiently resolve potential conflicts at the strategic and pre-tactical levels by keeping the resulting trajectories close to the initial WO ones.

N-acetyltransferase gene polymorphisms & plasma isoniazid concentrations in patients with tuberculosis.

PubMed

Hemanth Kumar, A K; Ramesh, K; Kannan, T; Sudha, V; Haribabu, Hemalatha; Lavanya, J; Swaminathan, Soumya; Ramachandran, Geetha

2017-01-01

Variations in the N-acetyltransferase (NAT2) gene among different populations could affect the metabolism and disposition of isoniazid (INH). This study was performed to genotype NAT2 gene polymorphisms in tuberculosis (TB) patients from Chennai, India, and compare plasma INH concentrations among the different genotypes. Adult patients with TB treated in the Revised National TB Control Programme (RNTCP) in Chennai, Tamil Nadu, were genotyped for NAT2 gene polymorphism, and two-hour post-dosing INH concentrations were compared between the different genotypes. Plasma INH was determined by high-performance liquid chromatography. Genotyping of the NAT2 gene polymorphism was performed by real-time polymerase chain reaction method. Among the 326 patients genotyped, there were 189 (58%), 114 (35%) and 23 (7%) slow, intermediate and fast acetylators, respectively. The median two-hour INH concentrations in slow, intermediate and fast acetylators were 10.2, 8.1 and 4.1 μg/ml, respectively. The differences in INH concentrations among the three genotypes were significant (P<0.001). Genotyping of TB patients from south India for NAT2 gene polymorphism revealed that 58 per cent of the study population comprised slow acetylators. Two-hour INH concentrations differed significantly among the three genotypes.

Experience of German Red Cross blood donor services with nucleic acid testing: results of screening more than 30 million blood donations for human immunodeficiency virus-1, hepatitis C virus, and hepatitis B virus.

PubMed

Hourfar, Michael K; Jork, Christine; Schottstedt, Volkmar; Weber-Schehl, Marijke; Brixner, Veronika; Busch, Michael P; Geusendam, Geert; Gubbe, Knut; Mahnhardt, Christina; Mayr-Wohlfart, Uschi; Pichl, Lutz; Roth, W Kurt; Schmidt, Michael; Seifried, Erhard; Wright, David J

2008-08-01

The risk of transfusion-transmitted human immunodeficiency virus-1 (HIV-1), hepatitis C virus (HCV), and hepatitis B virus (HBV) infections is predominantly attributable to donations given during the early stage of infection when diagnostic tests may fail. In 1997, nucleic acid amplification technique (NAT)-testing was introduced at the German Red Cross (GRC) blood donor services to reduce this diagnostic window period (WP). A total of 31,524,571 blood donations collected from 1997 through 2005 were screened by minipool NAT, predominantly with pool sizes of 96 donations. These donations cover approximately 80 percent of all the blood collected in Germany during that period. Based on these data, the WP risk in the GRC blood donor population was estimated by using a state-of-the-art mathematic model. During the observation period, 23 HCV, 7 HIV-1, and 43 HBV NAT-only-positive donations were detected. On the basis of these data and estimated pre-NAT infectious WPs, the residual risk per unit transfused was estimated at 1 in 10.88 million for HCV (95% confidence interval [CI], 7.51-19.72 million), 1 in 4.30 million for HIV-1 (95% CI, 2.39-21.37 million), and 1 in 360,000 for HBV (95% CI, 0.19-3.36 million). Based on observed cases of breakthrough infections, the risk of transfusion-related infections may be even lower. The risk of a blood recipient becoming infected with HCV, HIV-1, or HBV has reached an extremely low level. Introduction of individual donation testing for HCV and HIV-1 would have a marginal effect on interception of WP donations.

Cost-effectiveness of additional blood screening tests in the Netherlands.

PubMed

Borkent-Raven, Barbara A; Janssen, Mart P; van der Poel, Cees L; Bonsel, Gouke J; van Hout, Ben A

2012-03-01

During the past decade, blood screening tests such as triplex nucleic acid amplification testing (NAT) and human T-cell lymphotropic virus type I or I (HTLV-I/II) antibody testing were added to existing serologic testing for hepatitis B virus (HBV), human immunodeficiency virus (HIV), and hepatitis C virus (HCV). In some low-prevalence regions these additional tests yielded disputable benefits that can be valuated by cost-effectiveness analyses (CEAs). CEAs are used to support decision making on implementation of medical technology. We present CEAs of selected additional screening tests that are not uniformly implemented in the EU. Cost-effectiveness was analyzed of: 1) HBV, HCV, and HIV triplex NAT in addition to serologic testing; 2) HTLV-I/II antibody test for all donors, for first-time donors only, and for pediatric recipients only; and 3) hepatitis A virus (HAV) for all donations. Disease progression of the studied viral infections was described in five Markov models. In the Netherlands, the incremental cost-effectiveness ratio (ICER) of triplex NAT is €5.20 million per quality-adjusted life-year (QALY) for testing minipools of six donation samples and €4.65 million/QALY for individual donation testing. The ICER for anti-HTLV-I/II is €45.2 million/QALY if testing all donations, €2.23 million/QALY if testing new donors only, and €27.0 million/QALY if testing blood products for pediatric patients only. The ICER of HAV NAT is €18.6 million/QALY. The resulting ICERs are very high, especially when compared to other health care interventions. Nevertheless, these screening tests are implemented in the Netherlands and elsewhere. Policy makers should reflect more explicit on the acceptability of costs and effects whenever additional blood screening tests are implemented. © 2011 American Association of Blood Banks.

A fully disposable and integrated paper-based device for nucleic acid extraction, amplification and detection.

PubMed

Tang, Ruihua; Yang, Hui; Gong, Yan; You, MinLi; Liu, Zhi; Choi, Jane Ru; Wen, Ting; Qu, Zhiguo; Mei, Qibing; Xu, Feng

2017-03-29

Nucleic acid testing (NAT) has been widely used for disease diagnosis, food safety control and environmental monitoring. At present, NAT mainly involves nucleic acid extraction, amplification and detection steps that heavily rely on large equipment and skilled workers, making the test expensive, time-consuming, and thus less suitable for point-of-care (POC) applications. With advances in paper-based microfluidic technologies, various integrated paper-based devices have recently been developed for NAT, which however require off-chip reagent storage, complex operation steps and equipment-dependent nucleic acid amplification, restricting their use for POC testing. To overcome these challenges, we demonstrate a fully disposable and integrated paper-based sample-in-answer-out device for NAT by integrating nucleic acid extraction, helicase-dependent isothermal amplification and lateral flow assay detection into one paper device. This simple device allows on-chip dried reagent storage and equipment-free nucleic acid amplification with simple operation steps, which could be performed by untrained users in remote settings. The proposed device consists of a sponge-based reservoir and a paper-based valve for nucleic acid extraction, an integrated battery, a PTC ultrathin heater, temperature control switch and on-chip dried enzyme mix storage for isothermal amplification, and a lateral flow test strip for naked-eye detection. It can sensitively detect Salmonella typhimurium, as a model target, with a detection limit of as low as 10 2 CFU ml -1 in wastewater and egg, and 10 3 CFU ml -1 in milk and juice in about an hour. This fully disposable and integrated paper-based device has great potential for future POC applications in resource-limited settings.

Quantitative Analysis of Human Cancer Cell Extravasation Using Intravital Imaging.

PubMed

Willetts, Lian; Bond, David; Stoletov, Konstantin; Lewis, John D

2016-01-01

Metastasis, or the spread of cancer cells from a primary tumor to distant sites, is the leading cause of cancer-associated death. Metastasis is a complex multi-step process comprised of invasion, intravasation, survival in circulation, extravasation, and formation of metastatic colonies. Currently, in vitro assays are limited in their ability to investigate these intricate processes and do not faithfully reflect metastasis as it occurs in vivo. Traditional in vivo models of metastasis are limited by their ability to visualize the seemingly sporadic behavior of where and when cancer cells spread (Reymond et al., Nat Rev Cancer 13:858-870, 2013). The avian embryo model of metastasis is a powerful platform to study many of the critical steps in the metastatic cascade including the migration, extravasation, and invasion of human cancer cells in vivo (Sung et al., Nat Commun 6:7164, 2015; Leong et al., Cell Rep 8, 1558-1570, 2014; Kain et al., Dev Dyn 243:216-28, 2014; Leong et al., Nat Protoc 5:1406-17, 2010; Zijlstra et al., Cancer Cell 13:221-234, 2008; Palmer et al., J Vis Exp 51:2815, 2011). The chicken chorioallantoic membrane (CAM) is a readily accessible and well-vascularized tissue that surrounds the developing embryo. When the chicken embryo is grown in a shell-less, ex ovo environment, the nearly transparent CAM provides an ideal environment for high-resolution fluorescent microcopy approaches. In this model, the embryonic chicken vasculature and labeled cancer cells can be visualized simultaneously to investigate specific steps in the metastatic cascade including extravasation. When combined with the proper image analysis tools, the ex ovo chicken embryo model offers a cost-effective and high-throughput platform for the quantitative analysis of tumor cell metastasis in a physiologically relevant in vivo setting. Here we discuss detailed procedures to quantify cancer cell extravasation in the shell-less chicken embryo model with advanced fluorescence microscopy techniques.

Residential energy demand models: Current status and future improvements

NASA Astrophysics Data System (ADS)

Peabody, G.

1980-12-01

Two models currently used to analyze energy use by the residential sector are described. The ORNL model is used to forecast energy use by fuel type for various end uses on a yearly basis. The MATH/CHRDS model analyzes variations in energy expenditures by households of various socioeconomic and demographic characteristics. The essential features of the ORNL and MATH/CHRDS models are retained in a proposed model and integrated into a framework that is more flexible than either model. The important determinants of energy use by households are reviewed.

Theranostic Perspectives in Prostate Cancer with the Gastrin-Releasing Peptide Receptor Antagonist NeoBOMB1: Preclinical and First Clinical Results.

PubMed

Nock, Berthold A; Kaloudi, Aikaterini; Lymperis, Emmanouil; Giarika, Athina; Kulkarni, Harshad R; Klette, Ingo; Singh, Aviral; Krenning, Eric P; de Jong, Marion; Maina, Theodosia; Baum, Richard P

2017-01-01

We recently introduced the potent gastrin-releasing peptide receptor (GRPR) antagonist 68 Ga-SB3 ( 68 Ga-DOTA-p-aminomethylaniline-diglycolic acid-DPhe-Gln-Trp-Ala-Val-Gly-His-Leu-NHEt), showing excellent tumor localizing efficacy in animal models and in patients. By replacement of the C-terminal Leu 13 -Met 14 -NH 2 dipeptide of SB3 by Sta 13 -Leu 14 -NH 2 , the novel GRPR antagonist NeoBOMB1 was generated and labeled with different radiometals for theranostic use. We herein report on the biologic profile of resulting 67/68 Ga-, 111 In-, and 177 Lu-NeoBOMB1 radioligands in GRPR-expressing cells and mouse models. The first evidence of prostate cancer lesion visualization in men using 68 Ga-NeoBOMB1 and PET/CT is also presented. NeoBOMB1 was radiolabeled with 67/68 Ga, 111 In, and 177 Lu according to published protocols. The respective metalated species nat Ga-, nat In-, and nat Lu-NeoBOMB1 were also synthesized and used in competition binding experiments against [ 125 I-Tyr 4 ]BBN in GRPR-positive PC-3 cell membranes. Internalization of 67 Ga-, 111 In-, and 177 Lu-NeoBOMB1 radioligands was studied in PC-3 cells at 37°C, and their metabolic stability in peripheral mouse blood was determined by high-performance liquid chromatography analysis of blood samples. Biodistribution was performed by injecting a 67 Ga-, 111 In-, or 177 Lu-NeoBOMB1 bolus (74, 74, or 370 kBq, respectively, 100 μL, 10 pmol total peptide ± 40 nmol Tyr 4 -BBN: for in vivo GRPR blockade) in severe combined immunodeficiency mice bearing PC-3 xenografts. PET/CT images with 68 Ga-NeoBOMB1 were acquired in prostate cancer patients. NeoBOMB1 and nat Ga-, nat In-, and nat Lu-NeoBOMB1 bound to GRPR with high affinity (half maximal inhibitory concentration, 1-2 nM). 67 Ga-, 111 In-, and 177 Lu-NeoBOMB1 specifically and strongly bound on the cell membrane of PC-3 cells displaying low internalization, as expected for receptor antagonists. They showed excellent metabolic stability in peripheral mouse blood (>95% intact at 5 min after injection). After injection in mice, all 3 ( 67 Ga-, 111 In-, and 177 Lu-NeoBOMB1) showed comparably high and GRPR-specific uptake in the PC-3 xenografts (e.g., 30.6 ± 3.9, 28.6 ± 6.0, and >35 percentage injected dose per gram at 4 h after injection, respectively), clearing from background predominantly via the kidneys. During a translational study in prostate cancer patients, 68 Ga-NeoBOMB1 rapidly localized in pathologic lesions, achieving high-contrast imaging. The GRPR antagonist radioligands 67 Ga-, 111 In-, and 177 Lu-NeoBOMB1, independent of the radiometal applied, have shown comparable behavior in prostate cancer models, in favor of future theranostic use in GRPR-positive cancer patients. Such translational prospects were further supported by the successful visualization of prostate cancer lesions in men using 68 Ga-NeoBOMB1 and PET/CT. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Contact dynamics math model

NASA Technical Reports Server (NTRS)

Glaese, John R.; Tobbe, Patrick A.

1986-01-01

The Space Station Mechanism Test Bed consists of a hydraulically driven, computer controlled six degree of freedom (DOF) motion system with which docking, berthing, and other mechanisms can be evaluated. Measured contact forces and moments are provided to the simulation host computer to enable representation of orbital contact dynamics. This report describes the development of a generalized math model which represents the relative motion between two rigid orbiting vehicles. The model allows motion in six DOF for each body, with no vehicle size limitation. The rotational and translational equations of motion are derived. The method used to transform the forces and moments from the sensor location to the vehicles' centers of mass is also explained. Two math models of docking mechanisms, a simple translational spring and the Remote Manipulator System end effector, are presented along with simulation results. The translational spring model is used in an attempt to verify the simulation with compensated hardware in the loop results.

Polymorphisms in heterocyclic aromatic amines metabolism-related genes are associated with colorectal adenoma risk

PubMed Central

Eichholzer, Monika; Rohrmann, Sabine; Barbir, Aline; Hermann, Silke; Teucher, Birgit; Kaaks, Rudolf; Linseisen, Jakob

2012-01-01

Colorectal adenoma (CRA) and colorectal cancer (CRC) risks have been linked to the intake of red and processed meat. Heterocyclic aromatic amines (HCA) formed herein during high temperature cooking, are metabolized by a variety of enzymes, and allelic variation in the coding genes could influence individual CRA risk. Associations of polymorphisms in NAT1, NAT2, GSTA1, SULT1A1, CYP1A2, UGT1A7, UGT1A9, GSTP1 genes with colorectal adenoma risk were investigated in a nested case-control study of the EPIC-Heidelberg cohort including 428 cases matched by age, sex and year of recruitment with one or two controls (n=828) with negative colonoscopy per case. Genoyping was preformed with the Sequenom MassArray system and the LightCycler 480. Conditional logistic regression was used to compute odds ratios (OR) and corresponding 95% confidence intervals (CI). For rs15561 (NAT1) and rs1057126 (NAT1), the rarer allel was significantly inversely associated with adenoma risk OR=0.80 (95% CI 0.65-0.97) and (OR=0.81 (95% CI 0.65-0.99) and, respectively). For the combined NAT2 alleles encoding for enzymes with medium (versus slow) activity we also observed a significantly inverse association with adenoma risk (OR=0.75; 95% CI 0.85-0.97). In addition, homozygous carriers of the A allele of rs3957357 (GSTA1), i.e., those with a decreased enzyme activity, had a decreased risk of colorectal adenoma with an OR of 0.68 (95% CI 0.50-0.92; AA versus GG/GA). Polymorphisms in the other tested genes did not modify the risk of colorectal adenomas. In conclusion, polymorphisms in NAT1, NAT2, and GSTA1 are related to colorectal adenoma risk in this German cohort. PMID:22724046

Polymorphisms in heterocyclic aromatic amines metabolism-related genes are associated with colorectal adenoma risk.

PubMed

Eichholzer, Monika; Rohrmann, Sabine; Barbir, Aline; Hermann, Silke; Teucher, Birgit; Kaaks, Rudolf; Linseisen, Jakob

2012-01-01

Colorectal adenoma (CRA) and colorectal cancer (CRC) risks have been linked to the intake of red and processed meat. Heterocyclic aromatic amines (HCA) formed herein during high temperature cooking, are metabolized by a variety of enzymes, and allelic variation in the coding genes could influence individual CRA risk. Associations of polymorphisms in NAT1, NAT2, GSTA1, SULT1A1, CYP1A2, UGT1A7, UGT1A9, GSTP1 genes with colorectal adenoma risk were investigated in a nested case-control study of the EPIC-Heidelberg cohort including 428 cases matched by age, sex and year of recruitment with one or two controls (n=828) with negative colonoscopy per case. Genoyping was preformed with the Sequenom MassArray system and the LightCycler 480. Conditional logistic regression was used to compute odds ratios (OR) and corresponding 95% confidence intervals (CI). For rs15561 (NAT1) and rs1057126 (NAT1), the rarer allel was significantly inversely associated with adenoma risk OR=0.80 (95% CI 0.65-0.97) and (OR=0.81 (95% CI 0.65-0.99) and, respectively). For the combined NAT2 alleles encoding for enzymes with medium (versus slow) activity we also observed a significantly inverse association with adenoma risk (OR=0.75; 95% CI 0.85-0.97). In addition, homozygous carriers of the A allele of rs3957357 (GSTA1), i.e., those with a decreased enzyme activity, had a decreased risk of colorectal adenoma with an OR of 0.68 (95% CI 0.50-0.92; AA versus GG/GA). Polymorphisms in the other tested genes did not modify the risk of colorectal adenomas. In conclusion, polymorphisms in NAT1, NAT2, and GSTA1 are related to colorectal adenoma risk in this German cohort.

Mathematical outcomes and working memory in children with TBI and orthopedic injury.

PubMed

Raghubar, Kimberly P; Barnes, Marcia A; Prasad, Mary; Johnson, Chad P; Ewing-Cobbs, Linda

2013-03-01

This study compared mathematical outcomes in children with predominantly moderate to severe traumatic brain injury (TBI; n550) or orthopedic injury (OI; n547) at 2 and 24 months post-injury. Working memory and its contribution to math outcomes at 24 months post-injury was also examined. Participants were administered an experimental cognitive addition task and standardized measures of calculation, math fluency, and applied problems; as well as experimental measures of verbal and visual-spatial working memory. Although children with TBI did not have deficits in foundational math fact retrieval, they performed more poorly than OIs on standardized measures of math. In the TBI group, performance on standardized measures was predicted by age at injury, socioeconomic status, and the duration of impaired consciousness. Children with TBI showed impairments on verbal, but not visual working memory relative to children with OI. Verbal working memory mediated group differences on math calculations and applied problems at 24 months post-injury. Children with TBI have difficulties in mathematics, but do not have deficits in math fact retrieval, a signature deficit of math disabilities. Results are discussed with reference to models of mathematical cognition and disability and the role of working memory in math learning and performance for children with TBI.

Mathematical Outcomes and Working Memory in Children With TBI and Orthopedic Injury

PubMed Central

Raghubar, Kimberly P.; Barnes, Marcia A.; Prasad, Mary; Johnson, Chad P.; Ewing-Cobbs, Linda

2013-01-01

This study compared mathematical outcomes in children with predominantly moderate to severe traumatic brain injury (TBI; n =50) or orthopedic injury (OI; n=47) at 2 and 24 months post-injury. Working memory and its contribution to math outcomes at 24 months post-injury was also examined. Participants were administered an experimental cognitive addition task and standardized measures of calculation, math fluency, and applied problems; as well as experimental measures of verbal and visual-spatial working memory. Although children with TBI did not have deficits in foundational math fact retrieval, they performed more poorly than OIs on standardized measures of math. In the TBI group, performance on standardized measures was predicted by age at injury, socioeconomic status, and the duration of impaired consciousness. Children with TBI showed impairments on verbal, but not visual working memory relative to children with OI. Verbal working memory mediated group differences on math calculations and applied problems at 24 months post-injury. Children with TBI have difficulties in mathematics, but do not have deficits in math fact retrieval, a signature deficit of math disabilities. Results are discussed with reference to models of mathematical cognition and disability and the role of working memory in math learning and performance for children with TBI. PMID:23164058

Polymorphisms in NAT2 (N-acetyltransferase 2) gene in patients with systemic lupus erythematosus.

PubMed

Santos, Elaine Cristina Lima Dos; Pinto, Amanda Chaves; Klumb, Evandro Mendes; Macedo, Jacyara Maria Brito

To investigate potential associations of four substitutions in NAT2 gene and of acetylator phenotype of NAT2 with systemic lupus erythematosus (SLE) and clinical phenotypes. Molecular analysis of 481C>T, 590G>A, 857G>A, and 191G>A substitutions in the NAT2 gene was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique, from DNA extracted from peripheral blood samples obtained from patients with SLE (n=91) and controls (n=97). The 857GA genotype was more prevalent among nonwhite SLE patients (OR=4.01, 95% CI=1.18-13.59). The 481T allele showed a positive association with hematological disorders that involve autoimmune mechanisms, specifically autoimmune hemolytic anemia or autoimmune thrombocytopenia (OR=1.97; 95% CI=1.01-3.81). Copyright © 2016 Elsevier Editora Ltda. All rights reserved.

Disease activity return after natalizumab cessation in multiple sclerosis.

PubMed

Rasenack, Maria; Derfuss, Tobias

2016-05-01

Natalizumab (NAT) was the first monoclonal antibody to be approved for the treatment of relapsing-remitting multiple sclerosis. Its considerable and sustained efficacy has been demonstrated in two phase III studies. However, there are several reasons why its use is limited in clinical practice. The main argument for stopping use of the drug is the risk of the rare but serious progressive multifocal leukencephalopathy. Other reasons are neutralizing antibodies and pregnancy. There is compelling evidence from some clinical trials and many case series that disease activity returns upon suspension or cessation of NAT. Several therapeutic strategies that have been tested to prevent or reduce the recurrence of disease activity will be reviewed in this article. Considering these data, it is evident that the decision to stop NAT treatment has different implications and consequences. A subsequent therapy after cessation of NAT is needed to reduce the risk of disease recurrence.

Markovian Anderson Model: Bounds for the Rate of Propagation

NASA Astrophysics Data System (ADS)

Tcheremchantsev, Serguei

We consider the Anderson model in with potentials whose values at any site of the lattice are Markovian independent random functions of time. For solutions to the time-dependent Schrödinger equation we show under some conditions that with probability 1 where for d=1,2 and for .

Early Math Trajectories: Low-Income Children's Mathematics Knowledge from Ages 4 to 11

ERIC Educational Resources Information Center

Rittle-Johnson, Bethany; Fyfe, Emily R.; Hofer, Kerry G.; Farran, Dale C.

2017-01-01

Early mathematics knowledge is a strong predictor of later academic achievement, but children from low-income families enter school with weak mathematics knowledge. An early math trajectories model is proposed and evaluated within a longitudinal study of 517 low-income American children from ages 4 to 11. This model includes a broad range of math…

Early Math Trajectories: Low-Income Children's Mathematics Knowledge from Age 4 to 11

ERIC Educational Resources Information Center

Rittle-Johnson, Bethany; Fyfe, Emily R.; Hofer, Kerry G.; Farran, Dale C.

2016-01-01

Early mathematics knowledge is a strong predictor of later academic achievement, but children from low-income families enter school with weak mathematics knowledge. An Early Math Trajectories model is proposed and evaluated within a longitudinal study of 517 low-income American children from age 4 to 11. This model includes a broad range of math…

Math anxiety: Brain cortical network changes in anticipation of doing mathematics.

PubMed

Klados, Manousos A; Pandria, Niki; Micheloyannis, Sifis; Margulies, Daniel; Bamidis, Panagiotis D

2017-12-01

Following our previous work regarding the involvement of math anxiety (MA) in math-oriented tasks, this study tries to explore the differences in the cerebral networks' topology between self-reported low math-anxious (LMA) and high math-anxious (HMA) individuals, during the anticipation phase prior to a mathematical related experiment. For this reason, multichannel EEG recordings were adopted, while the solution of the inverse problem was applied in a generic head model, in order to obtain the cortical signals. The cortical networks have been computed for each band separately, using the magnitude square coherence metric. The main graph theoretical parameters, showed differences in segregation and integration in almost all EEG bands of the HMAs in comparison to LMAs, indicative of a great influence of the anticipatory anxiety prior to mathematical performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Distinct influences of affective and cognitive factors on children's non-verbal and verbal mathematical abilities.

PubMed

Wu, Sarah S; Chen, Lang; Battista, Christian; Smith Watts, Ashley K; Willcutt, Erik G; Menon, Vinod

2017-09-01

Individual differences in children's math performance have been associated with math anxiety, attention problems, working memory (WM), and reading skills, but the mechanisms by which these factors jointly contribute to children's math achievement are unknown. Here, we use structural equation modeling to characterize the relation between these factors and their influence on non-verbal Numerical Operations (NO) and verbal Math Reasoning (MR) in 330 children (M=8.34years). Our findings indicate that WM plays a central role in both non-verbal NO and verbal MR, whereas math anxiety and reading comprehension have unique and more pronounced influences on MR, compared to NO. Our study elucidates how affective and cognitive factors distinctly influence non-verbal and verbal mathematical problem solving. Copyright © 2017 Elsevier B.V. All rights reserved.

The influence of female social models in corporate STEM initiatives on girls' math and science attitudes

NASA Astrophysics Data System (ADS)

Medeiros, Donald J.

The United States' Science, Technology, Engineering, and Mathematics (STEM) workforce is growing slower than in the past, in comparison to demand, and in comparison to other countries. Competitive talent conditions require the United States to develop a strong pipeline of STEM talent within its own citizens. Given the number of female college graduates and their underrepresentation in the STEM workforce, women provide the greatest opportunity for fulfilling this need. The term social model represents the individuals and media that shape children's self-perceptions. Social models have been shown to positively influence girl's perceptions of the value of math and science as well as their expectations of success. This study examined differences in attitudes towards math and science among student participants in corporate STEM programs. Differences were measured based on participant gender and ethnicity, their mentor's gender and ethnicity, and program design differences. The research purpose was to inform the design of corporate STEM programs to improve female participants' attitudes towards math and science and eventually increase the number of women in the STEM workforce. Over three hundred students in differing corporate STEM programs completed math and science attitudinal scales at the start and end of their programs. Study results revealed, prior to program start, female participants had a better attitude towards math and science than male participants. Analysis of the Trends in International Mathematics and Science Study data showed similar results. Overall program results demonstrated higher post program math and science attitudes with no differences based on gender, age, or ethnicity of the participant or mentor. Participants with high program or mentor satisfaction were found to have higher attitudes towards math and science. These results may suggest improving female academic choice requires more focus on their expectations of success than perceived task value. Male attitudes towards women's role in STEM fields may also require attention. Increasing attitudes seems best achieved through ensuring a highly satisfying experience with the program and their mentor. Study results suggest this requires more considerations than simply matching mentor and mentee race or gender. Reliability results of attitudinal scales provided guidance on assessment strategies.

Eulerian Dynamics with a Commutator Forcing

DTIC Science & Technology

2017-01-09

SIAM Review 56(4) (2014) 577–621. [Pes2015] J. Peszek. Discrete Cucker-Smale flocking model with a weakly singular weight. SIAM J. Math . Anal., to...viscosities in bounded domains. J. Math . Pures Appl. (9), 87(2):227– 235, 2007. [CV2010] L. Caffarelli, A. Vasseur, Drift diffusion equations with...Further time regularity for fully non-linear parabolic equations. Math . Res. Lett., 22(6):1749–1766, 2015. [CCTT2016] José A. Carrillo, Young-Pil

Modifying effect of N-acetyltransferase 2 genotype on the association between systemic lupus erythematosus and consumption of alcohol and caffeine-rich beverages.

PubMed

Kiyohara, Chikako; Washio, Masakazu; Horiuchi, Takahiko; Asami, Toyoko; Ide, Saburo; Atsumi, Tatsuya; Kobashi, Gen; Takahashi, Hiroki; Tada, Yoshifumi

2014-07-01

N-acetyltransferase 2 (NAT2) is involved in the metabolism of various environmental substances, both with and without carcinogenic potential. Alcoholic and nonalcoholic caffeine-rich beverages may be associated with markers of inflammation. Systemic lupus erythematosus (SLE) is a chronic, multifaceted inflammatory disease. We investigated the effects of alcoholic and nonalcoholic caffeine-rich beverages on risk of SLE and determined whether the effects were modified by NAT2 status. The NAT2 polymorphism was genotyped in 152 SLE cases and 427 healthy controls, all women and Japanese. We assessed effect modification by testing an interaction term for the NAT2 polymorphism and consumption of beverages. Consumption of black tea (odds ratio [OR] 1.88, 95% confidence interval [95% CI] 1.03-3.41) and coffee (OR 1.57, 95% CI 0.95-2.61), but not green tea, was associated with an increased risk of SLE, while alcohol use (OR 0.33, 95% CI 0.20-0.55) was associated with a decreased risk of SLE. There were significant interactions between the NAT2 polymorphism and either alcohol use (Pinteraction = 0.026) or consumption of black tea (Pinteraction = 0.048). The NAT2 polymorphism significantly modified the effects of alcohol use and black tea consumption on SLE, emphasizing the importance of incorporating genetic and metabolic information in studies on management of SLE. Additional studies are warranted to confirm the findings suggested in this study. Copyright © 2014 by the American College of Rheumatology.

Nyctanthes arbor-tristis Ameliorated FCA-Induced Experimental Arthritis: A Comparative Study among Different Extracts

PubMed Central

Uroos, Maliha; Sattar, Shumaila; Umer, Nigarish; Sharif, Ahsan

2017-01-01

Nyctanthes arbor-tristis (NAT) is commonly used traditionally for the treatment of rheumatism and inflammatory diseases. Current study evaluates the antiarthritic potential of NAT using Freund's adjuvant-induced arthritic rat model. Treatments with methanolic, ethyl acetate, and n-hexane extracts were continued for consecutive 20 days. Macroscopic arthritic scoring and water displacement plethysmometry were used to evaluate arthritic development. Hematological and biochemical parameters were investigated and ankle joints were processed for histopathological evaluation. Qualitative phytochemical analysis and GC-MS analysis were conducted for identification of constituents. NAT extracts suppressed arthritic scoring, paw edema, infiltration of inflammatory cells, pannus formation, and bone erosion. The plant extracts ameliorated total leukocytes and platelet counts and nearly normalized red blood cells (RBC) counts and hemoglobin (Hb) content. The extracts were found safe in terms of hepatotoxicity and nephrotoxicity as determined by aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and urea levels. Comparative analysis showed that ethyl acetate extract produced the highest inhibition of paw edema. The major constituents found in ethyl acetate extract can be classified into three major classes, that is, terpenes, terpenoids, fatty acids, and iridoid glycosides. Current study showed that Nyctanthes arbor-tristis ameliorated experimental rheumatoid arthritis and ethyl acetate extract possessed the highest inhibitory activity. PMID:28676830

Testicular dysfunction in experimental chronic renal insufficiency: a deficiency of nocturnal pineal N-acetyltransferase activity.

PubMed Central

Holmes, E. W.; Hojvat, S. A.; Kahn, S. E.; Bermes, E. W.

1989-01-01

Biochemical correlates of neuroendocrine/gonadal function and nocturnal levels of serotonin N-acetyltransferase (NAT) activity were determined in partially nephrectomized (PNx), male, Long Evans rats following a 5-week period of chronic renal insufficiency (CRI). PNx animals demonstrated two to four-fold elevations in urea nitrogen and three to four-fold reductions (P less than 0.02) in plasma total testosterone concentrations as compared to sham-operated controls. The pituitary LH contents of PNx rats were decreased to approximately 60% of the control value (P less than 0.05). There were no differences in plasma prolactin levels between the control and PNx groups either at mid-day or in the middle of the night. Nocturnal pineal NAT activity in PNx rats was markedly reduced to approximately 20% of the control value (P less than 0.001). Similar evidence of gonadal dysfunction (reduced plasma total testosterone and testes testosterone content) and a significant decrease in night-time levels of pineal NAT activity were also observed after 13 weeks of CRI in PNx rats of the Sprague-Dawley strain that were housed under a different photoperiod. These results suggest that pineal gland dysfunction is a feature of CRI in the PNx model. Such an abnormality might contribute to the pathogenesis of gonadal dysfunction in CRI. PMID:2765391

Remediation of Childhood Math Anxiety and Associated Neural Circuits through Cognitive Tutoring.

PubMed

Supekar, Kaustubh; Iuculano, Teresa; Chen, Lang; Menon, Vinod

2015-09-09

Math anxiety is a negative emotional reaction that is characterized by feelings of stress and anxiety in situations involving mathematical problem solving. High math-anxious individuals tend to avoid situations involving mathematics and are less likely to pursue science, technology, engineering, and math-related careers than those with low math anxiety. Math anxiety during childhood, in particular, has adverse long-term consequences for academic and professional success. Identifying cognitive interventions and brain mechanisms by which math anxiety can be ameliorated in children is therefore critical. Here we investigate whether an intensive 8 week one-to-one cognitive tutoring program designed to improve mathematical skills reduces childhood math anxiety, and we identify the neurobiological mechanisms by which math anxiety can be reduced in affected children. Forty-six children in grade 3, a critical early-onset period for math anxiety, participated in the cognitive tutoring program. High math-anxious children showed a significant reduction in math anxiety after tutoring. Remarkably, tutoring remediated aberrant functional responses and connectivity in emotion-related circuits anchored in the basolateral amygdala. Crucially, children with greater tutoring-induced decreases in amygdala reactivity had larger reductions in math anxiety. Our study demonstrates that sustained exposure to mathematical stimuli can reduce math anxiety and highlights the key role of the amygdala in this process. Our findings are consistent with models of exposure-based therapy for anxiety disorders and have the potential to inform the early treatment of a disability that, if left untreated in childhood, can lead to significant lifelong educational and socioeconomic consequences in affected individuals. Significance statement: Math anxiety during early childhood has adverse long-term consequences for academic and professional success. It is therefore important to identify ways to alleviate math anxiety in young children. Surprisingly, there have been no studies of cognitive interventions and the underlying neurobiological mechanisms by which math anxiety can be ameliorated in young children. Here, we demonstrate that intensive 8 week one-to-one cognitive tutoring not only reduces math anxiety but also remarkably remediates aberrant functional responses and connectivity in emotion-related circuits anchored in the amygdala. Our findings are likely to propel new ways of thinking about early treatment of a disability that has significant implications for improving each individual's academic and professional chances of success in today's technological society that increasingly demands strong quantitative skills. Copyright © 2015 the authors 0270-6474/15/3512574-10$15.00/0.

Simulations of Flame Acceleration and Deflagration-to-Detonation Transitions in Methane-Air Systems

DTIC Science & Technology

2010-03-17

are neglected. 3. Model parameter calibration The one-step Arrhenius kinetics used in this model cannot ex- actly reproduce all properties of laminar...with obstacles are compared to previ- ously reported experimental data. The results obtained using the simple reaction model qualitatively, and in...have taken in developing a multidimensional numerical model to study explosions in large-scale systems containing mixtures of nat- ural gas and air

Recent Naval Postgraduate School Publications.

DTIC Science & Technology

1982-04-01

477 p. Haney, R L; et al.; eds. Ocean models for climate research: A workshop Sponsored by the U.S. Committee for the Global Atmos. Hes. Program. Nat... climate variability Oceanus, vol. 21, no. 4, p. 33-39, (1978). Williams, R T A review of theoretical models of atmospheric frontogenesis Chapman Conf...structure in large-scale optimization models Symp. 9 n Computer-Assisted Analysis and Model Simpification, Boulder, Colo., Mar. 24, 1980. Brown, G G

3-D microphysical model studies of Arctic denitrification: comparison with observations

NASA Astrophysics Data System (ADS)

Davies, S.; Mann, G. W.; Carslaw, K. S.; Chipperfield, M. P.; Kettleborough, J. A.; Santee, M. L.; Oelhaf, H.; Wetzel, G.; Sasano, Y.; Sugita, T.

2005-11-01

Simulations of Arctic denitrification using a 3-D chemistry-microphysics transport model are compared with observations for the winters 1994/95, 1996/97 and 1999/2000. The model of Denitrification by Lagrangian Particle Sedimentation (DLAPSE) couples the full chemical scheme of the 3-D chemical transport model, SLIMCAT, with a nitric acid trihydrate (NAT) growth and sedimentation scheme. We use observations from the Microwave Limb Sounder (MLS) and Improved Limb Atmospheric Sounder (ILAS) satellite instruments, the balloon-borne Michelsen Interferometer for Passive Atmospheric Sounding (MIPAS-B), and the in situ NOy instrument on-board the ER-2. As well as directly comparing model results with observations, we also assess the extent to which these observations are able to validate the modelling approach taken. For instance, in 1999/2000 the model captures the temporal development of denitrification observed by the ER-2 from late January into March. However, in this winter the vortex was already highly denitrified by late January so the observations do not provide a strong constraint on the modelled rate of denitrification. The model also reproduces the MLS observations of denitrification in early February 2000. In 1996/97 the model captures the timing and magnitude of denitrification as observed by ILAS, although the lack of observations north of ~67° N in the beginning of February make it difficult to constrain the actual timing of onset. The comparison for this winter does not support previous conclusions that denitrification must be caused by an ice-mediated process. In 1994/95 the model notably underestimates the magnitude of denitrification observed during a single balloon flight of the MIPAS-B instrument. Agreement between model and MLS HNO3 at 68 hPa in mid-February 1995 is significantly better. Sensitivity tests show that a 1.5 K overall decrease in vortex temperatures, or a factor 4 increase in assumed NAT nucleation rates, produce the best statistical fit to MLS observations. Both adjustments would be required to bring the model into agreement with the MIPAS-B observations. The agreement between the model and observations suggests that a NAT-only denitrification scheme (without ice), which was discounted by previous studies, must now be considered as one mechanism for the observed Arctic denitrification. The timing of onset and the rate of denitrification remain poorly constrained by the available observations.

3-D microphysical model studies of Arctic denitrification: comparison with observations

NASA Astrophysics Data System (ADS)

Davies, S.; Mann, G. W.; Carslaw, K. S.; Chipperfield, M. P.; Kettleborough, J. A.; Santee, M. L.; Oelhaf, H.; Wetzel, G.; Sasano, Y.; Sugita, T.

2005-01-01

Simulations of Arctic denitrification using a 3-D chemistry-microphysics transport model are compared with observations for the winters 1994/1995, 1996/1997 and 1999/2000. The model of Denitrification by Lagrangian Particle Sedimentation (DLAPSE) couples the full chemical scheme of the 3-D chemical transport model, SLIMCAT, with a nitric acid trihydrate (NAT) growth and sedimentation scheme. We use observations from the Microwave Limb Sounder (MLS) and Improved Limb Atmospheric Sounder (ILAS) satellite instruments, the balloon-borne Michelsen Interferometer for Passive Atmospheric Sounding (MIPAS-B), and the in situ NOy instrument on-board the ER-2. As well as directly comparing model results with observations, we also assess the extent to which these observations are able to validate the modelling approach taken. For instance, in 1999/2000 the model captures the temporal development of denitrification observed by the ER-2 from late January into March. However, in this winter the vortex was already highly denitrified by late January so the observations do not provide a strong constraint on the modelled rate of denitrification. The model also reproduces the MLS observations of denitrification in early February 2000. In 1996/1997 the model captures the timing and magnitude of denitrification as observed by ILAS, although the lack of observations north of ~67° N make it difficult to constrain the actual timing of onset. The comparison for this winter does not support previous conclusions that denitrification must be caused by an ice-mediated process. In 1994/1995 the model notably underestimates the magnitude of denitrification observed during a single balloon flight of the MIPAS-B instrument. Agreement between model and MLS HNO3 at 68 hPa in mid-February 1995 was significantly better. Sensitivity tests show that a 1.5 K overall decrease in vortex temperatures or a factor 4 increase in assumed NAT nucleation rates produce the best statistical fit to MLS observations. Both adjustments would be required to bring the model into agreement with the MIPAS-B observations. The agreement between the model and observations suggests that a NAT-only denitrification scheme (without ice), which was discounted by previous studies, must now be considered as one mechanism for the observed Arctic denitrification. The timing of onset and the rate of denitrification remain poorly constrained by the available observations.

Predictive model for early math skills based on structural equations.

PubMed

Aragón, Estíbaliz; Navarro, José I; Aguilar, Manuel; Cerda, Gamal; García-Sedeño, Manuel

2016-12-01

Early math skills are determined by higher cognitive processes that are particularly important for acquiring and developing skills during a child's early education. Such processes could be a critical target for identifying students at risk for math learning difficulties. Few studies have considered the use of a structural equation method to rationalize these relations. Participating in this study were 207 preschool students ages 59 to 72 months, 108 boys and 99 girls. Performance with respect to early math skills, early literacy, general intelligence, working memory, and short-term memory was assessed. A structural equation model explaining 64.3% of the variance in early math skills was applied. Early literacy exhibited the highest statistical significance (β = 0.443, p < 0.05), followed by intelligence (β = 0.286, p < 0.05), working memory (β = 0.220, p < 0.05), and short-term memory (β = 0.213, p < 0.05). Correlations between the independent variables were also significant (p < 0.05). According to the results, cognitive variables should be included in remedial intervention programs. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Effects of Small-Group Tutoring with and without Validated Classroom Instruction on At-Risk Students' Math Problem Solving: Are Two Tiers of Prevention Better Than One?

PubMed

Fuchs, Lynn S; Fuchs, Douglas; Craddock, Caitlin; Hollenbeck, Kurstin N; Hamlett, Carol L; Schatschneider, Christopher

2008-01-01

The purpose of this study was to assess the effects of small-group tutoring with and without validated classroom instruction on at-risk (AR) students' math problem solving. Stratifying within schools, 119 3(rd)-grade classes were randomly assigned to conventional or validated problem-solving instruction (Hot Math [schema-broadening instruction]). Students identified as AR (n = 243) were randomly assigned, within classroom conditions, to receive Hot Math tutoring or not. Students were tested on problem-solving and math applications measures before and after 16 weeks of intervention. Analyses of variance, which accounted for the nested structure of the data, revealed the tutored students who received validated classroom instruction achieved better than tutored students who received conventional classroom instruction (ES = 1.34). However, the advantage for tutoring over no tutoring was similar whether or not students received validated or conventional classroom instruction (ESs = 1.18 and 1.13). Tutoring, not validated classroom instruction reduced the prevalence of math difficulty. Implications for responsiveness-to-intervention prevention models and for enhancing math problem-solving instruction are discussed.

Effects of Small-Group Tutoring with and without Validated Classroom Instruction on At-Risk Students' Math Problem Solving: Are Two Tiers of Prevention Better Than One?

PubMed Central

Fuchs, Lynn S.; Fuchs, Douglas; Craddock, Caitlin; Hollenbeck, Kurstin N.; Hamlett, Carol L.; Schatschneider, Christopher

2008-01-01

The purpose of this study was to assess the effects of small-group tutoring with and without validated classroom instruction on at-risk (AR) students' math problem solving. Stratifying within schools, 119 3rd-grade classes were randomly assigned to conventional or validated problem-solving instruction (Hot Math [schema-broadening instruction]). Students identified as AR (n = 243) were randomly assigned, within classroom conditions, to receive Hot Math tutoring or not. Students were tested on problem-solving and math applications measures before and after 16 weeks of intervention. Analyses of variance, which accounted for the nested structure of the data, revealed the tutored students who received validated classroom instruction achieved better than tutored students who received conventional classroom instruction (ES = 1.34). However, the advantage for tutoring over no tutoring was similar whether or not students received validated or conventional classroom instruction (ESs = 1.18 and 1.13). Tutoring, not validated classroom instruction reduced the prevalence of math difficulty. Implications for responsiveness-to-intervention prevention models and for enhancing math problem-solving instruction are discussed. PMID:19122881

A Temperature-Dependent Phase-Field Model for Phase Separation and Damage

NASA Astrophysics Data System (ADS)

Heinemann, Christian; Kraus, Christiane; Rocca, Elisabetta; Rossi, Riccarda

2017-07-01

In this paper we study a model for phase separation and damage in thermoviscoelastic materials. The main novelty of the paper consists in the fact that, in contrast with previous works in the literature concerning phase separation and damage processes in elastic media, in our model we encompass thermal processes, nonlinearly coupled with the damage, concentration and displacement evolutions. More particularly, we prove the existence of "entropic weak solutions", resorting to a solvability concept first introduced in Feireisl (Comput Math Appl 53:461-490, 2007) in the framework of Fourier-Navier-Stokes systems and then recently employed in Feireisl et al. (Math Methods Appl Sci 32:1345-1369, 2009) and Rocca and Rossi (Math Models Methods Appl Sci 24:1265-1341, 2014) for the study of PDE systems for phase transition and damage. Our global-in-time existence result is obtained by passing to the limit in a carefully devised time-discretization scheme.

Integrating Security into the Curriculum

DTIC Science & Technology

1998-12-01

predicate calculus, discrete math , and finite-state machine the- ory. In addition to applying standard mathematical foundations to constructing hardware and...models, specifi- cations, and the use of formal methods for verification and covert channel analysis. The means for analysis is based on discrete math , information

Strategy for selecting nanotechnology carriers to overcome immunological and hematological toxicities challenging clinical translation of nucleic acid-based therapeutics.

PubMed

Dobrovolskaia, Marina A; McNeil, Scott E

2015-07-01

Clinical translation of nucleic acid-based therapeutics (NATs) is hampered by assorted challenges in immunotoxicity, hematotoxicity, pharmacokinetics, toxicology and formulation. Nanotechnology-based platforms are being considered to help address some of these challenges due to the nanoparticles' ability to change drug biodistribution, stability, circulation half-life, route of administration and dosage. Addressing toxicology and pharmacology concerns by various means including NATs reformulation using nanotechnology-based carriers has been reviewed before. However, little attention was given to the immunological and hematological issues associated with nanotechnology reformulation. This review focuses on application of nanotechnology carriers for delivery of various types of NATs, and how reformulation using nanoparticles affects immunological and hematological toxicities of this promising class of therapeutic agents. NATs share several immunological and hematological toxicities with common nanotechnology carriers. In order to avoid synergy or exaggeration of undesirable immunological and hematological effects of NATs by a nanocarrier, it is critical to consider the immunological compatibility of the nanotechnology platform and its components. Since receptors sensing nucleic acids are located essentially in all cellular compartments, a strategy for developing a nanoformulation with reduced immunotoxicity should first focus on precise delivery to the target site/cells and then on optimizing intracellular distribution.

N-acetyltransferase gene polymorphisms & plasma isoniazid concentrations in patients with tuberculosis

PubMed Central

Hemanth Kumar, A. K.; Ramesh, K.; Kannan, T.; Sudha, V.; Haribabu, Hemalatha; Lavanya, J.; Swaminathan, Soumya; Ramachandran, Geetha

2017-01-01

Background & objectives: Variations in the N-acetyltransferase (NAT2) gene among different populations could affect the metabolism and disposition of isoniazid (INH). This study was performed to genotype NAT2 gene polymorphisms in tuberculosis (TB) patients from Chennai, India, and compare plasma INH concentrations among the different genotypes. Methods: Adult patients with TB treated in the Revised National TB Control Programme (RNTCP) in Chennai, Tamil Nadu, were genotyped for NAT2 gene polymorphism, and two-hour post-dosing INH concentrations were compared between the different genotypes. Plasma INH was determined by high-performance liquid chromatography. Genotyping of the NAT2 gene polymorphism was performed by real-time polymerase chain reaction method. Results: Among the 326 patients genotyped, there were 189 (58%), 114 (35%) and 23 (7%) slow, intermediate and fast acetylators, respectively. The median two-hour INH concentrations in slow, intermediate and fast acetylators were 10.2, 8.1 and 4.1 μg/ml, respectively. The differences in INH concentrations among the three genotypes were significant (P<0.001). Interpretation & conclusions: Genotyping of TB patients from south India for NAT2 gene polymorphism revealed that 58 per cent of the study population comprised slow acetylators. Two-hour INH concentrations differed significantly among the three genotypes. PMID:28574024

N-terminal acetylation -an Essential Protein Modification Emerges as an Important Regulator of Stress Responses.

PubMed

Linster, Eric; Wirtz, Markus

2018-06-26

N-terminal acetylation (NTA) is a prevalent protein modification in eukaryotes. The majority of proteins is acetylated at their N-terminus in a co-translational manner by ribosome-associated N-terminal acetyltransferases (NAT). However, the recent discovery of Golgi-membrane localized NATs in metazoan, and plastid-localized NATs in plants challenged the dogma of static, co-translational imprinting of the proteome by NTA. Indeed, NTA by the cytosolic NatA is highly dynamic and under hormonal control in plants. Such active control has not been evidenced yet in other eukaryotes and might be an adaptation to the sessile lifestyle of plants forcing them to cope with diverse environmental challenges. The function of NTA for individual proteins is distinct and yet unpredictable. In yeast and humans, NTA has been shown to affect protein-protein interactions, subcellular localization, folding, aggregation, or degradation of a handful of proteins. In particular, the impact of NTA on the protein-turnover is documented by diverse examples in yeast. Consequently, NTA has recently dicovered to be a degradation signal in a distinct branch of the N-end rule pathway ubiquitin-mediated proteolysis. In this review, we summarize the current knowledge on the NAT machinery in higher plants and discuss the potential function of NTA during biotic and abiotic stresses.

Bystander protein protects potential vaccine-targeting ligands against intestinal proteolysis.

PubMed

Reuter, Fabian; Bade, Steffen; Hirst, Timothy R; Frey, Andreas

2009-07-20

Endowing mucosal vaccines with ligands that target antigen to mucosal lymphoid tissues may improve immunization efficacy provided that the ligands withstand the proteolytic environment of the gastro-intestinal tract until they reach their destination. Our aim was to investigate whether and how three renowned ligands - Ulex europaeus agglutinin I and the B subunits of cholera toxin and E. coli heat-labile enterotoxin - master this challenge. We assessed the digestive power of natural murine intestinal fluid (natIF) using assays for trypsin, chymotrypsin and pancreatic elastase along with a test for nonspecific proteolysis. The natIF was compared with simulated murine intestinal fluid (simIF) that resembled the trypsin, chymotrypsin and elastase activities of its natural counterpart but lacked or contained albumins as additional protease substrates. The ligands were exposed to the digestive fluids and degradation was determined. The studies revealed that (i) the three pancreatic endoproteases constitute only one third of the total protease activity of natIF and (ii) the ligands resist proteolysis in natIF and protein-enriched simIF over 3 h but (iii) are partially destroyed in simIF that lacks additional protease substrate. We assume that the proteins of natIF are preferred substrates for the intestinal proteases and thus can protect vaccine-targeting ligands from destruction.

Nitroxidative chemistry interferes with fluorescent probe chemistry: implications for nitric oxide detection using 2,3-diaminonaphthalene.

PubMed

Hu, Teh-Min; Chiu, Shih-Jiuan; Hsu, Yu-Ming

2014-08-22

Simultaneous production of nitric oxide (NO) and superoxide generates peroxynitrite and causes nitroxidative stress. The fluorometric method for NO detection is based on the formation of a fluorescent product from the reaction of a nonfluorescent probe molecule with NO-derived nitrosating species. Here, we present an example of how nitroxidative chemistry could interact with fluorescent probe chemistry. 2,3-Naphthotriazole (NAT) is the NO-derived fluorescent product of 2,3-diaminonaphthalene (DAN), a commonly used NO-detecting molecule. We show that NO/superoxide cogeneration, and particularly peroxynitrite, mediates the chemical decomposition of NAT. Moreover, the extent of NAT decomposition depends on the relative fluxes of NO and superoxide; the maximum effect being reached at almost equivalent generation rates for both radicals. The rate constant for the reaction of NAT with peroxynitrite was determined to be 2.2×10(3)M(-1)s(-1). Further, various peroxynitrite scavengers were shown to effectively inhibit NO/superoxide- and peroxynitrite-mediated decomposition of NAT. Taken together, the present study suggests that the interference of a fluorometric NO assay can be originated from the interaction between the final fluorescent product and the formed reactive nitrogen and oxygen species. Copyright © 2014 Elsevier Inc. All rights reserved.

Cocaine alters Homer1 natural antisense transcript in the nucleus accumbens.

PubMed

Sartor, Gregory C; Powell, Samuel K; Velmeshev, Dmitry; Lin, David Y; Magistri, Marco; Wiedner, Hannah J; Malvezzi, Andrea M; Andrade, Nadja S; Faghihi, Mohammad A; Wahlestedt, Claes

2017-12-01

Natural antisense transcripts (NATs) are an abundant class of long noncoding RNAs that have recently been shown to be key regulators of chromatin dynamics and gene expression in nervous system development and neurological disorders. However, it is currently unclear if NAT-based mechanisms also play a role in drug-induced neuroadaptations. Aberrant regulation of gene expression is one critical factor underlying the long-lasting behavioral abnormalities that characterize substance use disorder, and it is possible that some drug-induced transcriptional responses are mediated, in part, by perturbations in NAT activity. To test this hypothesis, we used an automated algorithm that mines the NCBI AceView transcriptomics database to identify NAT overlapping genes linked to addiction. We found that 22% of the genes examined contain NATs and that expression of Homer1 natural antisense transcript (Homer1-AS) was altered in the nucleus accumbens (NAc) of mice 2h and 10days following repeated cocaine administration. In in vitro studies, depletion of Homer1-AS lead to an increase in the corresponding sense gene expression, indicating a potential regulatory mechanisms of Homer1 expression by its corresponding antisense transcript. Future in vivo studies are needed to definitely determine a role for Homer1-AS in cocaine-induced behavioral and molecular adaptations. Copyright © 2017 Elsevier Inc. All rights reserved.

Application of nonlinear adaptive motion washout to transport ground-handling simulation

NASA Technical Reports Server (NTRS)

Parrish, R. V.; Martin, D. J., Jr.

1983-01-01

The application of a nonlinear coordinated adaptive motion washout to the transport ground-handling environment is documented. Additions to both the aircraft math model and the motion washout system are discussed. The additions to the simulated-aircraft math model provided improved modeling fidelity for braking and reverse-thrust application, and the additions to the motion-base washout system allowed transition from the desired flight parameters to the less restrictive ground parameters of the washout.

ERRATUM: Papers published in incorrect sections

NASA Astrophysics Data System (ADS)

2004-04-01

A number of J. Phys. A: Math. Gen. articles have mistakenly been placed in the wrong subject section in recent issues of the journal. We would like to apologize to the authors of these articles for publishing their papers in the Fluid and Plasma Theory section. The correct section for each article is given below. Statistical Physics Issue 4: Microcanonical entropy for small magnetizations Behringer H 2004 J. Phys. A: Math. Gen. 37 1443 Mathematical Physics Issue 9: On the solution of fractional evolution equations Kilbas A A, Pierantozzi T, Trujillo J J and Vázquez L 2004 J. Phys. A: Math. Gen. 37 3271 Quantum Mechanics and Quantum Information Theory Issue 6: New exactly solvable isospectral partners for PT-symmetric potentials Sinha A and Roy P 2004 J. Phys. A: Math. Gen. 37 2509 Issue 9: Symplectically entangled states and their applications to coding Vourdas A 2004 J. Phys. A: Math. Gen. 37 3305 Classical and Quantum Field Theory Issue 6: Pairing of parafermions of order 2: seniority model Nelson C A 2004 J. Phys. A: Math. Gen. 37 2497 Issue 7: Jordan-Schwinger map, 3D harmonic oscillator constants of motion, and classical and quantum parameters characterizing electromagnetic wave polarization Mota R D, Xicoténcatl M A and Granados V D 2004 J. Phys. A: Math. Gen. 37 2835 Issue 9: Could only fermions be elementary? Lev F M 2004 J. Phys. A: Math. Gen. 37 3285

Comparative genomic and phylogenetic investigation of the xenobiotic metabolizing arylamine N-acetyltransferase enzyme family

USDA-ARS?s Scientific Manuscript database

Arylamine N-acetyltransferases (NATs) are xenobiotic metabolizing enzymes characterized in several bacteria and eukaryotic organisms. We report a comprehensive phylogenetic analysis employing an exhaustive dataset of NAT-homologous sequences recovered through inspection of 2445 genomes. We describe ...

Mathematical and Computational Aspects Related to Soil Modeling and Simulation

DTIC Science & Technology

2017-09-26

and simulation challenges at the interface of applied math (homogenization, handling of discontinuous behavior, discrete vs. continuum representations...applied math tools need to be established and used to figure out how to impose compatible boundary conditions, how to better approximate the gradient

Studying Gender and Ethnic Differences in Participation in Math, Physical Science, and Information Technology

ERIC Educational Resources Information Center

Eccles, Jacquelynne S.

2005-01-01

This chapter describes the history of the Eccles et al. Expectancy Value Model and research on the influence of social and psychological factors on gender and ethnic differences in math, science, and information technology choices. (Contains 1 figure.)

Performing Big Math Ideas across the Grades

ERIC Educational Resources Information Center

Gadanidis, George; Hughes, Janette M.

2011-01-01

A storied math context helps students engage both emotionally and cognitively with mathematics and helps show that mathematics develops out of human experience. Children's literature also models mathematical storytelling for students, and creates opportunities for them to retell and extend stories. This article describes mathematics investigations…

Special health care needs explains the effect of extremely low birth weight on math but not language achievement.

PubMed

Litt, Jonathan S; Minich, Nori; Taylor, H Gerry; Hack, Maureen

2017-12-01

Extremely low birth weight (ELBW; <1kg) adolescents are at risk for special health care needs (SHCN) and poor math achievement compared to normal birth weight (NBW) peers. SHCN are associated with poor academic achievement among NBW children. We hypothesize that SHCN explain the effect of ELBW on math achievement. We compared age 14 Woodcock-Johnson Calculation standard scores between 181 ELBW infants and 115 NBW controls. Persistent SHCN included: 1) prescription medication or equipment use, 2) subspecialty or therapeutic service use, or 3) hospitalization. We used nonlinear marginal effects models to decompose the total effect of ELBW on math into the following 4 components: the effect of ELBW controlling for SHCN, the effect of SHCN controlling for ELBW, effect modification by SHCN, and mediated interaction where SHCN is both causal mediator and effect modifier. Models were adjusted for sociodemographic factors. ELBW adolescents had lower mean math scores than NBW peers (81.3 vs. 96.4). SHCN were more common among ELBW adolescents (54.1% vs. 27%). The total effect of ELBW on math scores was -15.7 points (95% CI -21.0, -10.5). The effect of birth weight alone was -7.6 points (95% CI -13.7, -1.4); the effect of SHCN alone was negligible. SHCN interaction and mediated interaction effects each accounted for 25% of the total effect. Birth weight alone explains only half of the effect of ELBW on math achievement. We found evidence of effect modification and mediation by SHCN. Understanding these explanatory pathways may lead to targeted interventions for improved outcomes. Copyright © 2017. Published by Elsevier B.V.

Single nucleotide polymorphism coverage and inference of N-acetyltransferase-2 acetylator phenotypes in wordwide population groups.

PubMed

Suarez-Kurtz, Guilherme; Fuchshuber-Moraes, Mateus; Struchiner, Claudio J; Parra, Esteban J

2016-08-01

Several algorithms have been proposed to reduce the genotyping effort and cost, while retaining the accuracy of N-acetyltransferase-2 (NAT2) phenotype prediction. Data from the 1000 Genomes (1KG) project and an admixed cohort of Black Brazilians were used to assess the accuracy of NAT2 phenotype prediction using algorithms based on paired single nucleotide polymorphisms (SNPs) (rs1041983 and rs1801280) or a tag SNP (rs1495741). NAT2 haplotypes comprising SNPs rs1801279, rs1041983, rs1801280, rs1799929, rs1799930, rs1208 and rs1799931 were assigned according to the arylamine N-acetyltransferases database. Contingency tables were used to visualize the agreement between the NAT2 acetylator phenotypes on the basis of these haplotypes versus phenotypes inferred by the prediction algorithms. The paired and tag SNP algorithms provided more than 96% agreement with the 7-SNP derived phenotypes in Europeans, East Asians, South Asians and Admixed Americans, but discordance of phenotype prediction occurred in 30.2 and 24.8% 1KG Africans and in 14.4 and 18.6% Black Brazilians, respectively. Paired SNP panel misclassification occurs in carriers of NATs haplotypes *13A (282T alone), *12B (282T and 803G), *6B (590A alone) and *14A (191A alone), whereas haplotype *14, defined by the 191A allele, is the major culprit of misclassification by the tag allele. Both the paired SNP and the tag SNP algorithms may be used, with economy of scale, to infer NAT2 acetylator phenotypes, including the ultra-slow phenotype, in European, East Asian, South Asian and American populations represented in the 1KG cohort. Both algorithms, however, perform poorly in populations of predominant African descent, including admixed African-Americans, African Caribbeans and Black Brazilians.

Interactions of Cigarette Smoking with NAT2 Polymorphisms Impact Rheumatoid Arthritis Risk in African Americans

PubMed Central

Mikuls, Ted R.; LeVan, Tricia; Gould, Karen A.; Yu, Fang; Thiele, Geoffrey M.; Bynote, Kimberly K.; Conn, Doyt; Jonas, Beth L.; Callahan, Leigh F.; Smith, Edwin; Brasington, Richard; Moreland, Larry W.; Reynolds, Richard; Gaffo, Angelo; Bridges, S. Louis

2011-01-01

Objective To examine whether polymorphisms in genes coding for drug metabolizing enzymes (DMEs) impact rheumatoid arthritis (RA) risk due to cigarette smoking in African Americans. Methods Smoking status was evaluated in African American RA cases and non-RA controls categorized as heavy (≥ 10 pack-years) vs. other. Individuals were genotyped for a homozygous deletion polymorphism in glutathione S-transferase Mu-1 (GSTM1-null) in addition to tagging single nucleotide polymorphisms (SNPs) in N-acetyltransferase (NAT)1, NAT2, and epoxide hydrolase (EPXH1). Associations of genotypes with RA were examined using logistic regression and gene-smoking interactions were assessed. Results There were no significant associations of any DME genotype with RA. After adjustment for multiple comparisons, there were significant additive interactions between heavy smoking and NAT2 SNPs rs9987109 (Padd = 0.000003) and rs1208 (Padd = 0.00001); attributable proportions (APs) due to interaction ranged from 0.61 to 0.67. None of the multiplicative gene-smoking interactions examined remained significant after adjustment for multiple testing in overall disease risk. There was no evidence of significant gene-smoking interactions in analyses of GSTM1-null, NAT1, or EPXH1. DME gene-smoking interactions were similar when cases were limited to anti-citrullinated protein antibody (ACPA) positive individuals. Conclusion Among African Americans, RA risk imposed by heavy smoking appears to be mediated in part by genetic variation in NAT2. While further studies are needed to elucidate mechanisms underpinning these interactions, these SNPs appear to identify African American smokers at a much higher risk for RA with relative risks that are at least two-fold higher compared to non-smokers lacking these risk alleles. PMID:21989592

Cancer-specific production of N-acetylaspartate via NAT8L overexpression in non-small cell lung cancer and its potential as a circulating biomarker

PubMed Central

Lou, Tzu-Fang; Sethuraman, Deepa; Dospoy, Patrick; Srivastva, Pallevi; Kim, Hyun Seok; Kim, Joongsoo; Ma, Xiaotu; Chen, Pei-Hsuan; Huffman, Kenneth E.; Frink, Robin E.; Larsen, Jill E.; Lewis, Cheryl; Um, Sang-Won; Kim, Duk-Hwan; Ahn, Jung-Mo; DeBerardinis, Ralph J.; White, Michael A.; Minna, John D.; Yoo, Hyuntae

2015-01-01

In order to identify new cancer-associated metabolites that may be useful for early detection of lung cancer, we performed a global metabolite profiling of a non-small cell lung cancer (NSCLC) line and immortalized normal lung epithelial cells from the same patient. Among several metabolites with significant cancer/normal differences, we identified a unique metabolic compound, N-acetylaspartate (NAA) in cancer cells — undetectable in normal lung epithelium. NAA’s cancer-specific detection was validated in additional cancer and control lung cells as well as selected NSCLC patient tumors and control tissues. NAA’s cancer-specificity was further supported in our analysis of NAA synthetase (gene symbol: NAT8L) gene expression levels in The Cancer Genome Atlas: elevated NAT8L expression in approximately 40% of adenocarcinoma and squamous cell carcinoma cases (N=577), with minimal expression in all non-malignant lung tissues (N=74). We then showed that NAT8L is functionally involved in NAA production of NSCLC cells through siRNA-mediated suppression of NAT8L, which caused selective reduction of intracellular and secreted NAA. Our cell culture experiments also indicated that NAA biosynthesis in NSCLC cells depends on glutamine availability. For preliminary evaluation of NAA’s clinical potential as a circulating biomarker, we developed a sensitive NAA blood assay and found that NAA blood levels were elevated in 46% of NSCLC patients (N=13) in comparison with age-matched healthy controls (N=21) among individuals aged 55 years or younger. Taken together, these results indicate that NAA is produced specifically in NSCLC tumors through NAT8L overexpression and its extracellular secretion can be detected in blood. PMID:26511490

Impact of nucleic acid testing relative to antigen/antibody combination immunoassay on the detection of acute HIV infection.

PubMed

De Souza, Mark S; Phanuphak, Nittaya; Pinyakorn, Suteeraporn; Trichavaroj, Rapee; Pattanachaiwit, Supanit; Chomchey, Nitiya; Fletcher, James L; Kroon, Eugene D; Michael, Nelson L; Phanuphak, Praphan; Kim, Jerome H; Ananworanich, Jintanat

2015-04-24

To assess the addition of HIV nucleic acid testing (NAT) to fourth-generation (4thG) HIV antigen/antibody combination immunoassay in improving detection of acute HIV infection (AHI). Participants attending a major voluntary counseling and testing site in Thailand were screened for AHI using 4thG HIV antigen/antibody immunoassay and sequential less sensitive HIV antibody immunoassay. Samples nonreactive by 4thG antigen/antibody immunoassay were further screened using pooled NAT to identify additional AHI. HIV infection status was verified following enrollment into an AHI study with follow-up visits and additional diagnostic tests. Among 74 334 clients screened for HIV infection, HIV prevalence was 10.9% and the overall incidence of AHI (N = 112) was 2.2 per 100 person-years. The inclusion of pooled NAT in the testing algorithm increased the number of acutely infected patients detected, from 81 to 112 (38%), relative to 4thG HIV antigen/antibody immunoassay. Follow-up testing within 5 days of screening marginally improved the 4thG immunoassay detection rate (26%). The median CD4 T-cell count at the enrollment visit was 353 cells/μl and HIV plasma viral load was 598 289 copies/ml. The incorporation of pooled NAT into the HIV testing algorithm in high-risk populations may be beneficial in the long term. The addition of pooled NAT testing resulted in an increase in screening costs of 22% to identify AHI: from $8.33 per screened patient to $10.16. Risk factors of the testing population should be considered prior to NAT implementation given the additional testing complexity and costs.

Correlation of AH-1G airframe test data with a NASTRAN mathematical model

NASA Technical Reports Server (NTRS)

Cronkhite, J. D.; Berry, V. L.

1976-01-01

Test data was provided for evaluating a mathematical vibration model of the Bell AH-1G helicopter airframe. The math model was developed and analyzed using the NASTRAN structural analysis computer program. Data from static and dynamic tests were used for comparison with the math model. Static tests of the fuselage and tailboom were conducted to verify the stiffness representation of the NASTRAN model. Dynamic test data were obtained from shake tests of the airframe and were used to evaluate the NASTRAN model for representing the low frequency (below 30 Hz) vibration response of the airframe.

Generalized Poisson-Kac Processes: Basic Properties and Implications in Extended Thermodynamics and Transport

NASA Astrophysics Data System (ADS)

Giona, Massimiliano; Brasiello, Antonio; Crescitelli, Silvestro

2016-04-01

We introduce a new class of stochastic processes in Rn,{{{mathbb R}}^n}, referred to as generalized Poisson-Kac (GPK) processes, that generalizes the Poisson-Kac telegrapher's random motion in higher dimensions. These stochastic processes possess finite propagation velocity, almost everywhere smooth trajectories, and converge in the Kac limit to Brownian motion. GPK processes are defined by coupling the selection of a bounded velocity vector from a family of N distinct ones with a Markovian dynamics controlling probabilistically this selection. This model can be used as a probabilistic tool for a stochastically consistent formulation of extended thermodynamic theories far from equilibrium.

Expanding Girls' Horizons: Strengthening Persistence in the Early Math and Science Education Pipeline

NASA Astrophysics Data System (ADS)

Virnoche, Mary E.

Little longitudinal or follow-up data is available on the impact of Expanding Your Horizons (EYH) conferences. The purpose of the conferences is to encourage girls to take more math and science in high school by exposing them to hands-on activities and role models in math and science professions. This paper is based on 2005 and 2006 one-to-one and small-group interview data from 22 high school girls who attended an EYH conference during their middle school years. The data suggests that EYH strengthens girls' persistence in math and science pathways. Most girls came to the conferences already interested in math and science and at the urging of parents or teachers. Most felt empowered through the shared experience with hundreds of other girls and women, and relayed detailed and enthusiastic descriptions of hands-on activities. Many of the girls also drew connections between EYH and their course-taking actions and career goals. This paper highlights examples of these experiences and makes recommendations for future math and science early pipeline diversity work.

Designing Studies to Test Causal Questions About Early Math: The Development of Making Pre-K Count.

PubMed

Mattera, Shira K; Morris, Pamela A; Jacob, Robin; Maier, Michelle; Rojas, Natalia

2017-01-01

A growing literature has demonstrated that early math skills are associated with later outcomes for children. This research has generated interest in improving children's early math competencies as a pathway to improved outcomes for children in elementary school. The Making Pre-K Count study was designed to test the effects of an early math intervention for preschoolers. Its design was unique in that, in addition to causally testing the effects of early math skills, it also allowed for the examination of a number of additional questions about scale-up, the influence of contextual factors and the counterfactual environment, the mechanism of long-term fade-out, and the role of measurement in early childhood intervention findings. This chapter outlines some of the design considerations and decisions put in place to create a rigorous test of the causal effects of early math skills that is also able to answer these questions in early childhood mathematics and intervention. The study serves as a potential model for how to advance science in the fields of preschool intervention and early mathematics. © 2017 Elsevier Inc. All rights reserved.

The moderating effect of self-efficacy on normal-weight, overweight, and obese children's math achievement: a longitudinal analysis.

PubMed

Kranjac, Ashley Wendell

2015-03-01

Increased body weight is associated with decreased cognitive function in school-aged children. The role of self-efficacy in shaping the connection between children's educational achievement and obesity-related comorbidities has not been examined to date. Evidence of the predictive ability of self-efficacy in children is demonstrated in cognitive tasks, including math achievement scores. This study examined the relationship between self-efficacy and math achievement in normal weight, overweight, and obese children. I hypothesized that overweight and obese children with higher self-efficacy will be less affected in math achievement than otherwise comparable children with lower self-efficacy. I tested this prediction with multilevel growth modeling techniques using the ECLS-K 1998-1999 survey data, a nationally representative sample of children. Increased self-efficacy moderates the link between body weight and children's math achievement by buffering the risks that increased weight status poses to children's cognitive function. My findings indicate that self-efficacy moderates math outcomes in overweight, but not obese, children. Copyright © 2015 Elsevier Ltd. All rights reserved.

An IBM PC-based math model for space station solar array simulation

NASA Technical Reports Server (NTRS)

Emanuel, E. M.

1986-01-01

This report discusses and documents the design, development, and verification of a microcomputer-based solar cell math model for simulating the Space Station's solar array Initial Operational Capability (IOC) reference configuration. The array model is developed utilizing a linear solar cell dc math model requiring only five input parameters: short circuit current, open circuit voltage, maximum power voltage, maximum power current, and orbit inclination. The accuracy of this model is investigated using actual solar array on orbit electrical data derived from the Solar Array Flight Experiment/Dynamic Augmentation Experiment (SAFE/DAE), conducted during the STS-41D mission. This simulator provides real-time simulated performance data during the steady state portion of the Space Station orbit (i.e., array fully exposed to sunlight). Eclipse to sunlight transients and shadowing effects are not included in the analysis, but are discussed briefly. Integrating the Solar Array Simulator (SAS) into the Power Management and Distribution (PMAD) subsystem is also discussed.

Conflict Resolution for Wind-Optimal Aircraft Trajectories in North Atlantic Oceanic Airspace with Wind Uncertainties

NASA Technical Reports Server (NTRS)

Rodionova, Olga; Sridhar, Banavar; Ng, Hok K.

2016-01-01

Air traffic in the North Atlantic oceanic airspace (NAT) experiences very strong winds caused by jet streams. Flying wind-optimal trajectories increases individual flight efficiency, which is advantageous when operating in the NAT. However, as the NAT is highly congested during peak hours, a large number of potential conflicts between flights are detected for the sets of wind-optimal trajectories. Conflict resolution performed at the strategic level of flight planning can significantly reduce the airspace congestion. However, being completed far in advance, strategic planning can only use predicted environmental conditions that may significantly differ from the real conditions experienced further by aircraft. The forecast uncertainties result in uncertainties in conflict prediction, and thus, conflict resolution becomes less efficient. This work considers wind uncertainties in order to improve the robustness of conflict resolution in the NAT. First, the influence of wind uncertainties on conflict prediction is investigated. Then, conflict resolution methods accounting for wind uncertainties are proposed.

Activation cross-sections of proton induced reactions on natHf in the 38-65 MeV energy range: Production of 172Lu and of 169Yb

NASA Astrophysics Data System (ADS)

Tárkányi, F.; Hermanne, A.; Ditrói, F.; Takács, S.; Ignatyuk, A. V.

2018-07-01

In the frame of a systematical study of light ion induced nuclear reactions on hafnium, activation cross sections for proton induced reactions were investigated. Excitation functions were measured in the 38-65 MeV energy range for the natHf(p,xn)180g,177,176,175,173Ta, natHf(p,x)180m,179m,175,173,172,171Hf, 177g,173,172,171,170,169Lu and natHf(p,x)169Yb reactions by using the activation method, combining stacked foil irradiation and off line gamma ray spectroscopy. The experimental results are compared with earlier results in the overlapping energy range, and with the theoretical predictions of the ALICE IPPE and EMPIRE theoretical codes and of the TALYS code reported in the TENDL-2015 and TENDL-2017 libraries. The production routes of 172Lu (and its parent 172Hf) and of 169Yb are reviewed.

Electrochemical carbon dioxide concentrator subsystem math model. [for manned space station

NASA Technical Reports Server (NTRS)

Marshall, R. D.; Carlson, J. N.; Schubert, F. H.

1974-01-01

A steady state computer simulation model has been developed to describe the performance of a total six man, self-contained electrochemical carbon dioxide concentrator subsystem built for the space station prototype. The math model combines expressions describing the performance of the electrochemical depolarized carbon dioxide concentrator cells and modules previously developed with expressions describing the performance of the other major CS-6 components. The model is capable of accurately predicting CS-6 performance over EDC operating ranges and the computer simulation results agree with experimental data obtained over the prediction range.

Peer group contexts of girls' and boys' academic experiences.

PubMed

Crosnoe, Robert; Riegle-Crumb, Catherine; Field, Sam; Frank, Kenneth; Muller, Chandra

2008-01-01

Girls have caught up with boys in math course taking in high school but reasons for taking math still differ by gender. This study, therefore, investigated gender differences in the linkage between peer relations and math course taking by applying multilevel modeling to a nationally representative data set that includes peer networks and school transcripts (N= 6,457 American 9th to 11th graders, aged 13-19). For all adolescents, math course taking was associated with the achievement of their close friends and, to a lesser extent, their coursemates. These associations tended to be stronger toward the end of high school and weaker among adolescents with a prior record of failure in school. Each of these patterns was somewhat more consistent among girls.

Undergraduate nursing students' perceptions regarding factors that affect math abilities

NASA Astrophysics Data System (ADS)

Pyo, Katrina A.

2011-07-01

A review of the nursing literature reveals many undergraduate nursing students lack proficiency with basic mathematical skills, those necessary for safe medication preparation and administration. Few studies exploring the phenomenon from the undergraduate nursing student perspective are reported in the nursing literature. The purpose of this study was to explore undergraduate nursing students’ perceptions of math abilities, factors that affect math abilities, the use of math in nursing, and the extent to which specific math skills were addressed throughout a nursing curriculum. Polya’s Model for Problem Solving and the Bloom’s Taxonomy of Educational Objectives, Affective Domain served as the theoretical background for the study. Qualitative and quantitative methods were utilized to obtain data from a purposive sample of undergraduate nursing students from a private university in western Pennsylvania. Participants were selected based on the proficiency level with math skills, as determined by a score on the Elsevier’s HESI™ Admission Assessment (A2) Exam, Math Portion. Ten students from the “Excellent” benchmark group and eleven students from the “Needing Additional Assistance or Improvement” benchmark group participated in one-on-one, semi-structured interviews, and completed a 25-item, 4-point Likert scale survey that rated confidence levels with specific math skills and the extent to which these skills were perceived to be addressed in the nursing curriculum. Responses from the two benchmark groups were compared and contrasted. Eight themes emerged from the qualitative data. Findings related to mathematical approach and confidence levels with specific math skills were determined to be statistically significant.

Beyond adoption status: Post-adoptive parental involvement and children's reading and math performance from kindergarten to first grade.

PubMed

Tan, Tony Xing; Kim, Eun Sook; Baggerly, Jennifer; Mahoney, E Emily; Rice, Jessica

2017-01-01

In this study, we went beyond adoption status to examine the associations between postadoption parental involvement and children's reading and math performance from kindergarten to first grade. Secondary data on a sample of adopted children and nonadopted children were drawn from the Early Childhood Longitudinal Study-Kindergarten Class of 1998 to 1999 (ECLS-K). Weighted data on the children's reading performance were available for 13,900 children (181 were adopted); weighted data on the children's math performance were available for 14,128 children (184 were adopted). Descriptive data showed no group difference in reading scores at all 3 Waves but adopted children scored lower than nonadopted children in math at Wave 2 (Spring of kindergarten) and Wave 3 (Spring of first grade). However, controlling for 6 covariates, latent growth modeling showed that adoption status was unrelated to Wave 1 reading and math scores or subsequent growth rate. Rather, parents' beliefs on skills needed to succeed in kindergarten were a significant predictor of reading and math performance at Wave 1 and subsequent growth rates, and parents' educational expectation was a significant predictor of growth rate in reading and math. Our findings highlight the importance of parental involvement in adopted children's learning. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

77 FR 26300 - National Institute of Environmental Health Sciences; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-03

... Structural Biology. Place: Nat. Inst. of Environmental Health Sciences, Building 101, Rodbell Auditorium, 111... Environmental Health Sciences, Building 101, Rodbell Auditorium, 111 T. W. Alexander Drive, Research Triangle... Sessions. Place: Nat. Inst. of Environmental Health Sciences, Building 101, Rodbell Auditorium, 111 T. W...

AmeriFlux US-SP1 Slashpine-Austin Cary- 65yrs nat regen

DOE Data Explorer

Martin, Tim [University of Florida

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-SP1 Slashpine-Austin Cary- 65yrs nat regen. Site Description - The ACMF site is a 67 hectare naturally regenerated Pinus palustris and Pinus elliottii mixed stand.

Conformal invariance of the Lungren-Monin-Novikov equations for vorticity fields in 2D turbulence

NASA Astrophysics Data System (ADS)

Grebenev, V. N.; Wacławczyk, M.; Oberlack, M.

2017-10-01

We study the statistical properties of the vorticity field in two-dimensional turbulence. The field is described in terms of the infinite Lundgren-Monin-Novikov (LMN) chain of equations for multi-point probability density functions (pdf’s) of vorticity. We perform a Lie group analysis of the first equation in this chain using the direct method based on the canonical Lie-Bäcklund transformations devised for integro-differential equations. We analytically show that the conformal group is broken for the first LMN equation i.e. for the 1-point pdf at least for the inviscid case but the equation is still conformally invariant on the associated characteristic with zero-vorticity. Then, we demonstrate that this characteristic is conformally transformed. We find this outcome coincides with the numerical results about the conformal invariance of the statistics of zero-vorticity isolines, see e.g. Falkovich (2007 Russian Math. Surv. 63 497-510). The conformal symmetry can be understood as a ‘local scaling’ and its traces in two-dimensional turbulence were already discussed in the literature, i.e. it was conjectured more than twenty years ago in Polyakov (1993 Nucl. Phys. B 396 367-85) and clearly validated experimentally in Bernard et al (2006 Nat. Phys. 2 124-8).

Evaluation of COBAS AmpliPrep/COBAS TaqMan CMV Test for use in hematopoietic stem cell transplant recipients.

PubMed

Ramanan, Poornima; Razonable, Raymund R

2017-07-01

Cytomegalovirus (CMV) is a common opportunistic infection that contributes to poor outcomes in hematopoietic stem cell transplant (HSCT) recipients. Prevention of CMV end-organ disease in allogeneic HSCT recipients is commonly achieved by preemptive antiviral therapy of asymptomatic CMV reactivation that is detected by serial nucleic acid testing (NAT). However, there was no standardized CMV NAT until the development of the World Health Organization (WHO) International Standard. Areas covered: This article provides a comprehensive review on COBAS AmpliPrep/TaqMan (CAP/CTM) CMV assay (Roche) and emphasizes the limitations in the clinical use of CMV NAT in HSCT recipients. Expert commentary: The CAP/CTM CMV Test is the first US FDA approved commercial quantitative NAT for CMV viral load monitoring of plasma samples in solid organ transplant and HSCT recipients. The CAP/CTM assay has wide linear range of DNA quantification and demonstrates colinearity to the WHO International Standard. Studies of CAP/CTM CMV assay in HSCT recipients are still limited, but are now being reported to define viral thresholds for diagnosis, surveillance and monitoring. Results from these early studies in HSCT recipients suggest that, while the WHO IS has improved the inter-laboratory result variances, there are still important factors that continue to contribute to assay variability. This lack of harmony among NAT highlights the need for further standardization.

Tuning growth cycles of Brassica crops via natural antisense transcripts of BrFLC.

PubMed

Li, Xiaorong; Zhang, Shaofeng; Bai, Jinjuan; He, Yuke

2016-03-01

Several oilseed and vegetable crops of Brassica are biennials that require a prolonged winter cold for flowering, a process called vernalization. FLOWERING LOCUS C (FLC) is a central repressor of flowering. Here, we report that the overexpression of natural antisense transcripts (NATs) of Brassica rapa FLC (BrFLC) greatly shortens plant growth cycles. In rapid-, medium- and slow-cycling crop types, there are four copies of the BrFLC genes, which show extensive variation in sequences and expression levels. In Bre, a biennial crop type that requires vernalization, five NATs derived from the BrFLC2 locus are rapidly induced under cold conditions, while all four BrFLC genes are gradually down-regulated. The transgenic Bre lines overexpressing a long NAT of BrFLC2 do not require vernalization, resulting in a gradient of shortened growth cycles. Among them, a subset of lines both flower and set seeds as early as Yellow sarson, an annual crop type in which all four BrFLC genes have non-sense mutations and are nonfunctional in flowering repression. Our results demonstrate that the growth cycles of biennial crops of Brassica can be altered by changing the expression levels of BrFLC2 NATs. Thus, BrFLC2 NATs and their transgenic lines are useful for the genetic manipulation of crop growth cycles. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Benefit-risk perception of natalizumab therapy in neurologists and a large cohort of multiple sclerosis patients.

PubMed

Heesen, Christoph; Kleiter, Ingo; Meuth, Sven G; Krämer, Julia; Kasper, Jürgen; Köpke, Sascha; Gaissmaier, Wolfgang

2017-05-15

Natalizumab (NAT) is associated with the risk of progressive multifocal leukoencephalopathy (PML). Risk stratification algorithms have been developed, however, without detectable reduction of PML incidence. To evaluate to which extent patients and physicians understand and accept risks associated with NAT treatment. Prospective observational cohort study in German MS centers (n=73) among NAT-treated MS patients (n=801) and their neurologists (n=99). Patients included in this study had mean disease duration of 10.2years and a mean NAT treatment duration of 24months. More than 90% of patients and physicians voted for shared decision making or an informed choice decision making approach. Patients and physicians perceived a similar threat from MS as serious disease and both overestimated treatment benefits from NAT based on trial data. Men perceived MS more severe than women and perception of seriousness increased with age in both groups and in patients as well with increasing disability. Although patients evaluated their PML risk higher, their risk acceptance was significantly higher than of their neurologists. Risk stratification knowledge was good among neurologists and significantly lower among patients. While patients and physicians seem to have realistic risk perception of PML and knowledge of risk stratification concepts, the threat of MS and the perception of treatment benefits may explain the ongoing high acceptance of PML risk. Copyright © 2017 Elsevier B.V. All rights reserved.

Detection and identification of occult HBV in blood donors in Taiwan using a commercial, multiplex, multi-dye nucleic acid amplification technology screening test.

PubMed

Lin, K T; Chang, C L; Tsai, M H; Lin, K S; Saldanha, J; Hung, C M

2014-02-01

The ability of a new generation commercial, multiplex, multi-dye test from Roche, the cobas TaqScreen MPX test, version 2.0, to detect and identify occult HBV infections was evaluated using routine donor samples from Kaohsiung Blood Bank, Taiwan. A total of 5973 samples were tested by nucleic acid amplification technology (NAT); 5898 in pools of six, 66 in pools of less than six and nine samples individually. NAT-reactive samples were retested with alternative NAT tests, and follow-up samples from the donors were tested individually by NAT and for all the HBV serological markers. Eight NAT-only-reactive donors were identified, and follow-up samples were obtained from six of the donors. The results indicated that all eight donors had an occult HBV infection with viral loads <12 IU/ml. The cobas(®) TaqScreen MPX test, version 2.0, has an advantage over the current Roche blood screening test, the cobas TaqScreen MPX test, for screening donations in countries with a high prevalence of occult HBV infections since the uncertainty associated with identifying samples with very low viremia is removed by the ability of the test to identify the viral target in samples that are reactive with the cobas TaqScreen MPX test, version 2.0. © 2013 International Society of Blood Transfusion.

Searching for the Golden Model of Education: Cross-National Analysis of Math Achievement

ERIC Educational Resources Information Center

Bodovski, Katerina; Byun, Soo-yong; Chykina, Volha; Chung, Hee Jin

2017-01-01

We utilised four waves of TIMSS data in addition to the information we have collected on countries' educational systems to examine whether different degrees of standardisation, differentiation, proportion of students in private schools and governmental spending on education influence students' math achievement, its variation and socioeconomic…

Exploring Adolescent Motivations for Pursuing Maths-Related Careers

ERIC Educational Resources Information Center

Watt, Helen M. G.

2005-01-01

Adolescents from grade 9 in Sydney Australia (N = 60) were interviewed regarding why they would or would not consider pursuing maths-related careers. Open-ended interview data explored the comprehensiveness of explanations within the Expectancy-Value framework. The Expectancy-Value model is the major motivational framework for explaining students'…

Preparing Elementary Mathematics-Science Teaching Specialists.

ERIC Educational Resources Information Center

Miller, L. Diane

1992-01-01

Describes a professional development program to train math/science specialists for the upper elementary school grades. Using results from an interest survey, 30 teachers were chosen to participate in a 3-year program to become math/science specialists. Presents the teaching model used and the advantages for teachers and students in having subject…

Tactical Communications Network Modelling and Reliability Analysis: An Overview

DTIC Science & Technology

1991-11-01

Transactions on Reliability. Vol 31 (1982), pp 359-361. [62] B. N. Clark and C. L. Colbourn. "Unit Disk Graphs", Discrete Math ., Vol 86 (1990), pp 165-177. [63...C. L. Colbourn, "Network Resiliance". SIAM Journal of Algebra and Discrete Math . Vol 8. (1987), pp 404-409. [64] W. H. Debany, P. K. Varshney, and C...34Bibliography on Dominatinn in Graphs and Some Basic Definitions of Domination Parameters". Discrete Math .. Vol 86 (1990). pp 257-277. [76] C. L. Hwang. F. A

Longitudinal Relations among Parents' Reactions to Children's Negative Emotions, Effortful Control, and Math Achievement in Early Elementary School

ERIC Educational Resources Information Center

Swanson, Jodi; Valiente, Carlos; Lemery-Chalfant, Kathryn; Bradley, Robert H.; Eggum-Wilkens, Natalie D.

2014-01-01

Panel mediation models and fixed-effects models were used to explore longitudinal relations among parents' reactions to children's displays of negative emotions, children's effortful control (EC), and children's math achievement (N = 291; M age in fall of kindergarten = 5.66 years, SD = 0.39 year) across kindergarten through…

Network Traffic Generator for Low-rate Small Network Equipment Software

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lanzisera, Steven

2013-05-28

Application that uses the Python low-level socket interface to pass network traffic between devices on the local side of a NAT router and the WAN side of the NAT router. This application is designed to generate traffic that complies with the Energy Star Small Network Equipment Test Method.

78 FR 61366 - Agency Information Collection Activities: Submission to OMB for Review and Approval; Public...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-03

... Collection Request Title: Nurse Anesthetist Traineeship (NAT) Program Application OMB No. 0915-xxxx--NEW... training grants to educational institutions to increase the numbers of Nurse Anesthetists through the NAT... from which enrollees/trainees are graduating, and the distribution of Nurse Anesthetists to practice in...

77 FR 9673 - National Institute of Environmental Health Sciences; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

... Neurobiology. Place: Nat. Inst. of Environmental Health Sciences, Building 101, Rodbell Auditorium, 111 T. W... Sciences, Building 101, Rodbell Auditorium, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709...: Nat. Inst. of Environmental Health Sciences, Building 101, Rodbell Auditorium, 111 T. W. Alexander...

Muscle Moment Arms and Sensitivity Analysis of a Mouse Hindlimb Musculoskeletal Model

DTIC Science & Technology

2016-05-12

musculature in squirrels, rats, and guinea pigs with con- trast-enhanced microCT. Anat Rec (Hoboken) 294, 915–928. Deisseroth K (2011) Optogenetics. Nat...downhill running in mdx mice. Muscle Nerve 43, 878–886. Medler S (2002) Comparative trends in shortening velocity and force production in skeletal muscles

Light charged particle multiplicities in fusion and quasifission reactions

NASA Astrophysics Data System (ADS)

Kalandarov, Sh. A.; Adamian, G. G.; Antonenko, N. V.; Lacroix, D.; Wieleczko, J. P.

2018-01-01

The light charged particle evaporation from the compound nucleus and from the complex fragments in the reactions 32S+100Mo, 121Sb+27Al, 40Ar+164Dy, and 40Ar+ nat Ag is studied within the dinuclear system model. The possibility to distinguish the reaction products from different reaction mechanisms is discussed.

Microphysical Modelling of the 1999-2000 Arctic Winter. 3; Impact of Homogeneous Freezing on PSCs

NASA Technical Reports Server (NTRS)

Drdla, K.

2003-01-01

Simulations of the 1999-2000 winter have tested the effect on polar stratospheric clouds (PSCs) of the homogeneous freezing of liquid ternary solutions into nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD). Proposed laboratory-derived volume-based and surface-based homogeneous freezing rates have both been examined, including different assumptions about the extrapolation of laboratory measurements to atmospheric conditions. Widespread PSC formation and denitrification are possible in several of the scenarios examined. However, the simulations are all unable to explain the solid-phase PSCs observed early in the 1999-2000 winter, and are unable to reproduce the measured extent of vortex denitrification. These problems can both be attributed to the relatively cold temperatures, more than 5 K below the NAT condensation point, necessary for effective homogeneous freezing. Therefore synoptic-scale homogeneous freezing appears unlikely to be the primary mechanism responsible for solid-phase PSC formation.

Nucleation of nitric acid hydrates in polar stratospheric clouds by meteoric material

NASA Astrophysics Data System (ADS)

James, Alexander D.; Brooke, James S. A.; Mangan, Thomas P.; Whale, Thomas F.; Plane, John M. C.; Murray, Benjamin J.

2018-04-01

Heterogeneous nucleation of crystalline nitric acid hydrates in polar stratospheric clouds (PSCs) enhances ozone depletion. However, the identity and mode of action of the particles responsible for nucleation remains unknown. It has been suggested that meteoric material may trigger nucleation of nitric acid trihydrate (NAT, or other nitric acid phases), but this has never been quantitatively demonstrated in the laboratory. Meteoric material is present in two forms in the stratosphere: smoke that results from the ablation and re-condensation of vapours, and fragments that result from the break-up of meteoroids entering the atmosphere. Here we show that analogues of both materials have a capacity to nucleate nitric acid hydrates. In combination with estimates from a global model of the amount of meteoric smoke and fragments in the polar stratosphere we show that meteoric material probably accounts for NAT observations in early season polar stratospheric clouds in the absence of water ice.

Girls Entering Technology, Science, Math and Research Training (get Smart): a Model for Preparing Girls in Science and Engineering Disciplines

NASA Astrophysics Data System (ADS)

Mawasha, P. Ruby; Lam, Paul C.; Vesalo, John; Leitch, Ronda; Rice, Stacey

In this article, it is postulated that the development of a successful training program for women in science, math, engineering, and technology (SMET) disciplines is dependent upon a combination of several factors, including (a) career orientation: commitment to SMET as a career, reasons for pursuing SMET as a career, and opportunity to pursue a SMET career; (b) knowledge of SMET: SMET courses completed, SMET achievement, and hands-on SMET activities; (c) academic and social support: diversity initiatives, role models, cooperative learning, and peer counseling; and (d) self-concept: program emphasis on competence and peer competition. The proposed model is based on the GET SMART (Girls Entering Technology, Science, Math and Research Training) workshop program to prepare and develop female high school students as competitive future SMET professionals. The proposed model is not intended to serve as an elaborate theory, but as a general guide in training females entering SMET disciplines.

Developing a Drosophila Model of Schwannomatosis

DTIC Science & Technology

2013-02-01

Drosophila melanogaster has become an important model system for cancer studies. Reduced redundancy in the Drosophila genome compared with that of...of high-resolution deletion coverage of the Drosophila melanogaster genome . Nat. Genet. 36, 288-292. Pastor-Pareja, J. C., Wu, M. and Xu. T. (2008...microarray analysis of the entire Drosophila melanogaster genome and compared gene expression profiles of wild type, dCap-D3 and rbf1 mutant

Math and science community college faculty: A culture apart

NASA Astrophysics Data System (ADS)

Bradley, Jane

This is a quantitative, survey-based study of Iowa community college faculty members. The survey was administered in the spring of 2011 to all faculty members identified by their colleges as being employed full time. This study compares the demographics of math and science faculty members to faculty within the arts and sciences who do not teach math or science. Comparisons of how the two groups interact with students and what they identify as barriers to student success are included, as well as their attitudes about mentoring, encouraging students, and their roles in student recruitment and student retention. Highly correlated variables are grouped as factors and used in the construction of prediction models for faculty engagement in student recruitment and student retention efforts. A contrast in the cultures of the math/science faculty members as compared to the non-math/science faculty is considered for its impact on faculty engagement with students and those variables believed to support undergraduate student success.

Prevalence of human immunodeficiency virus RNA and antibody in first-time, lapsed, and repeat blood donations across five international regions and relative efficacy of alternative screening scenarios.

PubMed

Bruhn, Roberta; Lelie, Nico; Custer, Brian; Busch, Michael; Kleinman, Steven

2013-10-01

Twenty-one blood organizations from five geographical regions provided HIV individual donation (ID)-NAT and serology data on 11,787,610 donations. Infections were classified as anti-HIV-/RNA+ window period (WP), anti-HIV+/RNA+ concordant positive (CP) or anti-HIV+/RNA- elite controller (EC). Residual risk and efficacy of several screening scenarios were estimated for first time, lapsed and repeat donations. WP residual risk estimates assumed a 50% infectious dose of 3.16 virions and a 50% detection limit of 2.7 HIV RNA copies/mL for ID-NAT and 10,000 copies/mL for p24Ag. Infectivity for CP (100%) and EC (2.2%) donations was estimated based on viral load distributions and 100-fold reduced infectivity by antibody neutralization as reported elsewhere. Efficacy was calculated as proportion of transmission risk removed from baseline (i.e. in absence of any screening). There was no significant difference in transmission risk between lapsed and repeat donations in any region. Risk was 3.8-fold higher in first time than combined lapsed/repeat donations in South Africa but not in other regions. Screening strategies were most efficacious at interdicting infectious transfusions in first time (98.7-99.8%) followed by lapsed (97.6-99.7%) and repeat (86.8-97.7%) donations in all regions combined. In each donor category the efficacy of ID-NAT alone (97.7-99.8%) was superior to that of minipool (MP)-NAT/anti-HIV (95.0-99.6%) and p24 Ag/anti-HIV (89.8-99.1%). Efficacy patterns were similar by donor/donation status in each region despite large differences in HIV prevalence and transmission risk. As similar data become available for HBV and HCV, this modeling may be useful in cost effectiveness analyses of alternative testing scenarios. © 2013 American Association of Blood Banks.

Peer Group Contexts of Girls’ and Boys’ Academic Experiences

PubMed Central

Crosnoe, Robert; Riegle-Crumb, Catherine; Frank, Kenneth; Field, Sam; Muller, Chandra

2010-01-01

Girls have caught up with boys in math course taking in high school but reasons for taking math still differ by gender. This study, therefore, investigated gender differences in the linkage between peer relations and math course taking by applying multilevel modeling to a nationally representative data set that includes peer networks and school transcripts (N = 6,457 American 9th to 11th graders, aged 13 – 19). For all adolescents, math course taking was associated with the achievement of their close friends and, to a lesser extent, their coursemates. These associations tended to be stronger toward the end of high school and weaker among adolescents with a prior record of failure in school. Each of these patterns was somewhat more consistent among girls. PMID:18269514

A Short Note on the Scaling Function Constant Problem in the Two-Dimensional Ising Model

NASA Astrophysics Data System (ADS)

Bothner, Thomas

2018-02-01

We provide a simple derivation of the constant factor in the short-distance asymptotics of the tau-function associated with the 2-point function of the two-dimensional Ising model. This factor was first computed by Tracy (Commun Math Phys 142:297-311, 1991) via an exponential series expansion of the correlation function. Further simplifications in the analysis are due to Tracy and Widom (Commun Math Phys 190:697-721, 1998) using Fredholm determinant representations of the correlation function and Wiener-Hopf approximation results for the underlying resolvent operator. Our method relies on an action integral representation of the tau-function and asymptotic results for the underlying Painlevé-III transcendent from McCoy et al. (J Math Phys 18:1058-1092, 1977).

Non-accidental trauma in pediatric patients: a review of epidemiology, pathophysiology, diagnosis and treatment

PubMed Central

Adamo, Matthew A.

2014-01-01

Non-accidental trauma (NAT) is a leading cause of childhood traumatic injury and death in the United States. It is estimated that 1,400 children died from maltreatment in the United States in 2002 and abusive head trauma (AHT) accounted for 80% of these deaths. This review examines the epidemiology and risk factors for NAT as well as the general presentation and required medical work up of abused children. In addition, potential algorithms for recognizing cases of abuse are reviewed as well as outcomes in children with NAT and potential neurosurgical interventions which may be required. Finally, the evidence for seizure prophylaxis in this population is addressed. PMID:26835337

Ideal Gas with a Varying (Negative Absolute) Temperature: an Alternative to Dark Energy?

NASA Astrophysics Data System (ADS)

Saha, Subhajit; Mondal, Anindita; Corda, Christian

2018-02-01

The present work is an attempt to investigate whether the evolutionary history of the Universe from the offset of inflation can be described by assuming the cosmic fluid to be an ideal gas with a specific gas constant but a varying negative absolute temperature (NAT). The motivation of this work is to search for an alternative to the "exotic" and "supernatural" dark energy (DE). In fact, the NAT works as an "effective quintessence" and there is need to deal neither with exotic matter like DE nor with modified gravity theories. For the sake of completeness, we release some clarifications on NATs in Section 3 of the paper.

Fueling Interest in Science: An After-School Program Model that Works

ERIC Educational Resources Information Center

Koenig, Kathleen; Hanson, Margaret

2008-01-01

As our society becomes more technologically advanced and jobs require additional related skills, it is important that all girls, not just those interested in science, technology, engineering, and math (commonly referred to as the STEM disciplines), take advanced levels of science and math in high school. Evidence suggests that intervention…

An Inquiry into Flipped Learning in Fourth Grade Math Instruction

ERIC Educational Resources Information Center

D'addato, Teresa; Miller, Libbi R.

2016-01-01

The objective of this action research project was to better understand the impact of flipped learning on fourth grade math students in a socioeconomically disadvantaged setting. A flipped instructional model was implemented with the group of students enrolled in the researcher's class. Data was collected in the form of classroom observations,…

Racism, Parent Support, and Math-Based Career Interests, Efficacy, and Outcome Expectations among African American Adolescents

ERIC Educational Resources Information Center

Alliman-Brissett, Annette E.; Turner, Sherri L.

2010-01-01

Using an extended model of social cognitive career theory, this study investigated ways in which African American middle school adolescents perceive racism and the associations among various aspects of perceptions of racism, other background factors, and math-based career interests, efficacy, and outcome expectations. Results indicated that…

ICT for Children of Immigrants: Indirect and Total Effects via Self-Efficacy on Math Performance

ERIC Educational Resources Information Center

Kim, Sunha

2018-01-01

This study compared the direct, indirect, and total effects of information, communication, and technology (ICT) variables on math achievement for second-generation immigrant, first-generation immigrant, and nonimmigrant students. A path model was used to analyze U.S. nationally representative data from the Program for International Student…

Neuropsychological Predictors of Math Calculation and Reasoning in School-Aged Children

ERIC Educational Resources Information Center

Schneider, Dana Lynn

2012-01-01

After multiple reviews of the literature, which documented that multiple cognitive processes may be involved in mathematics ability and disability, Geary (1993) proposed a model that included three subtypes of math disability: Semantic, Procedural, and Visuospatial. A review of the extant literature produced three studies that examined Geary's…

Locus of Control and Academic Achievement: Integrating Social Learning Theory and Expectancy-Value Theory

ERIC Educational Resources Information Center

Youse, Keith Edward

2012-01-01

The current study examines predictors of math achievement and college graduation by integrating social learning theory and expectancy-value theory. Data came from a nationally-representative longitudinal database tracking 12,144 students over twelve years from 8th grade forward. Models for math achievement and college graduation were tested…

Teaching Math to My Scholars: Inner City Middle School Students

ERIC Educational Resources Information Center

Iyer, Ranjani; Pitts, Joseph

2017-01-01

Teaching in an inner city school requires classroom management, resilience, and most importantly strategies to promote learning and growth. There is a constant need for acceleration in student growth in core subjects, especially Math. A blended learning model can be an effective option for schools to personalize learning experiences for students…

Building Links between Early Socioeconomic Status, Cognitive Ability, and Math and Science Achievement

ERIC Educational Resources Information Center

Blums, Angela; Belsky, Jay; Grimm, Kevin; Chen, Zhe

2017-01-01

The present study examined whether and how socioeconomic status (SES) predicts school achievement in science, technology, engineering, and math (STEM) using structural equation modeling and data from the National Institute of Child Health and Human Development Study of Child Care and Youth Development. The present inquiry addresses gaps in…

Twins in spirit - episode I: comparative preclinical evaluation of [(68)Ga]DOTATATE and [(68)Ga]HA-DOTATATE.

PubMed

Schottelius, Margret; Šimeček, Jakub; Hoffmann, Frauke; Willibald, Marina; Schwaiger, Markus; Wester, Hans-Jürgen

2015-01-01

Recently, an intra-patient comparison demonstrated that the somatostatin (sst) ligand [(68)Ga]HA-DOTATATE ([(68)Ga]DOTA-3-iodo-Tyr(3)-octreotate) provides PET images comparable to or superior to those obtained with [(68)Ga]DOTATATE. To provide a comprehensive basis for nevertheless observed slight differences in tracer biodistribution and dosimetry, the characteristics of [(68)Ga]HA-DOTATATE were investigated in a detailed preclinical study. Affinities of (nat)Ga-HA-DOTATATE and (nat)Ga-DOTATATE to sst1-5 were determined using membrane preparations and [(125)I]SST-28 as radioligand. Internalization into AR42J cells was studied in dual-tracer studies with [(125)I]TOC as internal reference. Biodistribution was investigated using AR42J tumor-bearing CD1 mice, and specificity of tracer uptake was confirmed in competition studies by coinjection of 0.8 mg TOC/kg. Sst2 affinities (IC50) of [(nat)Ga]HA-DOTATATE (1.4 ± 0.8 nM, logP: -3.16) and [(nat)Ga]DOTATATE (1.2 ± 0.6 nM, logP: -3.69) were nearly identical. Both compounds displayed IC50 > 1 μM for sst1,3,4, while sst5 affinity was markedly increased for (nat)Ga-HA-DOTATATE (102 ± 65 nM vs >1 μM for (nat)Ga-DOTATATE). [(nat)Lu]HA-DOTATATE and [(nat)Lu]DOTATATE showed slightly lower, identical sst2 affinities (2.0 ± 1.6 and 2.0 ± 0.8 nM, respectively) and sst3 affinities of 93 ± 1 and 162 ± 16 nM. Internalization of [(68)Ga]HA-DOTATATE was tenfold higher than that of [(125)I]TOC but only sixfold higher for [(68)Ga]DOTATATE and [(177)Lu]HA-DOTATATE. While [(68)Ga]HA-DOTATATE and [(68)Ga]DOTATATE had shown similar target- and non-target uptake in patients, biodistribution studies in mice at 1 h post injection (n = 5) revealed slightly increased non-specific uptake of [(68)Ga]HA-DOTATATE in the blood, liver, and intestines (0.7 ± 0.3, 1.0 ± 0.2, and 4.0 ± 0.7 %iD/g vs 0.3 ± 0.1, 0.5 ± 0.1, and 2.7 ± 0.8 %iD/g for [(68)Ga]DOTATATE). However, sst-mediated accumulation of [(68)Ga]HA-DOTATATE in the pancreas, adrenals, and tumor was significantly enhanced (36.6 ± 4.3, 10.8 ± 3.2, and 33.6 ± 10.9 %iD/g vs 26.1 ± 5.0, 5.1 ± 1.4, and 24.1 ± 4.9 %iD/g, respectively). Consequently, tumor/background ratios for [(68)Ga]HA-DOTATATE in the AR42J model are comparable or slightly increased compared to [(68)Ga]DOTATATE. The present preclinical data fully confirm the general biodistribution pattern and excellent in vivo sst-targeting characteristics previously observed for [(68)Ga]HA-DOTATATE in patients. The effect of slightly enhanced lipophilicity on background accumulation and normal organ dose is compensated by the high uptake of [(68)Ga]HA-DOTATATE in tumor. Thus, [(68)Ga]HA-DOTATATE represents a fully adequate, freely available substitute for [(68)Ga]DOTATATE and, given the superb sst-targeting characteristics of [(177)Lu]HA-DOTATATE in vitro, potential applicability for sst-targeted PRRT.

Pharmacokinetics of Isoniazid, Pyrazinamide, and Ethambutol in Newly Diagnosed Pulmonary TB Patients in Tanzania

PubMed Central

Chigutsa, Emmanuel; Faurholt-Jepsen, Daniel; PrayGod, George; Range, Nyagosya; Castel, Sandra; Wiesner, Lubbe; Hagen, Christian Munch; Christiansen, Michael; Changalucha, John; McIlleron, Helen; Friis, Henrik; Andersen, Aase Bengaard

2015-01-01

Exposure to lower-than-therapeutic levels of anti-tuberculosis drugs is likely to cause selection of resistant strains of Mycobacterium tuberculosis and treatment failure. The first-line anti-tuberculosis (TB) regimen consists of rifampicin, isoniazid, pyrazinamide, and ethambutol, and correct management reduces risk of TB relapse and development of drug resistance. In this study we aimed to investigate the effect of standard of care plus nutritional supplementation versus standard care on the pharmacokinetics of isoniazid, pyrazinamide and ethambutol among sputum smear positive TB patients with and without HIV. In a clinical trial in 100 Tanzanian TB patients, with or without HIV infection, drug concentrations were determined at 1 week and 2 months post initiation of anti-TB medication. Data was analysed using population pharmacokinetic modelling. The effect of body size was described using allometric scaling, and the effects of nutritional supplementation, HIV, age, sex, CD4+ count, weight-adjusted dose, NAT2 genotype, and time on TB treatment were investigated. The kinetics of all drugs was well characterised using first-order elimination and transit compartment absorption, with isoniazid and ethambutol described by two-compartment disposition models, and pyrazinamide by a one-compartment model. Patients with a slow NAT2 genotype had higher isoniazid exposure and a lower estimate of oral clearance (15.5 L/h) than rapid/intermediate NAT2 genotype (26.1 L/h). Pyrazinamide clearance had an estimated typical value of 3.32 L/h, and it was found to increase with time on treatment, with a 16.3% increase after the first 2 months of anti-TB treatment. The typical clearance of ethambutol was estimated to be 40.7 L/h, and was found to decrease with age, at a rate of 1.41% per year. Neither HIV status nor nutritional supplementations were found to affect the pharmacokinetics of these drugs in our cohort of patients. PMID:26501782

Skin metabolism of aminophenols: Human keratinocytes as a suitable in vitro model to qualitatively predict the dermal transformation of 4-amino-2-hydroxytoluene in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goebel, C.; Hewitt, N.J.; Kunze, G.

2009-02-15

4-Amino-2-hydroxytolune (AHT) is an aromatic amine ingredient in oxidative hair colouring products. As skin contact occurs during hair dyeing, characterisation of dermal metabolism is important for the safety assessment of this chemical class. We have compared the metabolism of AHT in the human keratinocyte cell line HaCaT with that observed ex-vivo in human skin and in vivo (topical application versus oral (p.o.) and intravenous (i.v.) route). Three major metabolites of AHT were excreted, i.e. N-acetyl-AHT, AHT-sulfate and AHT-glucuronide. When 12.5 mg/kg AHT was applied topically, the relative amounts of each metabolite were altered such that N-acetyl-AHT product was the majormore » metabolite (66% of the dose in comparison with 37% and 32% of the same applied dose after i.v. and p.o. administration, respectively). N-acetylated products were the only metabolites detected in HaCaT cells and ex-vivo whole human skin discs for AHT and p-aminophenol (PAP), an aromatic amine known to undergo N-acetylation in vivo. Since N-acetyltransferase 1 (NAT1) is the responsible enzyme, kinetics of AHT was further compared to the standard NAT1 substrate p-aminobenzoic acid (PABA) in the HaCaT model revealing similar values for K{sub m} and V{sub max}. In conclusion NAT1 dependent dermal N-acetylation of AHT represents a 'first-pass' metabolism effect in the skin prior to entering the systemic circulation. Since the HaCaT cell model represents a suitable in vitro assay for addressing the qualitative contribution of the skin to the metabolism of topically-applied aromatic amines it may contribute to a reduction in animal testing.« less

Boundary layer transition: A review of theory, experiment and related phenomena

NASA Technical Reports Server (NTRS)

Kistler, E. L.

1971-01-01

The overall problem of boundary layer flow transition is reviewed. Evidence indicates a need for new, basic physical hypotheses in classical fluid mechanics math models based on the Navier-Stokes equations. The Navier-Stokes equations are challenged as inadequate for the investigation of fluid transition, since they are based on several assumptions which should be expected to alter significantly the stability characteristics of the resulting math model. Strong prima facie evidence is presented to this effect.

MATERNAL SMOKING DURING PREGNANCY, GENETIC VARIATION OF ACETYL-N-TRANSFERASES NAT1 AND NAT2, AND RISK FOR OROFACIAL CLEFTS. (R828292)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Production of ⁶¹Cu by the natZn(p,α) reaction: Improved separation and specific activity determination by titration with three chelators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asad, Ali H.; Smith, Suzanne V.; Morandeau, Laurence M.

In this study, the cyclotron-based production of position-emitting ⁶¹Cu using the (p,α) reaction at 11.7 MeV was investigated starting from natural-zinc ( natZn) and enriched ⁶⁴Zn-foil targets, as well as its subsequent purification. For natZn, a combination of three resins were assessed to separate ⁶¹Cu from contaminating 66,67,68Ga and natZn. The specific activity of the purified ⁶¹Cu determined using ICP-MS analysis ranged from 143.3±14.3(SD) to 506.2±50.6 MBq/μg while the titration method using p-SCN-Bn-DOTA, p-SCN-Bn-NOTA and diamsar gave variable results (4.7±0.2 to 412.5±15.3 MBq/μg), with diamsar lying closest to the ICP-MS values. Results suggest that the p-SCN-Bn-DOTA and p-SCN-Bn-NOTA titration methodsmore » are significantly affected by the presence of trace-metal contaminants.« less

64Cu, a powerful positron emitter for immunoimaging and theranostic: Production via natZnO and natZnO-NPs.

PubMed

Karimi, Zahra; Sadeghi, Mahdi; Mataji-Kojouri, Naimeddin

2018-07-01

64 Cu is one of the most beneficial radionuclide that can be used as a theranostic agent in Positron Emission Tomography (PET) imaging. In this current work, 64 Cu was produced with zinc oxide nanoparticles ( nat ZnONPs) and zinc oxide powder ( nat ZnO) via the 64 Zn(n,p) 64 Cu reaction in Tehran Research Reactor (TRR) and the activity values were compared with each other. The theoretical activity of 64 Cu also was calculated with MCNPX-2.6 and the cross sections of this reaction were calculated by using TALYS-1.8, EMPIRE-3.2.2 and ALICE/ASH nuclear codes and were compared with experimental values. Transmission Electronic Microscopy (TEM), Scanning Electronic Microscopy (SEM) and X-Ray Diffraction (XRD) analysis were used for samples characterizations. From these results, it's concluded that 64 Cu activity value with nanoscale target was achieved more than the bulk state target and had a good adaptation with the MCNPX result. Copyright © 2018 Elsevier Ltd. All rights reserved.

Production of ⁶¹Cu by the natZn(p,α) reaction: Improved separation and specific activity determination by titration with three chelators

DOE PAGES

Asad, Ali H.; Smith, Suzanne V.; Morandeau, Laurence M.; ...

2015-09-01

In this study, the cyclotron-based production of position-emitting ⁶¹Cu using the (p,α) reaction at 11.7 MeV was investigated starting from natural-zinc ( natZn) and enriched ⁶⁴Zn-foil targets, as well as its subsequent purification. For natZn, a combination of three resins were assessed to separate ⁶¹Cu from contaminating 66,67,68Ga and natZn. The specific activity of the purified ⁶¹Cu determined using ICP-MS analysis ranged from 143.3±14.3(SD) to 506.2±50.6 MBq/μg while the titration method using p-SCN-Bn-DOTA, p-SCN-Bn-NOTA and diamsar gave variable results (4.7±0.2 to 412.5±15.3 MBq/μg), with diamsar lying closest to the ICP-MS values. Results suggest that the p-SCN-Bn-DOTA and p-SCN-Bn-NOTA titration methodsmore » are significantly affected by the presence of trace-metal contaminants.« less

External quality assurance of malaria nucleic acid testing for clinical trials and eradication surveillance.

PubMed

Murphy, Sean C; Hermsen, Cornelus C; Douglas, Alexander D; Edwards, Nick J; Petersen, Ines; Fahle, Gary A; Adams, Matthew; Berry, Andrea A; Billman, Zachary P; Gilbert, Sarah C; Laurens, Matthew B; Leroy, Odile; Lyke, Kristen E; Plowe, Christopher V; Seilie, Annette M; Strauss, Kathleen A; Teelen, Karina; Hill, Adrian V S; Sauerwein, Robert W

2014-01-01

Nucleic acid testing (NAT) for malaria parasites is an increasingly recommended diagnostic endpoint in clinical trials of vaccine and drug candidates and is also important in surveillance of malaria control and elimination efforts. A variety of reported NAT assays have been described, yet no formal external quality assurance (EQA) program provides validation for the assays in use. Here, we report results of an EQA exercise for malaria NAT assays. Among five centers conducting controlled human malaria infection trials, all centers achieved 100% specificity and demonstrated limits of detection consistent with each laboratory's pre-stated expectations. Quantitative bias of reported results compared to expected results was generally <0.5 log10 parasites/mL except for one laboratory where the EQA effort identified likely reasons for a general quantitative shift. The within-laboratory variation for all assays was low at <10% coefficient of variation across a range of parasite densities. Based on this study, we propose to create a Molecular Malaria Quality Assessment program that fulfills the need for EQA of malaria NAT assays worldwide.

The role of self-math overlap in understanding math anxiety and the relation between math anxiety and performance

PubMed Central

Necka, Elizabeth A.; Sokolowski, H. Moriah; Lyons, Ian M.

2015-01-01

Recent work has demonstrated that math anxiety is more than just the product of poor math skills. Psychosocial factors may play a key role in understanding what it means to be math anxious, and hence may aid in attempts to sever the link between math anxiety and poor math performance. One such factor may be the extent to which individuals integrate math into their sense of self. We adapted a well-established measure of this degree of integration (i.e., self-other overlap) to assess individuals’ self-math overlap. This non-verbal single-item measure showed that identifying oneself with math (having higher self-math overlap) was strongly associated with lower math anxiety (r = -0.610). We also expected that having higher self-math overlap would leave one especially susceptible to the threat of poor math performance to the self. We identified two competing hypotheses regarding how this plays out in terms of math anxiety. Those higher in self-math overlap might be more likely to worry about poor math performance, exacerbating the negative relation between math anxiety and math ability. Alternatively, those higher in self-math overlap might exhibit self-serving biases regarding their math ability, which would instead predict a decoupling of the relation between their perceived and actual math ability, and in turn the relation between their math ability and math anxiety. Results clearly favored the latter hypothesis: those higher in self-math overlap exhibited almost no relation between math anxiety and math ability, whereas those lower in self-math overlap showed a strong negative relation between math anxiety and math ability. This was partially explained by greater self-serving biases among those higher in self-math overlap. In sum, these results reveal that the degree to which one integrates math into one’s self – self-math overlap – may provide insight into how the pernicious negative relation between math anxiety and math ability may be ameliorated. PMID:26528210

The role of self-math overlap in understanding math anxiety and the relation between math anxiety and performance.

PubMed

Necka, Elizabeth A; Sokolowski, H Moriah; Lyons, Ian M

2015-01-01

Recent work has demonstrated that math anxiety is more than just the product of poor math skills. Psychosocial factors may play a key role in understanding what it means to be math anxious, and hence may aid in attempts to sever the link between math anxiety and poor math performance. One such factor may be the extent to which individuals integrate math into their sense of self. We adapted a well-established measure of this degree of integration (i.e., self-other overlap) to assess individuals' self-math overlap. This non-verbal single-item measure showed that identifying oneself with math (having higher self-math overlap) was strongly associated with lower math anxiety (r = -0.610). We also expected that having higher self-math overlap would leave one especially susceptible to the threat of poor math performance to the self. We identified two competing hypotheses regarding how this plays out in terms of math anxiety. Those higher in self-math overlap might be more likely to worry about poor math performance, exacerbating the negative relation between math anxiety and math ability. Alternatively, those higher in self-math overlap might exhibit self-serving biases regarding their math ability, which would instead predict a decoupling of the relation between their perceived and actual math ability, and in turn the relation between their math ability and math anxiety. Results clearly favored the latter hypothesis: those higher in self-math overlap exhibited almost no relation between math anxiety and math ability, whereas those lower in self-math overlap showed a strong negative relation between math anxiety and math ability. This was partially explained by greater self-serving biases among those higher in self-math overlap. In sum, these results reveal that the degree to which one integrates math into one's self - self-math overlap - may provide insight into how the pernicious negative relation between math anxiety and math ability may be ameliorated.

GaAs Substrates for High-Power Diode Lasers

NASA Astrophysics Data System (ADS)

Mueller, Georg; Berwian, Patrick; Buhrig, Eberhard; Weinert, Berndt

GaAs substrate crystals with low dislocation density (Etch-Pit Density (EPD) < 500,^-2) and Si-doping ( ~10^18,^-3) are required for the epitaxial production of high-power diode-lasers. Large-size wafers (= 3 mathrm{in} -> >=3,) are needed for reducing the manufacturing costs. These requirements can be fulfilled by the Vertical Bridgman (VB) and Vertical Gradient Freeze (VGF) techniques. For that purpose we have developed proper VB/VGF furnaces and optimized the thermal as well as the physico-chemical process conditions. This was strongly supported by extensive numerical process simulation. The modeling of the VGF furnaces and processes was made by using a new computer code called CrysVUN++, which was recently developed in the Crystal Growth Laboratory in Erlangen.GaAs crystals with diameters of 2 and 3in were grown in pyrolytic Boron Nitride (pBN) crucibles having a small-diameter seed section and a conical part. Boric oxide was used to fully encapsulate the crystal and the melt. An initial silicon content in the GaAs melt of c (melt) = 3 x10^19,^-3 has to be used in order to achieve a carrier concentration of n = (0.8- 2) x10^18,^-3, which is the substrate specification of the device manufacturer of the diode-laser. The EPD could be reduced to values between 500,^-2 and 50,^-2 with a Si-doping level of 8 x10^17 to 1 x10^18,^-3. Even the 3in wafers have rather large dislocation-free areas. The lowest EPDs ( <100,^-2) are achieved for long seed wells of the crucible.

Quasi-additive estimates on the Hamiltonian for the one-dimensional long range Ising model

NASA Astrophysics Data System (ADS)

Littin, Jorge; Picco, Pierre

2017-07-01

In this work, we study the problem of getting quasi-additive bounds for the Hamiltonian of the long range Ising model, when the two-body interaction term decays proportionally to 1/d2 -α , α ∈(0,1 ) . We revisit the paper by Cassandro et al. [J. Math. Phys. 46, 053305 (2005)] where they extend to the case α ∈[0 ,ln3/ln2 -1 ) the result of the existence of a phase transition by using a Peierls argument given by Fröhlich and Spencer [Commun. Math. Phys. 84, 87-101 (1982)] for α =0 . The main arguments of Cassandro et al. [J. Math. Phys. 46, 053305 (2005)] are based in a quasi-additive decomposition of the Hamiltonian in terms of hierarchical structures called triangles and contours, which are related to the original definition of contours introduced by Fröhlich and Spencer [Commun. Math. Phys. 84, 87-101 (1982)]. In this work, we study the existence of a quasi-additive decomposition of the Hamiltonian in terms of the contours defined in the work of Cassandro et al. [J. Math. Phys. 46, 053305 (2005)]. The most relevant result obtained is Theorem 4.3 where we show that there is a quasi-additive decomposition for the Hamiltonian in terms of contours when α ∈[0,1 ) but not in terms of triangles. The fact that it cannot be a quasi-additive bound in terms of triangles lead to a very interesting maximization problem whose maximizer is related to a discrete Cantor set. As a consequence of the quasi-additive bounds, we prove that we can generalise the [Cassandro et al., J. Math. Phys. 46, 053305 (2005)] result, that is, a Peierls argument, to the whole interval α ∈[0,1 ) . We also state here the result of Cassandro et al. [Commun. Math. Phys. 327, 951-991 (2014)] about cluster expansions which implies that Theorem 2.4 that concerns interfaces and Theorem 2.5 that concerns n point truncated correlation functions in Cassandro et al. [Commun. Math. Phys. 327, 951-991 (2014)] are valid for all α ∈[0,1 ) instead of only α ∈[0 ,ln3/ln2 -1 ) .

Dynamics of human T-cell lymphotropic virus I (HTLV-I) infection of CD4+ T-cells.

PubMed

Katri, Patricia; Ruan, Shigui

2004-11-01

Stilianakis and Seydel (Bull. Math. Biol., 1999) proposed an ODE model that describes the T-cell dynamics of human T-cell lymphotropic virus I (HTLV-I) infection and the development of adult T-cell leukemia (ATL). Their model consists of four components: uninfected healthy CD4+ T-cells, latently infected CD4+ T-cells, actively infected CD4+ T-cells, and ATL cells. Mathematical analysis that completely determines the global dynamics of this model has been done by Wang et al. (Math. Biosci., 2002). In this note, we first modify the parameters of the model to distinguish between contact and infectivity rates. Then we introduce a discrete time delay to the model to describe the time between emission of contagious particles by active CD4+ T-cells and infection of pure cells. Using the results in Culshaw and Ruan (Math. Biosci., 2000) in the analysis of time delay with respect to cell-free viral spread of HIV, we study the effect of time delay on the stability of the endemically infected equilibrium. Numerical simulations are presented to illustrate the results.

Association of N-acetyltransferase-2 and glutathione S-transferase polymorphisms with idiopathic male infertility in Vietnam male subjects.

PubMed

Trang, Nguyen Thi; Huyen, Vu Thi; Tuan, Nguyen Thanh; Phan, Tran Duc

2018-04-25

N-acetyltransferase-2 (NAT2) and Glutathione S-transferases (GSTs) are phase-II xenobiotic metabolizing enzymes participating in detoxification of toxic arylamines, aromatic amines, hydrazines and reactive oxygen species (ROS), which are produced under oxidative and electrophile stresses. The purpose of this research was to investigate whether two common single-nucleotide polymorphisms (SNP) of NAT2 (rs1799929, rs1799930) and GSTP1 (rs1138272, rs1695) associated with susceptibility to idiopathic male infertility. A total 300 DNA samples (150 infertile patients and 150 healthy control) were genotyped for the polymorphisms by ARMS - PCR. We revealed a significant association between the NAT2 variant genotypes (CT + TT (rs1799929), (OR: 3.74; p < 0.001)) and (GA + AA (rs1799930), (OR: 3.75; p < 0.001)) or GSTP1 variant genotypes (GA + AA (rs1695), (OR: 5.11; p < 0,001)) and (CT + TT (rs1138272), (OR: 7.42; p < 0,001) with idiopathic infertility risk. Our findings rate the effect of single-nucleotide polymorphisms of GSTP1 and/or NAT2 in modulation of the risk of male infertility in subjects from Vietnam. This pilot study is the first (as far as we know) to reveal that polymorphisms of NAT2 (rs1799929, rs1799930) and GSTP1 (rs1138272, rs1695) are some novel genetic markers for susceptibility to idiopathic male infertility. Copyright © 2018 Elsevier B.V. All rights reserved.

Benzodiazepines: rat pinealocyte binding sites and augmentation of norepinephrine-stimulated N-acetyltransferase activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthew, E.; Parfitt, A.G.; Sugden, D.

1984-02-01

Studies of (/sup 3/H)diazepam binding to intact rat pineal cells were carried out in tissue culture preparations. The binding was saturable, reversible and proportional to the number of cells used. Scatchard analysis resulted in a linear plot (Kd . 23 nM, maximum binding sites (Bmax) . 1.56 pmol/mg of protein for cells in monolayer culture; Kd . 7 nM, Bmax . 1.3 pmol/mg of protein for cells in suspension culture). Inhibition constants (Ki) for clonazepam (500 nM), flunitrazepam (38 nM) and Ro-5-4864 (5 nM) indicated that the binding sites were probably of the ''peripheral'' type. In addition, the effects ofmore » diazepam on norepinephrine-stimulated N-acetyltransferase (NAT) activity were studied in organ culture and dissociated cell culture. Diazepam (10-50 microM) both prolonged and increased the magnitude of the norepinephrine-induced increase in NAT activity but did not affect the initial rate of rise of enzyme activity. The effect was dose-dependent and was also seen with clonazepam, flunitrazepam and Ro-5-4864, but not with Ro-15-1788. Diazepam, by itself, at these concentrations, had no effect on NAT, but enzyme activity was increased by higher concentrations (0.1-1 mM). Although a relationship between the (/sup 3/H)diazepam binding sites described here and the effect of benzodiazepines on NAT cannot be established from these studies, the data suggest that the benzodiazepines may alter melatonin levels through their action on NAT.« less

Improving Patient Safety in Hospitals: Contributions of High-Reliability Theory and Normal Accident Theory

PubMed Central

Tamuz, Michal; Harrison, Michael I

2006-01-01

Objective To identify the distinctive contributions of high-reliability theory (HRT) and normal accident theory (NAT) as frameworks for examining five patient safety practices. Data Sources/Study Setting We reviewed and drew examples from studies of organization theory and health services research. Study Design After highlighting key differences between HRT and NAT, we applied the frames to five popular safety practices: double-checking medications, crew resource management (CRM), computerized physician order entry (CPOE), incident reporting, and root cause analysis (RCA). Principal Findings HRT highlights how double checking, which is designed to prevent errors, can undermine mindfulness of risk. NAT emphasizes that social redundancy can diffuse and reduce responsibility for locating mistakes. CRM promotes high reliability organizations by fostering deference to expertise, rather than rank. However, HRT also suggests that effective CRM depends on fundamental changes in organizational culture. NAT directs attention to an underinvestigated feature of CPOE: it tightens the coupling of the medication ordering process, and tight coupling increases the chances of a rapid and hard-to-contain spread of infrequent, but harmful errors. Conclusions Each frame can make a valuable contribution to improving patient safety. By applying the HRT and NAT frames, health care researchers and administrators can identify health care settings in which new and existing patient safety interventions are likely to be effective. Furthermore, they can learn how to improve patient safety, not only from analyzing mishaps, but also by studying the organizational consequences of implementing safety measures. PMID:16898984

Improving outcomes for people with progressive cancer: interrupted time series trial of a needs assessment intervention.

PubMed

Waller, Amy; Girgis, Afaf; Johnson, Claire; Lecathelinais, Christophe; Sibbritt, David; Forstner, Dion; Liauw, Winston; Currow, David C

2012-03-01

Improving the effectiveness of cancer care delivery has become a major focus of research. This study assessed the uptake and impact of the Palliative Care Needs Assessment Guidelines and Needs Assessment Tool: Progressive Disease--Cancer (NAT: PD-C) on the outcomes of people with advanced cancer. Given widely varying survival in people with advanced cancer, an interrupted time series design was used, with data on unmet needs, depression, anxiety, and quality of life collected from 195 patients using telephone interviews every two months, for up to 18 months. Patients completed at least two baseline interviews before health professionals were academically detailed in the use of the Palliative Care Needs Assessment Guidelines and NAT: PD-C. Health professionals completed the NAT: PD-C with patients approximately monthly for the remainder of the study. Changes in patients' outcomes were compared prior to and following the introduction of the NAT: PD-C using general estimating equations. Moderate to high needs across all domains were frequently seen in the preintervention phase. The use of the NAT: PD-C was associated with a significant reduction in health system and information and patient care and support needs. These resources have the potential as an efficient and acceptable strategy for supporting needs-based cancer care. Further work is required to determine their unique contribution to improvements in patient outcomes. Copyright © 2012 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

Standing of nucleic acid testing strategies in veterinary diagnosis laboratories to uncover Mycobacterium tuberculosis complex members

PubMed Central

Costa, Pedro; Botelho, Ana; Couto, Isabel; Viveiros, Miguel; Inácio, João

2014-01-01

Nucleic acid testing (NAT) designate any molecular approach used for the detection, identification, and characterization of pathogenic microorganisms, enabling the rapid, specific, and sensitive diagnostic of infectious diseases, such as tuberculosis. These assays have been widely used since the 90s of the last century in human clinical laboratories and, subsequently, also in veterinary diagnostics. Most NAT strategies are based in the polymerase chain reaction (PCR) and its several enhancements and variations. From the conventional PCR, real-time PCR and its combinations, isothermal DNA amplification, to the nanotechnologies, here we review how the NAT assays have been applied to decipher if and which member of the Mycobacterium tuberculosis complex is present in a clinical sample. Recent advances in DNA sequencing also brought new challenges and have made possible to generate rapidly and at a low cost, large amounts of sequence data. This revolution with the high-throughput sequencing (HTS) technologies makes whole genome sequencing (WGS) and metagenomics the trendiest NAT strategies, today. The ranking of NAT techniques in the field of clinical diagnostics is rising, and we provide a SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis with our view of the use of molecular diagnostics for detecting tuberculosis in veterinary laboratories, notwithstanding the gold standard being still the classical culture of the agent. The complementary use of both classical and molecular diagnostics approaches is recommended to speed the diagnostic, enabling a fast decision by competent authorities and rapid tackling of the disease. PMID:25988157

Standing of nucleic acid testing strategies in veterinary diagnosis laboratories to uncover Mycobacterium tuberculosis complex members.

PubMed

Costa, Pedro; Botelho, Ana; Couto, Isabel; Viveiros, Miguel; Inácio, João

2014-01-01

Nucleic acid testing (NAT) designate any molecular approach used for the detection, identification, and characterization of pathogenic microorganisms, enabling the rapid, specific, and sensitive diagnostic of infectious diseases, such as tuberculosis. These assays have been widely used since the 90s of the last century in human clinical laboratories and, subsequently, also in veterinary diagnostics. Most NAT strategies are based in the polymerase chain reaction (PCR) and its several enhancements and variations. From the conventional PCR, real-time PCR and its combinations, isothermal DNA amplification, to the nanotechnologies, here we review how the NAT assays have been applied to decipher if and which member of the Mycobacterium tuberculosis complex is present in a clinical sample. Recent advances in DNA sequencing also brought new challenges and have made possible to generate rapidly and at a low cost, large amounts of sequence data. This revolution with the high-throughput sequencing (HTS) technologies makes whole genome sequencing (WGS) and metagenomics the trendiest NAT strategies, today. The ranking of NAT techniques in the field of clinical diagnostics is rising, and we provide a SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis with our view of the use of molecular diagnostics for detecting tuberculosis in veterinary laboratories, notwithstanding the gold standard being still the classical culture of the agent. The complementary use of both classical and molecular diagnostics approaches is recommended to speed the diagnostic, enabling a fast decision by competent authorities and rapid tackling of the disease.

The expression of Per1 and Aa-nat genes in the pineal gland of postnatal rats.

PubMed

Wongchitrat, Prapimpun; Govitrapong, Piyarat; Phansuwan-Pujito, Pansiri

2012-12-01

The circadian rhythm of melatonin synthesis is controlled by the master clock, suprachiasmatic nucleus (SCN). The level of melatonin changes throughout the aging process. The SCN's rhythm is driven by autoregulatory feedback loop composed of a set of clock genes families and their corresponding proteins. The Period (Per1), one of clock gene develops gradually during postnatal ontogenesis in the rat SCN and is also expressed in the pineal gland. It is of interest to study the relationship between the postnatal development of Per1 and Aa-nat, genes that produce the rate-limiting enzyme in melatonin synthesis, in the pineal. Daily profiles of mRNA expression of Per1 and Aa-nat were analyzed in the pineal gland of pups at postnatal ages 4 (P4), P8, P16 and P32, at puberty age of 6 weeks; and in 8 week-old adult rats by real-time PCR. As early as P4, Per1 and Aa-nat mRNAs were expressed and existed at relatively high levels during the nighttime. They gradually increased until puberty and decreased at 8 weeks of age. Additionally, the nocturnal changes of Per1 and Aa-nat mRNA levels in the rat pineal gland from P4 to adults were strongly correlated at r = 0.97 (p < 0.01). The present data indicate that there is a close relationship between the expression pattern of Per1 and that of melatonin synthesis during the development of postnatal rats.

A Navigation Analysis Tool (NAT) to assess spatial behavior in open-field and structured mazes.

PubMed

Jarlier, Frédéric; Arleo, Angelo; Petit, Géraldine H; Lefort, Julie M; Fouquet, Céline; Burguière, Eric; Rondi-Reig, Laure

2013-05-15

Spatial navigation calls upon mnemonic capabilities (e.g. remembering the location of a rewarding site) as well as adaptive motor control (e.g. fine tuning of the trajectory according to the ongoing sensory context). To study this complex process by means of behavioral measurements it is necessary to quantify a large set of meaningful parameters on multiple time scales (from milliseconds to several minutes), and to compare them across different paradigms. Moreover, the issue of automating the behavioral analysis is critical to cope with the consequent computational load and the sophistication of the measurements. We developed a general purpose Navigation Analysis Tool (NAT) that provides an integrated architecture consisting of a data management system (implemented in MySQL), a core analysis toolbox (in MATLAB), and a graphical user interface (in JAVA). Its extensive characterization of trajectories over time, from exploratory behavior to goal-oriented navigation with decision points using a wide range of parameters, makes NAT a powerful analysis tool. In particular, NAT supplies a new set of specific measurements assessing performances in multiple intersection mazes and allowing navigation strategies to be discriminated (e.g. in the starmaze). Its user interface enables easy use while its modular organization provides many opportunities of extension and customization. Importantly, the portability of NAT to any type of maze and environment extends its exploitation far beyond the field of spatial navigation. Copyright © 2013 Elsevier B.V. All rights reserved.

Establishment of the Ph. Eur. Hepatitis A virus RNA for NAT testing BRP batch 1.

PubMed

Chudy, M; Nübling, C M; Blümel, J; Daas, A; Costanzo, A

2017-01-01

Detection of viral contamination in plasma donations is critical to prevent transmission of infectious diseases. The European Pharmacopoeia (Ph. Eur.) monograph 1646 'Human plasma (pooled and treated for virus inactivation)', requires that plasma pools used for the manufacture of this product be tested, among others, for the presence of hepatitis A virus RNA by nucleic acid testing (NAT) using a positive control containing 100 International Units (IU) of hepatitis A virus (HAV) RNA per mL. To this end, the European Directorate for the Quality of Medicines & HealthCare (EDQM, Council of Europe) organised an international collaborative study under the aegis of the Biological Standardisation Programme, for the establishment of the 1 st Biological Reference Preparation (BRP) for HAV RNA for NAT testing. A freeze-dried candidate material was thus prepared and calibrated against the WHO 2 nd International Standard for HAV for NAT (00/562) in a study in which thirteen European and North American laboratories including Official Medicines Control Laboratories (OMCLs), manufacturers of plasma-derived products, producers of in vitro diagnostic kits and a blood transfusion centre participated. Based on the outcome of the study, an HAV RNA content of 40 000 IU/vial (corresponding approximately to 4.6 log 10 IU/vial) was assigned to the BRP, which was adopted by the Ph. Eur. Commission in March 2016 as Ph. Eur. hepatitis A virus RNA for NAT testing BRP batch 1.

Implications of non-accidental trauma on resource utilization and outcomes.

PubMed

Litz, Cristen N; Amankwah, Ernest K; Danielson, Paul D; Chandler, Nicole M

2018-06-01

The purpose was to compare the resource utilization and outcomes between patients with suspected (SUSP) and confirmed (CONF) non-accidental trauma (NAT). The institutional trauma registry was reviewed for patients aged 0-18 years presenting from 2007 to 2012 with a diagnosis of suspicion for NAT. Patients with suspected and confirmed NAT were compared. There were 281 patients included. CONF presented with a higher heart rate (142 ± 27 vs 128 ± 23 bpm, p < 0.01), lower systolic blood pressure (100 ± 18 vs 105 ± 16 mm Hg, p = 0.03), and higher Injury Severity Score (15 ± 11 vs 9 ± 5, p < 0.01). SUSP received fewer consultations (1.6 ± 0.7 vs 2.4 ± 1.1, 95% CI - 0.58 to - 0.09, p < 0.01) and had a shorter length of stay (1.6 ± 1.3 vs 7.8 ± 9.8 days, 95% CI - 4.58 to - 0.72, p < 0.01). SUSP were more often discharged home (OR 94.22, 95% CI: 21.26-417.476, p < 0.01). CONF had a higher mortality rate (8.2 vs 0%, p < 0.01). Patients with confirmed NAT present with more severe injuries and require more hospital resources compared to patients in whom NAT is suspected and ruled out.

Specific learning disability in mathematics: a comprehensive review.

PubMed

Soares, Neelkamal; Evans, Teresa; Patel, Dilip R

2018-01-01

Math skills are necessary for success in the childhood educational and future adult work environment. This article reviews the changing terminology for specific learning disabilities (SLD) in math and describes the emerging genetics and neuroimaging studies that relate to individuals with math disability (MD). It is important to maintain a developmental perspective on MD, as presentation changes with age, instruction, and the different models (educational and medical) of identification. Intervention requires a systematic approach to screening and remediation that has evolved with more evidence-based literature. Newer directions in behavioral, educational and novel interventions are described.

Specific learning disability in mathematics: a comprehensive review

PubMed Central

Evans, Teresa; Patel, Dilip R.

2018-01-01

Math skills are necessary for success in the childhood educational and future adult work environment. This article reviews the changing terminology for specific learning disabilities (SLD) in math and describes the emerging genetics and neuroimaging studies that relate to individuals with math disability (MD). It is important to maintain a developmental perspective on MD, as presentation changes with age, instruction, and the different models (educational and medical) of identification. Intervention requires a systematic approach to screening and remediation that has evolved with more evidence-based literature. Newer directions in behavioral, educational and novel interventions are described. PMID:29441282

Significance of the genetic polymorphism of CYP2D6 and NAT2 in patients with inflammatory bowel diseases.

PubMed

Dudarewicz, Michał; Rychlik-Sych, Mariola; Barańska, Małgorzata; Wojtczak, Anna; Trzciński, Radzisław; Dziki, Adam; Skrętkowicz, Jadwiga

2014-08-01

The main types of inflammatory bowel diseases (IBD) are ulcerative colitis (UC) and Crohn's disease (CD). There is evidence that, in addition to immunological and environmental factors, genetic factors also play an important role in the pathogenesis of IBD. Determination of polymorphism of CYP2D6 and NAT2 genes encoding I and II phase enzymes of xenobiotic biotransformation may have clinical value as an indicator of individual predisposition to diseases, and also contribute to effective and safe pharmacotherapy. The aim of this study was to investigate the association between genetic polymorphism of CYP2D6 and NAT2 and the incidence of IBD, including UC and CD, among inhabitants of central Poland. The study was performed in 258 individuals from central Poland (115 patients with IBD, including 65 patients with UC and 50 with CD; and in 143 healthy controls). The CYP2D6 genotypes of oxidation and NAT2 genotypes of acetylation were analyzed using the PCR-RFLP method. There were no statistically significant differences in the frequency of the CYP2D6 genotypes and alleles in patients with IBD, UC and CD in comparison with the control group. The relative risk (OR) of IBD, UC and CD was higher in carriers of the allele NAT2*7 and was OR=3.49 (p=0.0019), OR=3.86 (p=0.0019), and OR=3.02 (p=0.0247), respectively. Polymorphism of the gene encoding CYP2D6 does not affect the incidence of inflammatory bowel diseases. The carriers of the NAT2*7 allele which determines slow acetylation may be more predisposed to inflammatory bowel diseases, including ulcerative colitis and Crohn's disease. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Routine screening of blood donations at Qingdao central blood bank, China, for hepatitis B virus (HBV) DNA with a real-time, multiplex nucleic acid test for HBV, hepatitis C virus, and human immunodeficiency virus Types 1 and 2.

PubMed

Yang, Zhongsi; Xu, Lei; Liu, Li; Feng, Qiuxia; Zhang, Longmu; Ma, Weijuan; Saldanha, John; Wang, Mingmin; Zhao, Lin

2013-10-01

The Roche cobas TaqScreen MPX test was used to evaluate the rate of hepatitis B surface antigen (HBsAg)-negative donations that were hepatitis B virus (HBV) DNA reactive from June 2010 to January 2011 in Qingdao, China. HBsAg-negative samples from 65,800 voluntary blood donors were tested with the cobas TaqScreen MPX test in pools of 6 on the Roche cobas s 201 blood screening platform. Samples positive for HBV DNA and negative for HBsAg were quantitated with the Roche COBAS AmpliPrep/COBAS TaqMan HBV test. In addition, serologic tests for HBsAg, hepatitis B surface antibody, anti-hepatitis B core antigen (anti-HBc), anti-hepatitis B e antigen (anti-HBe), and hepatitis B e antigen (HBe) were done using the Roche electrochemiluminescence immunoassay. A total of 80 nucleic acid amplification technology (NAT) test-reactive pools were identified and 59 pools (74%) resolved to a reactive sample. All samples were HBV DNA reactive and the viral load in each sample was quantitated. The viral loads of the samples ranged from less than 20 to 34,600 IU/mL; 13 samples (22%) had viral loads of more than 20 IU/mL, 27 samples (45.8%) had viral loads of less than 20 IU/mL, and 19 samples (32.2%) had undetectable viral loads. Of the 59 NAT-reactive samples, 40 (67.8%) were anti-HBc positive. Fifteen of the 59 samples could not be confirmed as NAT reactive either by an alternative NAT test or by serology. The HBV NAT yield in blood donors in Qingdao is 0.06% (38/65,800). This study confirmed the value of NAT for interdicting HBV-positive donations and preventing transfusion-transmitted HBV infections. © 2013 American Association of Blood Banks.

The effects of gender composition on women's experience in math work groups.

PubMed

Grover, Sarah S; Ito, Tiffany A; Park, Bernadette

2017-06-01

The present studies tested a model outlining the effects of group gender composition on self- and others' perceptions of women's math ability in a truly interactive setting with groups composed entirely of naïve participants (N = 158 4-person groups across 3 studies). One woman in each group was designated to be the "expert" by having her complete a tutorial that gave her task-relevant knowledge for a subsequent group task. Group gender composition was hypothesized to influence perceptions of women's math ability through intrapersonal processes (stereotype threat effects on performance) and interpersonal processes (social cohesion between the expert and other group members). Group composition affected the experts' performance in the group math task, but importantly, it also affected their social cohesion with group members. Moreover, both of these effects-lowered performance and poorer social cohesion in male-dominated groups-made independent contributions in accounting for group gender composition effects on perceptions of women's math ability (Studies 1 and 2). Boundary conditions were examined in a 3rd study. Women who had a history of excelling in math and had chosen a math-intensive STEM major were selected to be the designated experts. We predicted and found this would be sufficient to eliminate the effect of group gender composition on interpersonal processes, and correspondingly the effect on women's perceived math ability. Interestingly (and consistent with past work on stereotype threat effects among highly domain-identified individuals), there were continued performance differences indicative of effects on intrapersonal processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Vibrio Phage KVP40 Encodes a Functional NAD+ Salvage Pathway.

PubMed

Lee, Jae Yun; Li, Zhiqun; Miller, Eric S

2017-05-01

The genome of T4-type Vibrio bacteriophage KVP40 has five genes predicted to encode proteins of pyridine nucleotide metabolism, of which two, nadV and natV , would suffice for an NAD + salvage pathway. NadV is an apparent nicotinamide phosphoribosyltransferase (NAmPRTase), and NatV is an apparent bifunctional nicotinamide mononucleotide adenylyltransferase (NMNATase) and nicotinamide-adenine dinucleotide pyrophosphatase (Nudix hydrolase). Genes encoding the predicted salvage pathway were cloned and expressed in Escherichia coli , the proteins were purified, and their enzymatic properties were examined. KVP40 NadV NAmPRTase is active in vitro , and a clone complements a Salmonella mutant defective in both the bacterial de novo and salvage pathways. Similar to other NAmPRTases, the KVP40 enzyme displayed ATPase activity indicative of energy coupling in the reaction mechanism. The NatV NMNATase activity was measured in a coupled reaction system demonstrating NAD + biosynthesis from nicotinamide, phosphoribosyl pyrophosphate, and ATP. The NatV Nudix hydrolase domain was also shown to be active, with preferred substrates of ADP-ribose, NAD + , and NADH. Expression analysis using reverse transcription-quantitative PCR (qRT-PCR) and enzyme assays of infected Vibrio parahaemolyticus cells demonstrated nadV and natV transcription during the early and delayed-early periods of infection when other KVP40 genes of nucleotide precursor metabolism are expressed. The distribution and phylogeny of NadV and NatV proteins among several large double-stranded DNA (dsDNA) myophages, and also those from some very large siphophages, suggest broad relevance of pyridine nucleotide scavenging in virus-infected cells. NAD + biosynthesis presents another important metabolic resource control point by large, rapidly replicating dsDNA bacteriophages. IMPORTANCE T4-type bacteriophages enhance DNA precursor synthesis through reductive reactions that use NADH/NADPH as the electron donor and NAD + for ADP-ribosylation of proteins involved in transcribing and translating the phage genome. We show here that phage KVP40 encodes a functional pyridine nucleotide scavenging pathway that is expressed during the metabolic period of the infection cycle. The pathway is conserved in other large, dsDNA phages in which the two genes, nadV and natV , share an evolutionary history in their respective phage-host group. Copyright © 2017 American Society for Microbiology.

Pareto-Lognormal Modeling of Known and Unknown Metal Resources. II. Method Refinement and Further Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agterberg, Frits, E-mail: agterber@nrcan.gc.ca

Pareto-lognormal modeling of worldwide metal deposit size–frequency distributions was proposed in an earlier paper (Agterberg in Nat Resour 26:3–20, 2017). In the current paper, the approach is applied to four metals (Cu, Zn, Au and Ag) and a number of model improvements are described and illustrated in detail for copper and gold. The new approach has become possible because of the very large inventory of worldwide metal deposit data recently published by Patiño Douce (Nat Resour 25:97–124, 2016c). Worldwide metal deposits for Cu, Zn and Ag follow basic lognormal size–frequency distributions that form straight lines on lognormal Q–Q plots. Aumore » deposits show a departure from the straight-line model in the vicinity of their median size. Both largest and smallest deposits for the four metals taken as examples exhibit hyperbolic size–frequency relations and their Pareto coefficients are determined by fitting straight lines on log rank–log size plots. As originally pointed out by Patiño Douce (Nat Resour Res 25:365–387, 2016d), the upper Pareto tail cannot be distinguished clearly from the tail of what would be a secondary lognormal distribution. The method previously used in Agterberg (2017) for fitting the bridge function separating the largest deposit size–frequency Pareto tail from the basic lognormal is significantly improved in this paper. A new method is presented for estimating the approximate deposit size value at which the upper tail Pareto comes into effect. Although a theoretical explanation of the proposed Pareto-lognormal distribution model is not a required condition for its applicability, it is shown that existing double Pareto-lognormal models based on Brownian motion generalizations of the multiplicative central limit theorem are not applicable to worldwide metal deposits. Neither are various upper tail frequency amplification models in their present form. Although a physicochemical explanation remains possible, it is argued that preferential mining of the largest and smallest orebodies can have economic historical reasons. The size–frequency distribution of uranium can be regarded as lognormal without Pareto tails. At the end of the paper, it is shown that original copper deposit size data can be used for forward projection of discovery trends toward the end of this century.« less

Intergenerational Effects of Parents' Math Anxiety on Children's Math Achievement and Anxiety.

PubMed

Maloney, Erin A; Ramirez, Gerardo; Gunderson, Elizabeth A; Levine, Susan C; Beilock, Sian L

2015-09-01

A large field study of children in first and second grade explored how parents' anxiety about math relates to their children's math achievement. The goal of the study was to better understand why some students perform worse in math than others. We tested whether parents' math anxiety predicts their children's math achievement across the school year. We found that when parents are more math anxious, their children learn significantly less math over the school year and have more math anxiety by the school year's end-but only if math-anxious parents report providing frequent help with math homework. Notably, when parents reported helping with math homework less often, children's math achievement and attitudes were not related to parents' math anxiety. Parents' math anxiety did not predict children's reading achievement, which suggests that the effects of parents' math anxiety are specific to children's math achievement. These findings provide evidence of a mechanism for intergenerational transmission of low math achievement and high math anxiety. © The Author(s) 2015.

Molecular Determinants and Clinical Implications of Breast Cancer Dormancy

DTIC Science & Technology

2014-12-01

repair mediates resistance of hair follicle bulge stem cells to DNA-damage- induced cell death. Nat Cell Biol 2010; 12: 572–582. 7. Chiruvella KK1...on the role of cellular dormancy in promoting cancer aggressiveness and drug resistance in recurred breast cancer. We aimed to determine the impact...period, we have successfully established a reliable in vitro breast cancer dormancy cell model. Using this model, we tested and confirmed the

Rural Math Excel Partnership (RMEP) Project Final Performance Report

ERIC Educational Resources Information Center

Harmon, Hobart; Tate, Veronica; Stevens, Jennifer; Wilborn, Sandy; Adams, Sue

2018-01-01

The goal of the Rural Math Excel Partnership (RMEP) project, a development project funded by the U.S. Department of Education Investing in Innovation (i3) grant program, was to develop a model of shared responsibility among families, teachers, and communities in rural areas as collective support for student success in and preparation for advanced…

The Role of PS Ability and RC Skill in Predicting Growth Trajectories of Mathematics Achievement

ERIC Educational Resources Information Center

Vista, Alvin

2016-01-01

There are relatively few studies in Australia and South-East Asian region that combine investigating models of math growth trajectories with predictors such as reasoning ability and reading comprehension skills. Math achievement is one of the major components of overall academic achievement and it is important to determine what factors (especially…

The Relation between Parental Involvement and Math Anxiety: Implications for Mathematics Achievement

ERIC Educational Resources Information Center

Roberts, Steven O.; Vukovic, Rose K.

2011-01-01

Previous research served as the platform for this study's research question: Does math anxiety mediate the relation between parental involvement and mathematics achievement? The primary purpose of this study was to examine this mediation model in a sample of at-risk second graders. Due to previous research, the investigators hypothesized that math…

DSMC Modeling of Flows with Recombination Reactions

DTIC Science & Technology

2017-06-23

Rogasinsky, “Analysis of the numerical techniques of the direct simulation Monte Carlo method in the rarefied gas dynamics,” Russ. J. Numer. Anal. Math ...reflection in steady flows,” Comput. Math . Appl. 35(1-2), 113–126 (1998). 45K. L. Wray, “Shock-tube study of the recombination of O atoms by Ar catalysts at

Young-Age Gender Differences in Mathematics Mediated by Independent Control or Uncontrollability

ERIC Educational Resources Information Center

Zirk-Sadowski, Jan; Lamptey, Charlotte; Devine, Amy; Haggard, Mark; Szucs, Dénes

2014-01-01

We studied whether the origins of math anxiety can be related to a biologically supported framework of stress induction: (un)controllability perception, here indicated by self-reported independent efforts in mathematics. Math anxiety was tested in 182 children (8- to 11-year-olds). "Latent factor modeling" was used to test hypotheses on…

Southmoreland Middle School: A Model of True Collaboration

ERIC Educational Resources Information Center

Principal Leadership, 2013

2013-01-01

In 2003, Southmoreland was a seventh- and eighth-grade junior high school in the warning category under NCLB for failing to make adequate yearly progress. Scores on state tests were grim--only 39% of the students were proficient or advanced in math and 55% in reading. Two years later, the combined improvement in reading and math scores resulted in…

Summary of Research on the Effectiveness of Math Professional Development Approaches. REL 2014-010

ERIC Educational Resources Information Center

Gersten, Russell; Taylor, Mary Jo; Keys, Tran D.; Rolfhus, Eric; Newman-Gonchar, Rebecca

2014-01-01

This study used a systematic process modeled after the What Works Clearinghouse (WWC) study review process to answer the question: What does the causal research say are effective math professional development interventions for K-12 teachers aimed at improving student achievement? The study identified and screened 910 research studies in a…

A Joint Probabilistic Classification Model of Relevant and Irrelevant Sentences in Mathematical Word Problems

ERIC Educational Resources Information Center

Cetintas, Suleyman; Si, Luo; Xin, Yan Ping; Zhang, Dake; Park, Joo Young; Tzur, Ron

2010-01-01

Estimating the difficulty level of math word problems is an important task for many educational applications. Identification of relevant and irrelevant sentences in math word problems is an important step for calculating the difficulty levels of such problems. This paper addresses a novel application of text categorization to identify two types of…

Preparing Graduate Students to Teach Math: Engaging with Activities and Viewing Teaching Models

ERIC Educational Resources Information Center

Mongillo, Maria Boeke

2016-01-01

Teacher self-efficacy is the belief a teacher holds that he or she can make a difference in student achievement, even when the student is difficult or unmotivated (Guskey & Passaro, 1994). It has been linked to positive teacher practices and student outcomes. This mixed methods study of preservice elementary and early childhood math teachers…

Rigor "and" Relevance: Enhancing High School Students' Math Skills through Career and Technical Education

ERIC Educational Resources Information Center

Stone, James R., III; Alfeld, Corinne; Pearson, Donna

2008-01-01

Numerous high school students, including many who are enrolled in career and technical education (CTE) courses, do not have the math skills necessary for today's high-skill workplace or college entrance requirements. This study tests a model for enhancing mathematics instruction in five high school CTE programs (agriculture, auto technology,…

Common Core Standards for High School Mathematics: A Quick-Start Guide

ERIC Educational Resources Information Center

Dempsey, Kathleen; Schwols, Armitra

2012-01-01

Shifting your high school's math program to new Common Core standards is much easier when teachers and leaders have this handy guide. Getting a copy for every staff member involved in the process ensures everyone knows: (1) How the six conceptual categories throughout the math standards are connected and reinforced; (2) How the modeling standards…

A Latent Curve Model of Parental Motivational Practices and Developmental Decline in Math and Science Academic Intrinsic Motivation

ERIC Educational Resources Information Center

Gottfried, Adele Eskeles; Marcoulides, George A.; Gottfried, Allen W.; Oliver, Pamella H.

2009-01-01

A longitudinal approach was used to examine the effects of parental task-intrinsic and task-extrinsic motivational practices on academic intrinsic motivation in the subject areas of math and science. Parental task-intrinsic practices comprise encouragement of children's pleasure and engagement in the learning process, whereas task-extrinsic…

Parent-child math anxiety and math-gender stereotypes predict adolescents' math education outcomes

PubMed Central

Casad, Bettina J.; Hale, Patricia; Wachs, Faye L.

2015-01-01

Two studies examined social determinants of adolescents' math anxiety including parents' own math anxiety and children's endorsement of math-gender stereotypes. In Study 1, parent-child dyads were surveyed and the interaction between parent and child math anxiety was examined, with an eye to same- and other-gender dyads. Results indicate that parent's math anxiety interacts with daughters' and sons' anxiety to predict math self-efficacy, GPA, behavioral intentions, math attitudes, and math devaluing. Parents with lower math anxiety showed a positive relationship to children's math outcomes when children also had lower anxiety. The strongest relationships were found with same-gender dyads, particularly Mother-Daughter dyads. Study 2 showed that endorsement of math-gender stereotypes predicts math anxiety (and not vice versa) for performance beliefs and outcomes (self-efficacy and GPA). Further, math anxiety fully mediated the relationship between gender stereotypes and math self-efficacy for girls and boys, and for boys with GPA. These findings address gaps in the literature on the role of parents' math anxiety in the effects of children's math anxiety and math anxiety as a mechanism affecting performance. Results have implications for interventions on parents' math anxiety and dispelling gender stereotypes in math classrooms. PMID:26579000

Parent-child math anxiety and math-gender stereotypes predict adolescents' math education outcomes.

PubMed

Casad, Bettina J; Hale, Patricia; Wachs, Faye L

2015-01-01

Two studies examined social determinants of adolescents' math anxiety including parents' own math anxiety and children's endorsement of math-gender stereotypes. In Study 1, parent-child dyads were surveyed and the interaction between parent and child math anxiety was examined, with an eye to same- and other-gender dyads. Results indicate that parent's math anxiety interacts with daughters' and sons' anxiety to predict math self-efficacy, GPA, behavioral intentions, math attitudes, and math devaluing. Parents with lower math anxiety showed a positive relationship to children's math outcomes when children also had lower anxiety. The strongest relationships were found with same-gender dyads, particularly Mother-Daughter dyads. Study 2 showed that endorsement of math-gender stereotypes predicts math anxiety (and not vice versa) for performance beliefs and outcomes (self-efficacy and GPA). Further, math anxiety fully mediated the relationship between gender stereotypes and math self-efficacy for girls and boys, and for boys with GPA. These findings address gaps in the literature on the role of parents' math anxiety in the effects of children's math anxiety and math anxiety as a mechanism affecting performance. Results have implications for interventions on parents' math anxiety and dispelling gender stereotypes in math classrooms.

Comparative genomic survey, exon-intron annotation and phylogenetic analysis of NAT-homologous sequences in archaea, protists, fungi, viruses, and invertebrates

USDA-ARS?s Scientific Manuscript database

We have previously published extensive genomic surveys [1-3], reporting NAT-homologous sequences in hundreds of sequenced bacterial, fungal and vertebrate genomes. We present here the results of our latest search of 2445 genomes, representing 1532 (70 archaeal, 1210 bacterial, 43 protist, 97 fungal,...

75 FR 3739 - Agency Information Collection Activities: Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-22

... Traineeship Database for the two nursing traineeship programs. The AENT and NAT tables are used annually by... as the number of enrollees, projected data on enrollees and graduates for the following academic year... and/or NAT grant application(s). The tables are also used in the Nurse Traineeship Database which is...

76 FR 72950 - Draft Guidance for Industry: Use of Nucleic Acid Tests on Pooled and Individual Samples From...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-28

... Hepatitis B Virus AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug... Risk of Transmission of Hepatitis B Virus (HBV), and Requalification of Donors Who Test HBV NAT...-licensed nucleic acid tests (NAT) to screen blood donors for hepatitis B virus (HBV) deoxyribonucleic acid...

Acetylation of aromatic cysteine conjugates by recombinant human N-acetyltransferase 8.

PubMed

Deol, Reema; Josephy, P David

2017-03-01

1. The mercapturic acid (MA) pathway is a metabolic route for the processing of glutathione conjugates to MA (N-acetylcysteine conjugates). An N-acetyltransferase enzyme, NAT8, catalyzes the transfer of an acetyl group from acetyl-CoA to the cysteine amino group, producing a MA, which is excreted in the urine. We expressed human NAT8 in HEK293T cells and developed an HPLC-MS method for the quantitation of the S-aryl-substituted cysteine conjugates and their MA. 2. We measured the activity of the enzyme for acetylation of benzyl-, 4-nitrobenzyl-, and 1-menaphthylcysteine substrates. 3. NAT8 catalyzed the acetylation of all three cysteine conjugates with similar Michaelis-Menten kinetics.

Measurement of neutron energy spectra for Eg=23.1 and 26.6 MeV mono-energetic photon induced reaction on natC using laser electron photon beam at NewSUBARU

NASA Astrophysics Data System (ADS)

Itoga, Toshiro; Nakashima, Hiroshi; Sanami, Toshiya; Namito, Yoshihito; Kirihara, Yoichi; Miyamoto, Shuji; Takemoto, Akinori; Yamaguchi, Masashi; Asano, Yoshihiro

2017-09-01

Photo-neutron energy spectra for Eg=23.1 and 26.6 MeV mono-energetic photons on natC were measured using laser Compton scattering facility at NewSUBARU BL01. The photon energy spectra were evaluated through measurements and simulations with collimator sizes and arrangements for the laser electron photon. The neutron energy spectra for the natC(g,xn) reaction were measured at 60 degrees in horizontal and 90 degrees in horizontal and vertical with respect to incident photon. The spectra show almost isotropic angular distribution and flat energy distribution from detection threshold to upper limit defined by reaction Q-value.

Detection of spallation neutrons and protons using the (nat)Cd activation technique in transmutation experiments at Dubna.

PubMed

Manolopoulou, M; Stoulos, S; Fragopoulou, M; Brandt, R; Westmeier, W; Krivopustov, M; Sosnin, A; Zamani, M

2006-07-01

Various spallation sources have been used to transmute long-lived radioactive waste, mostly making use of the wide energy neutron fluence. In addition to neutrons, a large number of protons and gamma rays are also emitted from these sources. In this paper (nat)Cd is proved to be a useful activation detector for determining both thermal-epithermal neutron as well as secondary proton fluences. The fluences measured with (nat)Cd compared with other experimental data and calculations of DCM-DEM code were found to be in reasonable agreement. An accumulation of thermal-epithermal neutrons around the center of the target (i.e. after approx. 10 cm) and of secondary protons towards the end of the target is observed.

Helicopter simulation validation using flight data

NASA Technical Reports Server (NTRS)

Key, D. L.; Hansen, R. S.; Cleveland, W. B.; Abbott, W. Y.

1982-01-01

A joint NASA/Army effort to perform a systematic ground-based piloted simulation validation assessment is described. The best available mathematical model for the subject helicopter (UH-60A Black Hawk) was programmed for real-time operation. Flight data were obtained to validate the math model, and to develop models for the pilot control strategy while performing mission-type tasks. The validated math model is to be combined with motion and visual systems to perform ground based simulation. Comparisons of the control strategy obtained in flight with that obtained on the simulator are to be used as the basis for assessing the fidelity of the results obtained in the simulator.

Mathematical modeling of high and low temperature heat pipes

NASA Technical Reports Server (NTRS)

Chi, S. W.

1971-01-01

Following a review of heat and mass transfer theory relevant to heat pipe performance, math models are developed for calculating heat-transfer limitations of high-temperature heat pipes and heat-transfer limitations and temperature gradient of low temperature heat pipes. Calculated results are compared with the available experimental data from various sources to increase confidence in the present math models. Complete listings of two computer programs for high- and low-temperature heat pipes respectively are included. These programs enable the performance to be predicted of heat pipes with wrapped-screen, rectangular-groove, or screen-covered rectangular-groove wick.

Inspection of the Math Model Tools for On-Orbit Assessment of Impact Damage Report

NASA Technical Reports Server (NTRS)

Harris, Charles E.; Raju, Ivatury S.; Piascik, Robert S> ; KramerWhite, Julie A.; KramerWhite, Julie A.; Labbe, Steve G.; Rotter, Hank A.

2007-01-01

In Spring of 2005, the NASA Engineering Safety Center (NESC) was engaged by the Space Shuttle Program (SSP) to peer review the suite of analytical tools being developed to support the determination of impact and damage tolerance of the Orbiter Thermal Protection Systems (TPS). The NESC formed an independent review team with the core disciplines of materials, flight sciences, structures, mechanical analysis and thermal analysis. The Math Model Tools reviewed included damage prediction and stress analysis, aeroheating analysis, and thermal analysis tools. Some tools are physics-based and other tools are empirically-derived. Each tool was created for a specific use and timeframe, including certification, real-time pre-launch assessments. In addition, the tools are used together in an integrated strategy for assessing the ramifications of impact damage to tile and RCC. The NESC teams conducted a peer review of the engineering data package for each Math Model Tool. This report contains the summary of the team observations and recommendations from these reviews.

Seven-panel solar wing deployment and on-orbit maneuvering analyses

NASA Astrophysics Data System (ADS)

Hwang, Earl

2005-05-01

BSS developed a new generation high power (~20kW) solar array to meet the customer demands. The high power solar array had the north and south solar wings of which designs were identical. Each side of the solar wing consists of three main conventional solar panels and the four-side panel swing-out new design. The fully deployed solar array surface area is 966 ft2. It was a quite challenging task to define the solar array's optimum design parameters and deployment scheme for such a huge solar array's successful deployment and on-orbit maneuvering. Hence, a deployable seven-flex-panel solar wing nonlinear math model and a fully deployed solar array/bus-payload math model were developed with the Dynamic Analysis and Design System (DADS) program codes utilizing the inherited and empirical data. Performing extensive parametric analyses with the math model, the optimum design parameters and the orbit maneuvering /deployment schemes were determined to meet all the design requirements, and for the successful solar wing deployment on-orbit.

The Deubiquitylase MATH-33 Controls DAF-16 Stability and Function in Metabolism and Longevity

PubMed Central

Heimbucher, Thomas; Liu, Zheng; Bossard, Carine; McCloskey, Richard; Carrano, Andrea C.; Riedel, Christian G.; Tanasa, Bogdan; Klammt, Christian; Fonslow, Bryan R.; Riera, Celine E.; Lillemeier, Bjorn F.; Kemphues, Kenneth; Yates, John R.; O'Shea, Clodagh; Hunter, Tony; Dillin, Andrew

2015-01-01

SUMMARY One of the major determinants of aging in organisms ranging from worms to man are FOXO family transcription factors, which are downstream effectors of Insulin/IGF-1 signaling (IIS). The molecular mechanisms that actively promote DAF16/FOXO stability and function are unknown. Here we identify the deubiquitylating enzyme MATH-33 as an essential DAF-16 regulator in IIS, which stabilizes active DAF-16 protein levels and, as a consequence, influences DAF-16 functions, such as metabolism, stress response and longevity in C. elegans. MATH-33 associates with DAF-16 in cellulo and in vitro. MATH-33 functions as a deubiquitylase by actively removing ubiquitin moieties from DAF-16, thus counteracting the action of the RLE-1 E3-ubiquitin ligase. Our findings support a model in which MATH-33 promotes DAF-16 stability in response to decreased IIS by directly modulating its ubiquitylation state, suggesting that regulated oscillations in the stability of DAF-16 protein play an integral role in controlling processes such as metabolism and longevity. PMID:26154057

Probability density functions characterizing PSC particle size distribution parameters for NAT and STS derived from in situ measurements between 1989 and 2010 above McMurdo Station, Antarctica, and between 1991-2004 above Kiruna, Sweden

NASA Astrophysics Data System (ADS)

Deshler, Terry

2016-04-01

Balloon-borne optical particle counters were used to make in situ size resolved particle concentration measurements within polar stratospheric clouds (PSCs) over 20 years in the Antarctic and over 10 years in the Arctic. The measurements were made primarily during the late winter in the Antarctic and in the early and mid-winter in the Arctic. Measurements in early and mid-winter were also made during 5 years in the Antarctic. For the analysis bimodal lognormal size distributions are fit to 250 meter averages of the particle concentration data. The characteristics of these fits, along with temperature, water and nitric acid vapor mixing ratios, are used to classify the PSC observations as either NAT, STS, ice, or some mixture of these. The vapor mixing ratios are obtained from satellite when possible, otherwise assumptions are made. This classification of the data is used to construct probability density functions for NAT, STS, and ice number concentration, median radius and distribution width for mid and late winter clouds in the Antarctic and for early and mid-winter clouds in the Arctic. Additional analysis is focused on characterizing the temperature histories associated with the particle classes and the different time periods. The results from theses analyses will be presented, and should be useful to set bounds for retrievals of PSC properties from remote measurements, and to constrain model representations of PSCs.