International Nuclear Information System (INIS)

The sodium- and potassium-dependent adenosine triphosphatase (Na+,K(+)-ATPase) maintains the transmembrane Na+ gradient to which is coupled all active cellular transport systems. The R and S alleles of the gene encoding the Na+,K(+)-ATPase alpha 1 subunit isoform were identified in Dahl salt-resistant (DR) and Dahl salt-sensitive (DS) rats, respectively. Characterization of the S allele-specific Na+,K(+)-ATPase alpha 1 complementary DNA identified a leucine substitution of glutamine at position 276. This mutation alters the hydropathy profile of a region in proximity to T3(Na), the trypsin-sensitive site that is only detected in the presence of Na+. This mutation causes a decrease in the rubidium-86 influx of S allele-specific sodium pumps, thus marking a domain in the Na+,K(+)-ATPase alpha subunit important for K+ transport, and supporting the hypothesis of a putative role of these ...

International Nuclear Information System (INIS)

... atp-ase azido compounds biochemical reaction kinetics endoplasmic reticulum

KoreaScience (Korea)

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A number of studies have indicated that plasma membrane calcium ATPases (PMCAs) are expressed in the brain and spinal cord and could play important roles not only in the maintenance of cellular calcium...Full Text Available

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Energy Technology Data Exchange (ETDEWEB)

The neutron transmutation doping (NTD) method was applied to the initially p-type silicon in order to extend the NTD applications at HANARO. The relationship between the irradiation neutron fluence and the final resistivity of the initially p-type silicon material was investigated. The proportional constant between the neutron fluence and the resistivity was determined to be 2.3473x10{sup 19} n {omega} cm{sup -1}. The deviation of the final resistivity from the target for almost all the irradiation results of the initially p-type silicon ingots was at a range from -5% to 2%. In addition, the burn-up effect of the boron impurities, the residual {sup 32}P activity and the effect of the compensation characteristics for the initially p-type silicon were studied. Conclusively, the practical methodology to perform the neutron transmutation doping of the initially p-type silicon ingot was ...

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In vivo effects of toxaphene on calcium pump activity in rat brain synaptosomes was studied. Male Sprague-Dawley rats were dosed with toxaphene at 0,25,50, and 100 mg/kg/day for 3 days and sacrificed 24 h after last dose. Ca/sup 2 +/-ATPase activity and /sup 45/Ca uptake were determined in brain P/sub 2/ fraction. Toxaphene inhibited both Ca/sup 2 +/-ATPase activity and /sup 45/Ca/sup 2 +/ uptake and the inhibition was dose dependent. Both substrate and Ca/sup 2 +/ activation kinetics of Ca/sup 2 +/-ATPase indicated non-competitive type of inhibition as evidenced by decreased catalytic velocity but not enzyme-substrate affinity. The inhibited Ca/sup 2 +/-ATPase activity and Ca/sup 2 +/ uptake were restored to normal level by exogenously added calmodulin which increased both velocity and affinity. The inhibition of Ca/sup 2 +/-ATPase activity and Ca/sup 2 +/ uptake and restoration by ...

Science.gov (United States)

is 10 seconds for P-type silicon material,. TO ,. In ordkr to determine the effects of unbalanced ionization between the two ...

UK PubMed Central (United Kingdom)

The thiadiazinon derivative EMD 57033 has been found previously in cardiac muscle to increase isometric force generation without a proportional increase in fiber ATPase, thus causing a reduction in...Full Text Available

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Extracellular ATP stimulates transmembrane ion fluxes in the mouse macrophage cell line J774. In the presence of Mg2+, nonhydrolyzable ATP analogs and other purine and pyrimidine nucleotides do not elicit this response, suggesting the presence of a specific receptor for ATP on the macrophage plasma membrane. One candidate for such a receptor is the ecto-ATPase expressed on these cells. We, therefore, investigated the role of this enzyme in ATP-induced /sup 86/Rb+ efflux in J774 cells. The ecto-ATPase had a broad nucleotide specificity and did not hydrolyze extracellular ATP in the absence of divalent cations. /sup 86/Rb+ efflux was not blocked by inhibition of the ecto-ATPase and did not require Ca2+ or Mg2+. In fact, ATP-stimulated /sup 86/Rb+ efflux was inhibited by Mg2+ and correlated with the availability of ATP4- in the medium. In the absence of divalent cations, the slowly hydrolyzable ATP analogs adenosine ...

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By ab-initio calculation we show that the (Ga,Fe)N ground state may be changed from anti-ferromagnetic to ferromagnetic by acceptor defect like Ga vacancies. The electronic structures are calculated by using the Korringa-Kohn-Rostoker (KKR) method combined with coherent potential approximation (CPA). We show that we can increase the magnetic moment of Fe in p-type GaN by oxygen co-doping. Mechanism of exchange interactions between magnetic ions in p-type (Ga,Fe)N is also studied. The effect of external magnetic field on the electronic structure of (Ga, Fe)N and p-type (Ga, Fe)N is investigated.

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We have examined in detail the electrochemistry of both n- and p-type single crystal (100) silicon in the porous silicon formation regime using a rotating Si disk apparatus with a Ag/AgCl reference electrode. Our findings impact the use and optimization of buried n- or p-type layer anodization for silicon-on-insulator (SOI) wafer synthesis. Results are briefly discussed. 3 refs.

International Nuclear Information System (INIS)

The heavy chains of Acanthamoeba myosins, IA, IB and II, turkey gizzard myosin, and rabbit skeletal muscle myosin subfragment-1 were specifically labeled by radioactive ATP, ADP, and UTP, each of which is a substrate or product of myosin ATPase activity, when irradiated with uv light at 0"0C. With UTP, as much as 0.45 mol/mol of Acanthamoeba myosin IA heavy chain and 1 mol/mol of turkey gizzard myosin heavy chain was incorporated. Evidence that the ligands were associated with the catalytic site included the observations that reaction occurred only with nucleotides that are substrates or products of the ATPase activity; that the reaction was blocked by pyrophosphate which is an inhibitor of the ATPase activity; that ATP was bound as ADP; and that label was probably restricted to a single peptide following limited subtilisin proteolysis of labeled Acanthamoeba myosin IA heavy chain and extensive cleavage with CNBr and ...

UK PubMed Central (United Kingdom)

In many dinoflagellate species, the plastid genome has been proposed to exist as a limited number of single-gene minicircles, and many genes normally found in the plastid genome are nuclear-encoded....Full Text Available

UK PubMed Central (United Kingdom)

The recombinant product (rK39) of the 39-amino-acid repeats encoded by a kinesin-like protein-encoding gene of Leishmania chagasi was evaluated by enzyme-linked immunosorbent assay...Full Text Available

UK PubMed Central (United Kingdom)

Recombinant mouse UDP-glucose pyrophosphatase (UGPPase), encoded by the Nudt14 gene, was produced in Escherichia coli and purified close to homogeneity. The...Full Text Available

UK PubMed Central (United Kingdom)

ATP is synthesized by ATP synthase (F_OF₁-ATPase). Its rotary electromotor (F_O) translocates protons (in some organisms sodium cations) and generates torque to drive...Full Text Available

UK PubMed Central (United Kingdom)

Thlaspi caerulescens is a heavy metal hyperaccumulator plant species that is able to accumulate extremely high levels of zinc (Zn) and cadmium (Cd) in its shoots (30,000 μg...Full Text Available

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This study is aimed at exploring the possible mechanism of hypnosis-enhancing effect of HgS or cinnabar (a traditional Chinese medicine containing more than 95% HgS) in mice treated with pentobarbital. We also examined whether the effect of HgS is different from that of the well-known methyl mercury (MeHg). After a short period (7 days) of oral administration to mice, a nontoxic dose (0.1 g/kg) of HgS not only significantly enhanced pentobarbital-induced hypnosis but also attenuated tolerance induction; while a higher dose (1 g/kg) of HgS or cinnabar exerted an almost irreversible enhancing effect on pentobarbital-hypnosis similar to that of MeHg (2 mg/kg) tested, which was still effective even after 10 or 35 days cessation of administration. To study comparatively the effects of different mercury forms from oral administration of MeHg and HgS on membrane ATPase activities of experimental mice, analysis of the Hg content in the cerebral cortex revealed that ...

Energy Technology Data Exchange (ETDEWEB)

Neutron transmutation doping(NTD) for producing ntype silicon semiconductor is based on the conversion of the Si-30 isotope into phosphorus atom by neutron absorption reaction. By using this method, silicon semiconductors with extremely uniform n-type dopant distributions can be produced, and this is the dominant advantage of NTD compared with the conventional chemical doping. HANARO has two vertical holes for NTD, and the commercial NTD service for 5 and 6 inch silicon ingots has been going on at the NTD2 hole. Generally, NTD method is applied to the initially n-type silicon material. But, an initially p-type silicon material can also be used for the production of uniformly doped n-type silicon by using NTD method. Therefore, in this work, we investigated the relationship between the irradiation neutron fluence and the final resistivity of the initially p-type silicon material. Thereafter, we established the methodology for the neutron ...

Science.gov (United States)

The specification describes a semiconductor solar cell and fabrication process therefor wherein a thin N-type gallium arsenide layer is deposited on a larger P-type substrate layer which is selected from the group of III-V ternary compounds consisting of aluminum phosphide antimonide, AlPSb, and aluminum indium phosphide, AlInP. P-type impurities are diffused from the substrate layer into a portion of the thin N-type gallium arsenide layer to form P-type region wherein which defines a PN junction in the thin gallium arsenide layer. Thus, the quantity of gallium arsenide required to provide this PN photovoltaic junction layer in the cell is minimized, and th P-type substrate serves as a high bandgap window layer for the cell. Such high bandgap of this window material is especially well suited for efficiently transmitting the blue spectrum of sunlight to the PN junction, thus enhancing the power ...

International Nuclear Information System (INIS)

In general there are actually two different types of A-15 compounds (A_3B) whose superconducting properties depend on whether the B atoms are transition elements (s-d type) or nontransition elements (s-p type). The properties in which the s-d type superconductors show marked differences in behavior from the s-p type include: (1) stoichiometry and range of composition, (2) the strong influence of N(O) on the stability and T/sub c/ of the phase, and (3), the effect of composition and atomic ordering on the T/sub c/ of the phase. These differences are discussed and a conclusion presented.

International Nuclear Information System (INIS)

The effect of the external pH on the intracellular pH in mung bean (Vigna mungo (L.) Hepper) root-tip cells was investigated with the "3"1P nuclear magnetic resonance (NMR) method. The "3"1P NMR spectra showed three peaks caused by cytoplasmic G-6-P, cytoplasmic Psub(i) and vacuolar Psub(i). The cytoplasmic and vacuolar pHs could be determined by comparing the Psub(i) chemical shifts with the titration curve. When the external pH was changed over a range from pH 3 to 10, the cytoplasmic pH showed smaller changes than the vacuolar pH, suggesting that the former is regulated more strictly than the latter. The H"+-ATPase inhibitor, DCCD, caused the breakdown of the mechanism that regulates the intracellular pH. H"+-ATPase appears to have an important part in the regulation of the intracellular pH. (author).

International Nuclear Information System (INIS)

This paper develops a fluid dynamic model using finite difference methods characterizing flow in phantoms simulating in vivo conditions and to compare those results with velocity encoded MR images. The phantom consisted of 1-inch (2.5-cm) tubing with semicircular insert and fluid with viscosity, T1, and T2 comparable to blood. Numeric solutions to Navier-Stokes equations for this system were obtained using finite difference methods, with velocity input function of zero at walls and parabolic at both ends. In resulting color raster (CR) images, color temperature represented velocity value. In velocity-encoded MR images acquired under the same flow conditions, phase is proportional to average velocity during application of flow-encoding gradients. Because these gradients are applied along one direction per acquisition, magnitude and direction of velocity are obtained.

Energy Technology Data Exchange (ETDEWEB)

Conductivity and Hall effect measurements were made in dark and IR-photoexcited p-type ZnTe samples between 77 and 300 K. Acceptor vacancy complexes of activation energies 0.09-0.1 eV were found to be present in the photoexcited samples. Different possible scattering mobilities were considered for both samples to explain the observed hole mobility. In the photoexcited sample a scattering mobility due to vacancy complexes was suggested for the first time to explain the results. The scattering centres were associated with native vacancy complexes segregated at the dislocations sites. The expression for the complex scattering mobility has been deduced using the curve fitting method to be {mu}{sub C}=(6.6x10{sup -11})T{sup 5} e{sup 725/T}. (orig.).

UK PubMed Central (United Kingdom)

Several early genes of murine cytomegalovirus (MCMV) encode proteins that mediate immune evasion by interference with the major histocompatibility complex class I (MHC-I) pathway of antigen presentation...Full Text Available

UK PubMed Central (United Kingdom)

A 269-kilobase conjugative plasmid, pK29, from a Klebsiella pneumoniae strain was sequenced. The plasmid harbors multiple antimicrobial resistance genes, including those encoding CMY-8...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe human endogenous retrovirus HERV-K(HML-2) family is associated with testicular germ cell tumors (GCT). Various HML-2 proviruses encode viral proteins such as Env and...Full Text Available

UK PubMed Central (United Kingdom)

The gene encoding N epsilon-(indole-3-acetyl)-L-lysine synthetase, iaaL, from Pseudomonas savastanoi was localized within a 4.25-kilobase EcoRI fragment derived from pIAA1 of oleander strain EW 2009....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

New techniques were developed to construct Schottky barrier and homojunction solar cells on GaAs substrates. Schottky barrier metal-semiconductor solar cells were produced for the first time on p-type GaAs substrate using a sputter-deposition method to form the barrier. The sputter deposition of gold or gold/palladium is the key to the method since normal thermal evaporation of gold onto p-type GaAs produces ohmic contacts. The results of this investigation are consistent with the idea that sputter damage produces donor type surface states on GaAs. Barrier heights were measured for both p-type sputtered and n-type thermally evaporated diodes using current-voltage and capacitance-voltage methods. Deep-level transient spectroscopy was used to identify the trap center concentration and energy levels for both diodes in an effort to explain the relatively large dark current in the p-type sputtered diodes. ...

Energy Technology Data Exchange (ETDEWEB)

The effects of orthovanadate on the uptake of sucrose by Ricinus cotyledons and on sucrose-coupled proton influx were measured in order to gain insight into the relationship to the plasma membrane proton pump. Vanadate had no effect on short-term sucrose uptake. In long-term experiments (> 30 min) sucrose uptake was progressively inhibited, but only at high external sucrose concentrations. Vanadate did not affect proton efflux pumping in the absence of sucrose and neither did it change the initial rate of sucrose-coupled proton influx. However, it enhanced the maximal level of sucrose-induced alkalization of the medium at all sucrose concentrations tested. This is interpreted as an inhibiting effect of vanadate on the proton pump that recycles protons during sucrose-proton cotransport. The sensitivity towards vanadate indicates that this proton pump is an ATPase. A second proton-translocating system, that is insensitive to vanadate, is postulated to function in ...

UK PubMed Central (United Kingdom)

In previous studies it has been established that in Escherichia coli the three known subunits of anaerobic nitrate reductase are encoded by the narGHI operon. From the nucleotide sequence of the narI...Full Text Available

UK PubMed Central (United Kingdom)

Werner syndrome (WS) is characterized by premature onset of age-associated disorders and predisposition to cancer. The WS protein, WRN, encodes 3′ → 5′ DNA helicase and 3′...Full Text Available

UK PubMed Central (United Kingdom)

The genes which encode glycosomal glyceraldehyde-phosphate dehydrogenase (gGAPDH) of Trypanosoma cruzi are arranged as a tandemly repeated pair on a single chromosome and are identical at the level...Full Text Available

UK PubMed Central (United Kingdom)

OBJECTIVETo determine if ProL1, a member of the opiorphin family of genes, can modulate erectile physiology, as it encodes a peptide which acts as...Full Text Available

UK PubMed Central (United Kingdom)

Pseudomonas putida encodes 20 extracytoplasmic sigma factors (ECFs). In this study, we show that one of these ECFs, known as ECF-Pp12...Full Text Available

UK PubMed Central (United Kingdom)

The Arabidopsis ref2 mutant was identified in a screen for plants having altered fluorescence under UV light. Characterization of the ref2 mutants showed that they...Full Text Available

UK PubMed Central (United Kingdom)

Understanding the mechanisms whereby information encoded within patterns of action potentials is deciphered by neurons is central to cognitive psychology. The multiprotein complexes formed by...Full Text Available

UK PubMed Central (United Kingdom)

A DNA sequence encoding the A chain of ricin toxin (RTA) from the castor bean plant, Ricinus communis, was placed under GAL1 promoter control and transformed into Saccharomyces cerevisiae. Induction...Full Text Available

UK PubMed Central (United Kingdom)

We have constructed a deletion-mutant rabies virus encoding EGFP and find it to be an excellent tool for studying detailed morphology and physiology of neurons projecting to injection sites...Full Text Available

UK PubMed Central (United Kingdom)

URA5 genes encode orotidine-5′-monophosphate pyrophosphorylase (OMPpase), an enzyme involved in pyrimidine biosynthesis. We cloned the Histoplasma capsulatum URA5...Full Text Available

UK PubMed Central (United Kingdom)

How transcription factors interpret the cis-regulatory logic encoded within enhancers to mediate quantitative changes in spatiotemporally restricted expression patterns during animal...Full Text Available

UK PubMed Central (United Kingdom)

Menin, which is encoded by the multiple endocrine neoplasia type 1 (MEN1) gene, is a tumor suppressor and transcriptional regulator. Menin controls proliferation and apoptosis of cells, especially pancreatic...Full Text Available

UK PubMed Central (United Kingdom)

The chaperone-encoding groESL and dnaK operons constitute the CIRCE regulon of Bacillus subtilis. Both operons are under negative control of the repressor...Full Text Available

UK PubMed Central (United Kingdom)

Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal dystrophies characterised ultimately by the loss of photoreceptor cells. We have recently identified a new gene (EYS) encoding...Full Text Available

UK PubMed Central (United Kingdom)

MicroRNAs (miRNAs) are endogenously encoded small noncoding RNAs, derived by processing of short RNA hairpins, that can inhibit the translation of mRNAs bearing partially complementary target sequences....Full Text Available

UK PubMed Central (United Kingdom)

SummaryThe general transcription factor TFIID is a large multi-subunit complex required for the transcription of most protein-encoding genes by RNA polymerase II. Taking advantage...Full Text Available

CERN Document Server

We show how one can associate to a given class of finite type G-structures a classifying Lie algebroid. The corresponding Lie groupoid gives models for the different geometries that one can find in the class, and encodes also the different types of symmetry groups.

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We describe the lethal, recessive accelerated-cell-death11 Arabidopsis mutant (acd11). Cell death in acd11 exhibits characteristics of animal apoptosis...Full Text Available

UK PubMed Central (United Kingdom)

Exploring the possibility of enhancing the properties of baculoviruses as biological control agents of insect pests, we tested the effect of expressing an insect gene (jhe) encoding juvenile hormone...Full Text Available

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Auxin autonomous growth of most crown gall tumor cells requires the expression of two auxin biosynthesizing genes (tms 1 and tms 2) from the T-DNA of Agrobacterium...Full Text Available

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Francisella tularensis is a highly infectious bacterium causing the zoonotic disease tularaemia. During its infectious cycle, F. tularensis is not only exposed to the...Full Text Available

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The hyaluronic acid capsule of Streptococcus uberis has been implicated in conferring resistance to phagocytosis by bovine neutrophils. Construction of a bank of random insertion mutants...Full Text Available

UK PubMed Central (United Kingdom)

The identification of host cell factors for virus replication holds great promise for the development of new anti-viral therapies. Recently, high-throughput screening methods have emerged as...Full Text Available

UK PubMed Central (United Kingdom)

A genomic clone that specifies a single polypeptide precursor for ricin, a toxic lectin of Ricinus communis (castor bean), was isolated, sequenced and Sl mapped. The gene encodes a 64 kDa precursor...Full Text Available

UK PubMed Central (United Kingdom)

Werner Syndrome (WS) is an inherited disease characterized by premature onset of aging, increased cancer incidence, and genomic instability. The WS gene encodes a 1,432-amino acid polypeptide (WRN)...Full Text Available

UK PubMed Central (United Kingdom)

Rapid place encoding by hippocampal neurons, as reflected by place-related firing, has been intensely studied, whereas the substrates that translate hippocampal place codes into behavior have received...Full Text Available

UK PubMed Central (United Kingdom)

Human apurinic/apyrimidinic endonuclease (hApe1) encodes two important functional activities: an essential base excision repair (BER) activity and a redox activity that regulates expression...Full Text Available

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We have identified five acyl coenzyme A (CoA) oxidase isozymes (Aox1 through Aox5) in the n-alkane-assimilating yeast Yarrowia lipolytica, encoded by the POX1...Full Text Available

UK PubMed Central (United Kingdom)

We have isolated a second gene (MLS1), which in addition to DAL7, encodes malate synthase from S. cerevisiae. Expression of the two genes is specific for their physiological roles in carbon and nitrogen...Full Text Available

UK PubMed Central (United Kingdom)

Recently reported technologies for DNA-directed organic synthesis and for DNA computing rely on routing DNA populations through complex networks. The reduction of these ideas to practice has been limited...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe emergence of plasmid-mediated carbapenemases, such as NDM-1 in Enterobacteriaceae is a major public health issue. Since they mediate resistance to...Full Text Available

UK PubMed Central (United Kingdom)

We cloned and sequenced structural gene choM, which encodes an insecticidally active cholesterol oxidase in Streptomyces sp. strain A19249. The primary translation product was predicted to be a 547-amino-acid...Full Text Available

UK PubMed Central (United Kingdom)

In Pseudomonas paucimobilis UT26, gamma-hexachlorocyclohexane (gamma-HCH) is converted by two steps of dehydrochlorination to a chemically unstable intermediate, 1,3,4,6-tetrachloro-1,4-cyclohexadiene...Full Text Available

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A chromosomally located β-lactamase gene, cloned and expressed in Escherichia coli from a reference strain of the enterobacterial species Kluyvera cryocrescens,...Full Text Available

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RNA is involved in a variety of chromatin modification events, ranging from large-scale structural rearrangements to subtle local affects. Here, we extend the evidence for RNA–chromatin interactions...Full Text Available

UK PubMed Central (United Kingdom)

SummaryDNA-based tests are increasingly being used to predict a blood group phenotype. This is possible because genes encoding 29 of the 30 blood group systems have been cloned and sequenced,...Full Text Available

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In filamentous fungi, RNA silencing is an attractive alternative to disruption experiments for the functional analysis of genes. We adapted the gene encoding the autofluorescent DsRed protein as a reporter...Full Text Available

UK PubMed Central (United Kingdom)

We develop a statistical framework to study the relationship between chromatin features and gene expression. This can be used to predict gene expression of protein coding genes, as well as microRNAs....Full Text Available

UK PubMed Central (United Kingdom)

A pentapeptide open reading frame equipped with a canonical ribosome-binding site is present in the Escherichia coli 23S rRNA. Overexpression of 23S rRNA fragments containing the mini-gene renders cells...Full Text Available

UK PubMed Central (United Kingdom)

During complementary chromatic adaptation (CCA), cyanobacterial light harvesting structures called phycobilisomes are restructured in response to ambient light quality shifts. Transcription of genes...Full Text Available

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The global acquired immunodeficiency syndrome (AIDS) pandemic is thought to have arisen by the transmission of human immunodeficiency virus (HIV-1)-like viruses from chimpanzees in southeastern...Full Text Available

UK PubMed Central (United Kingdom)

The nuo-6 and isp-1 genes of C. elegans encode, respectively, subunits of complex I and III of the mitochondrial respiratory chain. Partial loss-of-function...Full Text Available

UK PubMed Central (United Kingdom)

An enantio-specific polyphenol oxidase (PPO) was purified ≈1,700-fold to apparent homogeneity from the creosote bush (Larrea tridentata), and its encoding gene was cloned. The...Full Text Available

Science.gov (United States)

Cardiac contractile function is dependent on the integrity and function of the sarcolemmal membrane. Swimming exercise training is known to increase cardiac contractile performance. The purpose of the present study was to examine whether a swimming exercise program would alter sarcolemmal enzyme activity, ion flux, and composition in rat hearts. After approximately 11 wk of exercise training, cardiac myosin and actomyosin Ca2+-adenosinetriphosphatase (ATPase) activity was significantly higher in exercised rat hearts than in sedentary control rat hearts. Glycogen content was increased in plantaris and gastrocnemius muscles from exercised animals as was succinic dehydrogenase activity in gastrocnemius muscle of exercised rats in comparison to sedentary rat preparations. Sarcolemmal vesicles were isolated from hearts of exercise-trained and control rats. Sarcolemmal Na+-K+-ATPase and K+-p-nitrophenylphosphatase activities, Na+-Ca2+ exchange, and ...

DEFF Research Database (Denmark)

We extend the pi-calculus with polyadic synchronisation, a generalisation of the communication mechanism which allows channel names to be composite. We show that this operator embeds nicely in the theory of pi-calculus, we suggest that it permits divergence-free encodings of distributed calculi, and we show that a limited form of polyadic synchronisation can be encoded weakly in pi-calculus. After showing that matching cannot be derived in pi-calculus, we compare the expressivity of polyadic synchronisation, mixed choice and matching. In particular we show that the degree of synchronisation of a language increases its expressive power by means of a separation result in the style of Palamidessi's result for mixed choice.

Science.gov (United States)

Surface scientists argue about the fundamental nature of Schottky barriers, or more precisely what determines the location of the Fermi level at semiconductor surfaces and interfaces. Electrical and materials engineers worry about how to make Schottky barrier diodes and gates to field effect transistors and the control of barrier heights. There is some interesting middle ground in which the location of the surface and interface Fermi level can, for example, determine semiconductor doping characteristics during crystal growth. The authors will discuss several interesting and well known examples of doping characteristics which are still somewhat mysterious. Specifically, they address the following question: (1) why is Ge doped GaAs p type when grown from Ga melts but n type when grown from Au melts (2) why is low resistivity p type ZnSe, AlAs, and AlGaInP hard to make, and more importantly, how can the ...

International Nuclear Information System (INIS)

Semiconductor properties of passive films formed on the Fe-18Cr alloy in a borate buffer solution (pH = 8.4) and 0.1 M H_2SO_4 solution were examined using a photoelectrochemical spectroscopy and an electrochemical impedance spectroscopy. Photo current reveals two photo action spectra that derived from outer hydroxide and inner oxide layers. A typical n-type semiconductor behaviour is observed by both photo current and impedance for the passive films formed in the borate buffer solution. On the other hand, a negative photo current generated, the absolute value of which decreased as applied potential increased in the sulfuric acid solution. This indicates that the passive film behaves as a p-type semiconductor. However, Mott-Schottky plot revealed the typical n-type semiconductor property. It is concluded that the passive film on the Fe-18Cr alloy formed in the borate buffer solution is composed of both n-type outer hydroxide and inner oxide layers. On the other ...

Science.gov (United States)

Metallic contamination was monitored with Surface Photovoltage (SPV) technique in integrated circuit manufacturing facilities. Conventionally, Czochralski silicon bulk materials were used as monitor wafers. However, it has been observed that the diffusion length and the `Iron' concentration measured with SPV were inconsistent from run to run in one facility. The inconsistency is believed to be due to oxygen precipitate in silicon materials during the thermal cycle. By using low oxygen concentration or Float Zone wafers, metallic contaminants can be monitored more accurately and consistently.

Science.gov (United States)

Continuous wave lasing operation with the shortest wavelength for semiconductor lasers was obtained from AlGaInP double heterostructure lasers at 77 K. The structure was grown by metalorganic vapor phase epitaxy. Lasing wavelength was 583.6 nm (yellow). Threshold current was 43 mA (1.9 kA/cm/sup 2/). Magnesium was adopted as a p-type dopant, and was proved to be preferable for a high aluminum composition AlGaInP cladding layer.

Science.gov (United States)

The strategies employed by oral streptococci to resist the inimical influences of acidification reflect the diverse and dynamic niches of the human mouth. All of the oral streptococci are capable of rapid degradation of sugar to acidic end-products. As a result, the pH value of their immediate environment can plummet to levels where glycolysis and growth cease. At this point, the approaches for survival in acid separate the organisms. Streptococcus mutans, for example, relies on its F-ATPase, to protect itself from acidification by pumping protons out of the cells. S. salivarius responds by degrading urea to ammonia and S. sanguis produces ammonia by arginolysis. The mechanisms by which these organisms regulate their particular escape route are now being explored experimentally. The picture that emerges is that the acid-adaptive regulatory mechanisms of the oral streptococci differ markedly from those employed by Gram-negative bacteria. What remains to be ...

British Library Electronic Table of Contents (United Kingdom)

Low expression of osmotically responsive genes 2 (LOS2) encodes an enolase (2-phospho-D-glycerate hydrolase, EC 4.2.1.11) that converts 2-phospho-D-glycerate (PGA) to phosphoenolpyruvate (PEP) in the glycolytic pathway in Arabidopsis. Meanwhile, it is a transcriptional activator of cold-responsive gene, negatively controlling the expression of STZ/ZAT10, a zinc finger transcriptional repressor of cold-responsive gene from Arabidopsis. A novel LOS2 gene, designated PtrLOS2 (GenBank accession number GQ144341), was isolated from trifoliate orange [Poncirus trifoliata (L.) Raf.]. The PtrLOS2 cDNA is 1 662 bp in length with a 1 338 bp open reading frame (ORF), encoding a deduced 445 amino acid residue protein with a predicted molecular mass of 47.79 kDa and an isoelectric point of 5.54. The ded...

Energy Technology Data Exchange (ETDEWEB)

Building complex knowledge based applications requires encoding large amounts of domain knowledge. After acquiring knowledge from domain experts, much of the effort in building a knowledge base goes into verifying that the knowledge is encoded correctly. We consider the problem of verifying hybrid knowledge bases that contain both Horn rules and a terminology in a description logic. Our approach to the verification problem is based on showing a close relationship to the problem of query containment. Our first contribution, based on this relationship, is presenting a thorough analysis of the decidability and complexity of the verification problem, for knowledge bases containing recursive rules and the interpreted predicates =, {le}, < and {ne}. Second, we show that important new classes of constraints on correct inputs and outputs can be expressed in a hybrid setting, in which a description logic class hierarchy is also considered, and we ...

Energy Technology Data Exchange (ETDEWEB)

We introduce a novel scheme for one-way quantum computing (QC) based on the use of information encoded qubits in an effective cluster state resource. With the correct encoding structure, we show that it is possible to protect the entangled resource from phase damping decoherence, where the effective cluster state can be described as residing in a decoherence-free subspace (DFS) of its supporting quantum system. One-way QC then requires either single or two-qubit adaptive measurements. As an example where this proposal can be realized, we describe an optical lattice set-up where the scheme provides robust quantum information processing. We also outline how one can adapt the model to provide protection from other types of decoherence.

British Library Electronic Table of Contents (United Kingdom)

Abstract Alkali tolerance and the mechanism of microcystin (MC) degradation were investigated in the MC-degrading bacterial species, Sphingopyxis sp. C-1, to better understand the increased MC degradation under the alkaline conditions that arise during the disappearance of water blooms. MC-degrading bacteria harbour mlrA, mlrB and mlrC that encode MC-degrading enzymes. Sphingopyxis sp. C-1 also possesses these genes, as well as the mlrD gene that has been assumed to encode MC and its degradation transporter. This study demonstrated that MC degradation activity was promoted by the intermittent addition of microcystin-LR (MCLR) to cultures of strain C-1. That the expression of mlrA, mlrB and mlrC is induced by MCLR also was indicated, whereas that of mlrA and mlrB is induced by the MCLR degr...

Energy Technology Data Exchange (ETDEWEB)

A clone encoding a human D{sub 2} dopamine receptor was isolated from a pituitary cDNA library and sequenced. The deduced protein sequence is 96% identical with that of the cloned rat receptor with one major difference: the human receptor contains an additional 29 amino acids in its putative third cytoplasmic loop. Southern blotting demonstrated the presence of only one human D{sub 2} receptor gene. Two overlapping phage containing the gene were isolated and characterized. DNA sequence analysis of these clones showed that the coding sequence is interrupted by six introns and that the additional amino acids present in the human pituitary receptor are encoded by a single exon of 87 base pairs. The involvement of this sequence in alternative splicing and its biological significance are discussed.

Energy Technology Data Exchange (ETDEWEB)

Atomic layer epitaxy (ALE) was used to grow several components of the cascade solar cell structure in the AlGaAs/GaAs system. An ALE reactor was constructed for multiwafer growth with a growth rate of 0.6 {mu}m h{sup -1}. Device quality GaAs and Al{sub x}Ga{sub 1-x}As films were grown with p-type background carbon doping in the ranges 10{sup 16}-10{sup 19} cm{sup -3} and 10{sup 16}-10{sup 20} cm{sup -3} respectively. N-type films were achieved by SiH{sub 4} doping, producing carrier concentrations in the range 10{sup 16}-10{sup 18} cm{sup -3}. In addition, the potential applications of the ALE technique in the photovoltaic field are discussed. (orig.).

International Nuclear Information System (INIS)

By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of sample preparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.

Science.gov (United States)

We report on the formation of current blocking regions by O2 plasma treatment to reduce current crowding at the active region above the p-type electrodes of GaN-based vertical light emitting diodes (LEDs). The forward voltage and reverse current (at -5 V) of the plasma-treated LEDs slightly increase with increasing aging time. The output power (at 350 mA) of the plasma-treated LEDs is enhanced by 26% as compared to that of reference LEDs and is comparable to that of LEDs with SiO2 current blocking layers. It is shown that the output power (at 700 mA) of the plasma-treated LEDs is degraded by less than 2% of the initial value after 500 h.

International Nuclear Information System (INIS)

The electronic structures of platinum group elements (Ru, Os, Rh, Ir, Pd, and Pt) silicides have been calculated. Ir_3Si_5 is a semiconductor with the direct gap of 1.14 eV. Among monosilicides, RuSi and OsSi with the FeSi-type structure are semiconductors with the gap values of 0.21 and 0.41 eV but RhSi, IrSi, PdSi, and PtSi with the MnP-type structure are metals. No semiconducting compounds can be found in other platinum group elements silicides other than known Ru_2Si_3, Os_2Si_3, and OsSi_2.

International Nuclear Information System (INIS)

The chemical composition and the semiconducting properties of passive films formed on nickel based alloy (Alloy 600) in acidic sulphate solution, pH 2.0 at room temperature were studied using Auger analysis, voltammetric techniques and the Mott-Schottky approach. The results obtained revealed that the presence of both chromium and mixed nickel-iron oxides in the films leads to the development of a p-n heterojunction, which controls their electronic structure, similarly manner to the case of stainless steels and Alloy 600 in borate buffer solution. This behavior has been interpreted as representing of an oxide system, which has a duplex character, with an inner p-type semiconducting region, mainly formed by chromium oxide and an outer n-type semiconducting region, containing iron oxide. It could also be observed that the nickel oxide present in the films acts as a barrier layer conferring improved protection.

UK PubMed Central (United Kingdom)

Molybdopterin (MPT) is not produced by the Escherichia coli mutants chlA1, chlM, or chlN or by the Neurospora crassa mutant nit-1. Extracts of E. coli chlA1 contain an activity, the converting factor,...Full Text Available

UK PubMed Central (United Kingdom)

Lethal alleles of the Drosophila k43 gene result in small or missing imaginal discs, greatly reduced mitotic index, and fragmented and abnormally condensed chromosomes. A female-sterile...Full Text Available

UK PubMed Central (United Kingdom)

Pseudomonas syringae is a gram-negative bacterial plant pathogen that is dependent on a type III protein secretion system (TTSS) and the effector proteins it translocates into plant...Full Text Available

UK PubMed Central (United Kingdom)

Targeted genome capture combined with next-generation sequencing was used to analyze 2.9 Mb of the DFNB79 interval on chromosome 9q34.3, which includes 108 candidate genes. Genomic...Full Text Available

UK PubMed Central (United Kingdom)

Larvae of the sunburst diving beetle, Thermonectus marmoratus, have a cluster of six stemmata (E1-6) and one eye patch on each side of the head. Each eye has two retinas: a...Full Text Available

UK PubMed Central (United Kingdom)

We have identified two novel, very closely related genes, SAS1 and SAS2, from Dictyostelium discoideum. These encode small, approximately 20-kilodaton proteins with amino acid sequences thought to be...Full Text Available

UK PubMed Central (United Kingdom)

Pseudomonas syringae pv. glycinea PG4180 produces the polyketide phytotoxin coronatine. The coronatine synthesis genes in PG4180 were previously shown to reside on a 90-kb plasmid designated p4180A....Full Text Available

UK PubMed Central (United Kingdom)

BackgroundPlasmid encoded ^blaCTX-M enzymes represent an important sub-group of class A β-lactamases causing the ESBL phenotype which is increasingly...Full Text Available

International Nuclear Information System (INIS)

A measuring-basis encrypted quantum key distribution scheme is proposed by using twelve nonorthogonal states in a four-state system and the measuring-basis encryption technique. In this scheme, two bits of classical information can be encoded on one four-state particle and the transmitted particles can be fully used.

UK PubMed Central (United Kingdom)

Mycoreovirus 1 (MyRV1), a member of the Reoviridae family possessing a genome consisting of 11 dsRNA segments (S1–S11), and the prototype hypovirus (CHV1-EP713)...Full Text Available

UK PubMed Central (United Kingdom)

We have identified another Drosophila GTP-binding protein (G protein) alpha subunit, dGq alpha-3. Transcripts encoding dGq alpha-3 are derived from alternative splicing of the dGq alpha locus previously...Full Text Available

UK PubMed Central (United Kingdom)

A full-length complementary DNA clone encoding tryptophan decarboxylase (TDC; EC 4.1.1.28) from Catharanthus roseus (De Luca V, Marineau C, Brisson N [1989] Proc Natl Acad Sci USA 86:...Full Text Available

UK PubMed Central (United Kingdom)

Helicobacter pylori, a major cause of human gastric disease, is a microaerophilic bacterium that contains neither pyruvate nor 2-oxoglutarate dehydrogenase activity. Previous studies...Full Text Available

UK PubMed Central (United Kingdom)

X-linked sideroblastic anemia with ataxia (XLSA/A) is a rare inherited disorder characterized by mild anemia and ataxia. XLSA/A is caused by mutations in the ABCB7 gene, which encodes...Full Text Available

UK PubMed Central (United Kingdom)

The proteins encoded by polar-localized mRNAs play an important role in cell fate specification along the anteroposterior axis of the Drosophila embryo. The only maternally synthesized mRNA known previously...Full Text Available

UK PubMed Central (United Kingdom)

Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia/lymphoma (ATLL), HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and other diseases....Full Text Available

Science.gov (United States)

The definition of episodic memory includes the concept of mental time travel: the ability to re-experience a previously experienced trajectory through continuous dimensions of space and time, and to recall specific events or stimuli along this trajectory. Lesions of the hippocampus and entorhinal cortex impair human episodic memory function and impair rat performance in tasks that could be solved by retrieval of trajectories. Recent physiological data suggests a novel model for encoding and retrieval of trajectories, and for associating specific stimuli with specific positions along the trajectory. During encoding in the model, external input drives the activity of head direction cells. Entorhinal grid cells integrate the head direction input to update an internal representation of location, and drive hippocampal place cells. Trajectories are encoded by Hebbian modification of excitatory synaptic connections between ...

Energy Technology Data Exchange (ETDEWEB)

As the only non-polar plane the (110) surface has a unique role in GaAs. Together with Silicon as a dopant it is an important substrate orientation for the growth of n-type or p-type heterostructures. As a consequence, this thesis will concentrate on growth and research on that surface. In the course of this work we were able to realize two-dimensional electron systems with the highest mobilities reported so far on this orientation. Therefore, we review the necessary growth conditions and the accompanying molecular process. The two-dimensional electron systems allowed the study of a new, intriguing transport anisotropy not explained by current theory. Moreover, we were the first growing a two-dimensional hole gas on (110) GaAs with Si as dopant. For this purpose we invented a new growth modulation technique necessary to retrieve high mobility systems. In addition, we discovered and studied the metal-insulator transition in thin bulk p-type ...

Science.gov (United States)

What brain mechanisms underlie learning of new knowledge from single events? We studied encoding in long-term memory of a unique type of one-shot experience, induced perceptual insight. While undergoing an fMRI brain scan, participants viewed degraded images of real-world pictures where the underlying objects were hard to recognize ("camouflage"), followed by brief exposures to the original images ("solution"), which led to induced insight ("Aha!"). A week later, the participants' memory was tested; a solution image was classified as "remembered" if detailed perceptual knowledge was elicited from the camouflage image alone. During encoding, subsequently remembered images were associated with higher activity in midlevel visual cortex and medial frontal cortex, but most pronouncedly, in the amygdala, whose activity could be used to predict which solutions will remain in long-term memory. Our findings extend the known roles of amygdala in memory ...

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The uncoupling protein (UCP) is a proton/anion transporter found in the inner mitochondrial membrane of brown adipocyte. Although UCP has nor been detected in mitochondria from any other tissue, it shares structural and catalytic properties with several other mitochondrial carrier proteins. Although UCP was discovered only recently it is one of the most extensively studied mitochondrial carrier proteins.More recently, the mouse, rat, and human genes encoding for UCP have been isolated and sequenced. The availability of these various tools has led to several significant observations. UCP gene expression is strongly controlled at the level of transcription by signals that are activated after the stimulation of brown adipocytes by norepinephrine. The comparison of UCP gene with the genes encoding the adenine nucleotide translocator revealed the existence of structural and evolutionary homologies. Moreover, in humans the UCP gene and one form of ...

International Nuclear Information System (INIS)

Synthesis genes encoding the human #alpha#- and #beta#-globin polypeptides have been expressed from a single operon in Escherichia coli. The #alpha#- and #beta#-globin polypeptides associate into soluble tetramers, incorporate heme, and accumulate to >5% of the total cellular protein. Purified recombinant hemoglobin has the correct stoichiometry of #alpha#- and #beta#-globin chains and contains a full complement of heme. Each globin chain also contains an additional methionine as an extension to the amino terminus. The recombinant hemoglobin has a C_4 reversed-phase HPLC profile essentially identical to that of human hemoglobin A_0 and comigrates with hemoglobin A_0 on SDS/PAGE. The visible spectrum and oxygen affinity are similar to that of native human hemoglobin A_0. The authors have also expressed the #alpha#- and #beta#-globin genes separately and found that the expression of the #alpha#-globin gene alone results in a marked decrease in the accumulation of ...

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The PMS2 gene encodes a protein that is involved in DNA mismatch repair and is mutated in a subset of patients with hereditary nonpolyposis colon cancer (HNPCC). The previously published PMS2 cDNA sequence lack an upstream in-frame stop codon preceding the presumptive initiating methionine. To evaluate the 5` terminus of the PMS2 coding region further, we isolated additional cDNA clones, RT-PCR products, and the corresponding 5` genomic segment of the PMS2 locus. The PMS2 gene transcripts were found to have heterogeneous but colinear 5` termini, one of which contained an in-frame termination codon preceding the initiating methionine. In addition, a novel gene encoding a 34.5-kDa polypeptide was found to initiate transcriptionally within PMS2 from the opposite strand. 23 refs., 5 figs., 2 tabs.

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The effects of purified Helminthosporium maydis T (HmT) toxin on active Ca/sup 2 +/ transport into isolated mitochondria and microsomal vesicles were compared for a susceptible (T) and a resistant (N) strain of corn (Zea mays). ATP, malate, NADH, or succinate could drive /sup 45/Ca/sup 2 +/ transport into mitochondria of corn roots. Ca/sup 2 +/ uptake was dependent on the proton electrochemical gradient generated by the redox substrates or the reversible ATP synthetase, as oligomycin inhibited ATP-driven CA/sup 2 +/ uptake while KCN inhibited transport driven by the redox substrates. Purified native HmT toxin completely inhibited Ca/sup 2 +/ transport into T mitochondria at 5 to 10 nanograms per milliliter while transport into N mitochondria was decreased slightly by 100 nanograms per milliliter toxin. Malate-driven Ca/sup 2 +/ transport in T mitochondria was frequently more inhibited by 5 nanograms per milliliter toxin than succinate or ATP-driven Ca/sup 2 +/ uptake. However, ...

DEFF Research Database (Denmark)

We propose to encode a register of quantum bits in different collective electron spin wave excitations in a solid medium. Coupling to spins is enabled by locating them in the vicinity of a superconducting transmission line cavity, and making use of their strong collective coupling to the quantized radiation field. The transformation between different spin waves is achieved by applying gradient magnetic fields across the sample, while a Cooper pair box, resonant with the cavity field, may be used to carry out one- and two-qubit gate operations.

CERN Document Server

We investigate the parametrization issue for discrete-time stable all-pass multivariable systems by means of a Schur algorithm involving a Nudelman interpolation condition. A recursive construction of balanced realizations is associated with it, that possesses a very good numerical behavior. Several atlases of charts or families of local parametrizations are presented and for each atlas a chart selection strategy is proposed. The last one can be viewed as a nice mutual encoding property of lossless functions and turns out to be very efficient. These parametrizations allow for solving optimization problems within the fields of system identification and optimal control.

Science.gov (United States)

In this paper, we proposed a novel quantum secure direct communication scheme with one-time pad in stabilizer formalism. Based on the reuse of qubit sequence, an efficient secure communication of secret messages without first producing a shared secret key can be achieved. One hence may find that the amount of private key needed for quantum communication is smaller than that in the general case. Therefore, the present protocol which is feasible with the present-day techniques may be applied to quantum communication with short-length encoding.

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Human BTEB cDNA clones have been isolated, sequenced, and the corresponding gene has been assigned to human chromosome 9, region q13, by fluorescent in situ hybridization and DNA blot analysis using DNAs from hybrid cell clones containing a single human chromosome. The cDNA clone encodes a polypeptide of 244 amino acids whose sequence shows a high sequence similarity with the rat BTEB (98% amino acid identity).

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Screening of a human placenta lambdagt11 library has led to the isolation of the cDNA for the human ..beta../sub 1/-adrenergic receptor (..beta../sub 1/AR). Used as the probe was the human genomic clone termed G-21. This clone, which contains an intronless gene for a putative receptor, was previously isolated by virtue of its cross hybridization with the human ..beta../sub 2/-adrenergic receptor (..beta../sub 2/AR). The 2.4-kilobase cDNA for the human ..beta../sub 1/AR encodes a protein of 477 amino acid residues that is 69% homologous with the avian ..beta..AR but only 54% homologous with the human ..beta../sub 2/AR. This suggests that the avian gene encoding ..beta..AR and the human gene encoding ..beta../sub 1/AR evolved from a common ancestral gene. RNA blot analysis indicates a message of 2.5 kilobases in rat tissues, with a pattern of tissue distribution consistent with ..beta../sub 1/AR binding. This pattern is quite ...

International Nuclear Information System (INIS)

We have studied the correlation between the chemical state and the oxygen-sensing properties of an iron oxide thin film using a setup that allows simultaneous sensor resistance measurements and X-ray photoelectron spectroscopy (XPS) data acquisition. The gas exposures were performed at the highest operating pressure of the XPS spectrometer at a controlled sample temperature which allows direct comparison between the sensor response and the chemical state of the surface. The iron oxide film was modified by a sequence of argon ion sputtering steps and the induced changes in the chemical state, resistance, and sensitivity to oxygen were investigated. The sputtering was found to reduce the iron from the Fe"3"+ to the Fe"2"+ state and to decrease the sensor resistance. The measured sensitivity to oxygen first increased by a factor of two but then collapsed to its original level. The mechanism for oxygen sensing was found to be filling of the oxygen vacancies in the lattice. The effect of ...

British Library Electronic Table of Contents (United Kingdom)

The electrical characteristics of thin TiO2 films prepared by metal?organic chemical vapor deposition grown on a p-type InP substrate were studied. For a TiO2 film of 4.7?nm on InP without and with ammonium sulfide treatment, the leakage currents are 8.8?10?2 and 1.1?10?4?A/cm2 at +2 V bias and 1.6?10?1 and 8.3?10?4?A/cm2 at ?2?V bias. The lower leakage currents of TiO2 with ammonium sulfide treatment arise from the improvement of interface quality. The dielectric constant and effective oxide charge number density are 33 and 2.5?1013?cm2, respectively. The lowest mid-gap interface state density is around 7.6?1011?cm?2?eV?1. The equivalent oxide thickness is 0.52?nm. The breakdown electric field increases with decreasing thickness in the range of 2.5 to 7.6?nm and reaches 9.3?MV/cm at 2.5?n...

International Nuclear Information System (INIS)

Field emitter devices are being developed for the gigatron, a high-efficiency, high frequency and high power microwave source. One approach being investigated is porous silicon, where a dense matrix of nanoscopic pores are galvanically etched into a silicon surface. In the present paper pore morphologies were used to characterize these materials. Using of Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) images of both N-type and P-type porous layers, it is found that pores propagate along the <100> crystallographic direction, perpendicular to the surface of (100) silicon. Distinct morphologies were observed systematically near the surface, in the main bulk and near the bottom of N-type (100) silicon lift-off samples. It is seen that the pores are not cylindrical but exhibit more or less approximately square cross sections. X-ray diffraction spectra and electron diffraction patterns verified that bulk porous silicon is still a ...

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Techniques for fabricating P-type (Cu,Ag)/sub 2/Se with mesh-type bonds have been developed and are being evaluated for long-term use. In addition, methods for reducing vapor suppression by the use of coatings and/or baffling continue to show gains. The N-type alloy Gd/sub 2/Se/sub 3/ has been shown to be thermally unstable. It undergoes a sluggish cubic-to-orthorhombic phase change below 1000/sup 0/C, with an accompanying degradation in mechanical and thermoelectric properties. Fabrication studies conducted with the (Bi,Sb)/sub 2/(Se,Te)/sub 3/ alloys showed these materials to be sensitive to oxygen contamination if reproducible properties are to be obtained. Preparation of powdered material by explosive techniques was investigated. This technique appears to be useful in preparing homogeneous -325 mesh material, but it does not yield a useful amount of submicron-size powder.

Energy Technology Data Exchange (ETDEWEB)

Minority-carrier lifetime damage coefficients for 1 MeV electron, 3 MeV proton, and 6 MeV alpha particle irradiation of n-type (4.5{times}10{sup 15} and 1.3{times}10{sup 17}cm{sup {minus}3}) and p-type (2.5{times}10{sup 17}cm{sup {minus}3}) InP have been measured using time-resolved photoluminescence. These values are relatively insensitive to carrier type and show a slight increase with increasing carrier concentration. Evidence of comparable electron and hole capture lifetimes is found for the dominant recombination defect. The effect of 3 MeV proton and 6 MeV alpha particles relative to 1 MeV electrons is an increase in the lifetime damage coefficient by factors of about 10{sup 4} and 10{sup 5}, respectively. {copyright} {ital 1997 American Institute of Physics.}

Science.gov (United States)

A modified epitaxial design leads to straightforward implementation of short (1{lambda}) optical cavities and the use of C as the sole {ital p}-type dopant in AlGaInP/AlGaAs red vertical-cavity surface-emitting lasers (VCSELs). Red VCSELs fabricated into simple etched air posts operate continuous wave at room temperature at wavelengths between 670 and 690 nm, with a peak output power as high as 2.4 mW at 690 nm, threshold voltage of 2.2 V, and peak wallplug efficiency of 9%. These values are all significant improvements over previous results achieved in the same geometry with an extended optical cavity epitaxial design. The improved performance is due primarily to reduced optical losses and improved current constriction and dopant stability. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Science.gov (United States)

Ion implantation has been applied to magnesium-doped Al[sub 0.5]In[sub 0.5]P to produce high resistivity regions for the first time. Hydrogen, oxygen, and argon ions were implanted at a base dose ranging from 5[times]10[sup 12] to 5[times]10[sup 14] cm[sup [minus]2] and annealed from 400 to 900 [degree]C. Hydrogen did not appreciably compensate the In[sub 0.5]Al[sub 0.5]P layer while oxygen and argon produced sheet resistances up to 1[times]10[sup 9] [Omega]/[open square]. After annealing at 800 [degree]C, regions with high dose oxygen implants maintained a sheet resistance above 1[times]10[sup 7] [Omega]/[open square], while regions with high dose argon implants recovered most of the unimplanted conductivity.

Science.gov (United States)

Data are presented on the insulating properties and capacitance-voltage (CV) characteristics of metal-oxide-semiconductor (MOS) device-thickness (below approx. 100 nm) native oxides formed by wet thermal oxidation of thin InAlP epilayers lattice matched to GaAs. Low leakage current densities of J=1.4 x 10-9 A/cm2 and J=8.7 x 10-11 A/cm2 are observed at an applied field of 1 MV/cm for MOS capacitors fabricated with 17 nm and 48 nm oxides, respectively. TEM images show that the In-rich interfacial particles which exist in 110 nm oxides are absent in 17 nm oxide films. Quasi-static capacitance-voltage measurements of MOS capacitors fabricated on both n-type and p-type GaAs show that the InAlP oxide-GaAs interface is sufficiently free of traps to support inversion, indicating an unpinned Fermi level. These data suggest that InAlP native oxides may be a viable insulator for GaAs MOS device applications.

Science.gov (United States)

Snake envenomation employs three well integrated strategies: prey immobilization via hypotension, prey immobilization via paralysis, and prey digestion. Purines (adenosine, guanosine and inosine) evidently play a central role in the envenomation strategies of most advanced snakes. Purines constitute the perfect multifunctional toxins, participating simultaneously in all three envenomation strategies. Because they are endogenous regulatory compounds in all vertebrates, it is impossible for any prey organism to develop resistance to them. Purine generation from endogenous precursors in the prey explains the presence of many hitherto unexplained enzyme activities in snake venoms: 5'-nucleotidase, endonucleases (including ribonuclease), phosphodiesterase, ATPase, ADPase, phosphomonoesterase, and NADase. Phospholipases A(2), cytotoxins, myotoxins, and heparinase also participate in purine liberation, in addition to their better known functions. Adenosine contributes to ...

Energy Technology Data Exchange (ETDEWEB)

We have determined the actual RNA sequence of four mitochondrial genes: pcf, nad3, rps12, and coxII. Because plant mitochondrial proteins cannot be predicted from DNA sequences, the actual primary structures of the encoded proteins were unknown. We have gained information concerning the process of RNA editing. Editing can occur before splicing. Our data is consistent with the hypothesis that RNA editing is not simultaneous with transcription. Unlike other systems, the process of editing in plant does not exhibit a discernable direction. As a result of our RNA editing studies, we have produced a number of clones of the proper coding regions tube used for incorporating these mitochondrial genes into the nucleus. 6 refs., 4 figs.

British Library Electronic Table of Contents (United Kingdom)

The human genome encodes 11 cysteine cathepsins belonging to the papain-like family of cysteine peptidases that are known predominantly as endo-lysosomal enzymes. However, it is now understood that the functions and activities of cysteine cathepsins are not limited to endo-lysosomal compartments, as they are also active in the peri- and extracellular space. The thyroid gland is an endocrine organ where such intra- and extracellular proteolytic activities are required to solubilize the prohormone thyroglobulin from its luminal, covalently cross-linked storage forms for subsequent processing into smaller protein fragments and thyroid hormone liberation. Cathepsin K has been identified as one of the cysteine cathepsins with a crucial role in thyroglobulin processing. However, cathepsin K has ...

British Library Electronic Table of Contents (United Kingdom)

Purpose The paired-like homeodomain transcription factor 2 (PITX2) gene encodes a transcription factor controlled by the WNT/Dvl/CTNNB1 and Hedgehog/TGFB pathways in the pathogenesis of colorectal cancer (CRC). Although PITX2 is reportedly involved in various functions, including tissue development by controlling cell growth, its significance in CRC remains unclear. We report our findings regarding abnormal PITX2 expression in human CRC. Methods PITX2 expression was evaluated in 5 human CRC cell lines and 92 primary CRC samples. Cell growth was evaluated after inhibition of PITX2 expression or after exogenous introduction of PITX2. Results PITX2 expression was seen in all the five CRC cell lines. The study of tissue samples indicated that PITX2 expression was significantly higher in cancer...

British Library Electronic Table of Contents (United Kingdom)

Most heat shock proteins (Hsps) function as molecular chaperones that help organisms to cope with stress. Although the best empirical evidence is related to heat shock, there is evidence that Hsps and their encoding genes are involved in resistance to other ecologically relevant types of stresses such as those imposed by high population density. We quantified density-dependent gene expression of large (i.e. Hsp40, Hsc70 and Hsp90) and small (Hsp20.5, Hsp20.6 and Hsp20.7) heat shock genes in neural tissue of fifth-instar nymphs of the Australian plague locust, Chortoicetes terminifera, using reverse transcription-quantitative PCR. Locusts are of particular interest when studying the influence of stress induced by high population density since they show an extreme form of phenotypic plastici...

Science.gov (United States)

We propose a quantum secure direct communication scheme based on non-orthogonal entangled pairs and local measurement. In this scheme, we use eight non-orthogonal entangled pairs to act as quantum channels. Due to the non-orthogonality of the quantum channels, the present protocol can availably prohibit from all kinds of valid eavesdropping and acquire a secure quantum channel. By local measurement, the sender acquires a secret random sequence. The process of encoding on the random sequence is identical to the one in one-time-pad. So the present protocol is secure. Even for a highly lossy channel, our scheme is also valid. The scheme is feasible with present-day techniques.

Science.gov (United States)

An analysis is made of the basic principles and methods of construction of integrated optical circuits (IOC) for data processing, which are optical waveguide processors in the integrated form. A classification is provided of IOC in accordance with the nature of the input connections to optical components and in accordance with their intended function. An analysis is made of the current status of research and development of analog IOC for handling analog and digital signals, IOC for computing technology, and switching IOC. A detailed analysis is made of IOC with different functions in data processing: spectrum analyzers and correlators, analog-digital converters, circuits for identification of data sets and for encoding of signals, threshold and multistable circuits, logic and arithmetic units, and switching arrays. Descriptions are given of IOC for optically controlled data handling: bistable purely optical logic circuits, multivibrators, flip-flops, and optical ...

British Library Electronic Table of Contents (United Kingdom)

Toxigenic Clostridium sordellii strains are increasingly recognized to cause highly lethal infections in humans that are typified by a toxic shock syndrome (TSS). Two glucosylating toxins, lethal toxin (TcsL) and hemorrhagic toxin (TcsH) are believed to be important in the pathogenesis of TSS. While non-toxigenic strains of C. sordellii demonstrate reduced cytotoxicity in vitro and lower virulence in animal models of infection, there are few data regarding their behavior in humans. Here we report a non-TSS C. sordellii infection in the context of a polymicrobial bacterial cholangitis. The C. sordellii strain associated with this infection did not carry either the TcsL-encoding tcsL gene or the tcsH gene for TcsH. In addition, the strain was neither cytotoxic in vitro nor lethal in a murine...

Energy Technology Data Exchange (ETDEWEB)

Protein motions on all timescales faster than molecular tumbling are encoded in the spectral density. The dissection of complex protein dynamics is typically performed using relaxation rates determined at high and ultra-high field. Here we expand this range of the spectral density to low fields through field cycling using the nucleocapsid protein of the SARS coronavirus as a model system. The field-cycling approach enables site-specific measurements of R{sub 1} at low fields with the sensitivity and resolution of a high-field magnet. These data, together with high-field relaxation and heteronuclear NOE, provide evidence for correlated rigid-body motions of the entire {beta}-hairpin, and corresponding motions of adjacent loops with a time constant of 0.8 ns (mesodynamics). MD simulations substantiate these findings and provide direct verification of the time scale and collective nature of these motions.

British Library Electronic Table of Contents (United Kingdom)

Sensory stimuli are encoded differently across cortical layers and it is unknown how response characteristics relate to the morphological identity of responding cells. We therefore juxtasomally recorded action potential (AP) patterns from excitatory cells in layer (L) 2/3, L4, L5 and L6 of rat barrel cortex in response to a standard stimulus (e.g. repeated deflection of single whiskers in the caudal direction). Subsequent single-cell filling with biocytin allowed for post hoc identification of recorded cells. We report three major conclusions. First, sensory-evoked responses were layer- and cell-type-specific but always

British Library Electronic Table of Contents (United Kingdom)

The response regulator protein is a core element of two-component signaling pathway. In this study, we investigated functions of BRRG-1 of Botrytis cinerea, a gene that encodes a putative response regulator protein, which is homologous to Rrg-1 in Neurospora crassa. The BRRG-1 gene deletion mutant ?Brrg1-62 was unable to produce conidia. The mutant showed increased sensitivity to osmotic stress mediated by NaCl and KCl, and to oxidative stress generated by H2O2. Additionally, the mutant was more sensitive to the fungicides iprodione, fludioxonil, and triadimefon than the parental strain. Western-blot analysis showed that the Bos-2 protein, the putative downstream component of Brrg-1, was not phosphorylated in the ?Brrg1-62. Real-time polymerase chain reaction assays showed that expression ...

Energy Technology Data Exchange (ETDEWEB)

Normal human foreskin keratinocytes cotransfected with the neomycin resistance gene and recombinant human papillomavirus (HPV) DNAs (types 16, 18, 31, and 33) that have a high or moderate association with cervical malignancy acquired immortality and contained integrated and transcriptionally active viral genomes. Only transcripts from the intact E6 and E7 genes were detected in at least one cell line, suggesting that one or both of these genes are responsible for immortalization. Recombinant HPV DNAs with low or no oncogenic potential for cervical cancer (HPV1a, -5, -6b, and -11) induced small G418-resistant colonies that senesced as did the nontransfected cells. These colonies contained only episomal virus DNA; therefore, integration of HPV sequences is important for immortalization of keratinocytes. This study suggests that the virus-encoded immortalization function contributes to the pathogenesis of cervical carcinoma.

Energy Technology Data Exchange (ETDEWEB)

The gene encoding the human type I pituitary adenylate cyclase activating polypeptide receptor (ADCYAP1R1) was mapped to chromosome 7 by PCR analysis of genomic DNA from a human/rodent somatic cell hybrid mapping panel. This assignment was confirmed and the gene localized to chromosome band 7p14 by fluorescence in situ hybridization. A yeast artificial chromosome containing ADCYAP1R1 was identified in the CEPH {open_quotes}B{close_quotes} Mega-YAC library. This YAC includes two highly polymorphic dinucleotide repeat sequences that will facilitate genetic studies of the contribution of ADCYAP1R1 in disease states of the central nervous and neuroendocrine systems. 13 refs., 1 fig.

CERN Document Server

Gravitational lensing distorts the cosmic microwave background (CMB) temperature and polarization fields and encodes valuable information on distances and growth rates at intermediate redshifts into the lensed power spectra. The non-Gaussian bandpower covariance induced by the lenses is negligible to l=2000 for all but the B polarization field where it increases the net variance by up to a factor of 10 and favors an observing strategy with 3 times more area than if it were Gaussian. To quantify the cosmological information, we introduce two lensing observables, characterizing nearly all of the information, which simplify the study of non-Gaussian impact, parameter degeneracies, dark energy models, and complementarity with other cosmological probes. Information on the intermediate redshift parameters rapidly becomes limited by constraints on the cold dark matter density and initial amplitude of fluctuations as observations improve. Extraction of this information ...

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We determined the chromosomal localization and structure of the gene encoding human type II inosine 5{prime}-monophosphate dehydrogenase (IMPDH, EC 1.1.1.205), an enzyme associated with cellular proliferation, malignant transformation, and differentiation. Using polymerase chain reaction (PCR) primers specific for type II IMPDH, we screened a panel of human-Chinese hamster cell somatic hybrids and a separate deletion panel of chromosome 3 hybrids and localized the gene to 3p21.1{yields}p24.2. Two overlapping yeast artificial chromosome clones containing the full gene for type II IMPDH were isolated and a physical map of 117 kb of human genomic DNA in this region of chromosome 3 was constructed. The gene for type II IMPDH was localized and oriented on this map and found to span no more than 12.5 kb.

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Linear-optical passive (LOP) devices and photon counters are sufficient to implement universal quantum computation with single photons, and particular schemes have already been proposed. In this paper we discuss the link between the algebraic structure of LOP transformations and quantum computing. We first show how to decompose the Fock space of N optical modes in finite-dimensional subspaces that are suitable for encoding strings of qubits and invariant under LOP transformations (these subspaces are related to the spaces of irreducible unitary representations of U (N). Next we show how to design in algorithmic fashion LOP circuits which implement any quantum circuit deterministically. We also present some simple examples, such as the circuits implementing a cNOT gate and a Bell state generator/analyser.

International Nuclear Information System (INIS)

A very simple theoretical scheme is proposed to implement two- and three-qubit controlled-phase gates firstly only using a single resonant interaction between ladder-type three-level atoms and the single-mode cavity. In the presented protocol, the quantum information is encoded on the stable ground states of the atoms (as the controlling qubits) and the zero- and one-photon Fock states of cavity-field (as the target qubit). Under the influence of the atomic spontaneous emission, the decay of the cavity-mode, and deviation of the coupling strength, the three-qubit controlled-phase gate may have a comparatively high fidelity. The experimental feasibility of controlled-phase gate and the case that is extended to realize N-qubit controlled-phase gate are also discussed. (general)

CERN Document Server

Logic Programming languages and combinational circuit synthesis tools share a common "combinatorial search over logic formulae" background. This paper attempts to reconnect the two fields with a fresh look at Prolog encodings for the combinatorial objects involved in circuit synthesis. While benefiting from Prolog's fast unification algorithm and built-in backtracking mechanism, efficiency of our search algorithm is ensured by using parallel bitstring operations together with logic variable equality propagation, as a mapping mechanism from primary inputs to the leaves of candidate Leaf-DAGs implementing a combinational circuit specification. After an exhaustive expressiveness comparison of various minimal libraries, a surprising first-runner, Strict Boolean Inequality "<" together with constant function "1" also turns out to have small transistor-count implementations, competitive to NAND-only or NOR-only libraries. As a practical outcome, a more realistic ...

Science.gov (United States)

Two plasmids which express either nearly intact or truncated filamentous hemagglutinin (FHA) from Bordetella pertussis and which are marked with a tetracycline resistance (Tcr) gene were transformed into Salmonella dublin SL1438, an aroA deletion mutant intended for use as an attenuated oral vaccine against salmonellosis. These S. dublin recombinants, when fed to mice, induced serum immunoglobulin, immunoglobulin M (IgM), and sometimes IgA antibody responses to FHA and S. dublin. In addition, IgA antibodies against FHA were found in gut wash fluids. S. dublin carrying pDB2300, a multicopy plasmid encoding truncated FHA protein, induced a better antibody response than did S. dublin carrying pDB2000, a low-copy-number plasmid encoding full-sized FHA. Administration of tetracycline to mice enhanced the stability of recombinant plasmids, and tetracycline-treated mice developed higher anti-FHA titers. Although neither strain examined is suitable for ...

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By catalyzing the rate-limiting step in adipose tissue lipolysis, hormone-sensitive lipase (HSL) is an important regulator of energy homeostasis. The role and importance of HSL in tissues other than adipose are poorly understood. We report here the cloning and expression of a testicular isoform, designated HSL{sub tes}. Due to an addition of amino acids at the NH{sub 2}-termini, rat and human HSL{sub tes} consist of 1068 and 1076 amino acids, respectively, compared to the 768 and 775 amino acids, respectively, of the adipocyte isoform (HSL{sub adi}). A novel exon of 1.2 kb, encoding the human testis-specific amino acids, was isolated and mapped to the HSL gene, 16 kb upstream of the exons encoding HSL{sub adi}. The transcribed mRNA of 3.9 kb was specifically expressed in testis. No significant similarity with other known proteins was found for the testis-specific sequence. The amino acid composition differs from the HSL{sub adi} sequence, with ...

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ZnO thin films were electrodeposited in aqueous solution on gilded p-type Si wafer substrates. Thermal treatments were carried out on different films in Ar atmosphere at different temperatures, between 200 and 600 {sup 0}C. Surface morphology studies using scanning electron microscopy and atomic force microscopy show a smooth surface for an annealing temperature of 400 {sup 0}C with a roughness mean square value of about 15 nm and a precipitation of ZnO microcrystals on the deposit surface at 600 {sup 0}C. X-ray diffraction experiments reveal a decrease in the c-parameter value from 5.223 to 5.206 A after treatment at 600 {sup 0}C, due to the removal of hydrogen from the film. Raman spectroscopy analyses show an improvement in the crystal quality of the film and a decrease in the compressive stress inside the deposit. Photoluminescence observations reveal an important change in the UV emission band after annealing at 200 {sup 0}C. A visible region emission band at ...

International Nuclear Information System (INIS)

A systematic study for the materials design of III-V and II-VI compound-based ferromagnetic diluted magnetic semiconductors is given based on ab initio calculations within the local spin density approximation. The electronic structures of 3d-transition-metal-atom-doped GaN and Mn-doped InN, InP, InAs, InSb, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs and AlSb were calculated by the Korringa-Kohn-Rostoker method combined with the coherent potential approximation. It is found that the ferromagnetic ground states are readily achievable in V-, Cr- or Mn-doped GaN without any additional carrier doping treatments, and that InN is the most promising candidate for high-T_C ferromagnet. A simple explanation of the systematic behavior of the magnetic states in III-V and II-VI compound-based diluted magnetic semiconductors is also given. It is also shown that V or Cr-doped ZnS, ZnSe, and ZnTe are ferromagnetic without p- or n-type doping treatment. However, Mn-, Fe-, Co- or Ni-doped ZnS, ZnSe and ZnTe ...

Energy Technology Data Exchange (ETDEWEB)

This thesis details the first direct ultrafast measurements of the dynamic thermal expansion of a surface and the temperature dependent surface thermal diffusivity using a two-color reflection transient grating technique. Studies were performed on p-type, n-type, and undoped GaAs(100) samples over a wide range of temperatures. By utilizing a 90 fs ultraviolet probe with visible excitation beams, the effects of interband saturation and carrier dynamics become negligible; thus lattice expansion due to heating and subsequent contraction caused by cooling provided the dominant influence on the probe. At room temperature a rise due to thermal expansion was observed, corresponding to a maximum net displacement of {approximately} 1 {Angstrom} at 32 ps. The diffracted signal was composed of two components, thermal expansion of the surface and heat flow away from the surface, thus allowing a determination of the rate of expansion as well as the surface thermal diffusivity, ...

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Transient enhanced diffusion (TED) and dose loss (pile-up) are investigated for phosphorus-implanted samples covered with both oxide and nitride films. P ions were implanted into p-type (1 0 0) CZ-Si (dose 5x10{sup 13} cm{sup -3}, 100 keV) through a chemical vapor deposition (CVD) Si{sub 3}N{sub 4} film. For a half of samples, Si{sub 3}N{sub 4} was etched off and SiO{sub 2} films were grown by CVD. Both samples were annealed for 20-360 min at 700 deg. C. Diffusivity of P and the dose loss were estimated based on the secondary-ion mass spectrometry (SIMS) P profiles. Both Si/Si{sub 3}N{sub 4} and Si/SiO{sub 2} interfaces were investigated with transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS). There is no significant difference in P diffusivity between the SiO{sub 2} and Si{sub 3}N{sub 4} films for the present annealing condition of 700 deg. C for 20-360 min. Regarding dose loss, a distinct different behavior was observed. In case ...

Science.gov (United States)

The simultaneous diffusion of Si and the dopants B, P, and As has been studied by the use of a multilayer structure of isotopically enriched Si. This structure, consisting of 5 pairs of 120 nm thick natural Si and {sup 28}Si enriched layers, enables the observation of {sup 30}Si self-diffusion from the natural layers into the {sup 28}Si enriched layers, as well as dopant diffusion from an implanted source in an amorphous Si cap layer, via Secondary Ion Mass Spectrometry (SIMS). The dopant diffusion created regions of the multilayer structure that were extrinsic at the diffusion temperatures. In these regions, the Fermi level shift due to the extrinsic condition altered the concentration and charge state of the native defects involved in the diffusion process, which affected the dopant and self-diffusion. The simultaneously recorded diffusion profiles enabled the modeling of the coupled dopant and self-diffusion. From the modeling of the simultaneous diffusion, the dopant diffusion ...

Science.gov (United States)

We cloned and characterized horse preproendothelin-2 (PPET-2) cDNA from intestinal tissue. The cDNA encoded 178 amino acids of the PPET-2 polypeptide, in which a 21-amino-acid mature endothelin-2 peptide and a 16-amino acid endothelin-2-like peptide were found. For the open reading frame the correspondence of horse PPET-2 cDNA with those of the ferret, human, dog, mouse and rat was 85.1%, 84.9%, 82.1%, 77.8% and 77.2%, respectively. Analysis of the organ distribution of PPET-2 mRNA by reverse transcription-polymerase chain reaction demonstrated that the kidney, stomach and small intestine are major sites of expression of the PPET-2 gene. Surprisingly, the mRNA is not detected in the large intestine, where high expression is demonstrated in the mouse and rat. This difference may result from the underlying functional differences of the large intestine between a herbivore (horse) and an omnivore (mouse and rat). PMID:15838341

Science.gov (United States)

Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1), a cold-inducible coactivator of nuclear receptors, stimulates mitochondrial biogenesis and respiration in muscle cells. In the present study, we first cloned a rat PGC-1 gene from a brown adipose tissue cDNA library which encodes a predicted 796-amino-acid protein and exhibits respectively 98% and 95% identity with the mouse and human homologues. Next, we examined the effect of swimming exercise training on the level of expression of the PGC-1 gene in rat epitrochlearis (Epi) muscle. PGC-1 mRNA level in Epi muscle in rats that swam 2 h a day for 3 and 7 days increased dramatically by 154% and 163%, respectively, compared to the non-exercised control group. PGC-1 mRNA up-regulation was not observed in an immersion group treated at 35 degrees C during the training program but without swimming exercise. These results demonstrate that expression of the PGC-1 gene in Epi muscle is induced not only ...

CERN Document Server

We consider a noisy Slepian-Wolf problem where two correlated sources are separately encoded and transmitted over two independent binary memoryless symmetric channels. Each channel capacity is assumed to be characterized by a single parameter which is not known at the transmitter. The receiver has knowledge of both the source correlation and the channel parameters. We call a system universal if it retains near-capacity performance without channel knowledge at the transmitter. Kudekar et al. recently showed that terminated low-density parity-check (LDPC) convolutional codes (a.k.a. spatially-coupled LDPC ensembles) can have belief-propagation thresholds that approach their maximum a-posteriori thresholds. This was proven for binary erasure channels and shown empirically for binary memoryless symmetric channels. They also conjectured that the principle of spatial coupling is very general and the phenomenon of threshold saturation applies to a very broad class of ...

CERN Document Server

We use a superspin Hamiltonian defined on an infinite-dimensional Fock space with positive definite scalar product to study localization and delocalization of noninteracting spinless quasiparticles in quasi-one-dimensional quantum wires perturbed by weak quenched disorder. Past works using this approach have considered a single chain. Here, we extend the formalism to treat a quasi-one-dimensional system: a quantum wire with an arbitrary number of channels coupled by random hopping amplitudes. The computations are carried out explicitly for the case of a chiral quasi-one-dimensional wire with broken time-reversal symmetry (chiral-unitary symmetry class). By treating the space direction along the chains as imaginary time, the effects of the disorder are encoded in the time evolution induced by a single site superspin (non-Hermitian) Hamiltonian. We obtain the density of states near the band center of an infinitely long quantum wire. Our results agree with those based ...

Energy Technology Data Exchange (ETDEWEB)

Mutations in the mouse formin (Fmn) gene, formerly known as the limb deformity (ld) gene, give rise to recessively inherited limb deformities and renal malformations or aplasia. The Fmn gene encodes many differentially processed transcripts that are expressed in both adult and embryonic tissues. To study the genomic organization of the Fmn locus, we have used Fmn probes to isolate and characterize genomic clones spanning 500 kb. Our analysis of these clones shows that the Fmn gene is composed of at least 24 exons and spans 400 kb. We have identified two novel exons that are expressed in the developing embryonic limb bud as well as adult tissues such as brain and kidney. We have also used a microsatellite polymorphism from within the Fmn gene to map it genetically to a 2.2-cM interval between D2Mit58 and D2Mit103. 36 refs., 6 figs., 1 tab.

Science.gov (United States)

The iron hormone hepcidin is inhibited by matriptase-2, a liver serine-protease encoded by TMPRSS6 gene. Cleaving the BMP-coreceptor hemojuvelin, matriptase-2 impairs the BMP/SMAD signaling pathway, downregulates hepcidin and facilitates iron absorption. TMPRSS6 inactivation causes iron-deficiency-anemia refractory to iron administration both in humans and mice. Genome wide association studies have shown that the SNP rs855791, which causes the matriptase-2 V736A amino acid substitution, is associated with variations of serum iron, transferrin saturation, hemoglobin and erythrocyte traits. Here we show that in vitro matriptase-2 736(A) inhibits hepcidin more efficiently than 736(V). Moreover, in a genotyped population, after exclusion of samples with iron deficiency and inflammation, hepcidin, hepcidin/transferrin saturation and hepcidin/ferritin ratios were significantly lower and iron parameters were consistently higher in homozygotes 736(A) than in 736(V). Our ...

British Library Electronic Table of Contents (United Kingdom)

Emerging evidence suggests that E3 ligases play critical roles in diverse biological processes, including innate immune responses in plants. However, the mechanism of the E3 ligase involvement in plant innate immunity is unclear. We report that a rice gene, OsBBI1, encoding a RING finger protein with E3 ligase activity, mediates broad-spectrum disease resistance. The expression of OsBBI1 was induced by rice blast fungus Magnaporthe oryzae, as well as chemical inducers, benzothiadiazole and salicylic acid. Biochemical analysis revealed that OsBBI1 protein possesses E3 ubiquitin ligase activity in vitro. Genetic analysis revealed that the loss of OsBBI1 function in a Tos17-insertion line increased susceptibility, while the overexpression of OsBBI1 in transgenic plants conferred enhanced resi...

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This thesis discusses an advanced dynamical two-dimensional cylinder symmetric model for the high temperature part of the carbothermic silicon metal process, and its computer encoding. The situation close to that which is believed to exist around one of three electrodes in full-scale industrial furnaces is modelled. This area comprises a gas filled cavity surrounding the lower tip of the electrode, the metal pool underneath and the lower parts of the materials above. The most important phenomena included are: Heterogeneous chemical reactions taking place in the high-temperature zone (above 1860 {sup o}C), Evaporation and condensation of silicon, Transport of materials by dripping, Turbulent or laminar fluid flow, DC electric arcs, Heat transport by convection, conduction and radiation. The results from the calculations, such as production rates, gas- and temperature distributions, furnace- and particle geometries, fluid flow fields etc, are presented graphically. ...

British Library Electronic Table of Contents (United Kingdom)

Coutinho MF, Encarnao M, Gomes R, da Silva Santos L, Martins S, Sirois-Gagnon D, Bargal R, Filocamo M, Raas-Rothschild A, Tappino B, Laprise C, Cury GK, Schwartz IV, Artigals O, Prata MJ, Alves S. Origin and spread of a common deletion causing mucolipidosis type II: insights from patterns of haplotypic diversity. Mucolipidosis II (ML II alpha/beta), or I-cell disease, is a rare genetic disease in which activity of the uridine diphosphate (UDP)-N-acetylglucosamine:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase (GlcNAc-phosphotransferase) is absent. GlcNAc-phosphotransferase is a multimeric enzyme encoded by two genes, GNPTAB and GNPTG. A spectrum of mutations in GNPTAB has been recently reported to cause ML II alpha/beta. Most of these mutations were found to be private or rare. ...

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Pancreatitis-associated protein (PAP) is a secretory pancreatic protein present in small amounts in normal pancreas and overexpressed during the acute phase of pancreatitis. In this paper, the authors describe the cloning, characterization, and chromosomal mapping of the human PAP gene. The gene spans 2748 bp and contains six exons interrupted by five introns. The gene has a typical promoter containing the sequences TATAAA and CCAAT 28 and 52 bp upstream of the cap site, respectively. They found striking similarities in genomic organization as well as in the promoter sequences between the human and rat PAP genes. The human PAP gene was mapped to chromosome 2p12 using rodent-human hybrid cells and in situ chromosomal hybridization. This localization coincides with that of the reg/lithostathine gene, which encodes a pancreatic secretory protein structurally related to PAP, suggesting that both genes derived from the same ancestral gene by duplication. 35 refs., 4 ...

British Library Electronic Table of Contents (United Kingdom)

Expressed sequence tags (ESTs) of the maxillary galea of the silkworm were analyzed to identify proteins involved in food selection systems. From the 1251 redundant genes of the ESTs, we identified 7 odorant-binding protein-like genes (bmObpL), 6 takeout-like genes (bmToL), and 6 chemosensory protein genes (bmCsp). Quantitative RT-PCR analysis indicated that bmObpL1, bmObpL2, bmObpL3, bmObpL5, bmToL1, bmToL3, and bmorCsp15 were predominantly expressed in the larval oral appendages, such as the maxilla, labrum, labium and antenna. Immunocytochemical analysis indicated that the proteins of bmObpL1, bmObpL3, and bmToL1 were localized in the gustatory chemosensilla on the maxillary galea and olfactory sensilla in the antenna. The proteins encoded by bmObpL1 and bmObpL3 were detected in the gus...

British Library Electronic Table of Contents (United Kingdom)

Aims: The present study explored the integrative effect of genes encoding methadone pharmacokinetic and pharmacodynamic pathways on methadone maintenance doses in Han Chinese Patients. Materials & methods: Genomic DNA was extracted from 321 opioid-dependent patients and 202 healthy controls, and realtime-PCR and PCR-RFLP were conducted to determine the genotypes. Results: Pair-wise comparisons revealed that carriers of the variants ABCB1 3435C>T or CYP2B6 516G>T alleles were more likely to require a higher methadone dose than noncarriers (both p G or 939C>T allele had a two-fold chance of requiring a lower methadone dose than noncarriers (p = 0.001). Proportional odds regression with adjustment of cofactors demonstrated that ...

British Library Electronic Table of Contents (United Kingdom)

To understand the molecular mechanisms of how 5^oC-incubation activates mRNA expression of Hsp70a and Samui genes in Bombyx mori diapause eggs, we first searched the 5'-upstream regions of the Hsp70a and Samui genes for heat shock elements (HSEs) and found two regions [Hsp70aHSE-1 (-95 to -58) and -2 (-145 to -121), and SamuiHSE-1 (-84 to -55) and -2 (-304 to -290)] corresponding to HSEs (repeats of nGAAn and/or nTTCn). We cloned four cDNAs encoding heat shock factor (HSF)-a2 (627 amino acids), -b (685 aa), -c (682 aa) and -d (705 aa), which were produced by alternative splicing. When we exposed diapause eggs to 5^oC beginning at 2 day post-oviposition to break diapause, HSFd mRNA only increased after chilling for 6-8 days, a pattern very similar to those of Hsp70a and Samui mRNAs. To exam...

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The Drosophila hairy gene encodes a basic helix- loop-helix protein that functions in at least two steps during Drosophila development: (1) during embryogenesis, when it partakes in the establishment of segments, and (2) during the larval stage, when it functions negatively in determining the pattern of sensory bristles on the adult fly. In the rat, a structurally homologous gene (RHL) behaves as an immediate-early gene in its response to growth factors and can, like that in Drosophila, suppress neuronal differentiation events. Here, the authors report the genomic cloning of the human hairy gene homolog (HRY). The coding region of the gene is contained within four exons. The predicted amino acid sequence reveals only four amino acid differences between the human and rat genes. Analysis of the DNA sequence 5[prime] to the coding region reveals a putatitve untranslated exon. To increase the value of the HRY gene as a genetic marker and to assess its potential ...

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Scientists have just taken a big step toward understanding the cause of Lou Gehrig's disease, one of the most devastating nerve degenerative diseases. A large team of researchers, led by Robert Brown Jr. of Harvards's Massachusetts General Hospital and Robert Horvitz, a Howard Hughes Medical Institute investigator at the Massachusetts Institute of Technology, report in the 4 March Nature that they've identified the gene that causes a hereditary form of the condition, which also goes by the name amyothophic lateral sclerosis (ALS). While most ALS cases - approximately 90% - are apparently sporadic' and not caused by an inherited gene defect, all the patients have such similar symptons that researchers are hopeful that what they learn about hereditary ALS will also apply to the sporadic form, possibly leading to new therapeutic strategies that will help both. It's a very important finding,' says neurobiologist Donald Harter of the ...

CERN Document Server

Deduction modulo is a paradigm which consists in applying the inference rules of a deductive system (such as for instance natural deduction) modulo a rewrite system over terms and propositions. It has been shown that higher-order logic can be simulated into the first-order natural deduction modulo. However, a theorem stated by Goedel and proved by Parikh expresses that proofs in second-order arithmetic may be unboundedly shorter than proofs in first-order arithmetic, even when considering only formulae provable in first-order arithmetic. We investigate how deduction modulo can be used to translate proofs of higher-order arithmetic into first-order proofs without inflating their length. First we show how higher orders can be encoded through a quite simple (finite, terminating, confluent, left-linear) rewrite system. Then, a proof in higher-order arithmetic can be linearly translated into a proof in first-order arithmetic modulo this system. Second, in the ...

Energy Technology Data Exchange (ETDEWEB)

The feasibility of containing genetically engineered bacteria with enhanced dehalogenating properties for in situ bioremediation was investigated. (1) An agarose matrix microbead protocol and a detection system for contained microorganisms or DNA were developed. Multiplex Polymerase Chain Reaction (PCR) allowed tracking of a consortium of encapsulated organisms or several gene targets from a single species. Gene sequences encoding the enzymes responsible for initiating the biodegradation of toluene, octane, and 2,4-D were detected by multiplex PCR and nucleic acid probes from similar to 1-10 biodegradative cells/g soil. Improved DNA extraction methods resulted in PCR reactions detecting similar to 6 cells/g soil. (2) The pcpB gene (for the broad-spectrum detoxicant pentachlorophenol (PCP) hydroxylase) isolated from Flavobacterium sp. strain ATCC 39723 was used in attempts to develop an improved dehalogenating recombinant microorganism for containment experiments.

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The human CDC25 tyrosine phosphatases trigger activation of CDC2 by removing inhibitory phosphates; thus the genes encoding these phosphatases may be suspected as potential oncogenes due to their role in promoting cell division. To date, three human CDC25 genes have been identified: CDC25A, B, and C. This communication describes the mapping of CDC25A to chromosome 3p21 and CDC25B to chromosome 20p13 by fluorescence in situ hybridization with confirmation by the polymerase chain reaction of hamster-human somatic cell hybrid DNA. 3p21 is near an area frequently involved in karyotypic abnormalities in renal carcinomas, small cell carcinomas of the lung, and benign tumors of the salivary gland. 20p13 does not seem to be a common area for karyotypic alteration in tumors. Mapping of these genes to their chromosomal loci may help identify tumors with abnormal regulation of CDC25 genes due to genomic alterations. 15 refs., 3 figs.

CERN Document Server

The centre of the symmetric group algebra $\\mathbb{C}[\\mathfrak{S}_n]$ has been used successfully for studying important problems in enumerative combinatorics. These include maps in orientable surfaces and ramified covers of the sphere by curves of genus $g$, for example. However, the combinatorics of some equally important $\\mathfrak{S}_n$-factorization problems forces $k$ elements in $\\{1,...,n\\}$ to be distinguished. Examples of such problems include the star factorization problem, for which $k=1,$ and the enumeration of 2-cell embeddings of dipoles with two distinguished edges \\cite{VisentinWieler:2007} associated with Berenstein-Maldacena-Nastase operators in Yang-Mills theory \\cite{ConstableFreedmanHeadrick:2002}, for which $k=2.$ Although distinguishing these elements obstructs the use of central methods, these problems may be encoded algebraically in the centralizer of $\\mathbb{C}[\\mathfrak{S}_n]$ with respect to the subgroup $\\mathfrak{S}_{n-k}.$ ...

British Library Electronic Table of Contents (United Kingdom)

Genome-wide association studies have linked lung cancer risk with a region of chromosome 15q25.1 containing CHRNA3, CHRNA5 and CHRNB4 encoding a3, a5 and b4 subunits of nicotinic acetylcholine receptors (nAChR), respectively. One of the strongest associations was observed for a non-silent single-nucleotide polymorphism at codon 398 in CHRNA5. Here, we have used pharmacological (antagonists) or genetic (RNA interference) interventions to modulate the activity of CHRNA5 in non-transformed bronchial cells and in lung cancer cell lines. In both cell types, silencing CHRNA5 or inhibiting receptors containing nAChR a5 with a-conotoxin MII exerted a nicotine-like effect, with increased motility and invasiveness in vitro and increasing calcium influx. The effects on motility were enhanced by addit...

British Library Electronic Table of Contents (United Kingdom)

Catalase is an important antioxidant protein which can protect organisms against various oxidative stresses by eliminating hydrogen peroxide. The catalase cDNA of Cristaria plicata@?cpCAT@? was cloned from the haemocytes using degenerate primers by the method of 3' and 5' rapid amplification of cDNA ends PCR. The gene is 4863 bp long and has a total of two introns and three exons. The precise size and location of the introns and exons have been determined. In addition the full-length cDNA of cpCAT contained 2618 bp, The cDNA contained a 5' untranslated region (UTR) of 136 nucleotides, the 3' UTR of 979 bp with a canonical polyadenylation signal sequence AATAAA and a polyA tail, and an open reading frame (ORF) of 1503 bp, encoding 501 amino acid residues with 56.86 kDa predicted molecular w...

Science.gov (United States)

Bacterial attachment-effacement (att-eff) is emerging as an important virulence characteristic common to both enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC). The contribution of the plasmid-encoded EPEC adherence factor to the production of mucosal lesions and diarrhea was investigated in gnotobiotic piglets. Bacterial att-aff in the intestinal mucosa of piglets infected with plasmid-cured EPEC strain E2348/69 (O127) was indistinguishable from that in piglets infected with the parent strain, but the distribution of lesions was different; it occurred in the small intestines of 6 of 7 piglets infected with the parent strain compared with only 2 of 11 (P = 0.006) infected with the plasmid-cured strain. Plasmid-encoded factors in EPEC and EHEC strains did not appear to contribute to bacterial competition with normal gut microflora. Of 13 strains belonging to five EPEC serogroups, O55, O142, O26, O119, and O111, 3 ...

Energy Technology Data Exchange (ETDEWEB)

This SBIR Phase I developed neutron detectors made from gallium arsenide (GaAs) p-type/ intrinsic/n-type (P-I-N) diodes grown by metalorganic chemical vapor deposition (MOCVD) onto semi-insulating (S1) bulk GaAs wafers. A layer of isotonically enriched boron-10 evaporated onto the front surface serves to convert incoming neutrons into lithium ions and a 1.47 MeV alpha particle which creates electron-hole pairs that are detected by the GaAs diode. Various thicknesses of ''intrinsic'' (I) undoped GaAs were tested, as was use of a back-surface field (BSF) formed from a layer of Al{sub x}Ga{sub 1-x}As. Schottky-barrier diodes formed from the same structures without the p+ GaAs top layer were tested as a comparison. After mesa etching and application of contacts, devices were tested in visible light before application of the boron coating. Internal quantum efficiency (IQE) of the best diode near the GaAs bandedge is over 90%. The ...

Science.gov (United States)

Drosophila melanogaster has long been at the forefront of studies of transcriptional regulation in animals. Many fundamental ideas--such as cis control elements that act over long distances, the regulation of development by hierarchical cascades of transcription factors, dosage compensation, and position effect variegation--originated from studies of the fruit fly. The recent completion of the euchromatic DNA sequence of Drosophila is another breakthrough. The sequence data highlight important unanswered questions. For example, only one-fifth of the 124 Mb of Drosophila euchromatic DNA codes for protein. The function of the remaining 100 Mb of mostly unique DNA is largely unknown. Some proportion of this non-reading frame DNA must encode the functional recognition sites targeted by the approximately 700 sequence-specific DNA binding proteins that regulate transcription in Drosophila, but what proportion? Most or very little? Promoter sequences by definition contain ...

Science.gov (United States)

Clostridium difficile (C. difficile) causes 25-30% of cases of antibiotic associated diarrhea and most cases of pseudomembranous colitis. Patients presenting with diarrhea after hospitalization for 3 or more days should be tested for C. difficile. There are many options available for testing, each of which has inherent advantages and disadvantages. Most laboratories perform toxin testing using an enzyme immunoassay method. In general these tests have sensitivities ranging from 60 to 70% and specificities of 98%. When using these methods, symptomatic patients with negative tests should be tested by another more sensitive method. Until recently, cell culture cytotoxicity neutralization assays (CCNAs) were considered the gold standard in the U.S. A two-step algorithm using an EIA for glutamate dehydrogenase detection followed by testing positives using CCNA, offered an improved alternative until the availability of molecular assays. Although early studies that compared the GDH assay to ...

Energy Technology Data Exchange (ETDEWEB)

We report an analysis of four strains of baker's yeast (Saccharomyces cerevisiae) using biocavity laser spectroscopy. The four strains are grouped in two pairs (wild type and altered), in which one strain differs genetically at a single locus, affecting mitochondrial function. In one pair, the wild-type rho+ and a rho0 strain differ by complete removal of mitochondrial DNA (mtDNA). In the second pair, the wild-type rho+ and a rho- strain differ by knock-out of the nuclear gene encoding Cox4, an essential subunit of cytochrome c oxidase. The biocavity laser is used to measure the biophysical optic parameter Deltalambda, a laser wavelength shift relating to the optical density of cell or mitochondria that uniquely reflects its size and biomolecular composition. As such, Deltalambda is a powerful parameter that rapidly interrogates the biomolecular state of single cells and mitochondria. Wild-type cells and mitochondria produce Gaussian-like distributions ...

Science.gov (United States)

The human olfactomedin 4 gene (OLFM4) encodes an olfactomedin-related glycoprotein. OLFM4 is normally expressed in a limited number of tissues, including the prostate, but its biological functions in prostate are largely unknown. In this study, we found that OLFM4 messenger RNA was reduced or undetectable in prostate cancer tissues and prostate cancer cell lines. To study the effects of OLFM4 on prostate cancer progression, we transfected PC-3 prostate cancer cells with OLFM4 to establish OLFM4-expressing PC-3 cell clones. The OLFM4-expressing PC-3 cell clones were found to have decreased proliferation and invasiveness compared with vector-transfected control PC-3 cells in vitro. In addition, nude mice injected with OLFM4-expressing PC-3 cells demonstrated reduced tumor growth and bone invasion and metastasis compared with mice injected with vector-transfected control cells. Mechanistic studies revealed that OLFM4 may exhibit its anticancer effects through ...

Science.gov (United States)

The natriuretic peptides are considered to be cardioprotective; however, their receptors have not been identified in human myocardium using radiolabeled analogs. Dendroaspis natriuretic peptide (DNP) has been recently identified as a new member of this peptide family and is thought to be less susceptible to enzymatic degradation. Therefore, we have developed the novel radiolabeled analog [125I]-DNP and used this to localize high-affinity (K(D)=0.2 nmol/L), saturable, specific binding sites in adult human heart (n=6) and coronary artery (n=8). In competition binding experiments, atrial natriuretic peptide and brain type natriuretic peptide had greater affinity for [125I]-DNP binding sites than C-type natriuretic peptide and the natriuretic peptide receptor (NPR)-C ligand, cANF. This rank order of potency suggested binding of [125I]-DNP was specific to NPR-A. Messenger RNA encoding NPR-A was identified in left ventricle and coronary artery smooth muscle, and ...

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Ratiometric fluorescent dyes are often used to monitor free ion concentrations in vivo, especially in cells that are recalcitrant to transformation with genetically encoded fluorescent markers. Although intracellular dye distributions are often found to be cytosolic, dye localisation has often not been examined in detail. We began exploring the use of BCECF (2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein) to monitor pH in the giant alga Chara australis and discovered that younger leaf cells could be loaded using the acetoxymethyl ester of BCECF. However, we were puzzled to find in microphotometric measurements that the fluorescence ratio appeared insensitive to manipulations affecting cytosolic pH. Confocal imaging of C. australis cells loaded with BCECF showed an accumulation of the dye in two locations: (1) on the outside of the chloroplasts in irregularly shaped stationary bodies; (2) within 1-1.5 mum structures that moved rapidly with the pericellular ...

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PNAS-4, a novel pro-apoptotic gene activated during the early response to DNA damage, can inhibit proliferation via apoptosis when overexpressed in some tumor cells. Recent studies have indicated that honokiol can induce apoptosis, inhibit angiogenesis, and suppress tumor growth. In the present study, we investigated whether mouse PNAS-4 (mPNAS-4) could augment the apoptosis of tumor cells induced by honokiol in vitro, and whether the antiangiogenic activity of honokiol and induction of apoptosis by mPNAS-4 could work cooperatively to improve the antitumor efficacy in vivo. In vitro, mPNAS-4 inhibited proliferation of murine colorectal carcinoma CT26 and Lewis lung carcinoma LL2 cells through induction of apoptosis, and significantly augmented the apoptosis of CT26 and LL2 cells induced by honokiol. Compared with treatment with mPNAS-4 or honokiol alone, in vivo systemic administration of an expression plasmid encoding mPNAS-4 and low-dose honokiol significantly ...

Science.gov (United States)

Rice is a very important food staple that feeds more than half the world's population. Two major Asian cultivated rice (Oryza sativa L.) subspecies, japonica and indica, show significant phenotypic variation in their stress responses. However, the molecular mechanisms underlying this phenotypic variation are still largely unknown. A common link among different stresses is that they produce an oxidative burst and result in an increase of reactive oxygen species (ROS). In this study, methyl viologen (MV) as a ROS agent was applied to investigate the rice oxidative stress response. We observed that 93-11 (indica) seedlings exhibited leaf senescence with severe lesions under MV treatment compared to Nipponbare (japonica). Whole-genome microarray experiments were conducted, and 1,062 probe sets were identified with gene expression level polymorphisms between the two rice cultivars in addition to differential expression under MV treatment, which were assigned as Core Intersectional Probesets ...

Science.gov (United States)

HEMATOLOGICAL MALIGNANCIES IN HUMANS TYPICALLY INVOLVE TWO TYPES OF GENETIC CHANGES: those that promote hematopoietic cell proliferation and survival (often the result of activation of tyrosine kinases) and those that impair hematopoietic cell differentiation (often the result of changes in transcription factors). The multi-stage erythroleukemia induced in mice by Friend spleen focus-forming virus (SFFV) is an excellent animal model for studying the molecular basis for both of these changes. Significant progress has been made in understanding the molecular basis for the multi-stage erythroleukemia induced by Friend SFFV. In the first stage of leukemia, the envelope protein encoded by SFFV interacts with and activates the erythropoietin (Epo) receptor and the receptor tyrosine kinase sf-Stk in erythroid cells, causing their Epo-independent proliferation, differentiation and survival. In the second stage, SFFV integration into the Sfpi1 locus activates the myeloid ...

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Autoreactive cytotoxic CD8 T-cells (CTLs) play a key pathogenic role in the destruction of insulin-producing beta-cells resulting in type 1 diabetes. However, knowledge regarding their targets is limited, restricting the ability to monitor the course of the disease and immune interventions. In a multi-step discovery process to identify novel CTL epitopes in human preproinsulin (PPI), PPI was digested with purified human proteasomes, and resulting COOH-fragments aligned with algorithm-predicted HLA-binding peptides to yield nine potential HLA-A1, -A2, -A3 or -B7-restricted candidates. An UV-exchange method allowed the generation of a repertoire of multimers including low-affinity HLA-binding peptides. These were labeled with quantum dot-fluorochromes and encoded in a combinatorial fashion, allowing parallel and sensitive detection of specific, low-avidity T-cells. Significantly increased frequencies of T-cells against four novel PPI epitopes (PPI(4-13)/B7, ...

Science.gov (United States)

Neuronal transcription factors play vital roles in the specification and development of neurons, including dopaminergic (DA) neurons. Mutations in the gene encoding the purine biosynthetic enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) cause the resulting intractable and largely untreatable neurological impairment of Lesch-Nyhan disease (LND). The disorder is associated with a defect in basal ganglia DA pathways. The mechanisms connecting the purine metabolic defect and the central nervous system (CNS) phenotype are poorly understood but have been presumed to reflect a developmental defect of DA neurons. We have examined the effect of HPRT deficiency on the differentiation of neurons in the well-established human (NT2) embryonic carcinoma neurogenesis model. We have used a retrovirus expressing a small hairpin RNA (shRNA) to knock down HPRT gene expression and have examined the expression of a number of transcription factors essential for neuronal ...

Energy Technology Data Exchange (ETDEWEB)

The large aggregating proteoglycan aggrecan is a major structural component of the extracellular matrix of articular cartilage. Recent cDNA cloning of the human aggrecan gene (AGC1) reveals a core protein of at least 2316 amino acids characterized by several distinct structural domains. Two globular domains, termed G1 and G2, are present at the amino terminus of the molecule and a third, termed G3, is present at the carboxy terminus. The G1 domain is homologous in structure to the cartilage link protein and accounts for the aggregating potential of aggrecan through its ability to interact with hyaluronic acid. The aggrecan gene is known to consist of 15 exons, with each exon encoding a distinct functional region of the mature protein. However, while the link protein gene is known to reside on chromosome 5 in the human, the location of the aggrecan gene is currently undetermined in any species. The probe (pAGG2) for the aggrecan gene was mapped on chromosome band ...

DEFF Research Database (Denmark)

Antisense- or RNAi-mediated suppression of the biosynthesis of nutritionally inferior storage proteins is a promising strategy for improving the amino acid profile of seeds. However, the potential pleiotropic effects of this on interconnected pathways and the agronomic quality traits need to be addressed. In the current study, a transcriptomic analysis of an antisense C-hordein line of barley was performed, using a grain-specific cDNA array. The C-hordein antisense line is characterized by marked changes in storage protein and amino acid profiles, while the seed weight is within the normal range and no external morphological irregularities were observed. The results of the transcriptome analysis showed excellent correlation with data on changes in the relative proportions of storage proteins and amino acid composition. The antisense line had a lower C-hordein level and down-regulated transcript encoding C-hordein. The production of the S-rich B/ - and D-hordeins ...

Energy Technology Data Exchange (ETDEWEB)

ATR-X (alpha-thalassemia/mental retardation, X-linked) syndrome is a human congenital disorder that causes severe intellectual disabilities. Mutations in the ATRX gene, which encodes an ATP-dependent chromatin-remodeler, are responsible for the syndrome. Approximately 50% of the missense mutations in affected persons are clustered in a cysteine-rich domain termed ADD (ATRX-DNMT3-DNMT3L, ADD{sub ATRX}), whose function has remained elusive. Here we identify ADD{sub ATRX} as a previously unknown histone H3-binding module, whose binding is promoted by lysine 9 trimethylation (H3K9me3) but inhibited by lysine 4 trimethylation (H3K4me3). The cocrystal structure of ADD{sub ATRX} bound to H3{sub 1-15}K9me3 peptide reveals an atypical composite H3K9me3-binding pocket, which is distinct from the conventional trimethyllysine-binding aromatic cage. Notably, H3K9me3-pocket mutants and ATR-X syndrome mutants are defective in both H3K9me3 binding and localization at ...

International Nuclear Information System (INIS)

CANDU 600 nuclear reactors are usually fuelled with STANDARD (STD), 37 rods fuel bundles. Natural uranium (NU) dioxide (UO_2), is used as fuel composition. A new fuel bundle geometry called CANFLEX (CFX) with 43 rods is proposed and some new fuel composition are considered. Flexibility is the key word for the attempt to use some different fuel geometries and compositions for CANDU 600 nuclear reactors as well as for innovative ACR-700/1000 nuclear reactors. The fuel bundle considered in this paper is CFX-RU-0.90 that encodes the CANFLEX geometry, recycled dioxide uranium (RU) with 0.90% enrichment. The goal of this proposal is ambitious: a higher average discharge burn-up up to 14000 MWd/tU and, for the same amount of generated electric power, reduction in nuclear fuel fabrication, reduction of spent nuclear fuel radioactive waste and reduction of refueling operational work by using fewer bundles. An improved sub-channel approach for thermal-hydraulic analysis is ...

Energy Technology Data Exchange (ETDEWEB)

Purpose: In vitro evaluation of possible deflection and heating of present-day prosthetic heart valves, 12 technical and 5 biological, were investigated using a 1.5 Tesla Siemens Vision system. Deflection was measured at the edge of a 1.5 Tesla superconducting magnet. Each valve was then submerged in a vial of a 1/1 electrolyte solution and temperature was measured before and after imaging with a turbo-spin-echo sequence (TR 5200 ms, TE 138 ms, Flip angle 180 C, acquisition time 10.5 minutes, length of echo train 29). MR imaging was performed with phase encoding parallel and perpendicular to the plane of the valves. Results: None of the investigated prosthetic heart valves was deflected. The maximal observed temperature rise was 0.5 C. During MR investigation of the prostheses, artifacts caused by metallic parts were less evident using a spin-echo sequence than a gradient-echo sequence. Conclusions: Patients with the tested present-day prosthetic heart valves can ...

Energy Technology Data Exchange (ETDEWEB)

Purpose: Measurement of the oscillating CSF flow in the spinal canal (SC) of healthy volunteers and in patients with post-traumatic syringomyelia (PTS) using an optimized MRI protocol as well as to determine whether stenosis induced velocity changes are detectable using MRI. Methods: In 68 healthy volunteers quantitative studies of CSF flow in the cervical, thoracic, and lumbar regions were performed. First, an optimized sequence was developed and tested in 19 volunteers using four different flow-encoding velocities (4, 8, 12, 16 cm/s). Secondly, the optimized sequence was employed in 49 volunteers to measure the different CSF patterns in the cervical, thoracic, and lumbar spinal canals (CSC, TSC, LSC). Part three of the study, in which patients with PTS are being examined is still underway. We measured the maximum velocity (cm/s), the pixel area (mm{sup 2}), and the stroke volume (ml/s). Using a flow model the velocities prior to and after compression with 5 ...