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  1. Genetics Home Reference: Knobloch syndrome

    MedlinePlus

    ... the human phenotype. An Acad Bras Cienc. 2006 Mar;78(1):123-31. Epub 2006 Mar 8. Review. Citation on PubMed Seaver LH, Joffe ... XVIII in development and disease. Matrix Biol. 2011 Mar;30(2):83-92. doi: 10.1016/j. ...

  2. The Biomechanical Support of Eight Selected Sports Bras for Small, Medium and Large Breasted Women while Jogging.

    ERIC Educational Resources Information Center

    Lorentzen, Deana; Lawson, LaJean

    This study compared the biomechanical support offered by eight presently marketed sports bras for small-, medium-, and large-breasted women while jogging. Fifty-nine subjects were filmed while jogging on a treadmill in each of the bras and in the nude condition. The vertical displacement of the breast relative to the body during one average…

  3. Construction and Initial Validation of the Color-Blind Racial Attitudes Scale (CoBRAS).

    ERIC Educational Resources Information Center

    Neville, Helen A.; Lilly, Roderick L.; Duran, Georgia; Lee, Richard M.; Browne, LaVonne

    2000-01-01

    Describes development of a conceptually grounded scale to assess cognitive aspects of color-blind racial attitudes. Factor analysis suggests that the 3-factor model is a good fit of data. States that CoBRAS was positively related to other indexes of racial attitudes indicating that greater endorsement of color-blind racial attitudes was related to…

  4. Leishmania (Leishmania) hertigi in a porcupine (Coendou sp.) found in Brasília, Federal District, Brazil.

    PubMed

    Silva, Denise Amaro da; Madeira, Maria de Fatima; Barbosa Filho, Carlos José Lima; Schubach, Edvar Yuri Paheco; Barros, Juliana Helena da Silva; Figueiredo, Fabiano Borges

    2013-01-01

    Studies report the occurrence of Leishmania (Leishmania) hertigi in northern states of Brazil. In the present investigation, we describe the isolation of L. (L.) hertigi from a porcupine (Coendou sp.) found in Brasília, Federal District, center-west region of Brazil. During a study on canine visceral leishmaniasis conducted in the city of Brasília, Federal District, a porcupine was found dead on a public road. The animal was identified and fragments of intact skin and spleen were collected for isolation of parasite in the culture. This report of the occurrence of L. hertigi in another part of Brazil may help establish the distribution of this parasite in the country. Further studies are needed to better understand the role of L. hertigi in the pathology and pathogenesis of leishmaniasis and its survival in mammals and possible vectors. PMID:23538497

  5. Reveal genes functionally associated with ACADS by a network study.

    PubMed

    Chen, Yulong; Su, Zhiguang

    2015-09-15

    Establishing a systematic network is aimed at finding essential human gene-gene/gene-disease pathway by means of network inter-connecting patterns and functional annotation analysis. In the present study, we have analyzed functional gene interactions of short-chain acyl-coenzyme A dehydrogenase gene (ACADS). ACADS plays a vital role in free fatty acid β-oxidation and regulates energy homeostasis. Modules of highly inter-connected genes in disease-specific ACADS network are derived by integrating gene function and protein interaction data. Among the 8 genes in ACADS web retrieved from both STRING and GeneMANIA, ACADS is effectively conjoined with 4 genes including HAHDA, HADHB, ECHS1 and ACAT1. The functional analysis is done via ontological briefing and candidate disease identification. We observed that the highly efficient-interlinked genes connected with ACADS are HAHDA, HADHB, ECHS1 and ACAT1. Interestingly, the ontological aspect of genes in the ACADS network reveals that ACADS, HAHDA and HADHB play equally vital roles in fatty acid metabolism. The gene ACAT1 together with ACADS indulges in ketone metabolism. Our computational gene web analysis also predicts potential candidate disease recognition, thus indicating the involvement of ACADS, HAHDA, HADHB, ECHS1 and ACAT1 not only with lipid metabolism but also with infant death syndrome, skeletal myopathy, acute hepatic encephalopathy, Reye-like syndrome, episodic ketosis, and metabolic acidosis. The current study presents a comprehensible layout of ACADS network, its functional strategies and candidate disease approach associated with ACADS network. PMID:26045367

  6. Complex I assembly function and fatty acid oxidation enzyme activity of ACAD9 both contribute to disease severity in ACAD9 deficiency

    PubMed Central

    Schiff, Manuel; Haberberger, Birgit; Xia, Chuanwu; Mohsen, Al-Walid; Goetzman, Eric S.; Wang, Yudong; Uppala, Radha; Zhang, Yuxun; Karunanidhi, Anuradha; Prabhu, Dolly; Alharbi, Hana; Prochownik, Edward V.; Haack, Tobias; Häberle, Johannes; Munnich, Arnold; Rötig, Agnes; Taylor, Robert W.; Nicholls, Robert D.; Kim, Jung-Ja; Prokisch, Holger; Vockley, Jerry

    2015-01-01

    Acyl-CoA dehydrogenase 9 (ACAD9) is an assembly factor for mitochondrial respiratory chain Complex I (CI), and ACAD9 mutations are recognized as a frequent cause of CI deficiency. ACAD9 also retains enzyme ACAD activity for long-chain fatty acids in vitro, but the biological relevance of this function remains controversial partly because of the tissue specificity of ACAD9 expression: high in liver and neurons and minimal in skin fibroblasts. In this study, we hypothesized that this enzymatic ACAD activity is required for full fatty acid oxidation capacity in cells expressing high levels of ACAD9 and that loss of this function is important in determining phenotype in ACAD9-deficient patients. First, we confirmed that HEK293 cells express ACAD9 abundantly. Then, we showed that ACAD9 knockout in HEK293 cells affected long-chain fatty acid oxidation along with Cl, both of which were rescued by wild type ACAD9. Further, we evaluated whether the loss of ACAD9 enzymatic fatty acid oxidation affects clinical severity in patients with ACAD9 mutations. The effects on ACAD activity of 16 ACAD9 mutations identified in 24 patients were evaluated using a prokaryotic expression system. We showed that there was a significant inverse correlation between residual enzyme ACAD activity and phenotypic severity of ACAD9-deficient patients. These results provide evidence that in cells where it is strongly expressed, ACAD9 plays a physiological role in fatty acid oxidation, which contributes to the severity of the phenotype in ACAD9-deficient patients. Accordingly, treatment of ACAD9 patients should aim at counteracting both CI and fatty acid oxidation dysfunctions. PMID:25721401

  7. Political implications of science popularisation strategies: Frontiers of S cience.

    PubMed

    Burns, Maureen

    2016-07-01

    This examination of the mediation strategies of a very popular factual science comic strip series from the 1960s and 1970s illustrates, in this case by highlighting the ways in which women were targeted as an audience, that science popularisations are always political. For that reason, they should not be evaluated merely in terms of scientific accuracy. I demonstrate tensions between the dissemination model of communication used in the distribution of science popularisations, on the one hand, with the advocacy of a dialogue model in their content, on the other. PMID:26265711

  8. A new interpretation for the interference zone between the southern Brasília belt and the central Ribeira belt, SE Brazil

    NASA Astrophysics Data System (ADS)

    Trouw, Rudolph A. J.; Peternel, Rodrigo; Ribeiro, Andre; Heilbron, Mônica; Vinagre, Rodrigo; Duffles, Patrícia; Trouw, Camilo C.; Fontainha, Marcos; Kussama, Hugo H.

    2013-12-01

    In southeastern Brazil, the Neoproterozoic NNW-SSE trending southern Brasília belt is apparently truncated by the ENE-WSW central Ribeira belt. Different interpretations in the literature of the transition between these two belts motivated detailed mapping and additional age dating along the contact zone. The result is a new interpretation presented in this paper. The southern Brasília belt resulted from E-W collision between the active margin of the Paranapanema paleocontinent, on the western side, now forming the Socorro-Guaxupé Nappe, with the passive margin of the São Francisco paleocontinent on the eastern side. The collision produced an east vergent nappe stack, the Andrelândia Nappe System, along the suture. At its southern extreme the Brasília belt was thought to be cut off by a shear zone, the "Rio Jaguari mylonites", at the contact with the Embu terrane, pertaining to the Central Ribeira belt. Our detailed mapping revealed that the transition between the Socorro-Guaxupé Nappe (Brasília belt) and the Embu terrane (Ribeira belt) is not a fault but rather a gradational transition that does not strictly coincide with the Rio Jaguari mylonites. A typical Cordilleran type magmatic arc batholith of the Socorro-Guaxupé Nappe with an age of ca. 640 Ma intrudes biotite schists of the Embu terrane and the age of zircon grains from three samples of metasedimentary rocks, one to the south, one to the north and one along the mylonite zone, show a similar pattern of derivation from a Rhyacian source area with rims of 670-600 Ma interpreted as metamorphic overgrowth. We dated by LA-MC-ICPMS laser ablation (U-Pb) zircon grains from a calc-alkaline granite, the Serra do Quebra-Cangalha Batholith, located within the Embu terrane at a distance of about 40 km south of the contact with the Socorro Nappe, yielding an age of 680 ± 13 Ma. This age indicates that the Embu terrane was part of the upper plate (Socorro-Guaxupé Nappe) by this time. Detailed mapping

  9. Le syndrome des loges du bras: une complication inhabituelle de l'intoxication au monoxyde de carbone

    PubMed Central

    Chkoura, Khalid; Kechna, Hicham; Loutid, Jaouad; Ouzad, Omar; Cherradi, Toufiq; Hachimi, Moulay Ahmed

    2015-01-01

    Le monoxyde de carbone (CO) surnommé “Silent killer” par les Anglo-Saxons représente la première cause de mortalité par intoxication accidentelle ou volontaire en Europe comme aux États-Unis. Au Maroc, le centre anti poison a collecté entre 1991 et 2008, 12976 cas d'intoxication au monoxyde de carbone dont 98,7% étaient accidentelles. Cette intoxication est très exceptionnellement compliquée d'un syndrome de loge qui peut contribuer à une aggravation certaine du pronostic fonctionnel et vital quand il est ignoré ou dominé par d'autres symptômes en particulier neurologiques. Nous rapportons le cas d'un gardien de nuit qui a présenté un syndrome de loge particulier par sa localisation (bras) au cours d'une intoxication au CO qui a évolué favorablement. PMID:26301009

  10. Nd isotopes and the provenance of detrital sediments of the Neoproterozoic Brası´lia Belt, central Brazil

    NASA Astrophysics Data System (ADS)

    Pimentel, M. M.; Dardenne, M. A.; Fuck, R. A.; Viana, M. G.; Junges, S. L.; Fischel, D. P.; Seer, H. J.; Dantas, E. L.

    2001-11-01

    The Neoproterozoic Brası´lia Belt, in central Brazil, includes in its eastern part a thick pile of sediments deposited and deformed along the western margin of the São Francisco-Congo Craton. Several lithostratigraphic units are identified (the Araı´, Paranoá, Serra da Mesa, Araxá, Ibiá, Vazante, Canastra and Bambuı´ groups) and have been traditionally interpreted as part of a passive margin association (<1.2 Ga), with sediments being derived from Archaean or Paleoproterozoic continental sources to the north and east. Nd isotopic signatures of fine-grained detrital sediments of the several rock units of the belt were investigated in order to assess: (i) the nature and average crustal residence ages of the source areas, and (ii) the tectonic significance of the different sedimentary units in respect to the evolution of the Brası´lia Belt. TDM model ages of the ca. 1.2-0.9 Ga old Paranoá and Canastra rhythmites, shales and phyllites vary within the interval between 1.9 and 2.3 Ga, suggesting relatively uniform Paleoproterozoic continental sources within the São Francisco continent. The sediments of the detritic/carbonatic Vazante Group also display Paleoproterozoic model ages indicating, however, a distinct shift towards slightly younger TDM values (1.7-2.1 Ga). These three sequences are interpreted as the typical representatives of the passive margin sequence, with dominance of Paleoproterozoic sources. The Ibiá and Araxá groups show a bimodal distribution of model age values, with a set of samples displaying TDM values between 1.8 and 2.1 Ga (similar to the passive margin sequence), and another set with younger model ages, between ca. 1.0 and 1.3 Ga. Younger sources such as those represented by the Neoproterozoic Goiás Magmatic Arc (0.93-0.64 Ga) in the west, are required to explain the young model ages for these sediments. Immature sediments (feldspathic micaschists) within the magmatic arc, in fact, have TDM model ages mostly between 1.0 and 1

  11. The tectonic evolution of the Neoproterozoic Brasília Belt, central Brazil, based on SHRIMP and LA-ICPMS U-Pb sedimentary provenance data: A review

    NASA Astrophysics Data System (ADS)

    Pimentel, Márcio M.; Rodrigues, Joseneusa B.; DellaGiustina, Maria Emilia S.; Junges, Sergio; Matteini, Massimo; Armstrong, Richard

    2011-04-01

    The Brasília Belt is a Neoproterozoic orogenic belt in central Brazil, developed between the Amazon, São Francisco-Congo and Paranapanema cratons. It consists of a thick sedimentary pile, made up of several stratigraphic units, which have been deformed and metamorphosed along the western margin of the São Francisco Craton during the Brasiliano orogenic cycle. In the western part of the belt, a large, juvenile magmatic arc is exposed (the Goiás Magmatic Arc), consisting of calc-alkaline plutonic suites as well as volcano-sedimentary sequences, ranging in age between ca. 860 and 650 Ma. Regional-scale, west-dipping thrusts and reverse faults normally mark the limits between the main stratigraphic units, and clearly indicate tectonic transport towards the east. The age of deposition and tectonic significance of the sedimentary units comprising the Brasília Belt have been a matter of continuous debate over the last three decades. In the present paper, recent provenance data based on LA-ICPMS U-Pb ages of detrital zircon grains from several of these units, are reviewed and their significance for the age of deposition of the original sediments and tectonic evolution of the Brasília Belt are discussed. The Paranoá, Canastra and the Vazante groups, in the central part of the Belt, have detrital zircon grains with ages older than ca. 900 Ma and are interpreted as representative of the passive margin sequence deposited on the western margin of the São Francisco Craton. On the other hand, samples from the Araxá and Ibiá groups have a much younger population of Neoproterozoic zircon grains, as young as 650 Ma, and have been interpreted as syn-orogenic (fore-arc?) deposits. The Bambuí Group, exposed in the easternmost part of the belt and covering large areas of the São Francisco Craton also has young zircon grains and is interpreted, at least in part, as the foreland basin of the Brasília Belt.

  12. Breasts and Bras

    MedlinePlus

    ... Kids Home How the Body Works Puberty & Growing Up Staying Healthy Recipes & Cooking Staying Safe Health Problems Illnesses & Injuries Health Problems of Grown Ups People, Places & Things That Help Feelings Q&A ...

  13. Thermobarometric and geochronologic constraints on the tectonic evolution of the southern Brasília Fold Belt, Brazil

    NASA Astrophysics Data System (ADS)

    Reno, B. L.; Brown, M.; Piccoli, P. M.; Trouw, R. A.; Kobayashi, K.; Usui, T.; Nakamura, E.

    2006-05-01

    The Brasília Fold Belt lies between the São Francisco, Amazonas and Paranapanema cratons in central Brazil. In the southern portion of this belt, the Andrelândia Group comprises a stack of nappes that record metamorphic conditions ranging from greenschist facies at the base to high pressure granulite facies at the top of the stack. Published conventional thermobarometric data indicate peak P-T conditions of ~1.3 GPa and ~900°C in the uppermost nappes, and the few published geochronologic data suggest an age of peak metamorphism around 630 Ma. Here we report new thermobarometry for the uppermost nappes calculated using the average P-T method in THERMOCALC, based on new analytical data from our own samples and literature data, in order compare published results based on conventional thermobarometry to results obtained using the average P-T method. In addition, we report new U-Pb zircon ages that constrain the timing of metamorphism in the uppermost nappes of the Andrelândia Group. Maximum average P-T conditions of 1.5±0.2 GPa and 1020±130°C were calculated for a mafic granulite in the uppermost Socorro --- Guaxupé Nappe, which compares to published results of ~1.1 GPa and ~890°C. The Três Pontas --- Varginha Nappe, immediately below the Socorro --- Guaxupé Nappe, yields an average P-T of 1.1±0.1 GPa and 880±40°C for literature data, compared with published results of ~1.3 GPa and ~730°C. In addition, our new analytical data from the Três Pontas --- Varginha Nappe yield P-T conditions comparable to the recalculated data, with typical peak P ranging from 0.9 to 1.2 GPa and T ranging from 750 to 880°C. These data suggest that the upper nappe was subjected to higher pressures than previously reported, and also may have been subjected to higher temperatures. For the Carmo da Cachoeira Nappe, immediately below the Três Pontas --- Varginha Nappe, we calculate P-T of 0.6 to 0.7 GPa and 520 to 580°C. For the Três Pontas --- Varginha Nappe, zircons were

  14. Factors associated with recidivism among adolescents girls in conflict with the law in an institution in Brasília, Federal District, Brazil.

    PubMed

    Gallassi, Andrea Donatti; dos Santos, Samantha Lima; Santos, Vagner Dos; Nakano, Eduardo Yoshio; Fischer, Benedikt; Galinkin, Ana Lúcia; Wagner, Gabriela Arantes

    2015-12-01

    Recidivism is a challenge for the Brazilian socio-educational system because it is associated with personal, social and environmental factors, especially among juvenile offenders. This study examined key characteristics and potential association with recidivism in 391 female adolescent offenders from a correctional institution in Brasília, Federal District, Brazil, between 2004 and 2011. Cross-sectional data on socio-demographics, drug use and offense characteristics from institutional information were examined. Associate factors with recidivism were examined using negative binomial regression analyses. 32.5% of offenders were recidivists at present admission and the mean frequency of recidivism among recidivists was 2.16. About half (53.6%) of the sample reported drug use. After the adjustment, recidivism was positively associated with: age; offender's drug use; residence status; offense type; and no family drug use. Factors associated with juvenile offenders' recidivism confirm findings from elsewhere, and should inform targeted interventions in Brazil. PMID:26872233

  15. Léiomyome vasculaire de l'avant bras: présentation d'un cas clinique et revue de la literature

    PubMed Central

    Moncef, Erraji; Abdessamad, Kharraji; Najib, Abassi; Najib, Abdeljawad; Yacoubi, Hicham

    2014-01-01

    Le léiomyome est une tumeur bénigne vasculaire qui peut se présenter sous la forme d'une masse localisée; cependant le diagnostic ne peut en être clinique. Le diagnostic définitif repose sur la réalisation de multiples examens d'imagerie radiologique et sur le résultat de l'examen histologique.une fois traitée par une excision large, passant en zone saine sur le vaisseau, la tumeur à un faible taux de récidive. Nous en rapportant un cas de patiente ayant un léiomyome siégeant au niveau de l'avant bras. PMID:25838850

  16. Evidence of a wide spectrum of cardiac involvement due to ACAD9 mutations: Report on nine patients.

    PubMed

    Dewulf, Joseph P; Barrea, Catherine; Vincent, Marie-Françoise; De Laet, Corinne; Van Coster, Rudy; Seneca, Sara; Marie, Sandrine; Nassogne, Marie-Cécile

    2016-07-01

    Acyl-CoA dehydrogenase 9 (ACAD9) is a mitochondrial protein involved in oxidative phosphorylation complex I biogenesis. This protein also exhibits acyl-CoA dehydrogenase (ACAD) activity. ACAD9-mutated patients have been reported to suffer from primarily heart, muscle, liver, and nervous system disorders. ACAD9 mutation is suspected in cases of elevated lactic acid levels combined with complex I deficiency, and confirmed by ACAD9 gene analysis. At least 18 ACAD9-mutated patients have previously been reported, usually displaying severe cardiac involvement. We retrospectively studied nine additional patients from three unrelated families with a wide spectrum of cardiac involvement between the families as well as the patients from the same families. All patients exhibited elevated lactate levels. Deleterious ACAD9 mutations were identified in all patients except one for whom it was not possible to recover DNA. To our knowledge, this is one of the first reports on isolated mild ventricular hypertrophy due to ACAD9 mutation in a family with moderate symptoms during adolescence. This report also confirms that dilated cardiomyopathy may occur in conjunction with ACAD9 mutation and that some patients may respond clinically to riboflavin treatment. Of note, several patients suffered from patent ductus arteriosus (PDA), with one exhibiting a complex congenital heart defect. It is yet unknown whether these cardiac manifestations were related to ACAD9 mutation. In conclusion, this disorder should be suspected in the presence of lactic acidosis, complex I deficiency, and any cardiac involvement, even mild. PMID:27233227

  17. New evidence of a magmatic arc in the southern Brasília Belt, Brazil: The Serra da Água Limpa batholith (Socorro-Guaxupé Nappe)

    NASA Astrophysics Data System (ADS)

    Vinagre, Rodrigo; Trouw, Rudolph A. J.; Mendes, Julio Cezar; Duffles, Patrícia; Peternel, Rodrigo; Matos, Gabriel

    2014-10-01

    This paper presents a detailed description of the Neoproterozoic Serra da Água Limpa batholith (SALB) and the interpretation of its genesis. The batholith, located along the border of the states of Minas Gerais and São Paulo, was involved in the Socorro-Guaxupé Nappe, a tectonic unit that integrates the southern Brasília Belt. The tectonic evolution of this nappe is related to the convergence and subsequent collision between the Paranapanema paleocontinent, representing the upper plate, with the São Francisco paleocontinent, resulting in the construction of the southern Brasília Belt. The active margin of the Paranapanema paleocontinent developed during the pre-collisional stage a magmatic arc composed of batholithic igneous bodies. The Socorro-Guaxupé Nappe represents this active margin and SALB is one of those bodies. U-Pb dating (Laser Ablation, LA-ICP-MS) in zircon was performed in five samples of SALB. The results are as follows: sample RDTM 62, 667 ± 10 Ma; RDPA 44, 645 ± 5 Ma; RDPA 46, 630 ± 12 Ma; VAC 10, 631 ± 7 Ma and RDIT 41, 635 ± 8 Ma. These ages indicate that the body crystallized between 670 and 630 Ma, with predominance of ages in the interval 645-630 Ma, demonstrating that the magmatic event that formed the arc lasted at least 40 myr. Younger ages, measured in rims of zircon grains, mainly in the range 625-600 Ma were interpreted as metamorphic ages. The lithogeochemical analyses indicate that the I-type rocks of the Serra da Água Limpa batholith belong to the high K calc-alkaline series, and are metaluminous to slightly peraluminous. Tectonic environment diagrams also indicate that the batholith was produced in a volcanic arc setting which is confirmed by negative anomalies of elements of high ionic potential (HFS) in multi-element diagrams. Whole rock Sm-Nd isotope analyses show highly negative εNd values (-12 to -7), indicating significant crustal contamination or origin of the magma by melting of enriched lower crust.

  18. Oviposition and predation by Speciomerus revoili (Coleoptera, Bruchidae) on seeds of Acrocomia aculeata (Arecaceae) in Brasília, DF, Brazil.

    PubMed

    Ramos, F A; Martins, I; Farias, J M; Silva, I C; Costa, D C; Miranda, A P

    2001-08-01

    Oviposition and predation levels by Speciomerus revoili bruchid beetles were quantified on fruits and seeds of the macaúba palm, Acrocomia aculeata, collected from below mother-trees within the Sarah Kubitschek Park of Brasília, DF, Brazil. A maximum of 12 eggs per fruit were found, with high variations observed between samples. No clear pattern was found for the distribution of the number of eggs per fruit, perhaps due to the artificial conditions of the study area, the absence of dispersers and/or the plasticity in the oviposition behavior of the insect. The number of eggs per fruit was not related to fruit size, but was associated with their availability under the tree-mother. This suggests that the density of eggs per fruit is a balance between the availability of this resource and the number of females in the beetle population. The observed mortality rate, from the egg phase to the final larval stages, was over 75%. About 40% of the seeds of Acrocomia aculeata were predated by Speciomerus revoili. PMID:11706572

  19. Thin-skinned thrust mineralization in the Brasília fold belt: the example of the old Luziânia gold deposit

    NASA Astrophysics Data System (ADS)

    Hagemann, S. G.; Brown, P. E.; Walde, D. H. G.

    1992-09-01

    The Luziânia gold deposits in southern Goiás lie within the Late Proterozoic Brasília fold belt. The rocks that host the gold mineralization are a monotonous series of hydrothermally altered phyllites that have been subject to low grade regional metamorphism. The major controls on the gold mineralization are northeast trending and gently northwest dipping ductile-brittle, dextral-reverse shear zones associated with regional thin-skinned thrusting of the Canastra Group. From a preliminary fluid inclusion study it is deduced that low salinity, ⩽ 7 eq. wt% NaCl, moderately dense, H2O-CO2 ± CH4 ore fluids deposited gold at temperatures of 300 ± 75°C and pressures of 1.5 to 3 kb in the filling stage of the vein formation. Post-filling stage gold deposition probably occured by mixing of fluids at higher crustal levels (1.5 2 kb). During thrusting, prograde metamorphism released pore water which penetrated along thrust planes that acted as high permeability zones for the ponding and release, by hydraulic fracturing, of overpressured fluids. Later in the tectonic evolution and at shallower crustal levels, there was likely an incursion of near suface water into the fault zone.

  20. Electrical resistivity measurements to estimate groundwater recharge potential of latosolos in Brasília as a working part of the IWAS Água DF Project

    NASA Astrophysics Data System (ADS)

    Gaffron, Anne; Hirsch, Markus; Weiss, Holger

    2010-05-01

    The IWAS Água DF Project is a bilateral cooperation project initiated in 2009, coordinated by German and Brazilian institutions, with the main objective to develop an Integrated Water Resource Management System, in order to guarantee the safe water supply of the Federal District of Brazil and its surrounding urban areas. In this project a working package for Water Cycle is settled in with a special task for a feasibility study for artificial groundwater recharge with pretreated municipal wastewater in typical regional soils of Brasília. Brazil's Federal District with the capital Brasília developed rapidly in the last 50 years and counts about 2.5 million inhabitants by now. The predicted water scarcity, caused by climate change, growing population and increasing agriculture requires short-term action in water resources management. Basically this part of the IWAS Água DF project is focusing on the investigation of artificial groundwater recharge to estimate the retardation potential of different soils by infiltration of pretreated wastewater. Therefore in São Sebastião (37 km SE of Brasilia) a field test site with two infiltration basins (5 x 5 m) has been established to investigate the infiltration processes. Pretreated municipal waste water originating from the local waste water treatment plant serving the city of São Sebastião and surrounding areas is used for infiltration. In this treatment plant the waste water is treated in three steps. After a first mechanical treatment step the pretreated waste water is pumped through a temporary basin for anaerobic treating. Following this, the water is spread over large area sloped meadows by a branched piping system where the main part of the treatment of waste water takes place. The waste water percolates through the upper soil layer and gets filtrated in the clayey horizons of the local latosols. As a result, an artificial O/A horizon of 10 to 15 cm is build up because of the high nutrient content of the

  1. Geochemical signatures of metasedimentary rocks of high-pressure granulite facies and their relation with partial melting: Carvalhos Klippe, Southern Brasília Belt, Brazil

    NASA Astrophysics Data System (ADS)

    Cioffi, Caue Rodrigues; Campos Neto, Mario da Costa; da Rocha, Brenda Chung; Moraes, Renato; Henrique-Pinto, Renato

    2012-12-01

    High-grade metasedimentary rocks can preserve geochemical signatures of their sedimentary protolith if significant melt extraction did not occur. Retrograde reaction textures provide the main evidence for trapped melt in the rock fabrics. Carvalhos Klippe rocks in Southern Brasília Orogen, Brazil, present a typical high-pressure granulite assemblage with evidence of mica breakdown partial melting (Ky + Grt + Kfs ± Bt ± Rt). The metamorphic peak temperatures obtained by Zr-in-Rt and ternary feldspar geothermometers are between 850 °C and 900 °C. The GASP baric peak pressure obtained using grossular rich garnet core is 16 kbar. Retrograde reaction textures in which the garnet crystals are partially to totally replaced by Bt + Qtz ± Fsp intergrowths are very common in the Carvalhos Klippe rocks. These reactions are interpreted as a result of interactions between residual phases and trapped melt during the retrograde path. In the present study the geochemical signatures of three groups of Carvalhos Klippe metasedimentary rocks are analysed. Despite the high metamorphic grade these three groups show well-defined geochemical features and their REE patterns are similar to average compositions of post-Archean sedimentary rocks (PAAS, NASC). The high-pressure granulite facies Grt-Bt-Pl gneisses with immature arenite (wacke, arkose or lithic-arenite) geochemical signatures present in the Carvalhos Klippe are compared to similar rocks in amphibolite facies from the same tectonic framework (Andrelândia Nappe System). The similar geochemical signatures between Grt-Bt-Pl gneisses metamorphosed in high-pressure granulite facies and Grt-Bt-Pl-Qtz schists from the Andrelândia and Liberdade Nappes, with minimal to absent melting conditions, are suggestive of low rates of melt extraction in these high-grade rocks. The rocks with pelitic compositions most likely had higher melt extraction and even under such circumstances nevertheless tend to show REE patterns similar to

  2. High incidence and variable clinical outcome of cardiac hypertrophy due to ACAD9 mutations in childhood.

    PubMed

    Collet, Marie; Assouline, Zahra; Bonnet, Damien; Rio, Marlène; Iserin, Franck; Sidi, Daniel; Goldenberg, Alice; Lardennois, Caroline; Metodiev, Metodi Dimitrov; Haberberger, Birgit; Haack, Tobias; Munnich, Arnold; Prokisch, Holger; Rötig, Agnès

    2016-08-01

    Acyl-CoA dehydrogenase family, member 9 (ACAD9) mutation is a frequent, usually fatal cause of early-onset cardiac hypertrophy and mitochondrial respiratory chain complex I deficiency in early childhood. We retrospectively studied a series of 20 unrelated children with cardiac hypertrophy and isolated complex I deficiency and identified compound heterozygosity for missense, splice site or frame shift ACAD9 variants in 8/20 patients (40%). Age at onset ranged from neonatal period to 9 years and 5/8 died in infancy. Heart transplantation was possible in 3/8. Two of them survived and one additional patient improved spontaneously. Importantly, the surviving patients later developed delayed-onset neurologic or muscular symptoms, namely cognitive impairment, seizures, muscle weakness and exercise intolerance. Other organ involvement included proximal tubulopathy, renal failure, secondary ovarian failure and optic atrophy. We conclude that ACAD9 mutation is the most frequent cause of cardiac hypertrophy and isolated complex I deficiency. Heart transplantation in children surviving neonatal period should be considered with caution, as delayed-onset muscle and brain involvement of various severity may occur, even if absent prior to transplantation. PMID:26669660

  3. The Santa Terezinha-Campos Verdes emerald district, central Brazil: structural and Sm-Nd data to constrain the tectonic evolution of the Neoproterozoic Brası´lia belt

    NASA Astrophysics Data System (ADS)

    D'el-Rey Silva, Luiz José Homem; Barros Neto, Leonel de Souza

    2002-12-01

    Structural analysis coupled with Sm-Nd isotope data and a detailed description of the geology of the Santa Terezinha-Campos Verdes emerald district (Goiás State, Central Brazil) constrain the evolution of the Neoproterozoic Brası´lia belt. The area is composed of tectonic slices of Archean-Paleoproterozoic gneiss, a Meso-Neoproterozoic metavolcanic sedimentary sequence called the Santa Terezinha sequence, and crustal-derived intrusive rocks such as mylonitic (ortho)gneiss and a syntectonic porphyry granite. It underwent a Neoproterozoic greenschist facies polyphase ductile deformation (D 1-D 3). Structures indicate an event of rotational deformation along a typical frontal ramp dipping gently to the west (i.e. an event of simple shear with top to ESE relative regional movement due to a subhorizontal WNW-ESE compression). A Sm-Nd whole-rock isochron age of 577±77 Ma for the intrusive rocks constrains the timing of at least part of the deformation/metamorphism in the area. Primary and metamorphic planar structures (mainly D 1-D 2) strike SW-NE and dip at low to moderate angles to the NW in the northern part of the area. However, they gradually rotate to SSE in the central SE part, where the Peixe River synclinorium is developed. This synclinorium is also the nest of the D 2 sheath folds that control emerald ore shoots. The Santa Cruz dome is a basement-cored, major elliptic structure in the SW of the area. The Santa Terezinha sequence represents a back-arc basin that received input from the Neoproterozoic Goiás magmatic arc to the west and the São Francisco ancient continental margin to the east. The basal and upper sections of this sequence correlate, respectively, with other passive margin and back-arc sequences of the Brası´lia belt.

  4. Riboflavin-responsive oxidative phosphorylation complex I deficiency caused by defective ACAD9: new function for an old gene.

    PubMed

    Gerards, Mike; van den Bosch, Bianca J C; Danhauser, Katharina; Serre, Valérie; van Weeghel, Michel; Wanders, Ronald J A; Nicolaes, Gerry A F; Sluiter, Wim; Schoonderwoerd, Kees; Scholte, Hans R; Prokisch, Holger; Rötig, Agnès; de Coo, Irenaeus F M; Smeets, Hubert J M

    2011-01-01

    Mitochondrial complex I deficiency is the most common oxidative phosphorylation defect. Mutations have been detected in mitochondrial and nuclear genes, but the genetics of many patients remain unresolved and new genes are probably involved. In a consanguineous family, patients presented easy fatigability, exercise intolerance and lactic acidosis in blood from early childhood. In muscle, subsarcolemmal mitochondrial proliferation and a severe complex I deficiency were observed. Exercise intolerance and complex I activity was improved by a supplement of riboflavin at high dosage. Homozygosity mapping revealed a candidate region on chromosome three containing six mitochondria-related genes. Four genes were screened for mutations and a homozygous substitution was identified in ACAD9 (c.1594 C>T), changing the highly conserved arginine-532 into tryptophan. This mutation was absent in 188 ethnically matched controls. Protein modelling suggested a functional effect due to the loss of a stabilizing hydrogen bond in an α-helix and a local flexibility change. To test whether the ACAD9 mutation caused the complex I deficiency, we transduced fibroblasts of patients with wild-type and mutant ACAD9. Wild-type, but not mutant, ACAD9 restored complex I activity. An unrelated patient with the same phenotype was compound heterozygous for c.380 G>A and c.1405 C>T, changing arginine-127 into glutamine and arginine-469 into tryptophan, respectively. These amino acids were highly conserved and the substitutions were not present in controls, making them very probably pathogenic. Our data support a new function for ACAD9 in complex I function, making this gene an important new candidate for patients with complex I deficiency, which could be improved by riboflavin treatment. PMID:20929961

  5. Active correction of aperture discontinuities (ACAD) for space telescope pupils: a parametic analysis

    NASA Astrophysics Data System (ADS)

    Mazoyer, Johan; Pueyo, Laurent; Norman, Colin; N'Diaye, Mamadou; Mawet, Dimitri; Soummer, Rémi; Perrin, Marshall; Choquet, Élodie; Carlotti, Alexis

    2015-09-01

    As the performance of coronagraphs improves, the achievable contrast is more and more dependent of the shape of the pupil. The future generation of space and ground based coronagraphic instruments will have to achieve high contrast levels on on-axis and/or segmented telescopes. To correct for the high amplitude aberrations introduced by secondary mirror structures and segmentation of the primary mirror, we explore a two deformable mirror (DM) method. The major difficulty of several DM methods is the non-linear relation linking actuator strokes to the point spread function in the coronagraph focal plane. The Active Compensation of Aperture Discontinuities (ACAD) method is achieving this minimization by solving a non linear differential Monge Ampere equation. Once this open loop method have reached the minimum, a close-loop stroke minimization method can be applied to correct for phase and amplitude aberrations to achieve the ultimate contrast. In this paper, I describe the results of the parametric analysis that that I have undertaken on this method. After recalling the principle of the method, I will described the explored parameter space (deformable mirror set-up, shape of the pupil, bandwidth, coronagraph designs). I will precisely described the way I simulated the Vortex coronagraph for this numerical simulation. Finally I will present the preliminary results of this parametric analysis for space telescope pupils only.

  6. Correlation between nutritional, hematological and infectious characteristics and classification of the type of epidermolysis bullosa of patients assisted at the Dermatology Clinic of the Hospital Universitário de Brasília*

    PubMed Central

    Sousa, Márcia Carolline dos Santos; de Paula, Carmen Dea Ribeiro; Tauil, Pedro Luiz; Costa, Izelda Maria Carvalho

    2015-01-01

    Epidermolysis bullosa comprises a group of phenotypically different genodermatosis, hereditary or acquired, characterized by skin fragility and subsequent formation of blisters in response to mechanical trauma, and which may also affect mucous membranes. This study aimed to analyze the relation between the nutritional, hematologic, infectious characteristics and the type of epidermolysis bullosa, through a descriptive case study based on data from medical records of 10 patients with epidermolysis bullosa assisted regularly at the Dermatology Clinic of the Hospital Universitário de Brasília. The old classification of the type of epidermolysis bullosa, weight and height, blood count, white blood cell count, platelet count and description of the type and frequency of secondary infections during the service were considered. We verified a predominance of iron deficiency anemia, chronic leukocytosis, thrombocytosis, chronic malnutrition, low height for age and thinness, and people with epidermolysis bullosa simplex exhibited appropriate relation between height/age and BMI/age. The non-specific skin infection was the most prevalent in both sexes. The severity of the type of epidermolysis bullosa and frequency of secondary infections did not form a directly proportional relation. The absence of direct proportion in all cases between the type of epidermolysis bullosa and the analysis parameters suggest a possible significant interference from other aspects such as the extent of the affected skin area, extracutaneous type of engagement and specific genetic mutation. The inclusion of these factors in the new classification proposed by Fine et al can contribute significantly to a better correlation of clinical parameters and appropriate preventive and therapeutic approaches. PMID:26734883

  7. Structural and lithological controls of gold-bearing veins associated with the Brasiliano-Pan African Orogeny: An example from the Buracão Area, Araí Group (Brasília Fold Belt, Brazil)

    NASA Astrophysics Data System (ADS)

    Pires, Gustavo Luiz Campos; Bongiolo, Everton Marques; Renac, Christophe; Nascimento, Débora Barros; Prado, Maurício

    2016-03-01

    The Buracão area, Central Brazil, comprises a group of structurally-controlled vein-type gold prospects, hosted in the metasedimentary Traíras Fm. of the Araí Group. This group records all tectonic stages of the Statherian taphrogenesis in Central Brazil and represents part of the Brasília Fold Belt (BFB) developed during the Neoproterozoic Brasiliano Orogeny. Three lithostratigraphic units were identified at the study area: two phyllitic and one composed of intercalation of quartzite and carbonaceous/sericite phyllites that hosted the Au mineralized vein systems. These units were metamorphosed to the biotite zone, greenschist facies. The high-grade mineralization (up to 31 g/t) occurs as subvertical zoned or massive veins with quartz, white mica, Fe-sulfides and Fe-oxides oriented in four main directions (i.e. N50°E; N°20E; N-S and E-W). Two deformational phases, each subdivided in two stages (D1a, D1b, D2a and D2b) were recognized in the study area. These deformational phases comprise different sets of structures, such as foliations, folds, faults, fractures and veins that represent regional deformational events on subordinated scale. The D1a and D1b stages represent the regional N-S trending thrust fronts and propagation folding developed during the evolution of W-E shortening, respectively. The D2a and D2b were correlated to the development and reactivation of regional-scale N- and NE-trending transpressive shear systems at different crustal levels, respectively. The gold-bearing quartz veins were developed during D2a stage as a complex shear fracture set according to a Riedel system, representing subordinated structures of the regional transpressive system. The structurally-controlled gold occurrences of the Buracão area is an example of orogenic vein-type gold mineralization developed during the Brasiliano-Pan African Orogeny at the BFB in Central Brazil. Our work suggests that this poorly studied part of BFB has good potential for additional high

  8. Neonatal multiorgan failure due to ACAD9 mutation and complex I deficiency with mitochondrial hyperplasia in liver, cardiac myocytes, skeletal muscle, and renal tubules.

    PubMed

    Leslie, Nancy; Wang, Xinjian; Peng, Yanyan; Valencia, C Alexander; Khuchua, Zaza; Hata, Jessica; Witte, David; Huang, Taosheng; Bove, Kevin E

    2016-03-01

    Complex I deficiency causes Leigh syndrome, fatal infant lactic acidosis, and neonatal cardiomyopathy. Mutations in more than 100 nuclear DNA and mitochondrial DNA genes miscode for complex I subunits or assembly factors. ACAD9 is an acyl-CoA dehydrogenase with a novel function in assembly of complex I; biallelic mutations cause progressive encephalomyopathy, recurrent Reye syndrome, and fatal cardiomyopathy. We describe the first autopsy in fatal neonatal lethal lactic acidosis due to mutations in ACAD9 that reduced complex I activity. We identified mitochondrial hyperplasia in cardiac myocytes, diaphragm muscle, and liver and renal tubules in formalin-fixed, paraffin-embedded tissue using immunohistochemistry for mitochondrial antigens. Whole-exome sequencing revealed compound heterozygous variants in the ACAD9 gene: c.187G>T (p.E63*) and c.941T>C (p.L314P). The nonsense mutation causes late infantile lethality; the missense variant is novel. Autopsy-derived fibroblasts had reduced complex I activity (53% of control) with normal activity in complexes II to IV, similar to reported cases of ACAD9 deficiency. PMID:26826406

  9. The End of Alchemy? The Repudiation and Persistence of Chrysopoeia at the Académie Royale des Sciences in the Eighteenth Century.

    PubMed

    Principe, Lawrence M

    2014-01-01

    The general abandonment of serious endeavor toward metallic transmutation represents a major development in the history of chemistry, yet its exact causes and timing remain unclear. This essay examines the fate of chrysopoeia at the eighteenth-century Académie Royale des Sciences. It reveals a long-standing tension between Académie chemists, who pursued transmutation, and administrators, who tried to suppress it. This tension provides background for Etienne-François Geoffroy's 1722 paper describing fraudulent practices around transmutation. Although transmutation seems to disappear after Geoffroy's paper, manuscripts reveal that most of the institution's chemists continued to pursue it privately until at least the 1760s, long after widely accepted dates for the "demise of alchemy" in learned circles. PMID:26103750

  10. The minor C-allele of rs2014355 in ACADS is associated with reduced insulin release following an oral glucose load

    PubMed Central

    2011-01-01

    Background A genome-wide association study (GWAS) using metabolite concentrations as proxies for enzymatic activity, suggested that two variants: rs2014355 in the gene encoding short-chain acyl-coenzyme A dehydrogenase (ACADS) and rs11161510 in the gene encoding medium-chain acyl-coenzyme A dehydrogenase (ACADM) impair fatty acid β-oxidation. Chronic exposure to fatty acids due to an impaired β-oxidation may down-regulate the glucose-stimulated insulin release and result in an increased risk of type 2 diabetes (T2D). We aimed to investigate whether the two variants associate with altered insulin release following an oral glucose load or with T2D. Methods The variants were genotyped using KASPar® PCR SNP genotyping system and investigated for associations with estimates of insulin release and insulin sensitivity following an oral glucose tolerance test (OGTT) in a random sample of middle-aged Danish individuals (n ACADS = 4,324; n ACADM = 4,337). The T2D-case-control study involved a total of ~8,300 Danish individuals (n ACADS = 8,313; n ACADM = 8,344). Results In glucose-tolerant individuals the minor C-allele of rs2014355 of ACADS associated with reduced measures of serum insulin at 30 min following an oral glucose load (per allele effect (β) = -3.8% (-6.3%;-1.3%), P = 0.003), reduced incremental area under the insulin curve (β = -3.6% (-6.3%;-0.9%), P = 0.009), reduced acute insulin response (β = -2.2% (-4.2%;0.2%), P = 0.03), and with increased insulin sensitivity ISIMatsuda (β = 2.9% (0.5%;5.2%), P = 0.02). The C-allele did not associate with two other measures of insulin sensitivity or with a derived disposition index. The C-allele was not associated with T2D in the case-control analysis (OR 1.07, 95% CI 0.96-1.18, P = 0.21). rs11161510 of ACADM did not associate with any indices of glucose-stimulated insulin release or with T2D. Conclusions In glucose-tolerant individuals the minor C-allele of rs2014355 of ACADS was associated with reduced measures of

  11. Variations in IBD (ACAD8) in children with elevated C4-carnitine detected by tandem mass spectrometry newborn screening.

    PubMed

    Pedersen, Christina B; Bischoff, Claus; Christensen, Ernst; Simonsen, Henrik; Lund, Allan M; Young, Sarah P; Koeberl, Dwight D; Millington, David S; Roe, Charles R; Roe, Diane S; Wanders, Ronald J A; Ruiter, Jos P N; Keppen, Laura D; Stein, Quinn; Knudsen, Inga; Gregersen, Niels; Andresen, Brage S

    2006-09-01

    The isobutyryl-CoA dehydrogenase (IBD) enzyme is involved in the degradation of valine. IBD deficiency was first reported in 1998 and subsequent genetic investigations identified acyl-CoA dehydrogenase (ACAD) 8, now IBD, as the gene responsible for IBD deficiency. Only three individuals homozygous or compound heterozygous for variations in the IBD gene have been reported. We present IBD deficiency in an additional four newborns with elevated C(4)-carnitine identified by tandem mass spectrometry (MS/MS) screening in Denmark and the United States. Three showed urinary excretions of isobutyryl-glycine, and in vitro probe analysis of fibroblasts from two newborns indicated enzymatic IBD defect. Molecular genetic analysis revealed seven new rare variations in the IBD gene (c.348C>A, c.400G>T, c.409G>A, c.455T>C, c.958G>A, c.1000C>T and c.1154G>A). Furthermore, sequence analysis of the short-chain acyl-CoA dehydrogenase (SCAD) gene revealed heterozygosity for the prevalent c.625G>A susceptibility variation in all newborns and in the first reported IBD patient. Functional studies in isolated mitochondria demonstrated that the IBD variations present in the Danish newborn (c.409G>A and c.958G>A) together with a previously published IBD variation (c.905G>A) disturbed protein folding and reduced the levels of correctly folded IBD tetramers. Accordingly, low/no IBD residual enzyme activity was detectable when the variant IBD proteins were overexpressed in Chang cells. PMID:16857760

  12. Soil transference patterns on bras: Image processing and laboratory dragging experiments.

    PubMed

    Murray, Kathleen R; Fitzpatrick, Robert W; Bottrill, Ralph S; Berry, Ron; Kobus, Hilton

    2016-01-01

    In a recent Australian homicide, trace soil on the victim's clothing suggested she was initially attacked in her front yard and not the park where her body was buried. However the important issue that emerged during the trial was how soil was transferred to her clothing. This became the catalyst for designing a range of soil transference experiments (STEs) to study, recognise and classify soil patterns transferred onto fabric when a body is dragged across a soil surface. Soil deposits of interest in this murder were on the victim's bra and this paper reports the results of anthropogenic soil transfer to bra-cups and straps caused by dragging. Transfer patterns were recorded by digital photography and photomicroscopy. Eight soil transfer patterns on fabric, specific to dragging as the transfer method, appeared consistently throughout the STEs. The distinctive soil patterns were largely dependent on a wide range of soil features that were measured and identified for each soil tested using X-ray Diffraction and Non-Dispersive Infra-Red analysis. Digital photographs of soil transfer patterns on fabric were analysed using image processing software to provide a soil object-oriented classification of all soil objects with a diameter of 2 pixels and above transferred. Although soil transfer patterns were easily identifiable by naked-eye alone, image processing software provided objective numerical data to support this traditional (but subjective) interpretation. Image software soil colour analysis assigned a range of Munsell colours to identify and compare trace soil on fabric to other trace soil evidence from the same location; without requiring a spectrophotometer. Trace soil from the same location was identified by linking soils with similar dominant and sub-dominant Munsell colour peaks. Image processing numerical data on the quantity of soil transferred to fabric, enabled a relationship to be discovered between soil type, clay mineralogy (smectite), particle size and soil moisture content that would not have been possible otherwise. Soil type (e.g. Anthropogenic, gravelly sandy loam soil or Natural, organic-rich soil), clay mineralogy (smectite) and soil moisture content were the greatest influencing factors in all the dragging soil transference tests (both naked eye and measured properties) to explain the eight categories of soil transference patterns recorded. This study was intended to develop a method for dragging soil transference laboratory experiments and create a baseline of preliminary soil type/property knowledge. Results confirm the need to better understand soil behaviour and properties of clothing fabrics by further testing of a wider range of soil types and clay mineral properties. PMID:26679633

  13. Clifford Fibrations and Possible Kinematics

    NASA Astrophysics Data System (ADS)

    McRae, Alan S.

    2009-07-01

    Following Herranz and Santander [Herranz F.J., Santander M., Mem. Real Acad. Cienc. Exact. Fis. Natur. Madrid 32 (1998), 59-84, physics/9702030] we will construct homogeneous spaces based on possible kinematical algebras and groups [Bacry H., Levy-Leblond J.-M., J. Math. Phys. 9 (1967), 1605-1614] and their contractions for 2-dimensional spacetimes. Our construction is different in that it is based on a generalized Clifford fibration: Following Penrose [Penrose R., Alfred A. Knopf, Inc., New York, 2005] we will call our fibration a Clifford fibration and not a Hopf fibration, as our fibration is a geometrical construction. The simple algebraic properties of the fibration describe the geometrical properties of the kinematical algebras and groups as well as the spacetimes that are derived from them. We develop an algebraic framework that handles all possible kinematic algebras save one, the static algebra.

  14. The white marble used in Brasília, a World Heritage and the capital of Brazil

    NASA Astrophysics Data System (ADS)

    Heloisa Barros de Oliveira Frascá, Maria

    2015-04-01

    Created as the Brazilian capital, in the central western part of Brazil, Brasilia is a definitive example of 20th century modernist urbanism. It was built in only four years, from 1956 to 1960, following the project of urban planner Lucio Costa and architect Oscar Niemeyer that intended that every element - from the layout of the residential and administrative districts (often compared to the shape of a bird in flight) to the symmetry of the buildings themselves - should be in harmony with the city's overall design. This description is from the World Heritage Centre, of Unesco, that nominated Brasilia as a Cultural Heritage Property in 1987. Most of the remarkable buildings designed Oscar Niemeyer, cited by Unesco, are around the Plaza of Three Powers, as the Planalto ("Plateau") Palace, the National Congress, the Supreme Court, the Cathedral, the National Theatre among others. Aside from the worldwide recognition of the architectonic value of these buildings, it is barely mentioned the expressive use of white marble as cladding. Very few are found in the literature about specification criteria, provenance, fixation method and conservation. According to Oscar Niemeyer Foundation, at this moment they know that the stone come from a supplier in the State of Rio de Janeiro. A preliminary research indicated that the marble used in most of Brasilia buildings are from the municipality of Italva, in the northwest of the State of Rio de Janeiro (DRM-RJ, 2012). In a study carried out by DRM-RJ, in 2003, it is mentioned two white marble commercialized as dimension stone in Italva: "Sparkling Marble" (SM) and "Italva White Marble" (IWM), respectively dolomite-calcite marble and dolomite marble. Their main characteristics are: bulk specific gravity: 2,792 kg/m3 (SM) and 2,852kg/m3 (IWM); water absorption: 0.08 % (SM) and 0.10 % (IWM); uniaxial compression strength: 84.3 MPa (SM) and 88.2 MPa (IWM); modulus of rupture: 9.92 MPa (SM) and 8.75 MPa (IWM); coefficient of linear dilatation: 6.0 10-3mm/m.oC (SM) and 5.2 10-3mm/m.oC (IWM). This data indicate that in spite the marble specification had not followed any technical or scientific criteria, or at least they are not easily available, they show good engineering properties and most of the slabs are still in the buildings. The preservation of this cultural world heritage is an urgent demand, as pointed by Unesco, and one of the main challenges is the stone conservation planning, to which is already necessary serious multidisciplinary technical and scientific studies. References DRM-RJ - DEPARTMENT OF MINERAL RESOURCES OF THE STATE OF RIO DE JANEIRO. (2003) Rio de Janeiro State dimension stones catalogue. DRM: Rio de Janeiro, 12 cards. DRM-RJ (2012) Mineral panorama of the State of Rio de Janeiro. DRM: Rio de Janeiro, 258p. (in Portuguese). UNESCO. World Heritage List. http://whc.unesco.org/en/list/445. (05/January/2015). FRASCÁ, M.H.B.O.; NAVARRO, F.C.; QUITETE, E.B. (2014) Staining tests for granitic stone conservation. In: Lollino, G. et al. (org.). Engineering Geology for Society and Territory - Preservation of cultural heritage. London: Springer International Publishing Switzerland, v. 8.

  15. Violence and youth in a territory of the Metropolitan Area of Brasília, Brazil: a socio-spatial approach.

    PubMed

    Moura, Leides Barroso Azevedo; Oliveira, Cesar de; Vasconcelos, Ana Maria Nogales

    2015-11-01

    Young people are impacted by the relations established in the context of multidimensional violence distributed in private and public spaces of urban areas. This article presents stories of violence suffered and committed by young individuals who live in Itapoã, part of the Metropolitan Area of Brasilia. This is a transversal and descriptive study, using a quantitative approach and a convenience sample of 190 young men and women aged 15 to 24 years. Forty-four questions previously validated were used as the data collection instrument. As for the experiences of violence, 51% reported having experienced some sort throughout life, and 24% in the last 12 months. Young people who have experienced some episode of violence throughout life also declared that the area or neighborhood where they live does not promote urban well-being for its residents (p <0.023); they expressed feelings compatible with depression (p = 001); and self-reported their health condition as bad (p = 000). The experiences of violence and youth vulnerabilities processes were discussed in the context of social injustice and limitations of human capabilities. PMID:26602717

  16. Continental block collision in the eastern arm of Sulawesi (Indonesia). Structure and geodynamic interpretationCollision de blocs continentaux dans le bras est de Sulawesi (Indonésie). Structure et interprétation géodynamique.

    NASA Astrophysics Data System (ADS)

    Villeneuve, Michel; Cornée, Jean-Jacques; Gunawan, Wahyu; Janin, Marie-Christine; Butterlin, Jacques; Saint-Marc, Pierre; Samodra, Hanang

    2000-03-01

    Recent investigations in East Indonesia lead us to consider the eastern arm of Sulawesi as the result of a collision between two continental blocks: the Tokala block to the west and the Banggai-Sula block to the east. The Tokala block results from the Oligocene obduction of an ophiolitic Asiatic basin onto the passive margin of a Gondwanian block (Banda block), with collision with the Asiatic active margin (western arm of Sulawesi) near the end of the Oligocene or at the beginning of the Miocene. The Tokala Block was then collided by the Irian Jaya derived Banggai-Sula block in the Early to Middle Pliocene times or later.

  17. Factors Affecting Academic Resilience in Middle School Students: A Case Study (Factores que Afectan la Resiliencia Académica en Estudiantes de Bachillerato)

    ERIC Educational Resources Information Center

    Rojas Flórez, Luisa Fernanda

    2015-01-01

    This research was carried out with the purpose of identifying how and which risk and protective factors affect academic outcomes. The study explored how different family and individual environmental factors foster academic resilience. The exploratory study took place with a group of six students from a public school in Bogotá, Colombia. The school…

  18. NaNoWriMo in the AcadLib: A Case Study of National Novel Writing Month Activities in an Academic Library

    ERIC Educational Resources Information Center

    Watson, Alex P.

    2012-01-01

    The J. D. Williams Library at the University of Mississippi launched a pilot program during the 2010 National Novel Writing Month, hosting related events to determine community demand and how such efforts could be quantified. Using participant-submitted word counts and the event's own tools, researchers were able to ascertain that such events had…

  19. Nursing Supplies

    MedlinePlus

    ... Stages Listen Español Text Size Email Print Share Nursing Supplies Page Content Article Body Throughout most of ... budget. (Nursing equipment also makes wonderful baby gifts.) Nursing Bras A well-made nursing bra that comfortably ...

  20. Importance of LA-ICP-MS Zircon Geochronology and Geochemistry in Determining the History of Magmatic Systems: Insights from the Graciosa A-type Province, Southern Brazil

    NASA Astrophysics Data System (ADS)

    Braun, S.; Gualda, G. A.; Bream, B. R.; Vlach, S. R.

    2010-12-01

    textural and geochemical evidence, we interpret these 3 age populations as being representative of inheritance (>620 Ma), magmatism (~581 Ma), and hydrothermal alteration (~540 Ma). In light of these results, it is not surprising that previous age determinations using whole-zircon TIMS U/Pb and whole-rock Rb/Sr found a wide range of ages. Our study highlights the benefits of in-situ LA-ICPMS zircon geochronology as a method to deconvolve the evolution of igneous provinces, and shows that adequate precision (~0.5%) can be achieved in favorable circumstances. 1 GAR Gualda & SRF Vlach (2007) Anais Acad. Bras. Ciências, 79: 405-430

  1. Struggling Authorial Identity of Second Language University Academic Writers in Mexico (La lucha de identidad de escritores académicos universitarios de segunda lengua en México)

    ERIC Educational Resources Information Center

    Crawford, Troy; Mora Pablo, Irasema; Lengeling, M. Martha

    2016-01-01

    This paper explores the different factors that appear to affect the on-going construction of second language authorial identity in a professional academic environment in Mexico. Through narrative research methodology from a qualitative paradigm, the everyday struggles of two university professors to maintain their professional status in second…

  2. Publishing and Academic Writing: Experiences of Authors Who Have Published in "PROFILE" (Publicación y escritura académica: experiencias de autores que han publicado en "PROFILE")

    ERIC Educational Resources Information Center

    Cárdenas, Melba L.

    2014-01-01

    The increase in the publication of academic journals is closely related to the growing interest of research communities as well as of institutional policies that demand visibility of the work done by their staff through publications in highly-ranked journals. The purpose of this paper is to portray the experiences of some authors who published…

  3. Developing Academic Literacy and Voice: Challenges Faced by a Mature ESL Student and Her Instructors (Desarrollo del discurso académico y la voz: retos de una estudiante de inglés como segunda lengua y sus profesores)

    ERIC Educational Resources Information Center

    Correa, Doris

    2010-01-01

    Drawing on critical, socio-cultural and sociolinguistic theories of writing, text and voice, this ethnographic study examines the challenges that a mature ESL student and her instructors in a university course on Spanish Language Media face as they co-construct a common understanding of academic literacy and voice in an undergraduate General…

  4. Teaching EFL Academic Writing in Colombia: Reflections in Contrastive Rhetoric (La enseñanza de escritura académica en Colombia: reflexiones en retórica contrastiva)

    ERIC Educational Resources Information Center

    Gómez, Juan D.

    2011-01-01

    This essay relates observations to the reasons that advanced students of English as a foreign language in Colombia struggle with English composition. It identifies some cultural, academic, and disciplinary influences that may obfuscate their assimilation of the conventions of written English. It concludes by proposing that the teaching of context…

  5. The "It's No Secret" bra drive: an example of collaborative practice.

    PubMed

    Bennett, Yvonne

    2015-01-01

    Evidence collection by sexual assault nurse examiners (SANEs) is a crucial part of the forensic medical examination. SANEs attempt to collect all possible evidence including swabs, slides, urine, blood, and clothing. Because biological evidence can be found on underwear, bras, and other clothing, the SANE often asks patients to relinquish these clothing items during the forensic medical examination. Some patients are reluctant to relinquish their bras, for varying reasons. The Riverside County Sexual Assault Multi-Disciplinary Team conducted a bra collection drive, in conjunction with Sexual Assault Awareness Month. The purpose of the bra drive was to enable the SANE to provide a replacement bra in exchange for the patient's bra, which may contain biological evidence. The community response was overwhelming and has already enabled the collection of bras from patients who were otherwise unwilling to give them up. PMID:25695211

  6. Psoriasis

    MedlinePlus

    ... treatment of psoriasis with biologics. J Am Acad Dermatol . 2008;5:826-850. PMID: 18423260 www.ncbi. ... of psoriasis with topical therapies. J Am Acad Dermatol . 2009;60:643-659. PMID: 19217694 www.ncbi. ...

  7. Cellulite

    MedlinePlus

    ... of cellulite: Part I. Pathophysiology. J Am Acad Dermatol . 2010 Mar;62(3):361-70. PMID: 20159304 ... Part II. Advances and controversies. J Am Acad Dermatol . 2010 Mar;62(3):373-84. PMID: 20159305 ...

  8. Cellulite

    MedlinePlus

    ... Part I. Pathophysiology. J Am Acad Dermatol . 2010 Mar;62(3):361-70. PMID: 20159304 www.ncbi. ... Advances and controversies. J Am Acad Dermatol . 2010 Mar;62(3):373-84. PMID: 20159305 www.ncbi. ...

  9. Condition-dependent migratory behaviour of endangered Atlantic salmon smolts moving through an inland sea.

    PubMed

    Crossin, Glenn T; Hatcher, Bruce G; Denny, Shelley; Whoriskey, Kim; Orr, Michael; Penney, Alicia; Whoriskey, Frederick G

    2016-01-01

    The Bras d'Or Lake watershed of Cape Breton Island, Nova Scotia, Canada is a unique inland sea ecosystem, UNESCO Biosphere Reserve and home to a group of regionally distinct Atlantic salmon (Salmo salar) populations. Recent population decreases in this region have raised concern about their long-term persistence. We used acoustic telemetry to track the migrations of juvenile salmon (smolts) from the Middle River into the Bras d'Or Lake and, subsequently, into the Atlantic Ocean. Roughly half of the tagged smolts transited the Bras d'Or Lakes to the Atlantic Ocean, using a migration route that took them through the Gulf of St Lawrence's northern exit at the Strait of Belle Isle (∼650 km from the home river) towards feeding areas in the Labrador Sea and Greenland. However, a significant fraction spent >70 days in the Lakes, suggesting that this population has an alternative resident form, in which smolts limit their migrations within the Bras d'Or. Smolts in good relative condition (as determined from length-to-mass relationships) tended to be residents, whereas fish in poorer condition were ocean migrants. We also found a covarying effect of river temperature that helped to predict residence vs. ocean migration. We discuss these results relative to their bioenergetic implications and provide suggestions for future studies aimed at the conservation of declining salmon populations in Canada. PMID:27293765

  10. All about Menstruation (For Children)

    MedlinePlus

    ... Got Homework? Here's Help White House Lunch Recipes All About Menstruation KidsHealth > For Kids > All About Menstruation Print A A A Text Size ... Period Cramps When Will I Get My Period? All About Puberty Pads and Tampons Breasts and Bras ...

  11. INHIBITORY EFFECTS OF VOLATILE ORGANIC COMPOUNDS ON NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS.

    EPA Science Inventory

    INHIBITORY EFFECTS OF VOLATILE ORGANIC COMPOUNDS ON NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS. <br>A.S. Bale*; P.J. Bushnell; C.A. Meacham; T.J. Shafer
    Neurotoxicology Division, NHEERL, ORD, US Environmental Protection Agency, Research Triangle Park, NC, USA
    Toluene (TOL...

  12. How I Manage Breast Problems in Athletes.

    ERIC Educational Resources Information Center

    Haycock, Christine E.

    1987-01-01

    This article reviews the anatomy of the breast and describes injuries and disorders that occur in both men and women, including runner's nipples, bicyclist's nipples, tumors, and trauma. Management of these problems and various types of sports bras are discussed. (Author/MT)

  13. Macroscopic retrocausation

    NASA Astrophysics Data System (ADS)

    Costa de Beauregard, O.

    1995-06-01

    Referring to Stapp's and Schmidt's recent papers: a Feynman transition amplitude | I>< M>< F| used retrodictively with post-selected outgoing bras< F| formalizes psychokinesis—Jaynes' qualification of the mind-induced-quantum-collapse concept. Time extendedness of matter, final cause, information-negentropy reversibility, are features inherent in relativistic quantum mechanics.

  14. EXAMINING REGIONAL LAND USE CHANGE: THE COMMUNITY GROWTH MODEL (CGM)

    EPA Science Inventory

    The U. S. Environmental Protection Agency's Regional Vulnerability Assessment
    Program (ReV A) is designed to develop and demonstrate approaches to identify the ecosystems at the greatest risk from regional population growth and economic activity. <br>As part of this program, ...

  15. What's Race Got to Do with It? Preservice Teachers and White Racial Identity

    ERIC Educational Resources Information Center

    Peters, Terri; Margolin, Marcia; Fragnoli, Kristi; Bloom, Diane

    2016-01-01

    This study examined changes in student teachers' White racial identity and color-blindness (using scores on the WRCDS-R and CoBRAS), as well as their perceptions of working with students of color, following a semester of student teaching in diverse classrooms. Paired samples t-tests demonstrated student teachers were more color-blind about…

  16. Quantitative trait loci mapping of heat tolerance in a doubled haploid population of broccoli using genotyping-by-sequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Broccoli is a cool weather vegetable crop with a vernalization requirement to initiate and maintain floral development. Breeding for heat tolerance in broccoli has the potential to both expand viable production areas and extend the growing season. A doubled haploid (DH) population of broccoli (Bras...

  17. ASSESSING THE VULNERABILITY OF AQUIFERS USING REGULARIZED POINT DATA.

    EPA Science Inventory

    The approach will be to collect available data on concentrations of dissolved nitrate. The data will be areally-averaged using covariance functions as Bras and Rodriguez-Iturbe (1993) described for the averaging of rainfall data. Polygon coverages of nitrate will be defined bas...

  18. Condition-dependent migratory behaviour of endangered Atlantic salmon smolts moving through an inland sea

    PubMed Central

    Crossin, Glenn T.; Hatcher, Bruce G.; Denny, Shelley; Whoriskey, Kim; Orr, Michael; Penney, Alicia; Whoriskey, Frederick G.

    2016-01-01

    The Bras d’Or Lake watershed of Cape Breton Island, Nova Scotia, Canada is a unique inland sea ecosystem, UNESCO Biosphere Reserve and home to a group of regionally distinct Atlantic salmon (Salmo salar) populations. Recent population decreases in this region have raised concern about their long-term persistence. We used acoustic telemetry to track the migrations of juvenile salmon (smolts) from the Middle River into the Bras d’Or Lake and, subsequently, into the Atlantic Ocean. Roughly half of the tagged smolts transited the Bras d’Or Lakes to the Atlantic Ocean, using a migration route that took them through the Gulf of St Lawrence’s northern exit at the Strait of Belle Isle (∼650 km from the home river) towards feeding areas in the Labrador Sea and Greenland. However, a significant fraction spent >70 days in the Lakes, suggesting that this population has an alternative resident form, in which smolts limit their migrations within the Bras d’Or. Smolts in good relative condition (as determined from length-to-mass relationships) tended to be residents, whereas fish in poorer condition were ocean migrants. We also found a covarying effect of river temperature that helped to predict residence vs. ocean migration. We discuss these results relative to their bioenergetic implications and provide suggestions for future studies aimed at the conservation of declining salmon populations in Canada. PMID:27293765

  19. Relationships Among the Knowledge, Efficacy, and Practices Instrument, Color-Blind Racial Attitudes Scale, Deamonte Driver Survey, and Defining Issues Test 2.

    PubMed

    Behar-Horenstein, Linda S; Garvan, Cynthia W

    2016-03-01

    Concordance studies indicate the degree to which instruments measure the same or similar constructs or something different. The aims of this study were to identify the factor structure of the Deamonte Driver Survey and determine the relationship between the Deamonte Driver (a measure of social class stereotyping), the Defining Issues Test 2 (DIT2; a measure of ethical sensitivity), the Color-Blind Racial Attitudes Scale (CoBRAS; a measure of racial stereotyping), and the Knowledge, Efficacy, and Practices Instrument (KEPI; a measure of cultural competence). The results showed a three-factor solution for the Deamonte Driver Survey and significant relationships between CoBRAS and DIT2 subscales and between CoBRAS and Deamonte Driver subscales. Significant relationships between the measures and exploratory variables, underrepresented minority status, age, citizenship, marital status, political stance, English as a first language, and gender were found. The lack of a significant relationship between the KEPI and Deamonte Driver, DIT2, or CoBRAS subscales suggests that the KEPI is measuring a unique construct. These findings showed how these scales contributed to the assessment of cultural competence among dental students and faculty. PMID:26933112

  20. Precocious Puberty (For Parents)

    MedlinePlus

    ... or pubic or underarm hair. The physical changes boys and girls go through during puberty are usually evident to ... About Puberty Understanding Puberty Acne All About Menstruation Boys and Puberty Breasts and Bras Girls and Puberty Word! Puberty Growth Disorders Thyroid Disorders ...

  1. Promoting Tenth Graders' Reading Comprehension of Academic Texts in the English Class (Promoción de la comprensión de lectura de textos académicos de estudiantes de grado décimo en la clase de inglés)

    ERIC Educational Resources Information Center

    Quiroga Carrillo, Claudia

    2010-01-01

    This article reports on an action research project conducted in a public school in Bogotá, Colombia, with tenth grade students. We decided to develop it because of the students' needs as well as the em phasis of the PEI (Proyecto Educativo Institucional = School Institutional Project), which is based on the requisite of improving reading…

  2. The Design of a Rubric to Evaluate Laboratory Reports in Astronomy: Academic Literacy in the Disciplines (El diseño de una rúbrica para evaluar informes de laboratorio en Astronomía: la alfabetización académica en las disciplinas)

    ERIC Educational Resources Information Center

    Arancibia Aguilera, María Cristina

    2014-01-01

    A rubric was developed to evaluate laboratory reports written by undergraduate students of astronomy and astrophysics from Universidad Católica de Chile. The process of elaboration, peer validation, and application of the rubric to the evaluation of written tasks extended from August 2011 to August 2012. The instrument proved to be effective as an…

  3. Exploring Conceptions about Writing and Learning: Undergraduates' Patterns of Beliefs and the Quality of Academic Writing (Acercamiento a las concepciones sobre la escritura y el aprendizaje: patrones de creencias de los universitarios y la calidad de su redacción académica)

    ERIC Educational Resources Information Center

    Martínez-Fernández, J. R.; Corcelles, M.; Bañales, G.; Castelló, M.; Gutiérrez-Braojos, C.

    2016-01-01

    Introduction: In this study, the conceptions of learning and writing of a group of undergraduates enrolled in a teacher education programme were identified. The relationship between them were analysed, and a set of patterns of beliefs about learning and writing were defined. Finally, the relation between these patterns and the quality of a text…

  4. Hydrology Section Executive Committee minutes

    NASA Astrophysics Data System (ADS)

    Mercer, James W.

    The AGU Hydrology Section Executive Committee Meeting was called to order at approximately 4 P.M. on Monday, December 8, 1986 by Marshall Moss. In attendance were George Pinder, Allan Freeze, Jim Mercer, Ron Cummings, Ken Bencala, Jim Wallis, Simon Ince, Jack Stone, Jeff Dozier, Don Nielson, Ivan Johnson, John Wilson, Helen Peters, Jurate Landwehr, Karen Prestegaard, Soroosh Sorooshian, Jery Stedinger, Peter Kitanidis, Rafael Bras, and Waldo Smith.

  5. Physical characteristics related to bra fit.

    PubMed

    Chen, Chin-Man; LaBat, Karen; Bye, Elizabeth

    2010-04-01

    Producing well-fitting garments has been a challenge for retailers and manufacturers since mass production began. Poorly fitted bras can cause discomfort or pain and result in lost sales for retailers. Because body contours are important factors affecting bra fit, this study analyses the relationship of physical characteristics to bra-fit problems. This study has used 3-D body-scanning technology to extract upper body angles from a sample of 103 college women; these data were used to categorise physical characteristics into shoulder slope, bust prominence, back curvature and acromion placement. Relationships between these physical categories and bra-fit problems were then analysed. Results show that significant main effects and two-way interactions of the physical categories exist in the fit problems of poor bra support and bra-motion restriction. The findings are valuable in helping the apparel industry create better-fitting bras. STATEMENT OF RELEVANCE: Poorly fitted bras can cause discomfort or pain and result in lost sales for retailers. The findings regarding body-shape classification provide researchers with a statistics method to quantify physical characteristics and the findings regarding the relationship analysis between physical characteristics and bra fit offer bra companies valuable information about bra-fit perceptions attributable to women with figure variations. PMID:20309747

  6. Chapman Conference on Sediment Transport Processes in Estuaries

    NASA Astrophysics Data System (ADS)

    Perillo, Gerardo M. E.; Lavelle, J. William

    During the week of June 13-17, 1988, 72 sediment transport researchers “aggregated” at the Universidad Nacional del Sur in Bahfa Blanca, Argentina, to participate in an AGU Chapman Conference on Sediment Transport Processes in Estuaries. The main goals of the meeting were to discuss recent advances in estuarine science, to appraise promising future research directions, and to develop contacts and establish working relationships between Latin American and non-Latin- American estuarine researchers. The meeting drew participants from Argentina, Brazil, Chile, Uruguay, Venezuela, the U.S., Canada, Britain, France, the Federal Republic of Germany, The Netherlands, and South Africa. Meeting cosponsors were UNESCO, Secretaria de Ciencía y Técnica, Consejo Nacional de Investigaciones Cientificas y Técnicas, Comision de Investigaciones Cientificas de la Provincia de Buenos Aires, Universidad del Sur, Municipalidad de Bahia Blanca, Asociaciôn Argentina de Geofisicos y Geodestas (AGU sister organization), and the Instituto Argentino de Oceanografia (IADO).

  7. Los Alamos National Laboratory

    SciTech Connect

    Dogliani, Harold O

    2011-01-19

    The purpose of the briefing is to describe general laboratory technical capabilities to be used for various groups such as military cadets or university faculty/students and post docs to recruit into a variety of Los Alamos programs. Discussed are: (1) development and application of high leverage science to enable effeictive, predictable and reliability outcomes; (2) deter, detect, characterize, reverse and prevent the proliferation of weapons of mass destruction and their use by adversaries and terrorists; (3) modeling and simulation to define complex processes, predict outcomes, and develop effective prevention, response, and remediation strategies; (4) energetic materials and hydrodynamic testing to develop materials for precise delivery of focused energy; (5) materials cience focused on fundamental understanding of materials behaviors, their quantum-molecular properties, and their dynamic responses, and (6) bio-science to rapidly detect and characterize pathogens, to develop vaccines and prophylactic remedies, and to develop attribution forensics.

  8. Friedreich ataxia in Acadian families from eastern Canada: Clinical diversity with conserved haplotypes

    SciTech Connect

    Richter, A.; Poirier, J.; Mercier, J.

    1996-09-06

    The gene for Friedreich ataxia (FRDA), an autosomal-recessive neurodegenerative disease, remains elusive. The current candidate region of about 150 kb lies between loci FR2 and F8101 near the D9S15/D9S5 linkage group at 9q13-21.1. Linkage homogeneity between classical FRDA and a milder, slowly progressive Acadian variant (FRDA-Acad) has been demonstrated. An extended D9S15-D9S5 haplotype (C6) predominates in FRDA-Acad chromosomes from Louisiana. We studied 10 Acadian families from New Brunswick, Canada. In eight families, affected individuals conformed to the clinical description of FRDA-Acad; in one, 2 sibs presented with spastic ataxia (SPA-Acad). In the last family, 2 sibs had FRDA-Acad, and one had SPA-Acad. We found that SPA-Acad is linked to the FRDA gene region. The C6 haplotype and a second major haplotype (137) were identified. The same ataxia-linked haplotypes segregated with both FRDA-Acad and SPA-Acad in two unrelated families. The parental origins of these haplotypes were different. Our observation of different phenotypes associated with the same combination of haplotypes may point to the influence of the parent of origin on gene expression, indicate the effect of modifier genes, or reflect the presence of different mutations on the same haplotype. Our findings underline the need to investigate families with autosomal-recessive ataxias for linkage to the FRDA region, despite lack of key diagnostic manifestations such as cardiomyopathy or absent deep-tendon reflexes. 28 refs., 4 figs., 3 tabs.

  9. Anomalous change of Airy disk with changing size of spherical particles

    NASA Astrophysics Data System (ADS)

    Pan, Linchao; Zhang, Fugen; Meng, Rui; Xu, Jie; Zuo, Chenze; Ge, Baozhen

    2016-02-01

    Use of laser diffraction is considered as a method of reliable principle and mature technique in measurements of particle size distributions. It is generally accepted that for a certain relative refractive index, the size of the scattering pattern (also called Airy disk) of spherical particles monotonically decreases with increasing particle size. This fine structure forms the foundation of the laser diffraction method. Here we show that the Airy disk size of non-absorbing spherical particles becomes larger with increasing particle size in certain size ranges. To learn more about this anomalous change of Airy disk (ACAD), we present images of Airy disk and curves of Airy disk size versus particle size for spherical particles of different relative refractive indices by using Mie theory. These figures reveal that ACAD occurs periodically for non-absorbing particles and will disappear when the absorbing efficiency is higher than certain value. Then by using geometrical optics (GO) approximation, we derive the analytical formulae for the bounds of the size ranges where ACAD occurs. From the formulae, we obtain laws of ACAD as follows: (1) for non-absorbing particles, ACAD occurs periodically, and when the particle size tends to infinity, the period tends to a certain value. As the relative refractive index increases, (2) the particle size ranges where ACAD occurs shift to smaller values, (3) the period of ACAD becomes smaller, and (4) the width of the size ranges where ACAD occurs becomes narrower. In addition, we can predict from the formulae that ACAD also exists for particles whose relative refractive index is smaller than 1.

  10. River dynamics and landscape evolution in La Réunion Island: insights from luminescence dating

    NASA Astrophysics Data System (ADS)

    Farvacque, Manon; Valla, Pierre

    2016-04-01

    Tropical volcanic islands are natural laboratories to investigate the competition between volcanic construction (lava eruptions) and erosional destruction (extreme climatic events) in long-term landscape evolution. In La Réunion Island (Indian Ocean), the present day topography of the Piton des Neiges results from these competing processes. It presents three large-scale excavations called "cirques" that have been significantly eroded since the latest eruptive events but whose origin and formation time are still unclear. Indeed, the morphologic evolution of the Piton des Neiges is mostly known from K-Ar dating of lava flows and associated reconstructions of post-eruption eroded volumes. However, involved erosion processes and their rates through time remain poorly constrained, making it difficult to understand the geomorphic response to volcanic activity in this setting. Here, we focus on the "Bras de Cilaos" river that drains the "Cilaos cirque" (southern part of the Piton des Neiges). The Cilaos cirque has been first excavated between 140-180 ka [1], and it has been filled again during a late-stage eruptive event at ~145 ka [2] that also entirely filled the Bras de Cilaos valley. Alternatively, some studies have proposed that the Cilaos cirque and the Bras de Cilaos have been more recently filled by an eruption event at ~70 ka [3]. The Bras de Cilaos river is characterized by high relief (400-650 m) with no remaining evidence for these late eruptive events, showing significant incision and efficient fluvial erosion/transport processes after lava emplacement. In its downstream part, it presents thick alluvial deposits preserved along its riverbanks. The presence of such deposits may provide important constraints on the river dynamics and especially its response to the latest eruption events. However this requires establishing a tight temporal framework for these sediment archives. We thus sampled five different sedimentary sequences along the river to date their

  11. Genetics Home Reference: leptin receptor deficiency

    MedlinePlus

    ... leptin receptor gene causes obesity and pituitary dysfunction. Nature. 1998 Mar 26;392(6674):398-401. Citation ... and human weight regulation: lessons from experiments of nature. Ann Acad Med Singapore. 2009 Jan;38(1): ...

  12. WORKSHOPS, SEMINARS, AND CONFERENCES (TECHNICAL SUPPORT CENTER, SUBSURFACE PROTECTION AND REMEDIATION DIVISION, NRMRL)

    EPA Science Inventory

    The mission of the Technical Support Center's (TSC's) technology transfer program includes conducting information transfer workshops, seminars, and conferences as well as training courses. These activities provide a forum for discussing cutting-edge issues among government, acade...

  13. Genetics Home Reference: nonsyndromic aplasia cutis congenita

    MedlinePlus

    ... cutis congenita: a clinical review and proposal for classification. J Am Acad Dermatol. 1986 Apr;14(4): ... Health & Human Services National Institutes of Health National Library of Medicine Lister Hill National Center for Biomedical ...

  14. Cassava genetic resources and their utilization for breeding of the crop.

    PubMed

    Nassar, Nagib M A

    2007-01-01

    Wild cassava relatives are perennials and vary in growth pattern from nearly acaulescent subshrubs to small trees. They have been used as a source of useful characters such as high protein content, apomixis, resistance to mealybug and mosaic disease, and tolerance to drought. Indigenous clones are a potential source of beta-carotene and lycopene. Apomixis genes have been transferred to the crop successfully through interspeci fi c hybridization, and apomictic clones arising from these hybrids are now being grown at the Universidade de Brasília. Interspeci fi c hybrids produced earlier were polyploidized and had their fertility restored. Different useful types of chimera were also produced. PMID:18273809

  15. Cassava in South America, Brazil's contribution and the lesson to be learned from India.

    PubMed

    Nassar, Nagib M A

    2006-01-01

    South America is responsible for about half of the cassava world production. In the 1970's productivity of the crop on the continent was about 15 ton/ha, and dropped continuously until reaching 12 ton/ha in 2004. India's productivity of cassava increased from 10 ton/ha in the 1970's to 28 ton/ha in 2004. Brazil contributed significantly to improving cassava crops through the Instituto Agronômico de Campinas in the 1960's and 1970's. The Universidade de Brasília released high-protein content hybrids, apomictic clones and explored the potential of indigenous landraces. PMID:17183479

  16. Upper mantle anisotropy in SE and Central Brazil from SKS splitting: Evidence of asthenospheric flow around a cratonic keel

    NASA Astrophysics Data System (ADS)

    Assumpção, Marcelo; Heintz, Maggy; Vauchez, Alain; Silva, Marcos Egydio

    2006-10-01

    We present results of upper mantle anisotropy derived from measurements of core refracted shear wave splitting (mainly SKS phases) recorded at 48 stations covering the major tectonic provinces in Central and SE Brazil, such as the Tocantins Province (Paraguay-Araguaia and Brasília belts between the Amazon and São Francisco cratons), the Paraná intracratonic basin, the southern part of the São Francisco craton, and the Mantiqueira province (with the coastal Ribeira belt). Although the fast polarization directions vary across the region, consistent orientations are observed over hundreds of kilometers. The fast polarization directions tend to be close to the absolute plate motion given by the hot-spot reference model HS3-NUVEL1A. However, correlations with geological structures are also observed in the southern Brasilia belt and in the Ribeira belt, respectively located SW and S of the São Francisco craton. On the other hand, in the northern Tocantins province, the fast shear-wave direction (˜ N60°S) is oblique to the SW-NE trend of the geological units and faults, and no anisotropy contribution from lithospheric sources can be clearly identified. Overall, the fast polarization directions show a fan-shaped pattern strongly suggesting asthenosperic flow around a thick and stiff keel in the southern part of the São Francisco craton, consistent with the high-velocity anomaly revealed by recent surface-wave tomography. The observed NW-SE directions in the southern part of the Brasília belt may also be interpreted as resulting from asthenospheric flow channeled between the São Francisco craton and a cratonic block beneath the Paraná basin. The largest splitting delays observed in the southern Brasília belt and in the Ribeira belt (up to 2.4 s) suggest contributions from both lithospheric and asthenospheric sources in those two areas. Our preferred model for the anisotropy causing the observed pattern of SKS splitting consists of flow-induced deformation in the

  17. Pb and O isotopic constraints on the source of granitic rocks from Cape Breton Island, Nova Scotia, Canada

    USGS Publications Warehouse

    Ayuso, R.A.; Barr, S.M.; Longstaffe, F.J.

    1996-01-01

    Pb isotopic compositions of leached feldspars from twenty-three plutons in Cape Breton Island can be divided into two groups: anorthosite, syenite, and granite in the Blair River Complex, which have the least radiogenic compositions on the Island, and granitic rocks from terranes (Aspy, Bras d'Or, and Mira) to the south. Pb isotopic data for the Blair River Complex (206Pb/204Pb = 17.399-18.107; 207Pb/204Pb = 15.505-15.560; 208Pb/204Pb = 36.689-37.733) are consistent with an old source region ultimately derived from the mantle and contaminated by sialic crust. Oxygen isotopic compositions of syenite in the Blair River Complex (??18O = +8.0 to +8.5 permil) are slightly higher than anorthosite (+7.0 to +8.3 permil); a Silurian granite in the Blair River Complex has ??18O = +7.5 permil. Cambrian to Devonian plutons in the Aspy, Bras d'Or, and Mira terranes are more radiogenic (206Pb/204Pb = 18.192-18.981; 207Pb/204Pb = 15.574-15.712; 208Pb/ 204Pb =37.815-38.936) than the Blair River Complex and were generated from source regions having a predominant crustal Pb signature (high ??). The ??18O values of granites and granodiorites in the Aspy terrane (+7.5 to +9.2 permil; avg = +8.6 permil) and Bras d'Or (+3.7 to +11.3 permil; avg = +9.4 permil) are also consistent with involvement of sialic crust. Many Late Proterozoic granites from the Mira terrane have anomalously low ??18O values (+0.2 to +5.9 permil), perhaps produced from protoliths that had undergone hydrothermal alteration prior to melting. Paleozoic granitic rocks from the Aspy, Bras d'Or, and Mira terranes cannot be uniquely distinguished on the basis of their Pb and O isotopic compositions. The granitic rocks could have been generated during terrane amalgamation from combinations of unradiogenic (Grenville-like) and more radiogenic (Avalon-like) sources.

  18. Tight Bra in a 34-Year-Old Woman: An Unusual Cause of Mondor's Disease.

    PubMed

    Vincenza Polito, Maria; De Cicco, Pierluigi; Apicella, Rosa

    2014-01-01

    Mondor's disease is characterized by thrombophlebitis of the superficial veins of the breast and the chest wall. The list of causes is long. Various types of clothing, mainly tight bras and girdles, have been postulated as causes. We report a case of a 34-year-old woman who referred typical symptoms and signs of Mondor's disease, without other possible risk factors, and showed the cutaneous findings of the tight bra. Therefore, after distinguishing benign causes of Mondor's disease from hidden malignant causes, the clinicians should consider this clinical entity. PMID:24995060

  19. Tight Bra in a 34-Year-Old Woman: An Unusual Cause of Mondor’s Disease

    PubMed Central

    2014-01-01

    Mondor’s disease is characterized by thrombophlebitis of the superficial veins of the breast and the chest wall. The list of causes is long. Various types of clothing, mainly tight bras and girdles, have been postulated as causes. We report a case of a 34-year-old woman who referred typical symptoms and signs of Mondor’s disease, without other possible risk factors, and showed the cutaneous findings of the tight bra. Therefore, after distinguishing benign causes of Mondor’s disease from hidden malignant causes, the clinicians should consider this clinical entity. PMID:24995060

  20. Characterization of Novel Acyl Coenzyme A Dehydrogenases Involved in Bacterial Steroid Degradation

    PubMed Central

    Ruprecht, Amanda; Maddox, Jaymie; Stirling, Alexander J.; Visaggio, Nicole

    2015-01-01

    ABSTRACT The acyl coenzyme A (acyl-CoA) dehydrogenases (ACADs) FadE34 and CasC, encoded by the cholesterol and cholate gene clusters of Mycobacterium tuberculosis and Rhodococcus jostii RHA1, respectively, were successfully purified. Both enzymes differ from previously characterized ACADs in that they contain two fused acyl-CoA dehydrogenase domains in a single polypeptide. Site-specific mutagenesis showed that only the C-terminal ACAD domain contains the catalytic glutamate base required for enzyme activity, while the N-terminal ACAD domain contains an arginine required for ionic interactions with the pyrophosphate of the flavin adenine dinucleotide (FAD) cofactor. Therefore, the two ACAD domains must associate to form a single active site. FadE34 and CasC were not active toward the 3-carbon side chain steroid metabolite 3-oxo-23,24-bisnorchol-4-en-22-oyl-CoA (4BNC-CoA) but were active toward steroid CoA esters containing 5-carbon side chains. CasC has similar specificity constants for cholyl-CoA, deoxycholyl-CoA, and 3β-hydroxy-5-cholen-24-oyl-CoA, while FadE34 has a preference for the last compound, which has a ring structure similar to that of cholesterol metabolites. Knockout of the casC gene in R. jostii RHA1 resulted in a reduced growth on cholate as a sole carbon source and accumulation of a 5-carbon side chain cholate metabolite. FadE34 and CasC represent unique members of ACADs with primary structures and substrate specificities that are distinct from those of previously characterized ACADs. IMPORTANCE We report here the identification and characterization of acyl-CoA dehydrogenases (ACADs) involved in the metabolism of 5-carbon side chains of cholesterol and cholate. The two homologous enzymes FadE34 and CasC, from M. tuberculosis and Rhodococcus jostii RHA1, respectively, contain two ACAD domains per polypeptide, and we show that these two domains interact to form a single active site. FadE34 and CasC are therefore representatives of a new class of

  1. Double Variational Binding—(SMILES) Conformational Analysis by Docking Mechanisms for Anti-HIV Pyrimidine Ligands

    PubMed Central

    Putz, Mihai V.; Dudaș, Nicoleta A.; Isvoran, Adriana

    2015-01-01

    Variational quantitative binding–conformational analysis for a series of anti-HIV pyrimidine-based ligands is advanced at the individual molecular level. This was achieved by employing ligand-receptor docking algorithms for each molecule in the 1,3-disubstituted uracil derivative series that was studied. Such computational algorithms were employed for analyzing both genuine molecular cases and their simplified molecular input line entry system (SMILES) transformations, which were created via the controlled breaking of chemical bonds, so as to generate the longest SMILES molecular chain (LoSMoC) and Branching SMILES (BraS) conformations. The study identified the most active anti-HIV molecules, and analyzed their special and relevant bonding fragments (chemical alerts), and the recorded energetic and geometric docking results (i.e., binding and affinity energies, and the surface area and volume of bonding, respectively). Clear computational evidence was also produced concerning the ligand-receptor pocket binding efficacies of the LoSMoc and BraS conformation types, thus confirming their earlier presence (as suggested by variational quantitative structure-activity relationship, variational-QSAR) as active intermediates for the molecule-to-cell transduction process. PMID:26295229

  2. An analysis of the daily precipitation variability in the Himalayan orogen using a statistical parameterisation and its potential in driving landscape evolution models with stochastic climatic forcing

    NASA Astrophysics Data System (ADS)

    Deal, Eric; Braun, Jean

    2015-04-01

    A current challenge in landscape evolution modelling is to integrate realistic precipitation patterns and behaviour into longterm fluvial erosion models. The effect of precipitation on fluvial erosion can be subtle as well as nonlinear, implying that changes in climate (e.g. precipitation magnitude or storminess) may have unexpected outcomes in terms of erosion rates. For example Tucker and Bras (2000) show theoretically that changes in the variability of precipitation (storminess) alone can influence erosion rate across a landscape. To complicate the situation further, topography, ultimately driven by tectonic uplift but shaped by erosion, has a major influence on the distribution and style of precipitation. Therefore, in order to untangle the coupling between climate, erosion and tectonics in an actively uplifting orogen where fluvial erosion is dominant it is important to understand how the 'rain dial' used in a landscape evolution model (LEM) corresponds to real precipitation patterns. One issue with the parameterisation of rainfall for use in an LEM is the difference between the timescales for precipitation (≤ 1 year) and landscape evolution (> 103 years). As a result, precipitation patterns must be upscaled before being integrated into a model. The relevant question then becomes: What is the most appropriate measure of precipitation on a millennial timescale? Previous work (Tucker and Bras, 2000; Lague, 2005) has shown that precipitation can be properly upscaled by taking into account its variable nature, along with its average magnitude. This captures the relative size and frequency of extreme events, ensuring a more accurate characterisation of the integrated effects of precipitation on erosion over long periods of time. In light of this work, we present a statistical parameterisation that accurately models the mean and daily variability of ground based (APHRODITE) and remotely sensed (TRMM) precipitation data in the Himalayan orogen with only a few

  3. High contrast imaging with an arbitrary aperture: active correction of aperture discontinuities: fundamental limits and practical trades offs

    NASA Astrophysics Data System (ADS)

    Pueyo, Laurent; Norman, Colin Arthur; Soummer, Remi; Perrin, Marshall D.; N'Diaye, Mamadou; Choquet, Elodie

    2015-01-01

    In a recent paper we discussed a new method to achieve high-contrast images using segmented and/or on-axis telescopes. Our approach, named Active Compensation of Aperture Discontinuities (ACAD) relies on two sequential Deformable Mirrors to compensate for the large amplitude excursions in the telescope aperture due to secondary support structures and/or segment gaps. In this configuration the parameter landscape of Deformable Mirror Surfaces that yield high contrast Point Spread Functions is not linear, and non-linear methods are needed to find the true minimum. In particular we showed that broadband high contrast solutions can be achieved using realistic surface deformations that are accessible using existing technologies for a variety of telescope pupil geometries. In this paper we first focus on the fundamental limits and practical trade-offs associated with ACAD. In a first part we will study the fundamental limits and practical tradeoffs associated with ACAD, regardless of the downstream coronagraphic architecture. The mathematical techniques to finding ACAD DM shapes require to solve a complex differential equation. We will first discuss the scaling laws underlying this non-linear solution and their impact of DM placement and geometry wishing the optical design of an instrument. We will then consider the sensitivity to low order aberrations: in principle an ACAD solution that comprises large strokes will be more sensitive to these aberrations than one with smaller strokes. As a consequence, we will quantify this sensitive both using analytical models and numerical simulations. We will present diffractive end to end simulations and quantify the ultimate contrast and bandwidth achievable with ACAD, which can be reached by superposing using a classical linear wavefront control algorithms on top of the Monge Ampere solution. Finally, recent work has shown that coronagraph designs can also accommodate for secondary support structures and/or segments gaps, at a

  4. Stiff-person syndrome treated with rituximab

    PubMed Central

    Lobo, Marcelo Evangelista; Araújo, Marx Lincoln Barros; Tomaz, Carlos Alberto Bezerra; Allam, Nasser

    2010-01-01

    Stiff-person syndrome (SPS) is a rare neurological condition consisting of progressive and fluctuating rigidity of the axial muscles combined with painful spasms. The pathophysiology of SPS is not fully understood, but there seems to be an autoimmune component. The use of rituximab, a chimeric monoclonal antibody targeting CD20 protein in the surface of mature B cells, for the treatment of SPS is a recent therapeutical approach showing promising results. The authors present a case report of a 41-year-old female patient diagnosed with SPS who was treated with rituximab in a public hospital in Brasília, Brazil, showing a good and safe response to the treatment so far. Our data go along with some recent articles published in the literature. PMID:22802263

  5. Genetic diversity in populations of Acrocomia aculeata (Arecaceae) in the northern region of Minas Gerais, Brazil.

    PubMed

    Oliveira, D A; Melo Júnior, A F; Brandão, M M; Rodrigues, L A; Menezes, E V; Ferreira, P R B

    2012-01-01

    Macaúba (Acrocomia aculeata) is a palm of economic importance, widely distributed in natural forests from Mexico to Uruguay. We analyzed the genetic diversity of populations of macaúba (A. aculeata) in the northern region of the State of Minas Gerais, Brazil. Young leaves from 10 macaúba individuals encompassing 49 genotypes of macaúba were collected from Montes Claros, Itacambira, Brasília de Minas, Mirabela, and Grão Mogol. After extraction and amplification of samples, the amplified fragments were separated by electrophoresis. We found high levels of genetic diversity within the populations. Genetic diversity indices were high, except in the Itacambira and Mirabela populations. Results show that Mirabela and Itacambira populations can require conservation strategies because they present lower values of genetic diversity. PMID:22535388

  6. Entry into labour: The experience of young adults in Brazil

    NASA Astrophysics Data System (ADS)

    Gomes, Candido A.

    1990-12-01

    This study focuses on the experience of young adults employed in the tertiary sector in Brasília. The results show that young people are prepared for work by on-the-job training and nonformal education; schooling is mainly an indicator of trainability. Entry into the labour force reinforces social differences in family background and schooling. The results tend to support the moderate version of classical theory with regard to the nature of school/work relationships. In the context of the conflict paradigm, the data run contrary to both reproductionism and the radical critique of this view. From the comparative standpoint youth is an underprivileged group in the labour market, regardless of sex, socioeconomic status and country of residence. Despite these variations, societies are stratified by age groups.

  7. Role of vegetation in modulating denudation and topography across the Himalaya

    NASA Astrophysics Data System (ADS)

    Olen, Stephanie; Bookhagen, Bodo; Strecker, Manfred

    2015-04-01

    Studies of Himalayan denudation, to date, have primarily focused on the effects of lithology, tectonic activity, and climate in shaping landscape and controlling denudation rates. Climate can impact denudation not only through increased precipitation, runoff, or glaciation, but also via its role in controlling vegetation cover. Since the classical study of Langbein and Schumm [1958] emphasizing the role of vegetation cover in determining erosional efficiency, theoretical and plot-scale studies have highlighted the role of vegetation on surface processes [Collins et al., 2004; Istanbulluoglu and Bras, 2005; Collins and Bras, 2010; Carretier et al., 2013; Jeffery et al., 2014]. Vegetation cover and density vary considerably in the Himalaya, both across and along strike. Across strike, vegetation transitions from dense forest and agriculturally-used plots in the Lesser Himalaya to sparse alpine and arid, virtually non-vegetated regions at high elevation and in the rain shadow north of the Higher Himalaya peaks. Along-strike vegetation densities also differ significantly and show a pronounced E-W gradient. To quantify the along-strike vegetation gradient, we use 14 years of MODIS 13C1 enhanced vegetation index (EVI) data to calculate mean annual, summer (MJJASO), and winter (NDJFMA) for the entire Himalaya. Additionally, we calculate a differential EVI that compares summer versus winter vegetation density (MJJASO/NDJFMA). A decrease in vegetation density is observed from east to west, with the greatest difference in winter vegetation cover (225% higher in the eastern than western Himalaya). In contrast, differential EVI is higher in the western Himalaya, increasing 170% from east to west. To evaluate the effect of vegetation on denudation and landscape evolution, we combine the 14-year EVI data, topographic analysis, and a compilation of >100 published and unpublished 10-Be terrestrial cosmogenic nuclide (TCN) catchment-mean denudation rates from across the Himalaya

  8. Isolation and characterization of 10 microsatellite loci for Pallas' long-tongued bat Glossophaga soricina (Phyllostomidae).

    PubMed

    Oprea, M; Peixoto, F P; Resende, L V; Collevatti, R G; Telles, M P C

    2012-01-01

    Glossophaga soricina is a widespread Neotropical nectarivorous bat. We characterized 10 microsatellite loci isolated from a shotgun genomic library. We analyzed tissues from wing membrane of 67 individuals collected from two populations of Central Brazil (Brasília and Alto Paraíso). The number of alleles per locus ranged from 2 to 20, and the observed and expected heterozygosities ranged from 0.015 to 0.666 and from 0.016 to 0.915, respectively. The high combined probability of genetic identity (4.369 x 10(-8)) and probability of paternity exclusion (0.996) showed that these microsatellite loci would be useful for population genetic structure and parentage studies in natural populations of G. soricina. PMID:23079846

  9. An Automated Telescope for Education and Outreach

    NASA Astrophysics Data System (ADS)

    Burks, G. S.; Guzik, T. G.; Tohline, J. E.; Landolt, A.

    1997-12-01

    In this time of limited resources, the problem of providing an up to date facility for education and outreach needs to be addressed. One solution to this problem is a joint venture between Louisiana State University, BREC (the Park and creation Commission of East Baton Rouge Parish), and BRAS (the Baton Rouge Astronomical Society). The result of this collaboration is a facility with outreach and educational space, a 20 inch Ritchey-Chretien telescope with CCD camera, and volunteers from the amateur community for help with the outreach mission. We present an overview of the project, and show how the telescope will be completely automated to allow use of the telescope by LSU students and our outreach partners on the Internet. We explore the possibility for use of this facility by a world wide audience over the web.

  10. Toxicity and genotoxicity of wastewater from gasoline stations

    PubMed Central

    2009-01-01

    The toxicity and genotoxicity of wastewater from eight gasoline stations in Brasília, Brazil's capital city, was studied by assessing chromosomal aberrations, chromosomal malsegregation and the mitotic index in Alliumcepa root cells, and the occurrence of micronucleus and nuclear abnormalities in peripheral erythrocytes of tilapia fish (Oreochromis niloticus). The content of gasoline station effluents was also analyzed based on several physico-chemical parameters. None of the wastewater samples was genotoxic to A. cepa root cells, although cell proliferation was significantly inhibited, especially at the highest concentrations. Likewise, no micronuclei were observed in O. niloticus peripheral erythrocytes, even after exposure to high concentrations, but there was an increase in the number of nuclear abnormalities and fish mortality. These results show that although the effluent from gasoline stations is processed by an oil/water separation system before being discharged into the main sewage system, the wastewater still contains toxic compounds. PMID:21637464

  11. Toxicity and genotoxicity of wastewater from gasoline stations.

    PubMed

    Oliveira-Martins, Cynthia R; Grisolia, Cesar K

    2009-10-01

    The toxicity and genotoxicity of wastewater from eight gasoline stations in Brasília, Brazil's capital city, was studied by assessing chromosomal aberrations, chromosomal malsegregation and the mitotic index in Alliumcepa root cells, and the occurrence of micronucleus and nuclear abnormalities in peripheral erythrocytes of tilapia fish (Oreochromis niloticus). The content of gasoline station effluents was also analyzed based on several physico-chemical parameters. None of the wastewater samples was genotoxic to A. cepa root cells, although cell proliferation was significantly inhibited, especially at the highest concentrations. Likewise, no micronuclei were observed in O. niloticus peripheral erythrocytes, even after exposure to high concentrations, but there was an increase in the number of nuclear abnormalities and fish mortality. These results show that although the effluent from gasoline stations is processed by an oil/water separation system before being discharged into the main sewage system, the wastewater still contains toxic compounds. PMID:21637464

  12. Chromosomal aberrations in lymphocytes from car painters.

    PubMed

    Silva, J M; Santos-Mello, R

    1996-05-01

    In the present paper we report the results of biological monitoring of a group of 25 car painters working in different automobile shops in Brasília. There was a significantly higher frequency of aneuplodies and chromosome deletions in the peripheral lymphocytes of car painters than in control subjects. We also detected a significant correlation between the time worked as a car painter and the frequency of aneuploidy. Smoking habits do not represent a significant factor in terms of production of the various types of chromosome aberrations among car painters. These results permitted us to conclude that the individuals studied represent a risk group and should be medically followed up with judicious periodic examinations. PMID:8637507

  13. Studying Health Histories of Cancer: A New Model Connecting Cancer Incidence and Survival

    PubMed Central

    Yashin, Anatoli I.; Akushevich, Igor; Arbeev, Konstantin; Akushevich, Lucy; Kulminski, Alexander; Ukraintseva, Svetlana

    2009-01-01

    The results of recent experimental and epidemiological studies provide evidence on the connection between carcinogenesis, cancer progression, and aging. Existing models, however, are traditionally focused only on one of these aspects of health deterioration. In this paper, we derive a new model of cancer, which describes the connection between the age at disease onset, the duration of disease, and life span of respective individuals. The model combines ideas used in the two hits model of carcinogenesis with those used in the Le Bras multistate model of aging with constant transition intensities. The model is used in the joint analyses of the U.S. demographic mortality data and SEER data for selected cancers. The results show that the developed approach is capable of explaining links among health history data and provides useful insights on mechanisms of cancer occurrence, disease progression, other aging-related changes, and mortality. Further developments of this model are discussed. PMID:19167410

  14. Pickless event detection and location: The waveform correlation event detection system (WCEDS) revisited

    DOE PAGESBeta

    Arrowsmith, Stephen John; Young, Christopher J.; Ballard, Sanford; Slinkard, Megan Elizabeth

    2016-01-01

    The standard paradigm for seismic event monitoring breaks the event detection problem down into a series of processing stages that can be categorized at the highest level into station-level processing and network-level processing algorithms (e.g., Le Bras and Wuster (2002)). At the station-level, waveforms are typically processed to detect signals and identify phases, which may subsequently be updated based on network processing. At the network-level, phase picks are associated to form events, which are subsequently located. Furthermore, waveforms are typically directly exploited only at the station-level, while network-level operations rely on earth models to associate and locate the events thatmore » generated the phase picks.« less

  15. Pickless event detection and location: The waveform correlation event detection system (WCEDS) revisited

    SciTech Connect

    Arrowsmith, Stephen John; Young, Christopher J.; Ballard, Sanford; Slinkard, Megan Elizabeth

    2016-01-01

    The standard paradigm for seismic event monitoring breaks the event detection problem down into a series of processing stages that can be categorized at the highest level into station-level processing and network-level processing algorithms (e.g., Le Bras and Wuster (2002)). At the station-level, waveforms are typically processed to detect signals and identify phases, which may subsequently be updated based on network processing. At the network-level, phase picks are associated to form events, which are subsequently located. Furthermore, waveforms are typically directly exploited only at the station-level, while network-level operations rely on earth models to associate and locate the events that generated the phase picks.

  16. The effect of a rainfall and discharge variability on erosion rates in a highly active tectonic setting: a stochastic approach

    NASA Astrophysics Data System (ADS)

    Braun, Jean; Deal, Eric; Andermann, Christoff

    2015-04-01

    The influence of climate on surface processes and consequently on landscape evolution is undeniably important; despite this, many fluvial landscape evolution models do not integrate an accurate or physically based parameterisation of precipitation, the climatic forcing most important for fluvial processes. This is likely due to two major challenges; first of all there is the difficulty in moving from the hourly, daily and monthly timescales most relevant to precipitation to the millennial timescales used in landscape evolution modelling. To confront this challenge, we adopt the approach of Tucker and Bras, 2000 and Lague, 2005, and upscale precipitation with a statistical parameterisation accounting for mean precipitation as well as short term (daily) variability. This technique is key in capturing and quantifying the importance of rare, extreme events. The second challenge stems from the fact that erosion rates are proportional not to precipitation, but rather to discharge, which results from a complex convolution of the regional precipitation patterns with the landscape. To address this second obstacle we present work that investigates the relationship between a stochastic description of precipitation and one of discharge, linking general patterns of precipitation and discharge rather than attempting to establish a deterministic relationship. To achieve this we model the effect of precipitation variability on runoff variability as well as compare associated precipitation and discharge measurements from a range of climatic regimes and spatial scales in the Himalayas. Using the results of this work, we integrate the statistical parameterisation of precipitation into a landscape evolution model, allowing us to explore the effect of realistic precipitation patterns, specifically precipitation variability, on the evolution of relief and topography. References Bras, R. L., & Tucker, G. E. (2000). A stochastic approach to modeling the role of rainfall variability in

  17. Multidrug resistance dissemination by extended-spectrum β-lactamase-producing Escherichia coli causing community-acquired urinary tract infection in the Central-Western Region, Brazil.

    PubMed

    Gonçalves, Laura Fernandes; de Oliveira Martins-Júnior, Paulo; de Melo, Ana Beatriz Fabrício; da Silva, Rafaella Christina Rocha Moreira; de Paulo Martins, Vicente; Pitondo-Silva, André; de Campos, Tatiana Amabile

    2016-09-01

    The aim of this work was to analyse extended-spectrum β-lactamase (ESBL)-producing Escherichia coli strains isolated from outpatients with signs of cystitis in Hospital Universitário de Brasília (Brasília, Brazil) during the period July 2013 to April 2014. E. coli isolated from urine culture were identified and their antibiotic susceptibility profile was determined by VITEK 2. ESBL-producing strains identified were submitted to PCR for Clermont phylotyping, CTX-M group typing and virulence determinant detection, and clonal relationships were determined by enterobacterial repetitive intergenic consensus (ERIC)-PCR. One strain belonging to each cluster of the dendrogram obtained by ERIC-PCR was selected for multilocus sequence typing (MLST). Among 324 uropathogenic E. coli (UPEC) analysed, 23 (7.1%) were identified as producing ESBL. All ESBL-producing strains were multidrug-resistant (MDR), i.e. presented non-susceptibility to at least one agent in three or more antimicrobial categories. Of the 23 ESBL-producing UPEC strains, 9 were assigned to phylogenetic group B2 and 7 each belonged to phylogenetic groups D and A. Virulence genotyping showed that aer was the most prevalent gene observed among the strains (21/23), followed by traT (18/23), pap (5/23), afa (5/23), PAI (5/23), cnf (3/23) and sfa (1/23). Analysis of the dendrogram showed that multidrug resistance and CTX-M ESBL groups were distributed among all strains, independent of clonality and phylogroup. Sequence types (STs) associated with pandemic resistance clones, such as B2-ST131 and D-ST648, were observed among the isolates. In conclusion, the results showed worrisome evidence of the potential for antibiotic multiresistant dissemination among community-acquired urinary tract infection caused by UPEC. PMID:27530830

  18. Exhumation history of the Serra do Mar, southeast Brazil

    NASA Astrophysics Data System (ADS)

    Carina Siqueira-Ribeiro, Marli; Hackspacher, Peter; Stuart, Finlay M.

    2016-04-01

    The Serra do Mar (SM) mountain range located along the southeast Brazilian continental margin is characterized by a low-lying coastal plateau separated from the elevated inland plateau by a steep escarpment. This morphology is a result of reactivation of Precambrian shear zones since the break-up of the Western Gondwana and opening of the South Atlantic Ocean in Early Cretaceous (1). Previous Thermochronological data from southeast Brazilian highlands (2,3), indicates that the landscape evolution is associated with several distinct exhumation events. In order to clarify the intensity and duration of the post-break up tectonic processes that shaped the SM we have undertaken a low temperature thermochronology study of crystalline basement, from the plateaus and escarpments situated between south of Rio de Janeiro and São Paulo state. Apatite fission track (AFT) and (U-Th/He) and (AHe) dating has been combined with geologic information to generate precise thermal histories and make initial attempts to quantify the amount of exhumation. AFT ages range from 145 to 53 Ma whereas preliminary AHe ages range from 75 to 37 Ma. Forward modeling using QTQt confirms Late Cretaceous-Paleogene cooling identified earlier (4,5) and identifies a distinct cooling phase in Neogene, between 30 and 10 Ma. Neogene cooling rapid caused exhumation of rocks 1 km through of the crust mainly in south portion of the SM in Rio de Janeiro state. (1) Almeida, 1976. An. Academia Bras de Cien 48 (suppl.), 15-(2) (2) Hackspacher et al. 2004. Gondwana Research,vol.2, 91-101. (3) Hiruma et al. 2010. Gondwana Research,18,674-687. (4) Siqueira-Ribeiro et al. 2011. Revista Bras. de Geomorfologia, 13, 3-14 (5) Cogné et al. 2012. Journal Geophysical Research, vol.117,1-16.

  19. Assessing the HIV-1 Epidemic in Brazilian Drug Users: A Molecular Epidemiology Approach

    PubMed Central

    Guimarães, Monick Lindenmeyer; Marques, Bianca Cristina Leires; Bertoni, Neilane; Teixeira, Sylvia Lopes Maia; Morgado, Mariza Gonçalves; Bastos, Francisco Inácio

    2015-01-01

    Person who inject illicit substances have an important role in HIV-1 blood and sexual transmission and together with person who uses heavy non-injecting drugs may have less than optimal adherence to anti-retroviral treatment and eventually could transmit resistant HIV variants. Unfortunately, molecular biology data on such key population remain fragmentary in most low and middle-income countries. The aim of the present study was to assess HIV infection rates, evaluate HIV-1 genetic diversity, drug resistance, and to identify HIV transmission clusters in heavy drug users (DUs). For this purpose, DUs were recruited in the context of a Respondent-Driven Sampling (RDS) study in different Brazilian cities during 2009. Overall, 2,812 individuals were tested for HIV, and 168 (6%) of them were positive, of which 19 (11.3%) were classified as recent seroconverters, corresponding to an estimated incidence rate of 1.58%/year (95% CI 0.92–2.43%). Neighbor joining phylogenetic trees from env and pol regions and bootscan analyses were employed to subtype the virus from132 HIV-1-infected individuals. HIV-1 subtype B was prevalent in most of the cities under analysis, followed by BF recombinants (9%-35%). HIV-1 subtype C was the most prevalent in Curitiba (46%) and Itajaí (86%) and was also detected in Brasília (9%) and Campo Grande (20%). Pure HIV-1F infections were detected in Rio de Janeiro (9%), Recife (6%), Salvador (6%) and Brasília (9%). Clusters of HIV transmission were assessed by Maximum likelihood analyses and were cross-compared with the RDS network structure. Drug resistance mutations were verified in 12.2% of DUs. Our findings reinforce the importance of the permanent HIV-1 surveillance in distinct Brazilian cities due to viral resistance and increasing subtype heterogeneity all over Brazil, with relevant implications in terms of treatment monitoring, prophylaxis and vaccine development. PMID:26536040

  20. OCCURRENCE AND ORIENTATION OF PARALICHTHID FLOUNDERS (BOTHIDAE: PARALICHTYS) ON AN INTERTIDAL BEACH

    EPA Science Inventory

    Middaugh, Douglas P. and Charles L. McKenney, Jr. 2003. Occurrence and Orientation of Flounders (Bothidae: Paralichthys) on an Intertidal Beach. J. North Carol. Acad. Sci. 119(4):157-171. (ERL,GB 1172).

    The intertidal movement and burying pattern of paralichthid flounders...

  1. A visual LISP program for voxelizing AutoCAD solid models

    NASA Astrophysics Data System (ADS)

    Marschallinger, Robert; Jandrisevits, Carmen; Zobl, Fritz

    2015-01-01

    AutoCAD solid models are increasingly recognized in geological and geotechnical 3D modeling. In order to bridge the currently existing gap between AutoCAD solid models and the grid modeling realm, a Visual LISP program is presented that converts AutoCAD solid models into voxel arrays. Acad2Vox voxelizer works on a 3D-model that is made up of arbitrary non-overlapping 3D-solids. After definition of the target voxel array geometry, 3D-solids are scanned at grid positions and properties are streamed to an ASCII output file. Acad2Vox has a novel voxelization strategy that combines a hierarchical reduction of sampling dimensionality with an innovative use of AutoCAD-specific methods for a fast and memory-saving operation. Acad2Vox provides georeferenced, voxelized analogs of 3D design data that can act as regions-of-interest in later geostatistical modeling and simulation. The Supplement includes sample geological solid models with instructions for practical work with Acad2Vox.

  2. Genetics Home Reference: McCune-Albright syndrome

    MedlinePlus

    ... Weinstein LS, Chen M, Liu J. Gs(alpha) mutations and imprinting defects in human disease. Ann N Y Acad Sci. 2002 Jun;968:173-97. Review. Citation on PubMed Weinstein LS, Liu J, Sakamoto ... LS. G(s)alpha mutations in fibrous dysplasia and McCune-Albright syndrome. J ...

  3. New Organisational Structures and the Transformation of Academic Work

    ERIC Educational Resources Information Center

    Nyhagen, Gigliola Mathisen; Baschung, Lukas

    2013-01-01

    This article will particularly focus on Norway and the consequences for academic work. Frequently in studies of academic work, focus has been on academics' individual autonomy and to what extent the latter is challenged (Altbach in "Ann Am Acad Pol Soc Sci" 448:1-14, 1980; Shattock in "High Educ" 41:27-47, 2001). One of…

  4. Langevin Theory of Anomalous Brownian Motion Made Simple

    ERIC Educational Resources Information Center

    Tothova, Jana; Vasziova, Gabriela; Glod, Lukas; Lisy, Vladimir

    2011-01-01

    During the century from the publication of the work by Einstein (1905 "Ann. Phys." 17 549) Brownian motion has become an important paradigm in many fields of modern science. An essential impulse for the development of Brownian motion theory was given by the work of Langevin (1908 "C. R. Acad. Sci.", Paris 146 530), in which he proposed an…

  5. Clinical relevance of short-chain acyl-CoA dehydrogenase (SCAD) deficiency: Exploring the role of new variants including the first SCAD-disease-causing allele carrying a synonymous mutation

    PubMed Central

    Tonin, Rodolfo; Caciotti, Anna; Funghini, Silvia; Pasquini, Elisabetta; Mooney, Sean D.; Cai, Binghuang; Proncopio, Elena; Donati, Maria Alice; Baronio, Federico; Bettocchi, Ilaria; Cassio, Alessandra; Biasucci, Giacomo; Bordugo, Andrea; la Marca, Giancarlo; Guerrini, Renzo; Morrone, Amelia

    2016-01-01

    Short-chain acyl-coA dehydrogenase deficiency (SCADD) is an autosomal recessive inborn error of mitochondrial fatty acid oxidation caused by ACADS gene alterations. SCADD is a heterogeneous condition, sometimes considered to be solely a biochemical condition given that it has been associated with variable clinical phenotypes ranging from no symptoms or signs to metabolic decompensation occurring early in life. A reason for this variability is due to SCAD alterations, such as the common p.Gly209Ser, that confer a disease susceptibility state but require a complex multifactorial/polygenic condition to manifest clinically. Our study focuses on 12 SCADD patients carrying 11 new ACADS variants, with the purpose of defining genotype–phenotype correlations based on clinical data, metabolite evaluation, molecular analyses, and in silico functional analyses. Interestingly, we identified a synonymous variant, c.765G > T (p.Gly255Gly) that influences ACADS mRNA splicing accuracy. mRNA characterisation demonstrated that this variant leads to an aberrant splicing product, harbouring a premature stop codon. Molecular analysis and in silico tools are able to characterise ACADS variants, identifying the severe mutations and consequently indicating which patients could benefit from a long term follow- up. We also emphasise that synonymous mutations can be relevant features and potentially associated with SCADD. PMID:27051597

  6. Genetics Home Reference: pseudohypoaldosteronism type 1

    MedlinePlus

    ... hyperkalaemic acidosis, pseudohypoaldosteronism type 1. Nat Genet. 1996 Mar;12(3):248-53. Citation on PubMed Chen ... sgk. Proc Natl Acad Sci U S A. 1999 Mar 2;96(5):2514-9. Citation on PubMed ...

  7. Clinical relevance of short-chain acyl-CoA dehydrogenase (SCAD) deficiency: Exploring the role of new variants including the first SCAD-disease-causing allele carrying a synonymous mutation.

    PubMed

    Tonin, Rodolfo; Caciotti, Anna; Funghini, Silvia; Pasquini, Elisabetta; Mooney, Sean D; Cai, Binghuang; Proncopio, Elena; Donati, Maria Alice; Baronio, Federico; Bettocchi, Ilaria; Cassio, Alessandra; Biasucci, Giacomo; Bordugo, Andrea; la Marca, Giancarlo; Guerrini, Renzo; Morrone, Amelia

    2016-06-01

    Short-chain acyl-coA dehydrogenase deficiency (SCADD) is an autosomal recessive inborn error of mitochondrial fatty acid oxidation caused by ACADS gene alterations. SCADD is a heterogeneous condition, sometimes considered to be solely a biochemical condition given that it has been associated with variable clinical phenotypes ranging from no symptoms or signs to metabolic decompensation occurring early in life. A reason for this variability is due to SCAD alterations, such as the common p.Gly209Ser, that confer a disease susceptibility state but require a complex multifactorial/polygenic condition to manifest clinically. Our study focuses on 12 SCADD patients carrying 11 new ACADS variants, with the purpose of defining genotype-phenotype correlations based on clinical data, metabolite evaluation, molecular analyses, and in silico functional analyses. Interestingly, we identified a synonymous variant, c.765G > T (p.Gly255Gly) that influences ACADS mRNA splicing accuracy. mRNA characterisation demonstrated that this variant leads to an aberrant splicing product, harbouring a premature stop codon. Molecular analysis and in silico tools are able to characterise ACADS variants, identifying the severe mutations and consequently indicating which patients could benefit from a long term follow- up. We also emphasise that synonymous mutations can be relevant features and potentially associated with SCADD. PMID:27051597

  8. Genetics Home Reference: hidradenitis suppurativa

    MedlinePlus

    ... Apr;60(4):539-61; quiz 562-3. doi: 10.1016/j.jaad.2008.11.911. Review. ... Acad Dermatol. 2009 Jul;61(1):51-7. doi: 10.1016/j.jaad.2009.02.013. Epub ... Dermatol Clin. 2010 Oct;28(4):779-93. doi: 10.1016/j.det.2010.07.003. Review. ...

  9. 78 FR 18354 - Government-Owned Inventions; Availability for Licensing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ... patent applications. Infectious Hepatitis E Virus Genotype 3 Recombinants--Prospective Vaccine Candidates... Hepatitis E virus (HEV) that has been adapted to grow in cell culture and can potentially be used to develop... cells by hepatitis E virus and discovery of an infectious virus-host recombinant. Proc Natl Acad Sci U...

  10. Hybridization and evolution of invasiveness in plants and other organisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Less than a decade ago, we proposed that hybridization could serve as a stimulus for the evolution of invasiveness in plants (Ellstrand and Schierenbeck Proc Nat Acad Sci USA 97:7043–7050, 2000). A substantial amount of research has taken place on that topic since the publication of that paper, stim...

  11. Adiabatic single scan two-dimensional NMR spectrocopy.

    PubMed

    Pelupessy, Philippe

    2003-10-01

    New excitation schemes, based on the use adiabatic pulses, for single scan two-dimensional NMR experiments (Frydman et al., Proc. Nat. Acad. Sci. 2002, 99, 15 858-15 862) are introduced. The advantages are discussed. Applications in homo- and heteronuclear experiments are presented. PMID:14519020

  12. Shrinking the FadE Proteome of Mycobacterium tuberculosis: Insights into Cholesterol Metabolism through Identification of an α2β2 Heterotetrameric Acyl Coenzyme A Dehydrogenase Family

    PubMed Central

    Wipperman, Matthew F.; Yang, Meng; Thomas, Suzanne T.

    2013-01-01

    The ability of the pathogen Mycobacterium tuberculosis to metabolize steroids like cholesterol and the roles that these compounds play in the virulence and pathogenesis of this organism are increasingly evident. Here, we demonstrate through experiments and bioinformatic analysis the existence of an architecturally distinct subfamily of acyl coenzyme A (acyl-CoA) dehydrogenase (ACAD) enzymes that are α2β2 heterotetramers with two active sites. These enzymes are encoded by two adjacent ACAD (fadE) genes that are regulated by cholesterol. FadE26-FadE27 catalyzes the dehydrogenation of 3β-hydroxy-chol-5-en-24-oyl-CoA, an analog of the 5-carbon side chain cholesterol degradation intermediate. Genes encoding the α2β2 heterotetrameric ACAD structures are present in multiple regions of the M. tuberculosis genome, and subsets of these genes are regulated by four different transcriptional repressors or activators: KstR1 (also known as KstR), KstR2, Mce3R, and SigE. Homologous ACAD gene pairs are found in other Actinobacteria, as well as Proteobacteria. Their structures and genomic locations suggest that the α2β2 heterotetrameric structural motif has evolved to enable catalysis of dehydrogenation of steroid- or polycyclic-CoA substrates and that they function in four subpathways of cholesterol metabolism. PMID:23836861

  13. The Threat of the Dyscompetent Resident: A Plea to Make the Implicit More Explicit!

    ERIC Educational Resources Information Center

    van Mook, Walther N. K. A.; van Luijk, Scheltus J.; Zwietering, P. J.; Southgate, L.; Schuwirth, Lambert W. T.; Scherpbier, Albert J. J. A.; van der Vleuten, Cees P. M.

    2015-01-01

    Although several examples of frameworks dealing with "students'" unprofessional behaviour are available, guidance on how to deal locally or regionally with dysfunctional "residents" is limited (Hickson et al. in "Acad Med" 82(11):1040-1048, 2007b; Leape and Fromson in "Ann Intern Med" 144(2):107-115, 2006).…

  14. High contrast imaging with an arbitrary aperture: active correction of aperture discontinuities: fundamental limits and practical trade- offs

    NASA Astrophysics Data System (ADS)

    Pueyo, Laurent; Norman, Colin; Soummer, Rémi; Perrin, Marshall; N'Diaye, Mamadou; Choquet, Élodie; Hoffmann, Jordan; Carlotti, Alexis; Mawet, Dimitri

    2014-08-01

    We present a new method to achieve high-contrast images using segmented and/or on-axis telescopes. Our approach relies on using two sequential Deformable Mirrors to compensate for the large amplitude excursions in the telescope aperture due to secondary support structures and / or segment gaps. We solve the highly non-linear Monge-Ampere equation that is the fundamental equation describing the physics of phase induced amplitude modulation. We determine the optimum configuration for our two sequential Deformable Mirror system and show that high-throughput and high contrast solutions can be achieved using realistic surface deformations that are accessible using existing technologies. We name this process Active Compensation of Aperture Discontinuities (ACAD). We show that for geometries similar to JWST, ACAD can attain at least 10-7 in contrast and an order of magnitude higher for future Extremely Large Telescopes, even when the pupil features a "missing segment" . Because the converging non-linear mappings resulting from our Deformable Mirror shapes damps near-field diffraction artifacts in the vicinity of the discontinuities this solution is particularly appealing in terms of spectral bandwidth. We present preliminary results that illustrate the performances of ACAD in the presence of diffraction for apertures for with secondary support structures of varying width and argue that the ultimate contrast achieved can by combining ACAD with modern wavefront control algorithms.

  15. An assessment of children's willingness to try new foods in the rural Lower Mississippi Delta (LMD)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our purpose was to assess elementary school children's willingness to eat an unfamiliar food at and away from home. Children often eat the same foods repeatedly, and those patterns have resulted in intakes that do not meet the Recommended Dietary Allowance (RDA) set for children by the National Acad...

  16. Role of vegetation in modulating denudation and topography across the Himalaya

    NASA Astrophysics Data System (ADS)

    Olen, Stephanie; Bookhagen, Bodo; Strecker, Manfred

    2015-04-01

    Studies of Himalayan denudation, to date, have primarily focused on the effects of lithology, tectonic activity, and climate in shaping landscape and controlling denudation rates. Climate can impact denudation not only through increased precipitation, runoff, or glaciation, but also via its role in controlling vegetation cover. Since the classical study of Langbein and Schumm [1958] emphasizing the role of vegetation cover in determining erosional efficiency, theoretical and plot-scale studies have highlighted the role of vegetation on surface processes [Collins et al., 2004; Istanbulluoglu and Bras, 2005; Collins and Bras, 2010; Carretier et al., 2013; Jeffery et al., 2014]. Vegetation cover and density vary considerably in the Himalaya, both across and along strike. Across strike, vegetation transitions from dense forest and agriculturally-used plots in the Lesser Himalaya to sparse alpine and arid, virtually non-vegetated regions at high elevation and in the rain shadow north of the Higher Himalaya peaks. Along-strike vegetation densities also differ significantly and show a pronounced E-W gradient. To quantify the along-strike vegetation gradient, we use 14 years of MODIS 13C1 enhanced vegetation index (EVI) data to calculate mean annual, summer (MJJASO), and winter (NDJFMA) for the entire Himalaya. Additionally, we calculate a differential EVI that compares summer versus winter vegetation density (MJJASO/NDJFMA). A decrease in vegetation density is observed from east to west, with the greatest difference in winter vegetation cover (225% higher in the eastern than western Himalaya). In contrast, differential EVI is higher in the western Himalaya, increasing 170% from east to west. To evaluate the effect of vegetation on denudation and landscape evolution, we combine the 14-year EVI data, topographic analysis, and a compilation of >100 published and unpublished 10-Be terrestrial cosmogenic nuclide (TCN) catchment-mean denudation rates from across the Himalaya

  17. Reconciling disagreement over climate–conflict results in Africa

    PubMed Central

    Hsiang, Solomon M.; Meng, Kyle C.

    2014-01-01

    A recent study by Burke et al. [Burke M, Miguel E, Satyanath S, Dykema J, Lobell D (2009) Proc Natl Acad Sci USA 106(49):20670–20674] reports statistical evidence that the likelihood of civil wars in African countries was elevated in hotter years. A following study by Buhaug [Buhaug H (2010) Proc Natl Acad Sci USA 107(38):16477–16482] reports that a reexamination of the evidence overturns Burke et al.’s findings when alternative statistical models and alternative measures of conflict are used. We show that the conclusion by Buhaug is based on absent or incorrect statistical tests, both in model selection and in the comparison of results with Burke et al. When we implement the correct tests, we find there is no evidence presented in Buhaug that rejects the original results of Burke et al. PMID:24520173

  18. Submit and disulfide structure of monomeric and dimeric forms of detergent-soluble HLA antigens.

    PubMed

    Springer, T A; Robb, R J; Terhorst, C; Strominger, J L

    1977-07-10

    The structure of monomeric and disulfide-bonded dimeric forms of HLA antigens has been studied. Detergent-soluble HLA antigen heavy chains contain one or two easily reduced sulfhydryl groups not found in papain-solubilized HLA antigens, as demonstrated by amino acid analysis (Springer, T. A., and Strominger, J.L. (1976) Proc. Natl. Acad. Sci. U.S.A. 73, 2481-2485, and Terhorst, C., Parham, P., Mann, D.L., and Strominger, J.L. (1976) Proc. Natl. Acad. Sci. U.S.A. 73, 910-914) and by labeling with iodo[3H]acetate. Dimer formation occurred during purification, since it was prevented by pretreatment of membranes containing HLA antigen with iodoacetamide. Cross-linking studies showed that the non-disulfide-bonded form of HLA antigens contains one subunit each of the Mr = 44,000 heavy chain and the Mr = 12,000 light chain (beta2-microglobulin). PMID:873911

  19. The academician astronomers travelling in the 18th century.

    NASA Astrophysics Data System (ADS)

    Dumont, S.; Débarbat, S.

    1999-04-01

    In the 18th century, astronomers of the Académie des sciences of Paris made various contributions to the improvement of navigation: terrestrial determinations of longitude which improved charts for navigators, testing of marine clocks for longitude determinations at sea. In order to resolve the Cassini-Newton controversy regarding the shape of the Earth, the Académie proposed in 1735, that two expeditions should be made with a view to measuring a meridian arc. The results concluded that the Earth was flat on the sides of the poles, as predicted by Newton. By the mid-18th century, the first purely astronomical expedition (La Caille, Cap of Good Hope) led to the creation of an austral celestial map and new parallaxes. Later, Chappe d'Auteroche, Le Gentil and Pingré travelled to observe two transits of Venus over the Sun (1761, 1769) for the improvement of the solar parallax.

  20. Le Fevre [Le Fèvre; LeFebvre], Jean (1652-1706)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Born in Lisieux, France, became an associate of JEAN PICARD and PHILIPPE DE LA HIRE, became a member of the Académie des Sciences and worked on rather routine work calculating ephemeredes, and surveying. Le Fevre accused La Hire of stealing his tables after Philippe de La Hire published Tabulae Astronomicae in 1687. In 1701, resentful at not having been named official publisher of ephemerides to ...

  1. Supercompact cardinals, sets of reals, and weakly homogeneous trees.

    PubMed

    Woodin, W H

    1988-09-01

    It is shown that if there exists a supercompact cardinal then every set of reals, which is an element of L(R), is the projection of a weakly homogeneous tree. As a consequence of this theorem and recent work of Martin and Steel [Martin, D. A. & Steel, J. R. (1988) Proc. Natl. Acad. Sci. USA 85, 6582-6586], it follows that (if there is a supercompact cardinal) every set of reals in L(R) is determined. PMID:16593979

  2. Unobserved time effects confound the identification of climate change impacts.

    PubMed

    Auffhammer, Maximilian; Vincent, Jeffrey R

    2012-07-24

    A recent study by Feng et al. [Feng S, Krueger A, Oppenheimer M (2010) Proc Natl Acad Sci USA 107:14257-14262] in PNAS reported statistical evidence of a weather-driven causal effect of crop yields on human migration from Mexico to the United States. We show that this conclusion is based on a different statistical model than the one stated in the paper. When we correct for this mistake, there is no evidence of a causal link. PMID:22783021

  3. Memory neuron: synapse microchemistry for the memory component of a neuroconnective brain model.

    PubMed Central

    Wooldridge, D E

    1980-01-01

    This paper examines the synaptic microchemistry required if a memory neuron is to have the operating characteristics previously attributed to it [Wooldridge, D.E. (1980) Proc. Natl. Acad. Sci. USA, 77,2305-2308]. It is concluded that the requirements can be met by a combination of membrane mechanisms not very different from those that are commonly postulated to explain the properties of known types of neurons. PMID:6248883

  4. Selection-mutation process of RNA viruses

    NASA Astrophysics Data System (ADS)

    Aafif, Amal; Lin, Juan

    1998-02-01

    RNA viruses mutate at a rate 105-106 times faster than their DNA counterparts. This process can be simulated by a continuous stochastic model on a smooth one-dimensional fitness landscape where selection forces the viral quasispecies to climb uphill to higher fitness values. Theoretical results of the model with drift velocity proportional to fitness are fitted to the experimental observations made by Novella et al. [Proc. Natl. Acad. Sci. U.S.A. 92, 5841 (1995)].

  5. Life in a ligand sphere.

    PubMed Central

    Wächtershäuser, G

    1994-01-01

    The most fundamental divide in biology is that between heterotrophic and autotrophic ways of life. Two of the leading proponents of a heterotrophic origin of life ("hetero-origin") in a prebiotic broth, C. de Duve and S. L. Miller, have criticized my theory of a pyrite-pulled chemo-autotrophic origin of life ("auto-origin") [De Duve, C. & Miller, S. L. (1991) Proc. Natl. Acad. Sci. USA 88, 10014-10017]. This criticism is now answered. PMID:8183902

  6. Non-Existence of Global Solutions For a Quasilinear Benney System

    NASA Astrophysics Data System (ADS)

    Antontsev, S.; Dias, J. P.; Figueira, M.; Oliveira, F.

    2011-06-01

    Benney introduced in 1977 (cf. Stud Appl Math 56:81-94, 1977) a general strategy for deriving systems of nonlinear PDEs describing the interaction between long and short waves. In Dias et al. (CR Acad Sci Paris I 344:493-496, 2007) we have studied the local existence and unicity of solutions to a quasilinear version of these systems. In the present paper we prove that in some important cases global strong solutions do not exist.

  7. Network analysis of human heartbeat dynamics

    NASA Astrophysics Data System (ADS)

    Shao, Zhi-Gang

    2010-02-01

    We construct the complex networks of human heartbeat dynamics and investigate their statistical properties, using the visibility algorithm proposed by Lacasa and co-workers [Proc. Natl. Acad. Sci. U.S.A. 105, 4972 (2008)]. Our results show that the associated networks for the time series of heartbeat interval are always scale-free, high clustering, hierarchy, and assortative mixing. In particular, the assortative coefficient of associated networks could distinguish between healthy subjects and patients with congestive heart failure.

  8. Comment on "Nonparametric forecasting of low-dimensional dynamical systems ".

    PubMed

    Kondrashov, Dmitri; Chekroun, Mickaël D; Ghil, Michael

    2016-03-01

    The comparison performed in Berry et al. [Phys. Rev. E 91, 032915 (2015)] between the skill in predicting the El Niño-Southern Oscillation climate phenomenon by the prediction method of Berry et al. and the "past-noise" forecasting method of Chekroun et al. [Proc. Natl. Acad. Sci. USA 108, 11766 (2011)] is flawed. Three specific misunderstandings in Berry et al. are pointed out and corrected. PMID:27078490

  9. Structural Basis for Substrate Fatty Acyl Chain Specificity: Crystal Structure of Human Very-Long-Chain Acyl-CoA Dehydrogenase

    SciTech Connect

    McAndrew, Ryan P.; Wang, Yudong; Mohsen, Al-Walid; He, Miao; Vockley, Jerry; Kim, Jung-Ja P.

    2008-08-26

    Very-long-chain acyl-CoA dehydrogenase (VLCAD) is a member of the family of acyl-CoA dehydrogenases (ACADs). Unlike the other ACADs, which are soluble homotetramers, VLCAD is a homodimer associated with the mitochondrial membrane. VLCAD also possesses an additional 180 residues in the C terminus that are not present in the other ACADs. We have determined the crystal structure of VLCAD complexed with myristoyl-CoA, obtained by co-crystallization, to 1.91-{angstrom} resolution. The overall fold of the N-terminal {approx}400 residues of VLCAD is similar to that of the soluble ACADs including medium-chain acyl-CoA dehydrogenase (MCAD). The novel C-terminal domain forms an {alpha}-helical bundle that is positioned perpendicular to the two N-terminal helical domains. The fatty acyl moiety of the bound substrate/product is deeply imbedded inside the protein; however, the adenosine pyrophosphate portion of the C14-CoA ligand is disordered because of partial hydrolysis of the thioester bond and high mobility of the CoA moiety. The location of Glu-422 with respect to the C2-C3 of the bound ligand and FAD confirms Glu-422 to be the catalytic base. In MCAD, Gln-95 and Glu-99 form the base of the substrate binding cavity. In VLCAD, these residues are glycines (Gly-175 and Gly-178), allowing the binding channel to extend for an additional 12{angstrom} and permitting substrate acyl chain lengths as long as 24 carbons to bind. VLCAD deficiency is among the more common defects of mitochondrial {beta}-oxidation and, if left undiagnosed, can be fatal. This structure allows us to gain insight into how a variant VLCAD genotype results in a clinical phenotype.

  10. Monte Carlo simulation of NaI(TL) detector in a shadow-shield scanning bed whole-body monitor for uniform and axial cavity activity distribution in a BOMAB phantom.

    PubMed

    Akar, D K; Patni, H K; Nadar, M Y; Ghare, V P; Rao, D D

    2013-07-01

    This study presents the simulation results for 10.16 cm diameter and 7.62 cm thickness NaI(Tl) detector response, which is housed in a partially shielded scanning bed whole-body monitor (WBM), due to activity distributed in the axial cavities provided in the Indian reference BOMAB phantom. Experimental detection efficiency (DE) for axial cavity activity distribution (ACAD) in this phantom for photon emissions of (133)Ba, (137)Cs and (60)Co is used to validate DEs estimated using Monte Carlo code FLUKA. Simulations are also carried out to estimate DEs due to uniform activity distribution (UAD) as in the standard BOMAB phantom. The results show that the DE is ∼3.8 % higher for UAD when compared with ACAD in the case of (40)K (1460 keV) and this relative difference increases to ∼7.0 % for (133)Ba (∼356 keV) photons. The corresponding correction factors for calibration with Indian phantom are provided. DEs are also simulated for activity distributed as a planar disc at the centre of the axial cavity in each part of the BOMAB phantom (PDAD) and the deviations of these DEs are within 1 % of the ACAD results. Thus, PDAD can also be used for ACAD in scanning geometry. An analytical solution for transmitted mono-energetic photons from a two-dimensional slab is provided for qualitative explanation of difference in DEs due to variation in activity distributions in the phantom. The effect on DEs due to different phantom part dimensions is also studied and lower DEs are observed for larger parts. PMID:23390143

  11. Lalande, Joseph-Jérôme Lefrançais de (1732-1807)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Astronomer, born in Bourg-en-Bresse, France. In what was one of the first internationally coordinated scientific campaigns, to determine the Moon's parallax, he was sent in 1752 to Berlin by the French Académie des Sciences. Other astronomers took up positions at six other sites located on more or less the same meridian from Stockholm to the Cape (where Lalande's colleague LACAILLE was located). ...

  12. Weathering Rinds and Soil Development on Basaltic Andesite, Guadeloupe

    NASA Astrophysics Data System (ADS)

    Sak, P. B.; Murphy, M.; Ma, L.; Engel, J.; Pereyra, Y.; Gaillardet, J.; Brantley, S. L.

    2014-12-01

    An oriented clast of basaltic andesite collected from the B horizon of a soil developed in a late Quaternary volcanoclastic debris flow on the eastern, windward side of Basse Terre Island, Guadeloupe exhibits weathering patterns like that observed in many clasts from tropical settings. The sample consists of unweathered core material overlain by a ~19 mm thick weathering rind and a narrow ≤ 2mm thick indurated horizon separating the outer portion of the rind from the overlying >10mm of soil matrix material. Elemental variations are constrained by a seven point bulk ICP-AES vertical transect extending from the core, across the rind and ~15 mm into the overlying soil matix and six parallel electron microprobe transections. The porous-hydrated fraction increases from the core to the rind to the surrounding soil from 7±4% to 45±18% to 60±15%, respectively. Like the well-studied clast from the nearby Bras David watershed (Sak et al., 2010) the isovolumetric transformation from core to rind material is marked by a narrow (< 1500 mm) reaction front and elemental depletion. The hierarchy of elemental loss across the core-rind boundary as characterized by open system mass balances varies in order Ca≈Na>Ba>K≈Mn>Mg>Si>Al≈P>Fe»Ti, consistent with the relative reactivity of phases in the clast from plagioclasepyroxeneglass>apatite>ilmenite. Unlike previously studied clasts, the preservation of the rind-soil interface permits characterization of weathering reactions between the weathering clast and surrounding soil matrix. The abrupt (<1000 μm wide) reaction front at the rind-soil interface is marked by the enrichment of Mn, Ba, Al, Mg and K. The enrichment trends may result from soil waters percolating through atmospherically depositioned dust within the upper few meters of the soil profile, as documented in a deep soil profile in the Bras David watershed. The lack of an enrichment signal within the weathering rind suggests that weathering processes active within

  13. Clinical Indicators of Child Development in the Capitals of Nine Brazilian States: The Influence of Regional Cultural Factors

    PubMed Central

    de Carvalho, André Laranjeira; da Silva, Luiz Fernando Ferraz; Grisi, Sandra Josefina Ferraz Ellero; de Ulhôa Escobar, Ana Maria

    2008-01-01

    OBJECTIVE Evaluating the interaction between mother or caregiver and infant through the Clinical Indicators of Risks in Infant Development and investigating whether local and cultural influences during infant development affect these clinical indicators. INTRODUCTION The Clinical Indicators of Risks in Infant Development was created in order to fully assess infants’ development and the subjective relationship between the babies and their caregivers. The absence of two or more Clinical Indicators of Risks in Infant Developments suggests a possibly inadequate mental development. Given the continental size of Brazil and its accentuated cultural differences, one might question how trustworthy these indicators can be when applied to each of the geographical regions of the country. METHODS This was a cross-sectional study with 737 infants from the capitals of 9 Brazilian states. The size of the initial sample population was based on a pilot study carried out in the cities of São Paulo and Brasília. The ages of children were grouped: 0–3 months, 4–7 months, 8–11 months and 12–18 months. The chi-square test was used together with analyses by the statistical software SPSS 13.0. RESULTS Statistical analysis of results from the different municipalities against the total sample did not reveal any statistically significant differences. Municipalities represented were Belém (p=0.486), Brasília (p=0.371), Porto Alegre (p=0.987), Fortaleza (p=0.259), Recife (p=0.630), Salvador (0.370), São Paulo (p=0.238), Curitiba (p=0.870), and Rio de Janeiro (p= 0.06). DISCUSSION Care for mental development should be considered a public health issue. Its evaluation and follow-up should be part of the already available mother-child assistance programs, which would then be considered to provide “full” care to children. CONCLUSIONS Local habits and culture did not affect the results of the Clinical Indicators of Risks in Infant Development indicators. Clinical Indicators of

  14. An alternative technique for the computation of the designator in the retinex theory of color vision.

    PubMed

    Land, E H

    1986-05-01

    Accepting the first postulate of the retinex theory of color vision that there are three independent lightness-determining mechanisms (one for long waves, one for middle waves, and one for short waves), each operative with less than a millisecond exposure and each served by its own retinal pigment, a basic task of retinex theory becomes the determination of the nature of these mechanisms. Earlier references proposed several workable algorithms. [Land, E. H. (1959) Proc. Natl. Acad. Sci. USA 45, 115-129; Land, E. H. (1959) Proc. Natl. Acad. Sci. USA 45, 636-644; Land, E. H. (1983) Proc. Natl. Acad. Sci. USA 80, 5163-5169; Land, E. H. & McCann, J. J. (1971) J. Opt. Soc. Am. 61, 1-11; Land, E. H. (1986) Vision Res. 26, 7-21.] The present paper describes a relatively simple alternative technique for the computation of the designator in retinex theory and reports the general operational effectiveness of the new technique, including the competence, not possessed by earlier algorithms, for generating Mach bands. PMID:3458165

  15. Community detection algorithms: A comparative analysis

    NASA Astrophysics Data System (ADS)

    Lancichinetti, Andrea; Fortunato, Santo

    2009-11-01

    Uncovering the community structure exhibited by real networks is a crucial step toward an understanding of complex systems that goes beyond the local organization of their constituents. Many algorithms have been proposed so far, but none of them has been subjected to strict tests to evaluate their performance. Most of the sporadic tests performed so far involved small networks with known community structure and/or artificial graphs with a simplified structure, which is very uncommon in real systems. Here we test several methods against a recently introduced class of benchmark graphs, with heterogeneous distributions of degree and community size. The methods are also tested against the benchmark by Girvan and Newman [Proc. Natl. Acad. Sci. U.S.A. 99, 7821 (2002)] and on random graphs. As a result of our analysis, three recent algorithms introduced by Rosvall and Bergstrom [Proc. Natl. Acad. Sci. U.S.A. 104, 7327 (2007); Proc. Natl. Acad. Sci. U.S.A. 105, 1118 (2008)], Blondel [J. Stat. Mech.: Theory Exp. (2008), P10008], and Ronhovde and Nussinov [Phys. Rev. E 80, 016109 (2009)] have an excellent performance, with the additional advantage of low computational complexity, which enables one to analyze large systems.

  16. Electrochemical Characterization of Escherichia coli Adaptive Response Protein AidB

    PubMed Central

    Hamill, Michael J.; Jost, Marco; Wong, Cintyu; Bene, Nicholas C.; Drennan, Catherine L.; Elliott, Sean J.

    2012-01-01

    When exposed to known DNA-damaging alkylating agents, Escherichia coli cells increase production of four DNA repair enzymes: Ada, AlkA, AlkB, and AidB. The role of three enzymes (Ada, AlkA, and AlkB) in repairing DNA lesions has been well characterized, while the function of AidB is poorly understood. AidB has a distinct cofactor that is potentially related to the elusive role of AidB in adaptive response: a redox active flavin adenine dinucleotide (FAD). In this study, we report the thermodynamic redox properties of the AidB flavin for the first time, both for free protein and in the presence of potential substrates. We find that the midpoint reduction potential of the AidB flavin is within a biologically relevant window for redox chemistry at −181 mV, that AidB significantly stabilizes the flavin semiquinone, and that small molecule binding perturbs the observed reduction potential. Our electrochemical results combined with structural analysis allow for fresh comparisons between AidB and the homologous acyl-coenzyme A dehydrogenase (ACAD) family of enzymes. AidB exhibits several discrepancies from ACADs that suggest a novel catalytic mechanism distinct from that of the ACAD family enzymes. PMID:23443126

  17. High-contrast imaging with an arbitrary aperture: Active compensation of aperture discontinuities

    SciTech Connect

    Pueyo, Laurent; Norman, Colin

    2013-06-01

    We present a new method to achieve high-contrast images using segmented and/or on-axis telescopes. Our approach relies on using two sequential deformable mirrors (DMs) to compensate for the large amplitude excursions in the telescope aperture due to secondary support structures and/or segment gaps. In this configuration the parameter landscape of DM surfaces that yield high-contrast point-spread functions is not linear, and nonlinear methods are needed to find the true minimum in the optimization topology. We solve the highly nonlinear Monge-Ampere equation that is the fundamental equation describing the physics of phase-induced amplitude modulation. We determine the optimum configuration for our two sequential DM system and show that high-throughput and high-contrast solutions can be achieved using realistic surface deformations that are accessible using existing technologies. We name this process Active Compensation of Aperture Discontinuities (ACAD). We show that for geometries similar to the James Webb Space Telescope, ACAD can attain at least 10{sup –7} in contrast and an order of magnitude higher for both the future extremely large telescopes and on-axis architectures reminiscent of the Hubble Space Telescope. We show that the converging nonlinear mappings resulting from our DM shapes actually damp near-field diffraction artifacts in the vicinity of the discontinuities. Thus, ACAD actually lowers the chromatic ringing due to diffraction by segment gaps and struts while not amplifying the diffraction at the aperture edges beyond the Fresnel regime. This outer Fresnel ringing can be mitigated by properly designing the optical system. Consequently, ACAD is a true broadband solution to the problem of high-contrast imaging with segmented and/or on-axis apertures. We finally show that once the nonlinear solution is found, fine tuning with linear methods used in wavefront control can be applied to further contrast by another order of magnitude. Generally speaking

  18. Infrared Laser Stark Spectroscopy of the OH\\cdot\\cdot\\cdotCH3OH Complex Isolated in Superfluid Helium Droplets

    NASA Astrophysics Data System (ADS)

    Leavitt, Christopher M.; Brice, Joseph T.; Douberly, Gary E.; Hernandez, Federico J.; Pino, Gustavo A.

    2015-06-01

    The elimination of volatile organic compounds (VOCs) from the atmosphere is initiated by reactions with OH, NO3 and O3. For oxygenated VOCs, such as alcohols, ketones, ethers, etc., reactions occur nearly exclusively with the hydroxyl radical. Furthermore, the potential energy surfaces associated with reactions between OH and oxygenated VOCs generally feature a pre-reactive complex, stabilized by hydrogen bonding, which results in rate constants that exhibit large negative temperature dependencies. This was explicitly demonstrated recently for the OH + methanol (MeOH) reaction, where the rate constant increased by nearly two orders of magnitude when the temperature decreased from 200 K to below 70 K, highlighting the potential impact of this reaction in the interstellar medium (ISM). In this study, we trap this postulated pre-reactive complex formed between OH and MeOH using He nanodroplet isolation (HENDI) techniques, and probe this species using a combination of mass spectrometry and infrared laser Stark spectroscopy. Atkinson, R.; Arey, J., Chem. Rev. 2003, 103, 4605-4638. Mellouki, A.; Le Bras, G.; Sidebottom, H., Chem. Rev. 2003, 103, 5077-5096. Smith, I. W. M.; Ravishankara, A. R., J. Phys. Chem. A 2002, 106, 4798-4807 Shannon, R. J.; Blitz, M. A.; Goddard, A.; Heard, D. E., Nat. Chem. 2013, 5, 745-749. Martin, J. C. G.; Caravan, R. L.; Blitz, M. A.; Heard, D. E.; Plane, J. M. C., J. Phys. Chem. A 2014, 118, 2693-2701.

  19. A case of swyer syndrome associated with advanced gonadal dysgerminoma involving long survival.

    PubMed

    Da Silva Rios, Salete; Monteiro, Isabella Christina Mazzaro; Braz Dos Santos, Larissa Gonçalves; Caldas, Natasha Garcia; Chen, Ana Carolina Rios; Chen, Juliana Rios; Silva, Helena Spindola Camargo

    2015-01-01

    Swyer syndrome is caused by abnormal sex differentiation during the embryonic period, resulting in incomplete intrauterine masculinization and undifferentiated gonads. The current case report describes a patient with Swyer syndrome associated with stage 3 gonadal dysgerminoma who has survived for 23 years. At age 18, this patient sought assistance for primary amenorrhea from the Gynecological Services Department of the University of Brasília Hospital. A physical examination revealed that the patient was at Tanner stage 4 with respect to axillary hair, breasts, and pubic hair; she presented with a eutrophic vagina and a small cervix. She was treated with a combination of estrogens and progestogens to induce cycling. Approximately 4 years later, a complex tumor was found and resected; a histopathological analysis revealed that this tumor was a right adnexal dysgerminoma with peritoneal affection. The patient was also subjected to chemotherapy. Her follow-up has continued to the present time, with no signs of tumor recurrence. In conclusion, this report describes an extremely rare case in which Swyer syndrome was associated with ovarian dysgerminoma; relative to similar patients, the described patient has survived for an unusually prolonged time. PMID:25960730

  20. [Genetic variability of the Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae) in vegetable crops in São Luís, state of Maranhão, Brazil].

    PubMed

    Da Silva, Maria C; De Lemos, Raimunda N S; Lima, Luzia H C; Gourlart Filho, Luiz R; Pereira, Silma R F

    2009-01-01

    The RAPD technique is widely used to investigate the distinct genetic characteristics of the complex Bemisia tabaci (Gennadius), which is currently constituted of approximately 41 biotypes. The objective of this research was to characterize populations of whitefly collected in crops of agricultural producing areas in São Luís, MA, like okra, beans and pepper, using RAPD molecular markers. Females from nine whitefly populations were analyzed and compared with B. tabaci biotype B taken from poinsettia culture of Embrapa Genetic Resources and Biotechnology (Brasília, DF). Twelve out of the 20 primers tested produced specific band patterns suitable to confirm that the evaluated specimens belong to the biotype B of B. tabaci, despite the high percentage of detected polymorphism. The analysis of the 96 RAPD molecular markers generated indicated that the populations on okra, beans and pepper were grouped according to the host cultures, sharing 80, 76 and 45% of genetic similarity, respectively, when compared with the control population of B. tabaci biotype B. A lower selective pressure was observed with the population of whitefly collected on pepper and minor genetic variability in the whitefly populations collected on okra and bean, when compared with the control population. PMID:20098922

  1. Biting behaviour and potential vector status of anthropophilic blackflies in a new focus of human onchocerciasis at Minaçu, central Brazil.

    PubMed

    Shelley, A J; Maia-Herzog, M; Dias, A P; Camargo, M; Costa, E G; Garritano, P; Lowry, C A

    2001-03-01

    Monthly collections were made of man-biting female blackflies: Simulium auripellitum Enderlein, S. guianense Wise, S. minusculum Lutz and S. nigrimanum Macquart (Diptera: Simuliidae) from four catching stations in the newly discovered focus of human onchocerciasis at Minaçu (13 degrees 35 minutes S 48 degrees 18 minutes W), 300 km north of Brasília in Goiás State. These provided baseline data on biting habits, population density and seasonal prevalence during the year before completion of the Serra da Mesa hydroelectric dam on the Rio Tocantins near Minaçu, in a project investigating the effect of dam construction on onchocerciasis transmission in the area. All four simuliid species were most abundant during the dry season, and only bit in low numbers (S. auripellitum S. minusculum, S. nigrimanum) or were absent (S. guianense) in the wet season. Simulium minusculum was the predominant species at all catching stations, being particularly abundant by the large River Tocantins. The other three species were mainly associated with smaller rivers. In the dry season, biting rhythms of S. minusculum varied with catching site, while S. nigrimanum showed peaks of activity in early morning and during the afternoon. Experimental infection with Onchocerca volvulus (Leuckart) (Nematoda: Onchocercidae), from a human volunteer, showed that this parasite could develop fully in the four simuliid species, which are all considered to be potential vectors in the area. PMID:11297099

  2. Economical, simple method for production of the gaseous environment required for cultivation of Campylobacter jejuni.

    PubMed Central

    Pennie, R A; Zunino, J N; Rose, C E; Guerrant, R L

    1984-01-01

    Campylobacter jejuni is an enteric pathogen recognized worldwide as a cause of diarrhea. Its isolation from stool samples requires a microaerophilic environment that heretofore has been expensive and cumbersome to create. An economical, portable, and simple method is described which involves the production of appropriate concentrations of oxygen and carbon dioxide. Inside a plastic bag are placed two cups, one containing fine steel wool (grade 0) previously soaked in a 2.5% aqueous solution of copper sulfate and the other containing an Alka-Seltzer tablet in tap water. As suggested by Jurgensen et al. (Rev. Bras. Pat. Clin. 18:58-63, 1982), we used the effervescent antacid to generate CO2. By plate counts, we found this method to be as reliable in the cultivation of 20 isolates of C. jejuni in pure and mixed fecal culture as the reference gas method (85% N2, 10% CO2, and 5% O2). Analyses of the gas mixture inside the bag after up to 24 h of incubation confirmed the creation of an atmosphere of reduced O2 and increased CO2 concentrations. This method is eminently suitable for field situations in which more costly supplies are not available. PMID:6436301

  3. Economical, simple method for production of the gaseous environment required for cultivation of Campylobacter jejuni.

    PubMed

    Pennie, R A; Zunino, J N; Rose, C E; Guerrant, R L

    1984-09-01

    Campylobacter jejuni is an enteric pathogen recognized worldwide as a cause of diarrhea. Its isolation from stool samples requires a microaerophilic environment that heretofore has been expensive and cumbersome to create. An economical, portable, and simple method is described which involves the production of appropriate concentrations of oxygen and carbon dioxide. Inside a plastic bag are placed two cups, one containing fine steel wool (grade 0) previously soaked in a 2.5% aqueous solution of copper sulfate and the other containing an Alka-Seltzer tablet in tap water. As suggested by Jurgensen et al. (Rev. Bras. Pat. Clin. 18:58-63, 1982), we used the effervescent antacid to generate CO2. By plate counts, we found this method to be as reliable in the cultivation of 20 isolates of C. jejuni in pure and mixed fecal culture as the reference gas method (85% N2, 10% CO2, and 5% O2). Analyses of the gas mixture inside the bag after up to 24 h of incubation confirmed the creation of an atmosphere of reduced O2 and increased CO2 concentrations. This method is eminently suitable for field situations in which more costly supplies are not available. PMID:6436301

  4. Acrocomia emensis (Arecaceae) genetic structure and diversity using SSR molecular markers.

    PubMed

    Neiva, D S; Melo Júnior, A F; Oliveira, D A; Royo, V A; Brandão, M M; Menezes, E V

    2016-01-01

    Acrocomia emensis, popularly known as the creeping tucum, belongs to the family Arecaceae, and is an oilseed specie of the Brazilian Savannah. The expansion of agricultural activity has rapidly destroyed its natural habitat, leading to a decrease in its population size. Genetic studies can be used to investigate the genetic variability, and may assist with the charting future conservation strategies. In this study the genetic diversity and structure of 150 individuals sampled in three locations in Minas Gerais were analysed, based on the transferability of six microsatellite markers, previously developed for A. aculeata. The results indicate that the populations studied have low levels of genetic variability (Ho = 0.148) and high, positive and significant inbreeding coefficient, indicating an excess of homozygotes. The average heterozygosity within the population (Hs = 0.700) accounted for 95.03% of the total genetic diversity, indicating that there is greater variability within population than between them, consistent with low genetic differentiation between population (GST = 0.046). Bayesian analysis identified three distinct groups; however, populations shared large numbers of alleles, which can be explained by the reduced distance between populations. These results reveal the need to implement genetic conservation programs for the maintenance of this species and to prioritize population from Bonito and Brasília, which showed the lowest values of genetic diversity. PMID:27050985

  5. [Self-medication: a qualitative approach of its motivations].

    PubMed

    Naves, Janeth de Oliveira Silva; Castro, Lia Lusitana Cardozo de; Carvalho, Christine Maria Soares de; Merchán-Hamann, Edgar

    2010-06-01

    A qualitative research was realized to verify the occurrence and motivations for self-medication and the quality of the information rendered by pharmacies. We conducted 3 focus groups with 25 patients of a reference public health service for STD treatment in Brasília, Brazil. We used the critical discourse analysis to interpret the data obtained during interviews. The analysis revealed that self-medication was a common practice among participants, motivated mainly by discontentment with the long waiting period and the quality of the public health services. Other motivations included: previous experience with medications, advice from friends and family members and the search for an anonymous service provided at pharmacies due to embarrassment and inadequate care environment at health care services. Care provided at pharmacies was also considered unsatisfactory. Viewed essentially as a commercial establishment, pharmacies have become, yet, an easy accessible alternative. Most of participants perceived the pharmacists as ordinary employees seeking only to increase profits. The results suggest a need to improve access to health care services, as well as to render it more humane. Community pharmacies should to be turned into health establishments to participate in health education and orientation for rational drugs use. PMID:20640337

  6. The length of the dry season may be associated with leaf scleromorphism in cerrado plants.

    PubMed

    Souza, Marcelo C; Franco, Augusto C; Haridasan, Mundayatan; Rossatto, Davi R; de Araújo, Janaína F; Morellato, Leonor P C; Habermann, Gustavo

    2015-09-01

    Despite limitations of low fertility and high acidity of the soils, the cerrado flora is the richest amongst savannas. Many cerrado woody species show sclerophyllous leaves, which might be related to the availability of water and nutrients in the soil. To better understand the function and structure of cerrado vegetation within its own variations, we compared two cerrado communities: one in its core region in central Brazil (Brasília, DF) and the other on its southern periphery (Itirapina, SP). We contrasted the length of the dry season, soil fertility rates, leaf concentrations of N, P, K, Ca and Mg and the specific leaf area (SLA) between these communities. The dry season was shorter on the periphery, where the soil was more fertile although more acidic. Plants from the periphery showed higher SLA and higher leaf concentrations of N, P, Ca and Mg. We propose that the higher SLA of plants from the periphery is related to the shorter dry season, which allows better conditions for nutrient uptake. PMID:26221991

  7. Genetic variability of Mahanarva sp (Hemiptera: Cercopidae) collected from different sites in Brazil.

    PubMed

    Auad, A M; Domingues, R; Machado, M A; Souza, L S; Carvalho, G S; Paula-Moraes, S V

    2010-01-01

    Spittlebugs are the leading cause of damage to tall grasses. Annual losses are estimated to reach 2.1 billion dollars in sugarcane crops and grazing land throughout the world. Correct identification of these species is difficult due to similarities in color, body size and male genitalia. Molecular markers have been useful in the identification and assessment of genetic diversity of many species. We investigated the genetic diversity of the spittlebug species Mahanarva fimbriolata, M. spectabilis and M. liturata and looked for markers that could aid in their identification. DNA from 34 spittlebug specimens, collected from six different regions of Brazil (Brasília, Campo Grande, Valença, Presidente Prudente, Juiz de Fora, and Porto Alegre), was analyzed with 29 RAPD primers, generating 501 polymorphic markers. High genetic variability was found among individuals M. fimbriolata (0.37), M. spectabilis (0.18) and M. liturata (0.69). Species-specific molecular RAPD markers were identified for each of the three species; these could be used as auxiliary tools for their correct identification. PMID:20533195

  8. Breast Support Garments are Ineffective at Reducing Breast Motion During an Aqua Aerobics Jumping Exercise

    PubMed Central

    Mills, Chris; Ayres, Bessie; Scurr, Joanna

    2015-01-01

    The buoyant forces of water during aquatic exercise may provide a form of ‘natural’ breast support and help to minimise breast motion and alleviate exercise induced breast pain. Six larger-breasted females performed standing vertical land and water-based jumps, whilst wearing three breast support conditions. Underwater video cameras recorded the motion of the trunk and right breast. Trunk and relative breast kinematics were calculated as well as exercised induced breast pain scores. Key results showed that the swimsuit and sports bra were able to significantly reduce the superioinferior breast range of motion by 0.04 and 0.05 m, respectively, and peak velocity by 0.23 and 0.33 m/s, respectively, during land-based jumping when compared to the bare-breasted condition, but were ineffective at reducing breast kinematics during water-based jumping. Furthermore, the magnitude of the swimsuit superioinferior breast range of motion during water-based jumping was significantly greater than land-based jumping (0.13 m and 0.06 m), yet there were no significant differences in exercise induced breast pain, thus contradicting previously published relationships between these parameters on land. Furthermore, the addition of an external breast support garment was able to reduce breast kinematics on land but not in water, suggesting the swimsuit and sports bras were ineffective and improvements in swimwear breast support garments may help to reduce excessive breast motion during aqua aerobic jumping exercises. PMID:26240648

  9. Investigation of the active site and the conformational stability of nucleoside diphosphate kinase by site-directed mutagenesis.

    PubMed

    Tepper, A D; Dammann, H; Bominaar, A A; Véron, M

    1994-12-23

    Nucleoside-diphosphate kinase (EC 2.7.4.6) catalyzes phosphate exchange between nucleoside triphosphates and nucleoside diphosphates. Its 17 kDa subunits are highly conserved throughout evolution in both sequence and tertiary structure. Using site-directed mutagenesis we investigated the function of 8 amino acids (Lys16, Tyr56, Arg92, Thr98, Arg109, Asn119, Ser124, and Glu133) that are totally conserved among all nucleoside diphosphate kinases known to date. The mutant proteins all show decreased specific activity and support roles for these residues in catalysis, substrate binding, or both, as was previously proposed on the basis of the x-ray structure (Moréra, S., Lascu, I., Dumas, C., LeBras, G., Briozzo, P., Véron, M., and Janin, J. (1994) Biochemistry 33, 459-467). Furthermore, residues Lys16, Arg109, and Asn 119 were identified to play important roles in conformational stability or subunit interactions. We show that Lys16 and Asn119 form a rigid structure that is important for enzymatic function and that Arg109, known to interact with the phosphate moiety of the substrate, also plays an important role in subunit association. The dual roles of Lys16, Arg109, and Asn119 in both substrate binding and subunit assembly provide further evidence for a functional coupling between catalytic activity and quaternary structure in nucleoside diphosphate kinase. PMID:7798215

  10. Le syndrome de Stewart-Treves compliquant un lymphœdème chronique idiopathique

    PubMed Central

    Safini, Fatima; Naim, Asmaa; Bouchbika, Zineb; Benchakroun, Nadia; Jouhadi, Hassan; Tawfiq, Nezha; Sahraoui, Souha; Benider, Abdellatif

    2014-01-01

    Le syndrome de Stewart-Treves (SST) est une entité rare, correspondant à un angiosarcome cutané compliquant un lymphoedème chronique. Il est de mauvais pronostic. Stewart et Treves ont rapportés en 1948, les premiers cas d'angiosarcome secondaire à un traitement du cancer du sein. Ce terme s'est généralisé pour regrouper l'ensemble des cas de lymphangiosarcome sur lymphoedème d'origine congénital héréditaire ou non héréditaire, post-traumatique ou post-infectieux. Le SST sur un lymphoedème idiopathique reste exceptionnel. Nous rapportons le cas rare d'une patiente présentant un lymphoedème chronique primitif idiopathique des quatre membres évoluant depuis l'adolescence et qui a développé un SST du membre supérieur droit. Elle a subi une amputation à mi- bras vu le caractère très évolué de la tumeur PMID:25883738

  11. Are opossums a relevant factor associated with asymptomatic Leishmania infection in the outskirts of the largest Brazilian cities?

    PubMed

    Carranza-Tamayo, César Omar; Werneck, Guilherme Loureiro; Romero, Gustavo Adolfo Sierra

    2016-01-01

    A population survey was conducted to explore the prevalence and factors associated with Leishmania infection in the Fercal region of the Federal District. The Fercal region is a group of neighborhoods in Brasília in which the first cases of visceral leishmaniasis were described. Leishmania infection was established by a positive leishmanin test. Although other tests were performed in the study (an immunochromatographic assay (Kalazar detect(®)) and a molecular assay), only the leishmanin skin test provided sufficient results for the measurement of the disease prevalence. Data on the epidemiological, clinical and environmental characteristics of individuals were collected along with the diagnostic tests. After sampling and enrollment, seven hundred people from 2 to 14 years of age were included in the study. The prevalence of Leishmania infection was 33.28% (95% CI 29.87-36.84). The factors associated with Leishmania infection according to the multivariate analysis were age of more than seven years and the presence of opossums near the home. Age is a known factor associated with Leishmania infection; however, the presence of wild animals, as described, is an understudied factor. The presence of opossums, which are known reservoirs of Leishmania, in peri-urban areas could be the link between the rural and urban occurrence of visceral leishmaniasis in the outskirts of largest Brazilian cities, as suggested by previous studies. PMID:26867473

  12. The influence of breast support on torso, pelvis and arm kinematics during a five kilometer treadmill run.

    PubMed

    Milligan, Alexandra; Mills, Chris; Corbett, Jo; Scurr, Joanna

    2015-08-01

    Many women wear sports bras due to positive benefits associated with these garments (i.e. reduction in breast movement and breast pain), however the effects these garments have on upper body running kinematics has not been investigated. Ten female participants (32 DD or 34 D) completed two five kilometer treadmill runs (9 km h(-1)), once in a low and once in a high breast support. The range of motion (ROM) and peak torso, pelvis, and upper arm Cardan joint angles were calculated over five gait cycles during a five kilometer run. Peak torso yaw, peak rotation of the pelvis, peak pelvis obliquity, ROM in rotation of the pelvis, and ROM in upper arm extension were significant, but marginally reduced when participants ran in the high breast support. The running kinematics reported in the high breast support condition more closely align with economical running kinematics previously defined in the literature, therefore, running in a high breast support may be more beneficial to female runners, with a high breast support advocated for middle distance runners. PMID:26079773

  13. On the Use of Dance as a Rehabilitation Approach for Children with Cerebral Palsy: A Single Case Study.

    PubMed

    Morán Pascual, Patricia; Mortes Roselló, Esther; Domingo Jacinto, Amparo; Belda Lois, Juan Manuel; Bermejo, Ignacio; Medina, Enric; Barberà Guillem, Ricard

    2015-01-01

    Cerebral Palsy (CP) is the most common motor disability in childhood. It is a group of permanent disorders that affect child development causing disorders of movement and posture and activity limitations. The impairment of psychomotor skills of children with Cerebral Palsy is attributed to a permanent alteration occurred in non-progressive brain development of the fetus or nursing infant. Some motor related symptoms can be treated using proper physical therapy. However, one of the biggest problems of the usual physical therapy is adherence to therapy. Ballet can be an alternative or a complement to physiotherapy, with the added attraction of not being part of a to therapy, but a fun activity with the extra reward associated with the realization of an artistic activity. For some years the ballet is used as therapeutically valuable for both children with cerebral palsy: Intensive ballet training can generate changes in the sensorimotor cortex. Ballet is characterized by a complex process of movements that have to be in a musical rhythm (hence have to be precise), in which there is an overall coordination of the muscles. It is also a highly motivating and rewarding activity that allows many children with CP sharing the activities of their peers without special needs. Objective measurements of the Full Port de Bras movement has been chosen as an index of improvement. The results shows progressive improvements of the execution in a single case. PMID:26294586

  14. Grid digital elevation model based algorithms for determination of hillslope width functions through flow distance transforms

    NASA Astrophysics Data System (ADS)

    Liu, Jintao; Chen, Xi; Zhang, Xingnan; Hoagland, Kyle D.

    2012-04-01

    Recently developed hillslope storage dynamics theory can represent the essential physical behavior of a natural system by accounting explicitly for the plan shape of a hillslope in an elegant and simple way. As a result, this theory is promising for improving catchment-scale hydrologic modeling. In this study, grid digital elevation model (DEM) based algorithms for determination of hillslope geometric characteristics (e.g., hillslope units and width functions in hillslope storage dynamics models) are presented. This study further develops a method for hillslope partitioning, established by Fan and Bras (1998), by applying it on a grid network. On the basis of hillslope unit derivation, a flow distance transforms method (TD∞) is suggested in order to decrease the systematic error of grid DEM-based flow distance calculation caused by flow direction approximation to streamlines. Hillslope width transfer functions are then derived to convert the probability density functions of flow distance into hillslope width functions. These algorithms are applied and evaluated on five abstract hillslopes, and detailed tests and analyses are carried out by comparing the derivation results with theoretical width functions. The results demonstrate that the TD∞ improves estimations of the flow distance and thus hillslope width function. As the proposed procedures are further applied in a natural catchment, we find that the natural hillslope width function can be well fitted by the Gaussian function. This finding is very important for applying the newly developed hillslope storage dynamics models in a real catchment.

  15. Particle-in-cell simulations of Hall plasma thrusters

    NASA Astrophysics Data System (ADS)

    Miranda, Rodrigo; Ferreira, Jose Leonardo; Martins, Alexandre

    2016-07-01

    Hall plasma thrusters can be modelled using particle-in-cell (PIC) simulations. In these simulations, the plasma is described by a set of equations which represent a coupled system of charged particles and electromagnetic fields. The fields are computed using a spatial grid (i.e., a discretization in space), whereas the particles can move continuously in space. Briefly, the particle and fields dynamics are computed as follows. First, forces due to electric and magnetic fields are employed to calculate the velocities and positions of particles. Next, the velocities and positions of particles are used to compute the charge and current densities at discrete positions in space. Finally, these densities are used to solve the electromagnetic field equations in the grid, which are interpolated at the position of the particles to obtain the acting forces, and restart this cycle. We will present numerical simulations using software for PIC simulations to study turbulence, wave and instabilities that arise in Hall plasma thrusters. We have sucessfully reproduced a numerical simulation of a SPT-100 Hall thruster using a two-dimensional (2D) model. In addition, we are developing a 2D model of a cylindrical Hall thruster. The results of these simulations will contribute to improve the performance of plasma thrusters to be used in Cubesats satellites currenty in development at the Plasma Laboratory at University of Brasília.

  16. 3-D breast anthropometry of plus-sized women in South Africa.

    PubMed

    Pandarum, Reena; Yu, Winnie; Hunter, Lawrance

    2011-09-01

    Exploratory retail studies in South Africa indicate that plus-sized women experience problems and dissatisfaction with poorly fitting bras. The lack of 3-D anthropometric studies for the plus-size women's bra market initiated this research. 3-D body torso measurements were collected from a convenience sample of 176 plus-sized women in South Africa. 3-D breast measurements extracted from the TC(2) NX12-3-D body scanner 'breast module' software were compared with traditional tape measurements. Regression equations show that the two methods of measurement were highly correlated although, on average, the bra cup size determining factor 'bust minus underbust' obtained from the 3-D method is approximately 11% smaller than that of the manual method. It was concluded that the total bust volume correlated with the quadrant volume (r = 0.81), cup length, bust length and bust prominence, should be selected as the overall measure of bust size and not the traditional bust girth and the underbust measurement. STATEMENT OF RELEVANCE: This study contributes new data and adds to the knowledge base of anthropometry and consumer ergonomics on bra fit and support, published in this, the Ergonomics Journal, by Chen et al. (2010) on bra fit and White et al. (2009) on breast support during overground running. PMID:21846287

  17. Aspects of Quantum Theory

    NASA Astrophysics Data System (ADS)

    Salam, Abdus; Wigner, E. P.

    2010-03-01

    Preface; List of contributors; Bibliography of P. A. M. Dirac; 1. Dirac in Cambridge R. J. Eden and J. C. Polkinghorne; 2. Travels with Dirac in the Rockies J. H. Van Vleck; 3. 'The golden age of theoretical physics': P. A. M. Dirac's scientific work from 1924 to 1933 Jagdish Mehra; 4. Foundation of quantum field theory Res Jost; 5. The early history of the theory of electron: 1897-1947 A. Pais; 6. The Dirac equation A. S. Wightman; 7. Fermi-Dirac statistics Rudolph Peierls; 8. Indefinite metric in state space W. Heisenberg; 9. On bras and kets J. M. Jauch; 10. The Poisson bracket C. Lanczos; 11. La 'fonction' et les noyaux L. Schwartz; 12. On the Dirac magnetic poles Edoardo Amadli and Nicola Cabibbo; 13. The fundamental constants and their time variation Freeman J. Dyson; 14. On the time-energy uncertainty relation Eugene P. Wigner; 15. The path-integral quantisation of gravity Abdus Salam and J. Strathdee; Index; Plates.

  18. Apomixis in cassava: advances and challenges.

    PubMed

    Freitas, D Y H; Nassar, N M A

    2013-01-01

    Cassava is the most important staple crop in the Tropics and Subtropics. Apomixis may revolutionize its production due to various attributes. These potential advantages include production by true seed, maintaining cultivar superiority over generations without segregation, and avoiding contamination by bacteria and viruses. Historically, apomixis was initially observed by International Institute of Tropical Agriculture researchers, in the 1980s, in homogenous progeny of hybrid crosses. Later, from 1980 through 2010, apomixis was extensively studied by Universidade de Brasília, in order to determine contributing mechanisms and occurrence. Apomixis genes occur naturally at low frequencies in cultivated cassava and can be transferred by crosses with wild species. Apparently, apomixis in cassava is controlled by more than one recessive gene, which act in an additive form. Aneuploidy is associated with apomixis in cassava and can provide the double dosages necessary for recessive gene action. By using molecular techniques, genetic homogeneous progeny has been demonstrated, while embryonic exams have shown nucellar multiembryos. Polyploidy was found to increase apomixis percentage. From an evolutionary viewpoint, polyploidy has contributed to production of new species, when combined with apomixis. Recently, somatic embryos have been detected in the integument, revealing a rare model of apomixis that has only been documented in cassava. PMID:23613244

  19. Biomedical Use of Aerospace Personal Cooling Garments

    NASA Technical Reports Server (NTRS)

    Webbon, Bruce W.; Montgomery, Leslie D.; Callaway, Robert K.

    1994-01-01

    Personal thermoregulatory systems are required during extravehicular activity (EVA) to remove the metabolic heat generated by the suited astronaut. The Extravehicular and Protective Systems (STE) Branch of NASA Ames Research Center has developed advanced concepts or liquid cooling garments for both industrial and biomedical applications for the past 25 years. Examples of this work include: (1) liquid cooled helmets for helicopter pilots and race car drivers; (2) vests for fire and mine rescue personnel; (3) bras to increase the definition of tumors during thermography; (4) lower body garments for young women with erythomelaigia; and (5) whole body garments used by patients with multiple sclerosis (MS). The benefits of the biomedical application of artificial thermoregulation received national attention through two recent events: (1) the liquid-cooled garment technology was inducted into the United States Space Foundation's Space Technology Hall of Fame (1993); and (2) NASA has signed a joint Memorandum of Understanding with the Multiple Sclerosis Association (1994) to share this technology for use with MS patient treatment. The STE Branch is currently pursuing a program to refine thermoregulatory design in light of recent technology developments that might be applicable for use by several medical patient populations. Projects have been initiated to apply thermoregulatory technology for the treatment and/or rehabilitation of patients with spinal cord injuries, multiple sclerosis, migraine headaches, and to help prevent the loss of hair during chemotherapy.

  20. Interventional bioethics: epistemology for peripheral countries.

    PubMed

    Garrafa, Volnei; Porto, Dora

    2008-01-01

    Principlism, which originated in the United States based on four supposedly universal principles, brought international visibility to the field of bioethics over the final years of the twentieth century. Nevertheless, from 1990 onwards, criticism regarding the universal applicability of these principles emerged, especially concerning their limitations in dealing with collective macroproblems--social, sanitary and environmental--that are seen in poor developing countries every day. In this respect, the idea of Intervention Bioethics was presented at the University of Brasília, Brazil, in 1998, and was subsequently expanded to encompass other Latin American countries. From the outset, this epistemological proposal of third-world construction and perspective advocated politicisation of the international bioethics agenda, and this aim was achieved through the content of UNESCO's Universal Declaration on Bioethics and Human Rights, which was adopted in 2005. Grounded in a utilitarian and consequentialistic approach, Intervention Bioethics gives priority, ahead of vulnerabilities relating to gender, sexual orientation, ethnicity and similar considerations, to the fields of social and sanitary justice in order to defend the poorest and most disempowered populations in the asymmetrical contemporary world. PMID:18664003

  1. From gene expressions to genetic networks

    NASA Astrophysics Data System (ADS)

    Cieplak, Marek

    2009-03-01

    A method based on the principle of entropy maximization is used to identify the gene interaction network with the highest probability of giving rise to experimentally observed transcript profiles [1]. In its simplest form, the method yields the pairwise gene interaction network, but it can also be extended to deduce higher order correlations. Analysis of microarray data from genes in Saccharomyces cerevisiae chemostat cultures exhibiting energy metabollic oscillations identifies a gene interaction network that reflects the intracellular communication pathways. These pathways adjust cellular metabolic activity and cell division to the limiting nutrient conditions that trigger metabolic oscillations. The success of the present approach in extracting meaningful genetic connections suggests that the maximum entropy principle is a useful concept for understanding living systems, as it is for other complex, nonequilibrium systems. The time-dependent behavior of the genetic network is found to involve only a few fundamental modes [2,3]. [4pt] REFERENCES:[0pt] [1] T. R. Lezon, J. R. Banavar, M. Cieplak, A. Maritan, and N. Fedoroff, Using the principle of entropy maximization to infer genetic interaction networks from gene expression patterns, Proc. Natl. Acad. Sci. (USA) 103, 19033-19038 (2006) [0pt] [2] N. S. Holter, M. Mitra, A. Maritan, M. Cieplak, J. R. Banavar, and N. V. Fedoroff, Fundamental patterns underlying gene expression profiles: simplicity from complexity, Proc. Natl. Acad. Sci. USA 97, 8409-8414 (2000) [0pt] [3] N. S. Holter, A. Maritan, M. Cieplak, N. V. Fedoroff, and J. R. Banavar, Dynamic modeling of gene expression data, Proc. Natl. Acad. Sci. USA 98, 1693-1698 (2001)

  2. Etienne-François Geoffroy (1672-1731), a Chemist on the Frontiers.

    PubMed

    Joly, Bernard

    2014-01-01

    Etienne-François Geoffroy is certainly the most representative chemist of the Paris Académie Royale des Sciences in the early eighteenth century. Interested in Newtonian ideas, he did not reject Cartesian mechanism. He is the inventor of the "Table des rapports entre les substances chimiques," which remained in use throughout the eighteenth century, but he drew from the alchemical tradition. He readily theorized about the composition of metals or the laws of chemical affinities, but he practiced a chemistry that was rooted in laboratory work and the search for substances useful to craftsmen. PMID:26103751

  3. The nucleotide sequence at the termini of adenovirus type 5 DNA.

    PubMed Central

    Steenbergh, P H; Maat, J; van Ormondt, H; Sussenbach, J S

    1977-01-01

    The sequences of the first 194 base pairs at both termini of adenovirus type 5 (Ad5) DNA have been determined, using the chemical degradation technique developed by Maxam and Gilbert (Proc. Nat. Acad. Sci. USA 74 (1977), pp. 560-564). The nucleotide sequences 1-75 were confirmed by analysis of labeled RNA transcribed from the terminal HhaI fragments in vitro. The sequence data show that Ad5 DNA has a perfect inverted terminal repetition of 103 base pairs long. Images PMID:600799

  4. Fractional Hamiltonian monodromy from a Gauss-Manin monodromy

    SciTech Connect

    Sugny, D.; Jauslin, H. R.; Mardesic, P.; Pelletier, M.; Jebrane, A.

    2008-04-15

    Fractional Hamiltonian monodromy is a generalization of the notion of Hamiltonian monodromy, recently introduced by [Nekhoroshev, Sadovskii, and Zhilinskii, C. R. Acad. Sci. Paris, Ser. 1 335, 985 (2002); and Ann. Henri Poincare 7, 1099 (2006)] for energy-momentum maps whose image has a particular type of nonisolated singularities. In this paper, we analyze the notion of fractional Hamiltonian monodromy in terms of the Gauss-Manin monodromy of a Riemann surface constructed from the energy-momentum map and associated with a loop in complex space which bypasses the line of singularities. We also prove some propositions on fractional Hamiltonian monodromy for 1:-n and m:-n resonant systems.

  5. Default taxonomy: Ernst Mayr's view of the microbial world.

    PubMed

    Woese, C R

    1998-09-15

    This perspective is a response to a taxonomic proposal by E. Mayr ["Two empires or three?" (1998) Proc. Natl. Acad. Sci. USA 95, 9720-9723]. Mayr has suggested that the now accepted classification of life into three primary domains, Archaea, Bacteria, and Eucarya-originally proposed by myself and others--be abandoned in favor of the earlier Prokaryote-Eukaryote classification. Although the matter appears a taxonomic quibble, it is not that simple. At issue here are differing views as to the nature of biological classification, which are underlain by differing views as to what biology is and will be--matters of concern to all biologists. PMID:9736686

  6. What does the arrest and release of Emile Borel and his colleagues in 1941 tell us about the German occupation of France?

    PubMed

    Mazliak, Laurent; Shafer, Glenn

    2011-12-01

    The Germans occupying Paris arrested Emile Borel and three other members of the Académie des Sciences in October 1941 and released them about five weeks later. Drawing on German and French archives and other sources, we argue that these events illustrate the complexity of the motivations and tactics of the occupiers and the occupied. While Borel and his colleagues were genuine members of the Resistance, and those who arrested them were full participants in a brutal occupation, both sides respected a bargain, of no small importance to the Vichy regime, that allowed the university to pursue its work if its members avoided overt acts of opposition. PMID:22397169

  7. Crystal Structures of Nitroalkane Oxidase: Insights into the Reaction Mechanism from a Covalent Complex of the Flavoenzyme Trapped during Turnover‡

    PubMed Central

    Nagpal, Akanksha; Valley, Michael P.; Fitzpatrick, Paul F.; Orville, Allen M.

    2006-01-01

    Nitroalkane oxidase (NAO) from Fusarium oxysporum catalyzes the oxidation of neutral nitroalkanes to the corresponding aldehydes or ketones with the production of H2O2 and nitrite. The flavoenzyme is a new member of the acyl-CoA dehydrogenase (ACAD) family, but it does not react with acyl-CoA substrates. We present the 2.2 Å resolution crystal structure of NAO trapped during the turnover of nitroethane as a covalent N5–FAD adduct (ES*). The homotetrameric structure of ES* was solved by MAD phasing with 52 Se-Met sites in an orthorhombic space group. The electron density for the N5-(2-nitrobutyl)-1,5-dihydro-FAD covalent intermediate is clearly resolved. The structure of ES* was used to solve the crystal structure of oxidized NAO at 2.07 Å resolution. The c axis for the trigonal space group of oxidized NAO is 485 Å, and there are six subunits (1½ holoenzymes) in the asymmetric unit. Four of the active sites contain spermine (EI), a weak competitive inhibitor, and two do not contain spermine (Eox). The active-site structures of Eox, EI, and ES* reveal a hydrophobic channel that extends from the exterior of the protein and terminates at Asp402 and the N5 position on the re face of the FAD. Thus, Asp402 is in the correct position to serve as the active-site base, where it is proposed to abstract the α proton from neutral nitroalkane substrates. The structures for NAO and various members of the ACAD family overlay with root-mean-square deviations between 1.7 and 3.1 Å. The homologous region typically spans more than 325 residues and includes Glu376, which is the active-site base in the prototypical member of the ACAD family. However, NAO and the ACADs exhibit differences in hydrogen-bonding patterns between the respective active-site base, substrate molecules, and FAD. These likely differentiate NAO from the homologues and, consequently, are proposed to result in the unique reaction mechanism of NAO. PMID:16430210

  8. A simplified method for extracting androgens from avian egg yolks

    USGS Publications Warehouse

    Kozlowski, C.P.; Bauman, J.E.; Hahn, D.C.

    2009-01-01

    Female birds deposit significant amounts of steroid hormones into the yolks of their eggs. Studies have demonstrated that these hormones, particularly androgens, affect nestling growth and development. In order to measure androgen concentrations in avian egg yolks, most authors follow the extraction methods outlined by Schwabl (1993. Proc. Nat. Acad. Sci. USA 90:11446-11450). We describe a simplified method for extracting androgens from avian egg yolks. Our method, which has been validated through recovery and linearity experiments, consists of a single ethanol precipitation that produces substantially higher recoveries than those reported by Schwabl.

  9. Crystal structures of nitroalkane oxidase: insights into the reaction mechanism from a covalent complex of the flavoenzyme trapped during turnover.

    PubMed

    Nagpal, Akanksha; Valley, Michael P; Fitzpatrick, Paul F; Orville, Allen M

    2006-01-31

    Nitroalkane oxidase (NAO) from Fusarium oxysporum catalyzes the oxidation of neutral nitroalkanes to the corresponding aldehydes or ketones with the production of H(2)O(2) and nitrite. The flavoenzyme is a new member of the acyl-CoA dehydrogenase (ACAD) family, but it does not react with acyl-CoA substrates. We present the 2.2 A resolution crystal structure of NAO trapped during the turnover of nitroethane as a covalent N5-FAD adduct (ES*). The homotetrameric structure of ES* was solved by MAD phasing with 52 Se-Met sites in an orthorhombic space group. The electron density for the N5-(2-nitrobutyl)-1,5-dihydro-FAD covalent intermediate is clearly resolved. The structure of ES was used to solve the crystal structure of oxidized NAO at 2.07 A resolution. The c axis for the trigonal space group of oxidized NAO is 485 A, and there are six subunits (1(1)/(2) holoenzymes) in the asymmetric unit. Four of the active sites contain spermine (EI), a weak competitive inhibitor, and two do not contain spermine (E(ox)). The active-site structures of E(ox), EI, and ES* reveal a hydrophobic channel that extends from the exterior of the protein and terminates at Asp402 and the N5 position on the re face of the FAD. Thus, Asp402 is in the correct position to serve as the active-site base, where it is proposed to abstract the alpha proton from neutral nitroalkane substrates. The structures for NAO and various members of the ACAD family overlay with root-mean-square deviations between 1.7 and 3.1 A. The homologous region typically spans more than 325 residues and includes Glu376, which is the active-site base in the prototypical member of the ACAD family. However, NAO and the ACADs exhibit differences in hydrogen-bonding patterns between the respective active-site base, substrate molecules, and FAD. These likely differentiate NAO from the homologues and, consequently, are proposed to result in the unique reaction mechanism of NAO. PMID:16430210

  10. Crystal Structures of Nitroalkane Oxidase: Insights into the Reaction Mechanism of a Covalent Complex of the Flavoenzyme Trapped During Turnover

    SciTech Connect

    Nagpal,A.; Valley, M.; Fitzpatrick, P.; Orville, A.

    2006-01-01

    Nitroalkane oxidase (NAO) from Fusarium oxysporum catalyzes the oxidation of neutral nitroalkanes to the corresponding aldehydes or ketones with the production of H2O2 and nitrite. The flavoenzyme is a new member of the acyl-CoA dehydrogenase (ACAD) family, but it does not react with acyl-CoA substrates. We present the 2.2 Angstroms resolution crystal structure of NAO trapped during the turnover of nitroethane as a covalent N5-FAD adduct (ES*). The homotetrameric structure of ES* was solved by MAD phasing with 52 Se-Met sites in an orthorhombic space group. The electron density for the N5-(2-nitrobutyl)-1,5-dihydro-FAD covalent intermediate is clearly resolved. The structure of ES* was used to solve the crystal structure of oxidized NAO at 2.07 Angstroms resolution. The c axis for the trigonal space group of oxidized NAO is 485 Angstroms, and there are six subunits (11/2 holoenzymes) in the asymmetric unit. Four of the active sites contain spermine (EI), a weak competitive inhibitor, and two do not contain spermine (E{sup ox}). The active-site structures of E{sup ox}, EI, and ES* reveal a hydrophobic channel that extends from the exterior of the protein and terminates at Asp402 and the N5 position on the re face of the FAD. Thus, Asp402 is in the correct position to serve as the active-site base, where it is proposed to abstract the {alpha} proton from neutral nitroalkane substrates. The structures for NAO and various members of the ACAD family overlay with root-mean-square deviations between 1.7 and 3.1 Angstroms. The homologous region typically spans more than 325 residues and includes Glu376, which is the active-site base in the prototypical member of the ACAD family. However, NAO and the ACADs exhibit differences in hydrogen-bonding patterns between the respective active-site base, substrate molecules, and FAD. These likely differentiate NAO from the homologues and, consequently, are proposed to result in the unique reaction mechanism of NAO.

  11. On Rank One Convex Functions that are Homogeneous of Degree One

    NASA Astrophysics Data System (ADS)

    Kirchheim, Bernd; Kristensen, Jan

    2016-07-01

    We show that positively 1-homogeneous rank one convex functions are convex at 0 and at matrices of rank one. The result is a special case of an abstract convexity result that we establish for positively 1-homogeneous directionally convex functions defined on an open convex cone in a finite dimensional vector space. From these results we derive a number of consequences including various generalizations of the Ornstein L1 non inequalities. Most of the results were announced in ( C R Acad Sci Paris Ser I 349:407-409, 2011).

  12. Purification and characterization of a Na+, K+ ATPase inhibitor found in an endotoxin of Leptospira interrogans.

    PubMed Central

    Burth, P; Younes-Ibrahim, M; Gonçalez, F H; Costa, E R; Faria, M V

    1997-01-01

    We showed previously that the glycolipoprotein fraction prepared from Leptospira interrogans inhibited the Na+,K+ ATPase enzyme purified from brain or kidney and in isolated nephron segments (M. Younes-Ibrahim, P. Burth, M. V. Castro Faria, B. Buffin-Meyer, S. Marsy, C. Barlet-Bas, L. Cheval, and A. Doucet, C. R. Acad. Sci. Paris Ser. III 318:619-625, 1995). In the present communication, we have demonstrated that unsaturated fatty acids such as oleic and palmitoleic acids, which are adsorbed to this fraction, are effective inhibitors of the enzyme. PMID:9119504

  13. The road to understanding an ion pump

    NASA Astrophysics Data System (ADS)

    Toyoshima, Chikashi

    2016-04-01

    In the past 25 years or so I have been working almost exclusively on two proteins: the Ca2+-ATPase of muscle sarcoplasmic reticulum, and the Na+, K+-ATPase expressed in all animal cells, both are membrane ion pumps representing P-type ion translocating ATPases. My ambition as a scientist is to completely understand the meaning of their atomic structures. How I became a scientist is described elsewhere (Nuzzo R 2006 Proc. Natl. Acad. Sci. USA 103 1165-7), and focus here is given to my struggle towards a deep understanding of Ca2+-ATPase. This is a long but very fascinating and rewarding journey.

  14. Nanoscale hydrodynamics in the cell: balancing motorized transport with diffusion

    PubMed Central

    Austin, Robert H.

    2008-01-01

    One of the central problems in the cell is how to transport molecules around the cell to desired locations. Since low Reynolds number conditions apply and diffusional times are large, without the aid of molecular motors to transport the fluid quickly cells could not survive, yet diffusion is still essential for the ultimate delivery of the goods. This paradox of low Reynolds number∕large Peclet number has been solved by the algal weed Chara corallina in ingenious ways, as the recent paper by Goldstein, et al. [Proc. Natl. Acad. Sci. 105, 3663–3667 (2008)] discusses at a deep but accessible way using modern hydrodynamic modeling. PMID:19404437

  15. Tendências de teses e dissertações sobre ensino de astronomia no Brasil

    NASA Astrophysics Data System (ADS)

    Bretones, P. S.; Megid Neto, J.

    2003-08-01

    Neste trabalho são apresentados os resultados de uma pesquisa do tipo estado da arte sobre teses e dissertações defendidas no Brasil e relativas ao ensino de Astronomia. Teve por objetivo identificar essa produção e conhecer as principais tendências da pesquisa nesse campo. O procedimento inicial consistiu de um levantamento bibliográfico junto ao Centro de Documentação em Ensino de Ciências (CEDOC) da Faculdade de Educação da UNICAMP e ao Banco de Teses da CAPES disponível na Internet. Foram localizadas 13 dissertações de mestrado e 3 teses de doutorado, as quais foram estudadas em função dos seguintes aspectos: instituição, ano de defesa, nível escolar abrangido no estudo, foco temático do estudo e gênero de trabalho acadêmico. Deste conjunto de pesquisas, 13 (81,3%) delas foram defendidas a partir da segunda metade dos anos 90, indicando uma preocupação mais recente com temas relativos ao ensino de Astronomia no conjunto da produção acadêmica em programas de pós-graduação no Brasil. Verificou-se que 43,7% dos trabalhos foram produzidas na USP e 18,8% na UNICAMP. Quanto ao nível escolar abrangido nos estudos, predominaram os estudos direcionados ao Ensino Fundamental de 5a a 8a séries (62,5%). No que diz respeito ao foco temático das pesquisas, as principais tendências voltaram-se: 56,3% para Conteúdo e Método; 43,8% para Concepções do Professor; 37,5% para Currículo e Programas; 37,5% para Recursos Didáticos. Quanto ao gênero de trabalho acadêmico, verificou-se que 43,8% são de Pesquisa Experimental e 31,3% de Pesquisa de Análise de Conteúdo. Estudos de revisão bibliográfica como este visam colaborar com a divulgação ampla da produção acadêmica em determinada área, traçando algumas de suas tendências. Ao mesmo tempo possibilita, a partir de investigações decorrentes, apontar as suas contribuições para o ensino e sinalizar com necessidades a serem supridas por futuras pesquisas.

  16. L'affleurement triasique du Debadib Ben Gasseur (Nord-Ouest de la Tunisie) : diapir enraciné à épanchements latéraux dans la mer Albienne, replissé au cours des phases de compression tertiairesThe Triassic rocks of the Debadib Ben Gasseur area (northwestern Tunisia): diapir with overhangs spreading downslope in the Albian Sea and deformed during the Tertiary compressional deformations

    NASA Astrophysics Data System (ADS)

    Chikhaoui, Mongi; Jallouli, Chokri; Turki, Mohamed Moncef; Soussi, Mohamed; Braham, Ahmed; Zaghbib-Turki, Dalia

    2002-12-01

    The Triassic outcrops of the Debadib-Ben Gasseur area, located in the Kef area (northwestern Tunisia) have recently been interpreted as submarine 'salt glaciers' interbedded within the Albian deposits (J.-M. Vila et al., C. R. Acad. Sci. Paris, Ser. II 318 (1994) 1661-1667). New cartographic, drills and gravimetric data recognised evidence for an Albian diapiric stage for the Triassic rocks. The Triassic rocks as pulling out of the sedimentary cover could spread laterally as small size 'salt glaciers' before they have been deformed during the Tertiary compressional deformations. To cite this article: M. Chikhaoui et al., C. R. Geoscience 334 (2002) 1129-1133.

  17. Periodicity of mass extinctions without an extraterrestrial cause

    NASA Astrophysics Data System (ADS)

    Lipowski, Adam

    2005-05-01

    We study a lattice model of a multispecies prey-predator system. Numerical results show that for a small mutation rate the model develops irregular long-period oscillatory behavior with sizeable changes in a number of species. The periodicity of extinctions on Earth was suggested by Raup and Sepkoski [Proc. Natl. Acad. Sci. 81, 801 (1984)], but thus far is lacking a satisfactory explanation. Our model indicates that this might be a natural consequence of the ecosystem dynamics and not the result of any extraterrestrial cause.

  18. Comment on "Nonparametric forecasting of low-dimensional dynamical systems "

    NASA Astrophysics Data System (ADS)

    Kondrashov, Dmitri; Chekroun, Mickaël D.; Ghil, Michael

    2016-03-01

    The comparison performed in Berry et al. [Phys. Rev. E 91, 032915 (2015), 10.1103/PhysRevE.91.032915] between the skill in predicting the El Niño-Southern Oscillation climate phenomenon by the prediction method of Berry et al. and the "past-noise" forecasting method of Chekroun et al. [Proc. Natl. Acad. Sci. USA 108, 11766 (2011), 10.1073/pnas.1015753108] is flawed. Three specific misunderstandings in Berry et al. are pointed out and corrected.

  19. Default taxonomy: Ernst Mayr's view of the microbial world

    NASA Technical Reports Server (NTRS)

    Woese, C. R.

    1998-01-01

    This perspective is a response to a taxonomic proposal by E. Mayr ["Two empires or three?" (1998) Proc. Natl. Acad. Sci. USA 95, 9720-9723]. Mayr has suggested that the now accepted classification of life into three primary domains, Archaea, Bacteria, and Eucarya-originally proposed by myself and others--be abandoned in favor of the earlier Prokaryote-Eukaryote classification. Although the matter appears a taxonomic quibble, it is not that simple. At issue here are differing views as to the nature of biological classification, which are underlain by differing views as to what biology is and will be--matters of concern to all biologists.

  20. Nanoscale hydrodynamics in the cell: balancing motorized transport with diffusion.

    PubMed

    Austin, Robert H

    2008-10-01

    One of the central problems in the cell is how to transport molecules around the cell to desired locations. Since low Reynolds number conditions apply and diffusional times are large, without the aid of molecular motors to transport the fluid quickly cells could not survive, yet diffusion is still essential for the ultimate delivery of the goods. This paradox of low Reynolds numberlarge Peclet number has been solved by the algal weed Chara corallina in ingenious ways, as the recent paper by Goldstein, et al. [Proc. Natl. Acad. Sci. 105, 3663-3667 (2008)] discusses at a deep but accessible way using modern hydrodynamic modeling. PMID:19404437

  1. Amino acid sequence of a vitamin K-dependent Ca2+-binding peptide from bovine prothrombin.

    PubMed

    Howard, J B; Fausch, M D

    1975-08-10

    The amino acid sequence of a 31-residue peptide from bovine prothrombin has been determined. This peptide has been shown to contain the vitamin K-dependent modification required for Ca2+ binding (Nelsestuen, G. L., and Suttie, J. W. (1973) Proc. Natl. Acad. Sci. U. S. A. 70, 3366-3370) and the modified amino acid, gamma-carboxyglutamic acid (Nelsestuen, G. L., Zytkovicz, T., and Howard, J. B. (1974) J. Biol. Chem. 249, 6347-6350). The peptide was shown to correspond to residues 12 to 42 of prothrombin. PMID:807581

  2. Identifying the occurrence time of mainshocks by means of Natural Time Analysis

    NASA Astrophysics Data System (ADS)

    Sarlis, Nicholas V.; Skordas, Efthimios S.; Lazaridou, Mary S.; Varotsos, Panayiotis A.

    2016-04-01

    By employing the new view of time, termed natural time [1], recent advances on the natural time analysis of a seismic catalogue [2] include: First, the fluctuations of the order parameter κ1 of seismicity exhibit a minimum almost simultaneous with the initiation of a Seismic Electric Signals (SES) activity [3,4]. This opens the window of a deeper understanding of the critical nature of preseismic process [5]. Second, a spatiotemporal study of the fluctuations of the order parameter of seismicity leads to an estimate of the epicentral area of a major impending mainshock [6]. Third, by starting the natural time analysis of the seismicity in the candidate epicentral area at the initiation time of the SES activity, we find that the κ1 values converge to the critical value [7-9] κ_1=0.070 a few days to one week before a mainshock. Recent applications of this procedure are presented for mainshocks that occurred close to Athens [10] during the last few years. References [1] P. A. Varotsos, N. V. Sarlis and E. S. Skordas, Phys. Rev. E {66} (2002) 011902; Practica of Athens Academy {76} (2001) 294. [2] P.A.Varotsos, N.V. Sarlis, H.K. Tanaka and E.S. Skordas, Phys. Rev. E {72} (2005) 041103. [3] P. Varotsos and M. Lazaridou, Tectonophysics {188} (1991) 321. [4] P. A. Varotsos, N. V. Sarlis, E. S. Skordas, and M. S. Lazaridou, Tectonophysics {589} (2013) 116. [5] P. Varotsos, K. Alexopoulos and M. Lazaridou, Tectonophysics {224} (1993) 1. [6] N.V. Sarlis, E.S. Skordas, P.A. Varotsos, T. Nagao, M. Kamogawa, and S. Uyeda Proc Natl Acad Sci USA {112} (2015) 986. [7] P. Varotsos, N.V. Sarlis, E.S. Skordas, S. Uyeda, and M. Kamogawa, Proc Natl Acad Sci USA {108} (2011) 11361. [8] N.V. Sarlis, E.S. Skordas, P.A. Varotsos, T. Nagao, M. Kamogawa, H. Tanaka and S. Uyeda Proc Natl Acad Sci USA {110} (2013) 13734. [9] N.V. Sarlis, E.S. Skordas, M.S. Lazaridou, and P.A. Varotsos, Proc Japan Acad Ser. ? {84} (2008) 331. [10] P.A. Varotsos, N.V. Sarlis, E.S. Skordas, S.-R. G

  3. The protein translocation machinery of the endoplasmic reticulum.

    PubMed

    Walter, P; Gilmore, R; Müller, M; Blobel, G

    1982-12-24

    The rough endoplasmic reticulum (r.e.r.) has been postulated to possess a single translation-coupled translocation system (in multiple copies) that effects signal sequence-mediated translocation of all secretory and lysosomal proteins and integration of all integral membrane proteins whose port of entry is the rough endoplasmic reticulum (G. Blobel 1980 Proc. natn. Acad. Sci. U.S.A. 77, 1496-1500). Two proteins have been isolated that are components of the r.e.r. translocation system. Their properties and function in protein translocation across and integration into membranes are discussed. PMID:6131460

  4. Generalized Klein-Kramers equation: solution and application

    NASA Astrophysics Data System (ADS)

    Sau Fa, Kwok; Wang, K. G.

    2013-09-01

    A generalized Klein-Kramers equation based on the continuous time random walk model is investigated. The equation generalizes the ordinary and fractional Klein-Kramers equations. Analytic solutions for the probability density and first two moments (for the force-free case) are obtained, and their dynamic behaviors are investigated in detail. The model is used to describe the cell migration of two migrating transformed renal epithelial Madin-Darby canine kidney (MDCK-F) cell strains: wild-type (NHE+) and NHE-deficient (NHE-) cells. Our theoretical predictions are in good agreement with experimental work in the paper (Dieterich et al 2008 Proc. Nat. Acad. Sci. USA 105 459).

  5. The significance of Cern

    ScienceCinema

    None

    2011-04-25

    Le Prof. V.Weisskopf, DG du Cern de 1961 à 1965, est né à Vienne, a fait ses études à Göttingen et a une carrière académique particulièrement riche. Il a travaillé à Berlin, Copenhague et Berlin et est parti aux Etats Unis pour participer au projet Manhattan et était Prof. au MTT jusqu'à 1960. Revenu en Europe, il a été DG du Cern et lui a donné l'impulsion que l'on sait.

  6. Astronomy in High School: Using a Mini-Planetarium to Understand Details of the Apparent Movement of Stars. (Spanish Title: Astronomía en la Escuela Secundaria: Comprendiendo los Detalles del Movimiento Aparente de Las Estrellas con un Miniplanetario.) Astronomia no Ensino Médio: Compreendendo Detalhes do Movimento Aparente das Estrelas com um Miniplanetário

    NASA Astrophysics Data System (ADS)

    dos Santos Leão, Demetrius

    2013-07-01

    en la comprensión de estas cuestiones y demostraron un gran interés por esta metodología. O objetivo deste artigo é apresentar parte dos resultados obtidos com a intervenção feita como projeto da dissertação de mestrado do autor, que consistiu no desenvolvimento de um conjunto de aulas de Astronomia, com alunos do 1º Ano do Ensino Médio de uma escola da rede privada do Distrito Federal (Brasília, Brasil), empregando como recurso principal um material didático chamado miniplanetário (MP). Utilizando como pressuposto teórico norteador dessas aulas as ideias de contextualização e dialogicidade de Paulo Freire, foi proposta aos estudantes a montagem e utilização desse recurso em uma sessão de planetário. Durante o projeto, enfatizaram-se assuntos como a trajetória aparente das estrelas para o céu de Brasília, a localização dos pontos cardeais a partir da constelação do Cruzeiro do Sul, as cores das estrelas e as estrelas vistas de uma determinada localidade. Apurou-se que os alunos apresentaram melhoria na compreensão desses assuntos, bem como demonstraram expressiva empolgação com essa metodologia desenvolvida.

  7. Oligomer Formation Reactions of Criegee Intermediates in the Ozonolysis of Small Unsaturated Hydrocarbons

    NASA Astrophysics Data System (ADS)

    Sakamoto, Y.; Inomata, S.; Hirokawa, J.

    2013-12-01

    hydroperoxides of low volatility formed in the gas phase are partitioned into the particle phase to contribute to the SOA formation. Here, we propose a new oligomer formation mechanism including sequential addition of Criegee intermediates to hydroperoxides. REFERENCE: (1)Kroll, J. H.; Seinfeld, J. H. Chemistry of Secondary Organic Aerosol: Formation and Evolution of Low-Volatility Organics in the Atmosphere. Atmos. Environ. 2008, 42, 3593-3624. (2)Sadezky, A.; Chaimbault, P.; Mellouki, A.; Roempp, A.; Winterhalter, R.; Le Bras, G.; Moortgat, G. K. Formation of Secondary Organic Aerosol and Oligomers from the Ozonolysis of Enol Ethers. Atmos. Chem. Phys. 2006, 6, 5009-5024. (3)Sadezky, A.; Winterhalter, R.; Kanawati, B.; Roempp, A.; Spengler, B.; Mellouki, A.; Le Bras, G.; Chaimbault, P.; Moortgat, G. K. Oligomer Formation during Gas-Phase Ozonolysis of Small Alkenes and Enol Ethers: New Evidence for the Central Role of the Criegee Intermediate as Oligomer Chain Unit. Atmos. Chem. Phys. 2008, 8, 2667-2699. (4)Klotz, B.; Barnes, I.; Imamura, T. Product Study of the Gas-Phase Reactions of O3, OH and NO3 Radicals with Methyl Vinyl Ether. Phys. Chem. Chem. Phys. 2004, 6, 1725-1734.

  8. Controls on rind thickness on basaltic andesite clasts weathering in Guadeloupe

    USGS Publications Warehouse

    Sak, P.B.; Navarre-Sitchler, A. K.; Miller, C.E.; Daniel, C.C.; Gaillardet, J.; Buss, H.L.; Lebedeva, M.I.; Brantley, S.L.

    2010-01-01

    A clast of low porosity basaltic andesite collected from the B horizon of a soil developed on a late Quaternary volcaniclastic debris flow in the Bras David watershed on Basse-Terre Island, Guadeloupe, exhibits weathering like that observed in many weathered clasts of similar composition in other tropical locations. Specifically, elemental profiles measured across the core-rind interface document that primary minerals and glass weather to Fe oxyhydroxides, gibbsite and minor kaolinite in the rind. The earliest reaction identified in the core is oxidation of Fe in pyroxene but the earliest reaction that creates significant porosity is plagioclase dissolution. Elemental loss varies in the order Ca???Na>K???Mg>Si>Al>Fe???P??Ti, consistent with the relative reactivity of phases in the clast from plagioclase???pyroxene???glass>apatite>ilmenite. The rind surrounds a core of unaltered material that is more spherical than the original clast. The distance from the core-rind boundary to a visually prominent rind layer, L, was measured as a proxy for the rind thickness at 36 locations on a slab cut vertically through the nominal center of the clast. This distance averaged 24.4??3.1mm. Maximum and minimum values for L, 35.8 and 20.6mm, were observed where curvature of the core-rind boundary is greatest (0.12mm-1) and smallest (0.018mm-1) respectively. Extrapolating from other rinds in other locations, the rate of rind formation is estimated to vary by a factor of about 2 (from ~4 to 7??10-14ms-1) from low to high curvature. The observation of a higher rate of rind formation for a higher curvature interface is consistent with a diffusion-limited model for weathering rind formation. The diffusion-limited model predicts that, like rind thickness, values of the thickness of the reaction front (h) for a given reaction, defined as the zone over which a parent mineral such as plagioclase completely weathers to rind material, should also increase with curvature. Values of h were

  9. Precambrian Cratons and Fold-Belts in Brazil: Overview

    NASA Astrophysics Data System (ADS)

    Fuck, R.

    2008-05-01

    The main Precambrian terrains recognized in Brazil comprise the Amazonian, São Francisco and Rio de la Plata cratons, surrounded by Neoproterozoic Brasiliano fold belts, making up the Borborema, Mantiqueira and Tocantins provinces. The Amazonian craton comprises an Archean core, surrounded by Paleoproterozoic terrains (Maroni-Itacaiunas, Ventuari-Tapajós, Rio Negro-Juruena), which southwestwards give way to the Mesoproterozoic Rondoniano-San Ignacio and Sunsas belts, the latter thought to be related to the Grenville belt of North America. The São Francisco craton comprises several Archean blocks (Gavião, Serrinha, Jequié) amalgamated by the Paleoproterozoic high-grade Itabuna-Salvador-Curaçá orogen. The Rio de la Plata craton, largely covered by Phanerozoic strata, is made of Paleoproterozoic basement gneiss and several Paleoproterozoic greenstone belts. Other cratonic blocks are hidden below large Phanerozoic basins, like the Paranapanema and Parnaíba blocks below the Paraná and Parnaíba basins, respectively. Several smaller Archean/Paleoproterozoic blocks appear within the Brasiliano provinces: some were strongly reworked during the Neoproterozoic orogenic events (São José do Campestre, Pernambuco-Alagoas, Goiás, Guanhães, Juiz de Fora, Curitiba), others were only marginally affected (São Luiz, Rio Apa, Luís Alves). The Brasiliano provinces are the result of Neoproterozoic to early Paleozoic orogenic events within the framework of West Gondwana amalgamation. The Mantiqueira Province extends from eastern Brazil to southern Uruguay and includes the Araçuaí, Ribeira and Dom Feliciano fold belts, bordering the São Francisco, Paranapanema and Rio de la Plata cratons and surrounding the Luís Alves craton. The Tocantins province in central Brazil includes the Araguaia, Paraguay and Brasília fold belts, the former bordering the Amazonian craton, the second bordering both the southern Amazonian craton and the Rio Apa block, and the last established on

  10. [Child prostitution: family disintegration, necessary planning, the laziness of the elite].

    PubMed

    1993-09-01

    Child and juvenile prostitution in Brazil has reached such proportions that a parliamentary commission launched an inquiry. The Brazilian Center of Children and Adolescents (CBIA) estimated that there are about 500,000 such prostitutes in the country, a record in Latin America. This type of prostitution flourishes in poor urban areas and in the North and Central-East. Not only girls become prostitutes; in Rio de Janeiro, 4000 boys cater to tourists from the industrialized world. 79% of these youngsters say that they use condoms, but 42% are infected with HIV. In many cases their families tolerate their homosexual encounters because of the extra income received. In the interior of the state of Rio, girls aged 11-15 years are enticed to cities as domestics and end up in prostitution. In Niteroi there is a prostitution network specializing in 13-year-old girls. Although there are 30,000 prostitutes in the state of Rio, the distribution of condoms among them has caused negative reactions among conservatives and Catholics claiming that it would increase licentiousness. The Brazilian Center for the Defense of the Rights of Children and Adolescents countered that condoms help prevent the spread of diseases. In Para, Acre, and Rondonia, 13-, 14-, and 15-year-old girls sell their bodies in order to survive. In the maternity ward of Barbara Heliodora, Rio Branco, Acre, 31% of deliveries are to girls aged 10-16 years. In Sao Paulo and in the neighborhoods of Bras and Belem, girls as young as 10 years of age become prostitutes under the protection of corrupt police who exact sexual favors or a share of receipts. According to CBIA, 80% of sexual violence against children and adolescents occurs in the home, with fathers being the main aggressors. The prostitution of children and adolescents in Brazil is connected to the destruction of the family and is the result of misery and hunger. PMID:12288821

  11. The "normal" elongation of river basins

    NASA Astrophysics Data System (ADS)

    Castelltort, Sebastien

    2013-04-01

    The spacing between major transverse rivers at the front of Earth's linear mountain belts consistently scales with about half of the mountain half-width [1], despite strong differences in climate and rock uplift rates. Like other empirical measures describing drainage network geometry this result seems to indicate that the form of river basins, among other properties of landscapes, is invariant. Paradoxically, in many current landscape evolution models, the patterns of drainage network organization, as seen for example in drainage density and channel spacing, seem to depend on both climate [2-4] and tectonics [5]. Hovius' observation [1] is one of several unexplained "laws" in geomorphology that still sheds mystery on how water, and rivers in particular, shape the Earth's landscapes. This narrow range of drainage network shapes found in the Earth's orogens is classicaly regarded as an optimal catchment geometry that embodies a "most probable state" in the uplift-erosion system of a linear mountain belt. River basins currently having an aspect away from this geometry are usually considered unstable and expected to re-equilibrate over geological time-scales. Here I show that the Length/Width~2 aspect ratio of drainage basins in linear mountain belts is the natural expectation of sampling a uniform or normal distribution of basin shapes, and bears no information on the geomorphic processes responsible for landscape development. This finding also applies to Hack's [6] law of river basins areas and lengths, a close parent of Hovius' law. [1]Hovius, N. Basin Res. 8, 29-44 (1996) [2]Simpson, G. & Schlunegger, F. J. Geophys. Res. 108, 2300 (2003) [3]Tucker, G. & Bras, R. Water Resour. Res. 34, 2751-2764 (1998) [4]Tucker, G. & Slingerland, R. Water Resour. Res. 33, 2031-2047 (1997) [5]Tucker, G. E. & Whipple, K. X. J. Geophys. Res. 107, 1-1 (2002) [6]Hack, J. US Geol. Surv. Prof. Pap. 294-B (1957)

  12. Le syndrome de Cri du Chat : A propos d’une observation

    PubMed Central

    Ouldim, Karim; Samri, Imane; Bouguenouch, Laila; Hamdaoui, Hasna; Otmani, Ihsan El; Hbibi, Mohamed; Chaouki, Sana; Hida, Moustapha

    2012-01-01

    Le syndrome du Cri du Chat (Cri du Chat syndrome, CdCS) est une anomalie chromosomique résultant d’une délétion de taille variable de l’extrémité du bras court du chromosome 5 (5p), incluant une région critique située en p15.2. Il représente une des délétions chromosomiques les plus fréquentes, son incidence dans la population générale est de 1/20 000 à 1/50 000. Les caractéristiques cliniques comprennent un cri monochromatique aigu, une microcéphalie, une dysmorphie cranio-faciale caractéristique évoluant avec l’âge et un retard mental et psychomoteur important. La taille de la délétion est variable, Le traitement est fonction des différents symptômes. Un remaniement chromosomique parental est retrouvé dans 12% des cas et la majorité des délétions responsables de la maladie du cri-du-chat surviennent de novo. Nous présentons une observation d’un syndrome du Cri du Chat, confirmé par caryotype métaphasique (46,XY,del(5)(p13) de novo). A travers cette observation nous mettrons à jour, les actualités scientifiques de ce rare syndrome, ainsi que la place des explorations cytogénétiques dans le diagnostic précis et le conseil génétique des syndromes dysmorphiques. PMID:22368747

  13. The new physician as unwitting quantum mechanic: is adapting Dirac's inference system best practice for personalized medicine, genomics, and proteomics?

    PubMed

    Robson, Barry

    2007-08-01

    What is the Best Practice for automated inference in Medical Decision Support for personalized medicine? A known system already exists as Dirac's inference system from quantum mechanics (QM) using bra-kets and bras where A and B are states, events, or measurements representing, say, clinical and biomedical rules. Dirac's system should theoretically be the universal best practice for all inference, though QM is notorious as sometimes leading to bizarre conclusions that appear not to be applicable to the macroscopic world of everyday world human experience and medical practice. It is here argued that this apparent difficulty vanishes if QM is assigned one new multiplication function @, which conserves conditionality appropriately, making QM applicable to classical inference including a quantitative form of the predicate calculus. An alternative interpretation with the same consequences is if every i = radical-1 in Dirac's QM is replaced by h, an entity distinct from 1 and i and arguably a hidden root of 1 such that h2 = 1. With that exception, this paper is thus primarily a review of the application of Dirac's system, by application of linear algebra in the complex domain to help manipulate information about associations and ontology in complicated data. Any combined bra-ket can be shown to be composed only of the sum of QM-like bra and ket weights c(), times an exponential function of Fano's mutual information measure I(A; B) about the association between A and B, that is, an association rule from data mining. With the weights and Fano measure re-expressed as expectations on finite data using Riemann's Incomplete (i.e., Generalized) Zeta Functions, actual counts of observations for real world sparse data can be readily utilized. Finally, the paper compares identical character, distinguishability of states events or measurements, correlation, mutual information, and orthogonal character, important issues in data mining

  14. Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

    SciTech Connect

    Hatzinger, Paul B.; Bohlke, J. K.; Sturchio, N. C.; Gu, Baohua

    2009-01-01

    An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br-as a conservative tracer of the injectate), perchlorate concentrations decreased by 78 % and nitrate concentrations decreased by 87 %, during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (ε18O/ε37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of approximately 0.8 (ε18O/ε15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (ε18O/ε37Cl, ε18O/ε15N) derived from homogeneous laboratory systems (e.g., pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent  values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion.

  15. Space science public outreach at Louisiana State University

    NASA Astrophysics Data System (ADS)

    Guzik, T.; Babin, E.; Cooney, W.; Giammanco, J.; Hartman, D.; McNeil, R.; Slovak, M.; Stacy, J.

    Over the last seven years the Astronomy / Astrophysics group in the Department of Physics and Astronomy of Louisiana State University has developed an exten- sive Space Science education and public outreach program. This program includes the local park district (the Recreation and Park Commission for the Parish of East Baton Rouge, BREC), the local amateur astronomer group (the Baton Rouge As- tronomical Society, BRAS), the Louisiana Arts and Science Museum (LASM), and Southern University (SU, part of the largest HBCU system in the nation). Our effort has directly led to the development of the Highland Road Park Observatory (HRPO, http://www.bro.lsu.edu/hrpo) that supports student astronomy training at LSU and SU, amateur observations and a public program for adults and children, establishment of a series of teacher professional development workshops in astronomy and physics, and the "Robots for Internet Experiences (ROBIE)" project (http://www.bro.lsu.edu/) where we have several instruments (e.g. HAM radio, radio telescope, optical tele- scopes) that can be controlled over the internet by students and teachers in the class- room along with associated lessons developed by a teacher group. In addition, this year the LASM, will be opening a new planetarium / space theater in downtown Baton Rouge, Louisiana. We are currently working to bring live views of the heavens from the HRPO telescope to audiences attending planetarium shows and will be working closely with planetarium staff to develop shows that highlight LSU astronomy / space science research. During the presentation we will provide some details about our in- dividual projects, the overall structure of our program, establishing community links and some of the lessons we learned along the way. Finally, we would like to acknowl- edge NASA, Louisiana State University, the Louisiana Systemic Initiatives Program and the Louisiana Technology Innovation Fund for their support.

  16. The Neoproterozoic-Cambrian Paraguay Belt, central Brazil: Part I - New structural data and a new approach on the regional implications

    NASA Astrophysics Data System (ADS)

    Silva, Luiz José Homem D'el-Rey; Walde, Detlef Hans-Gerd; Saldanha, Davi Oliveira

    2016-04-01

    Together with the Araguaia and Brasília belts, the Paraguay belt forms in central Brazil, the Tocantins Province that is one of the largest orogens of western Gondwana. The Corumbá area occupies the site where the northern and southern parts of the Paraguay belt form, together with the Chiquitos-Tucavaca aulacogen (stretching E-W in the adjacent Bolivian territory) an R-R-R basin system opened-filled in the ~ 700/650-540 Ma interval within the Amazon-Rio Apa paleo-continent. The sedimentary (volcanic) rocks of the Jacadigo and Corumbá Groups found around the Corumbá city record part of the Neoproterozoic-Cambrian passive margin precursor of the Paraguay belt. Our pioneer structural analysis reveals that these rocks experienced progressive deformation (phases D1-D2-D3) and low-grade metamorphism during the Brasiliano Cycle (540-513 Ma). The crystalline basement was also involved, according to structural data and K-Ar ages in the literature. The paleo-passive margin was thickened during the D1-D2 deformation and was lately shortened (D3) in two orthogonal directions, SE-NW (D3P) and SW-NE (D3T). Developed co-axially and verging to NW, D1-D2-D3P structures record the closure of the basin precursor of the Paraguay belt, whereas D3T structures seem related to the inversion of the aulacogen. Although the tectonic transport to NW, as observed in the Corumbá area, matches the reported transport of Paraguay belt's supracrustal rocks towards the eastern margin of the Rio Apa block and Araguaia belt's rocks towards the Amazon craton, the transport direction is opposite in other parts of the Paraguay belt. Our comprehensive discussion of these facts brings to light profound regional implications.

  17. Checklist of aquatic and marshy Monocotyledons from the Araguaia River basin, Brazilian Cerrado

    PubMed Central

    Bove, Claudia

    2016-01-01

    Abstract Background The Araguaia River basin runs through the states of Goiás, Mato Grosso, Tocantins, and Pará, covering 373,000 Km2, mostly within the Brazilian Cerrado. The region has a wide variety of wetlands. The climate is characterized by high temperatures and strongly seasonal precipitation. There are two well defined seasons: the dry season (winter-spring) and the rainy season (summer- fall). The Araguaia River basin is dominated by plinthosoils that are found in low flat areas, poorly drained and prone to flooding, yielding wetland habitats of high plant diversity. Since the 1970s, human activities have led to reduction in both the diversity and area of wetlands. The construction of the Belém-Brasília highway and hydroelectric dams, as well as the expansion of agricultural and mining activities, have had major impacts on the region. New information The flora diversity data of the Araguaia River basin was developed through field work, herbarium research, and use of a database (Species Link). The resulting checklist of 162 aquatic and marshy monocotyledons from the Araguaia River basin represents 20 families and 50 genera. Cyperaceae (51 spp.), Poaceae (39 spp.), and Eriocaulaceae (16 spp.) are the most representative families. Life form analysis indicates that helophytes predominate (98 spp.; 60.5%). One hundred one species are native to tropical and/or subtropical America and twenty one are endemic to Brazil. Ninety-three species are new occurrences for the Araguaia River basin. Among them, three species are reported in the Brazilian Cerrado for the first time. This work contributes to the understanding of aquatic plant diversity in the Cerrado and other savanna-like vegetation physiognomies; environments and habitats poorly understood taxonomically and undercollected generally. PMID:27099550

  18. Petrographic and geochemical characterization of the granitic rocks of the Araguainha impact crater, Brazil

    NASA Astrophysics Data System (ADS)

    Silva, Dailto; Lana, Cristiano; Souza Filho, Carlos Roberto

    2016-03-01

    Petrographic and geochemical data obtained on the Araguainha impact crater (Goiás/Mato Grosso States, Brazil) indicate the existence of several molten products that originated during impact-induced congruent melting of an alkali-granite exposed in the inner part of the central uplift of the structure. Although previous studies have described these melts to some extent, there is no detailed discussion on the petrographic and geochemical variability in the granite and its impactogenic derivatives, and therefore, little is known about the geochemical behavior and mobility of trace elements during its fusion in the central part of the Araguainha crater. This paper demonstrates that the preserved granitoid exposed in the core of the structure is a magnesium-rich granite, similar to postcollisional, A-type granites, also found in terrains outside the Araguainha crater, in the Brasília orogenic belt. The molten products are texturally distinct and different from the original rock, but have very similar geochemical composition, making it difficult to separate these lithotypes based on concentrations of major and minor elements. This also applies for trace and rare earth elements (REE), thus indicating a high degree of homogenization during impact-induced congruent melting under high pressure and postshock temperature conditions. Petrographic observations, along with geochemical data, indicate that melting occurs selectively, where some of the elements are transported with the melt. Simultaneously, there is an effective dissolution of the rock (granite), which leads to entrainment of the most resistant solid phases (intact or partially molten minerals) into the melt. Minerals more resistant to melting, such as quartz and oxides, contribute substantially to a chemical balance between the preserved granite and the fusion products generated during the meteoritic impact.

  19. Influence of superheated water on the hydrogen bonding and crystallography of piperazine-based (Co)polyamides.

    PubMed

    Vinken, Esther; Terry, Ann E; Spoelstra, Anne B; Koning, Cor E; Rastogi, Sanjay

    2009-05-01

    Here we demonstrate that superheated water is a solvent for polyamide 2,14 and piperazine-based copolyamides up to a piperazine content of 62 mol %. The incorporation of piperazine allows for a variation of the hydrogen bond density without altering the crystal structure (i.e., the piperazine units cocrystallize with the PA2,14 units (Hoffmann, S.; Vanhaecht, B.; Devroede, J.; Bras, W.; Koning, C. E.; Rastogi, S. Macromolecules 2005, 38, 1797-1803). It is shown that the crystallization of PA2,14 from superheated water greatly influences the crystal structure. Water molecules incorporated in the PA2,14 crystal lattice cause a slip on the hydrogen bonded planes, resulting in a coexistence of a triclinic and a monoclinic crystal structure. On heating above the Brill transition, the water molecules exit from the lattice, restoring the triclinic crystal structure. With increasing piperazine content, and hence decreasing hydrogen bond density, the dissolution temperature decreases. It is only possible to grow single crystals from superheated water up to a piperazine content of 62 mol %. For these single crystals, the incorporation of water molecules in the vicinity of the amide group is seen by the presence of COO- stretch vibrations with FTIR spectroscopy. These vibrations disappear on heating above the Brill transition temperature, and the water molecules leave the amide groups. For copolyamides with more than 62 mol % piperazine, no Brill transition is observed, no single crystals can be grown from water, and no water molecules are observed in the vicinity of the amide groups (Vinken, E.; Terry, A. E.; Hoffmann, S.; Vanhaecht, B.; Koning, C. E.; Rastogi, S. Macromolecules 2006, 39, 2546-2552). The high piperazine content (co)polyamides have fewer hydrogen bond donors and are therefore less likely to have interactions with the water molecules. This work demonstrates the relation among the Brill transition, the dissolution of polyamide in superheated water, and its

  20. Dual Nature of Heat Flux in Stable Atmospheric Surface Layer

    NASA Astrophysics Data System (ADS)

    Srivastava, P.; Sharan, M.

    2015-12-01

    The behavior of heat flux (H) with respect to the stability parameter (ζ) in stable surface layer (SSL) is analyzed with in the framework of Monin-Obukhov similarity (MOS) theory. The analytical expressions of H are obtained as functions of wind speed (U) and wind shear (dU/dz) using the linear similarity functions and accordingly two cases, (i) U = δ (constant) and (ii) dU/dz = δ are considered. The mathematical analysis shows that the magnitude of H increases with ζ till it attains a maximum value at ζ =ζc and then starts decreasing with increasing stability suggesting the dual characteristic of heat flux with stability parameter. The point of maximum heat flux is found to be dependent on the roughness length (z0) as well as the height above the surface. An attempt has been made to analyze the sensitivity of this dual characteristic of H with ζ using the non-linear similarity functions. The analysis shows that the dual nature of H persists in the case of linear as well as non-linear similarity functions. However, the point of extremum appears to be dependent on the nature of the similarity functions. Turbulent data over a tropical site Ranchi (India) is analyzed to validate the observed nature of H with the theoretical nature as predicted by MOS. The analysis of observational data reveals the non-existence of any preferred stability state in SSL as speculated by Wang and Bras (2010, 2011) and supports the conclusions of Malhi 1995, Derbyshire 1999, van de Wiel et al. 2007, Basu et al. 2008, and van de Wiel et al. 2011. Thus, the non-uniqueness of MOS equations does not appear to be a mathematical artifact and it is consistent with the observations as far as the nature of heat flux with respect to stability parameter in SSL is concerned.

  1. Minimum cross-sectional stream power as the criteria of shaping 3-D network-scale landscape

    NASA Astrophysics Data System (ADS)

    Paik, K.

    2008-12-01

    It has been widely accepted that the minimum total energy expenditure (MTEE) [Rodríguez-Iturbe et al., 1992] is the important tendency in the formation of self-similar tree river networks. However, this formulation has simplified the 3-D nature of landscape adaptation as a 2-D network connectivity problem. As a result, MTEE cannot capture other signatures of landform such as meandering. This leads to an idea that there could be another optimality condition which can better represent landscape evolution than MTEE. In this study, I focused on the theory of minimum cross-sectional stream power (MCSP) [Chang and Hill, 1977] which has been successfully used in channel-scale problems. I investigated the applicability of this rule of MCSP to the network-scale landscape formation. To test this idea, I devised a dynamic 2-D genetic algorithm which can handle the adaptation of 3-D landscape over time. The result shows that the landscape formed under the criteria of both MCSP and MTEE exhibit self-similar tree structure of natural river networks. However, the landscape formed by MCSP criteria also exhibits the meandering pattern of natural streams, which cannot be captured by MTEE. Chang, H. H., and J. C. Hill (1977), Minimum stream power for rivers and deltas, Journal of the Hydraulics Division (ASCE), 103, 1375--1389. Rodríguez-Iturbe, I., A. Rinaldo, R. Rigon, R. L. Bras, A. Marani, and E. J. Ijjasz-Váquez (1992), Energy dissipation, runoff production, and the three-dimensional structure of river basins, Water Resour. Res., 28, 1095--1103.

  2. An investigation of ionospheric F region response in the Brazilian sector to the super geomagnetic storm of May 2005

    NASA Astrophysics Data System (ADS)

    de Abreu, A. J.; Sahai, Y.; Fagundes, P. R.; de Jesus, R.; Bittencourt, J. A.; Pillat, V. G.

    2011-10-01

    In this paper, we have investigated the responses of the ionospheric F region at equatorial and low latitude regions in the Brazilian sector during the super geomagnetic storm on 15-16 May 2005. The geomagnetic storm reached a minimum Dst of -263 nT at 0900 UT on 15 May. In this paper, we present vertical total electron content (vTEC) and phase fluctuations (in TECU/min) from Global Positioning System (GPS) observations obtained at Belém, Brasília, Presidente Prudente, and Porto Alegre, Brazil, during the period 14-17 May 2005. Also, we present ionospheric parameters h'F, hpF2, and foF2, using the Canadian Advanced Digital Ionosonde (CADI) obtained at Palmas and São José dos Campos, Brazil, for the same period. The super geomagnetic storm has fast decrease in the Dst index soon after SSC at 0239 UT on 15 May. It is a good possibility of prompt penetration of electric field of magnetospheric origin resulting in uplifting of the F region. The vTEC observations show a trough at BELE and a crest above UEPP, soon after SSC, indicating strengthening of nighttime equatorial anomaly. During the daytime on 15 and 16 May, in the recovery phase, the variations in foF2 at SJC and the vTEC observations, particularly at BRAZ, UEPP, and POAL, show large positive ionospheric storm. There is ESF on the all nights at PAL, in the post-midnight (UT) sector, and phase fluctuations only on the night of 14-15 May at BRAZ, after the SSC. No phase fluctuations are observed at the equatorial station BELE and low latitude stations (BRAZ, UEPP, and POAL) at all other times. This indicates that the plasma bubbles are generated and confined on this magnetically disturbed night only up to the low magnetic latitude and drifted possibly to west.

  3. Investigation of a strong positive ionospheric storm during geomagnetic disturbances occurred in the Brazilian sector

    NASA Astrophysics Data System (ADS)

    de Abreu, A. J.; Sahai, Y.; Fagundes, P. R.; de Jesus, R.; Bittencourt, J. A.; Pillat, V. G.

    2012-12-01

    In this paper, we have investigated the responses of the ionospheric F region at equatorial and low latitude regions in the Brazilian sector during the super geomagnetic storm on 15-16 May 2005. The geomagnetic storm reached a minimum Dst of -263 nT at 0900 UT on 15 May. In this paper, we present vertical total electron content (vTEC) and phase fluctuations (in TECU/min) from Global Positioning System (GPS) observations obtained at Belém (BELE), Brasília (BRAZ), Presidente Prudente (UEPP), and Porto Alegre (POAL), Brazil, during the period 14-17 May 2005. Also, we present ionospheric parameters h'F, hpF2, and foF2, using the Canadian Advanced Digital Ionosonde (CADI) obtained at Palmas (PAL) and São José dos Campos (SJC), Brazil, for the same period. The super geomagnetic storm has fast decrease in the Dst index soon after SSC at 0239 UT on 15 May. It is a good possibility of prompt penetration of electric field of magnetospheric origin resulting in uplifting of the F region. The vTEC observations show a trough at BELE and a crest above UEPP, soon after SSC, indicating strengthening of nighttime equatorial anomaly. During the daytime on 15 and 16 May, in the recovery phase, the variations in foF2 at SJC and the vTEC observations, particularly at BRAZ, UEPP, and POAL, show large positive ionospheric storm. There is ESF on the all nights at PAL, in the post-midnight (UT) sector, and phase fluctuations only on the night of 14-15 May at BRAZ, after the SSC. No phase fluctuations are observed at the equatorial station BELE and low latitude stations (BRAZ, UEPP, and POAL) at all other times. This indicates that the plasma bubbles are generated and confined on this magnetically disturbed night only up to the low magnetic latitude and drifted possibly to west.

  4. La maladie de Hirayama: à propos de quatre observations tunisiennes et revue de la literature

    PubMed Central

    Amor, Sana Ben; Hassine, Anis; Chatti, Ines; Khefifi, Anissa; Doggui, Mohamed; Harzallah, Mohamed Salah; Benammou, Sofien

    2015-01-01

    Nous rapportons les aspects cliniques et électriques de la maladie de Hirayama en Tunisie à travers une série de quatre observations diagnostiquées au service de neurologie Sahloul. Il s'agit de quatre femmes. L’âge moyen était 30,25 ans avec des extrêmes de 27 et 37 ans. Une patiente avait un antécédent de traumatisme cervical, trois avaient une profession favorisant la position prolongée du rachis cervical en flexion. Un déficit moteur distal et une amyotrophie de la main et de l'avant bras droits d'installation progressive étaient observés dans tous les cas. Il n'avait ni des troubles sensitifs objectifs ni de modification des reflexes ostéotendineux et cutanés. L'EMG montrait une dénervation motrice dans le territoire des muscles dépendants des racines C7, C8, et D1. L'IRM cervicale était sans anomalie dans tous les cas. L’évolution était marquée par la bilatéralisation de la symptomatologie chez une patiente et une stabilisation clinique chez les autres. Ainsi, les aspects cliniques et électriques de la maladie de Hirayama dans cette série tunisienne sont comparables à ceux rapportés dans la littérature en dehors d'une atteinte strictement féminine. PMID:26185570

  5. Poussée de maladie de Kaposi et élévation du CA 19-9: penser à la tuberculose!

    PubMed Central

    Ajili, Faida; Hariz, Héla; Souissi, Asmahen; Abid, Rim; Boussetta, Najeh; Laabidi, Besma; Battikh, Riadh; Louzir, Bassem; Othmani, Salah

    2013-01-01

    La maladie de Kaposi (MK) est une entité pathologique qui peut survenir chez les patients VIH positifs et dans le cadre d'une immunodépression, d'origine tuberculeuse très rarement. On décrit le cas d'une MK chez un patient VIH négatif au décours d'une tuberculose. Nous rapportons le cas d'un patient âgé de 81 ans, VIH négatif, ayant présenté deux nodules angiomateux de l'avant bras gauche dont la biopsie cutanée était en faveur d'une MK. L’évolution était marquée 2 mois plus tard, par l'apparition de placards angiomateux extensifs des deux membres supérieurs et d'adénopathies cervicales jugulo-carotidiennes bilatérales. La biopsie ganglionnaire était en faveur d'une tuberculose ganglionnaire. Par ailleurs, il avait un taux sérique élevé des CA 19-9. La régression de l’étendue des lésions au niveau des membres supérieurs et la normalisation du taux sérique des CA 19-9 ont été obtenues sous traitement anti-tuberculeux. Chez les patients atteints d'une MK avec une élévation des CA 19-9, il faut penser à la tuberculose. PMID:24711871

  6. First record of a nematode Metastrongyloidea (Aelurostrongylus abstrusus larvae) in Achatina (Lissachatina) fulica (Mollusca, Achatinidae) in Brazil.

    PubMed

    Thiengo, Silvana C; Fernandez, Monica A; Torres, Eduardo J L; Coelho, Pablo M; Lanfredi, Reinalda M

    2008-05-01

    Achatina (Lissachatina) fulica was introduced in Brazil in the 1980s for commercial purposes ("escargot" farming) and nowadays, mainly by human activity, it is widespread in at least 23 out of 26 Brazilian states and Brasília, including the Amazonian region and natural reserves, where besides a general nuisance for people it is a pest and also a public health concern, since it is one of the natural intermediate host of Angiostrongylus cantonensis, ethiological agent of the meningoencephalitis in Asia. As Brazil is experiencing the explosive phase of the invasion, the Laboratório de Malacologia do Instituto Oswaldo Cruz/Fiocruz has been receiving samples of these molluscs for identification and search for Angiostrongylus cantonensis and Angiostrongylus costaricensis larvae. While examining samples of A. fulica different nematode larvae were obtained, including Aelurostrongylus, whose different species are parasites of felids, dogs, primates, and badger. Morphological and morphometric analyses presented herein indicated the species Aelurostrongylus abstrusus, as well as the occurrence of other nematode larvae (Strongyluris-like) found in the interior of the pallial cavity of A. fulica. This is the first report in Brazil of the development of A. abstrusus infective larvae in A. fulica evidencing the veterinary importance of this mollusc in the transmission of A. abstrusus to domestic cats. Since the spread of A. fulica is pointed out in the literature as one of the main causative spread of the meningoencephalitis caused by A. cantonensis the authors emphasize the need of sanitary vigilance of snails and rats from vulnerable areas for A. cantonensis introduction as the port side areas. PMID:18078952

  7. Cost estimate of hospital stays for premature newborns in a public tertiary hospital in Brazil

    PubMed Central

    Desgualdo, Claudia Maria; Riera, Rachel; Zucchi, Paola

    2011-01-01

    OBJECTIVES: To estimate the direct costs of hospital stays for premature newborns in the Interlagos Hospital and Maternity Center in São Paulo, Brazil and to assess the difference between the amount reimbursed to the hospital by the Unified Health System and the real cost of care for each premature newborn. METHODS: A cost-estimate study in which hospital and professional costs were estimated for premature infants born at 22 to 36 weeks gestation during the calendar year of 2004 and surviving beyond one hour of age. Direct costs included hospital services, professional care, diagnoses and therapy, orthotics, prosthetics, special materials, and blood products. Costs were estimated using tables published by the Unified Health System and the Brasíndice as well as the list of medical procedures provided by the Brazilian Classification of Medical Procedures. RESULTS: The average direct cost of care for initial hospitalization of a premature newborn in 2004 was $2,386 USD. Total hospital expenses and professional services for all premature infants in this hospital were $227,000 and $69,500 USD, respectively. The costs for diagnostic testing and blood products for all premature infants totaled $22,440 and $1,833 USD. The daily average cost of a premature newborn weighing less than 1,000 g was $115 USD, and the daily average cost of a premature newborn weighing more than 2,500 g was $89 USD. Amounts reimbursed to the hospital by the Unified Health System corresponded to only 27.42% of the real cost of care. CONCLUSIONS: The cost of hospital stays for premature newborns was much greater than the amount reimbursed to the hospital by the Unified Health System. The highest costs corresponded to newborns with lower birth weight. Hospital costs progressively and discretely decreased as the newborns' weight increased. PMID:22012050

  8. Dual universe and hyperboloidal relative velocity surface arising from extended special relativity

    NASA Astrophysics Data System (ADS)

    Hill, James M.; Cox, Barry J.

    2014-12-01

    In two recent and completely independent articles (Hill and Cox in Proc R Soc A 468:4174, 2012; Vieira in Rev Bras Ensino F's 34(3):1-15, 2012), the authors propose an extension of the Lorentz transformations of special relativity which are applicable to velocities in excess of the speed of light and do not involve the need to introduce imaginary quantities which are difficult to reconcile with everyday experience. These independent derivations, obtained from entirely distinct perspectives, mean that there is now some commonality of agreement in the basic equations underlying superluminal motion. One consequence of the new theories is that the standard special relativity formula for the addition of relative velocities also applies for velocities in excess of the speed of light. The new theories are based on the assumption that for any two inertial frames separated by an infinite relative velocity, the product of the two measured velocities for the same particle must necessarily be the square of the speed of light. Here, we amplify the major physical consequences embodied in the theory, including the surprising and novel idea of the co-existence of two "worlds", such that in a subluminal world, everything is travelling with speeds less than the speed of light, while in the superluminal world, everything is travelling with speeds greater than the speed of light. We also establish the remarkable result that the reciprocal surface for the relative velocity formula can be re-orientated as a fully axially symmetric hyperboloidal surface, the full physical implications of which are not altogether transparent.

  9. Tomographic Evaluation of Mandibular Thickness on Premolar and Molar Regions Related to Monocortical Screws.

    PubMed

    Ribeiro, Jonathan; Marin, Charles; Homsi, Nicolas; Rocha Junior, Hernando; Magacho, Luiz; Fidalgo, Guto; Zanela, Manuella

    2016-06-01

    The aim of this study was to measure the thickness of the mandible from the external cortical plate to the teeth roots on premolar and molar regions using CT scan to determine the safety margin for the application of monocortical screws for internal rigid fixation. Thirty-one patients underwent CT-scan imaging for surgical planning. The images were used to measure bilaterally the distance from the external cortex of the mandible to the roots of teeth on premolar and molar region by means of Dental Slice software (Bioparts Prototipagem Biomedica, Brasília, DF, Brazil). Mean, median, standard deviation, one-way ANOVA and post hoc Tukey's test were used for statistical analysis. No statistical differences for thickness were found between right and left side (p = 0.1652). The mean thickness for the left side was 4.17 ± 1.68 mm and for right side 3.93 ± 1.49 mm. Increase in mandibular thickness from anterior to posterior regions in both sides was observed and statistical difference was found among the different groups according to the measured region (p < 0.05). The present results can predict the safety zone for the use of monocortical screws in the mandible, but the use of CT scan is imperative and individual analysis is desired owing to anatomical variations. Further studies with larger samples are necessary to confirm these data and should include other anatomic structures, different regions of mandible/maxilla, as well as other ethnic groups. PMID:27162564

  10. Association between temporomandibular disorders and abnormal head postures.

    PubMed

    Faulin, Evandro Francisco; Guedes, Carlos Gramani; Feltrin, Pedro Paulo; Joffiley, Cláudia Maria Mithie Suda Costa

    2015-01-01

    This study examines the possible correlation between the prevalence of temporomandibular disorders (TMD) and different head postures in the frontal and sagittal planes using photographs of undergraduate students in the School of Dentistry at the Universidade de Brasília - UnB, Brazil. In this nonrandomized, cross-sectional study, the diagnoses of TMD were made with the Research Diagnostic Criteria (RDC)/TMD axis I. The craniovertebral angle was used to evaluate forward head posture in the sagittal plane, and the interpupillary line was used to measure head tilt in the frontal plane. The measurements to evaluate head posture were made using the Software for the Assessment of Posture (SAPO). Students were divided into two study groups, based on the presence or absence of TMD. The study group comprised 46 students and the control group comprised 80 students. Data about head posture and TMD were analyzed with the Statistical Package for the Social Sciences, version 13. Most cases of TMD were classified as degenerative processes (group III), followed by disk displacement (group II) and muscle disorders (group I). There was no sex predominance for the type of disorder. No association was found between prevalence rates for head postures in the frontal plane and the occurrence of TMD. The same result was found for the association of TMD diagnosis with craniovertebral angle among men and women, and the group that contained both men and women. Abnormal head postures were common among individuals both with and without TMD. No association was found between head posture evaluated in the frontal and sagittal planes and TMD diagnosis with the use of RDC/TMD. PMID:26017489

  11. Genetic parameters and breeding strategies for high levels of iron and zinc in Phaseolus vulgaris L.

    PubMed

    Martins, S M; Melo, P G S; Faria, L C; Souza, T L P O; Melo, L C; Pereira, H S

    2016-01-01

    One of the current focus of common bean breeding programs in Brazil is to increase iron (FeC) and zinc content (ZnC) in grains. The objectives of this study were to estimate genetic parameters for FeC and ZnC in common bean, verify the need for conducting multi-site evaluation tests, identify elite lines that combine high FeC and ZnC with good adaptability, stability, and agronomic potential, and examine the genetic association between FeC and ZnC. Elite lines (140) were evaluated for important agronomic traits in multiple environments. In one trial, FeC and ZnC were evaluated and genetic parameters were estimated. Based on the high heritability estimates and significant selection gains obtained, the conditions for a successful selection was favorable. Of the 140 evaluated lines, 17 had higher FeC and ZnC, and were included in the validation test (2013, five environments), specifically for the evaluation of FeC and ZnC. The line by environment interaction for FeC and ZnC was detected, but it was predominantly simple. The environmental effect strongly influenced FeC and ZnC . The environment Brasília/rainy season was selected as the best evaluation site for preliminary tests for FeC and ZnC, because it resulted in similar conclusions as the mean of the five environments. The lines CNFP 15701 and CNFC 15865 had higher FeC and ZnC and were highly adaptable and stable, and are recommended for utilization in breeding programs. The lines CNFC 15833, CNFC 15703, and CNFP 15676 showed excellent combined agronomic and nutritional traits, and were selected for the development of biofortified cultivars. Additionally, the genetic association between FeC and ZnC was detected. PMID:27323172

  12. Inter-relationship between scaling exponents for describing self-similar river networks

    NASA Astrophysics Data System (ADS)

    Yang, Soohyun; Paik, Kyungrock

    2015-04-01

    Natural river networks show well-known self-similar characteristics. Such characteristics are represented by various power-law relationships, e.g., between upstream length and drainage area (exponent h) (Hack, 1957), and in the exceedance probability distribution of upstream area (exponent ɛ) (Rodriguez-Iturbe et al., 1992). It is empirically revealed that these power-law exponents are within narrow ranges. Power-law is also found in the relationship between drainage density (the total stream length divided by the total basin area) and specified source area (the minimum drainage area to form a stream head) (exponent η) (Moussa and Bocquillon, 1996). Considering that above three scaling relationships all refer to fundamental measures of 'length' and 'area' of a given drainage basin, it is natural to hypothesize plausible inter-relationship between these three scaling exponents. Indeed, Rigon et al. (1996) demonstrated the relationship between ɛ and h. In this study, we expand this to a more general ɛ-η-h relationship. We approach ɛ-η relationship in an analytical manner while η-h relationship is demonstrated for six study basins in Korea. Detailed analysis and implications will be presented. References Hack, J. T. (1957). Studies of longitudinal river profiles in Virginia and Maryland. US, Geological Survey Professional Paper, 294. Moussa, R., & Bocquillon, C. (1996). Fractal analyses of tree-like channel networks from digital elevation model data. Journal of Hydrology, 187(1), 157-172. Rigon, R., Rodriguez-Iturbe, I., Maritan, A., Giacometti. A., Tarboton, D. G., & Rinaldo, A. (1996). On Hack's Law. Water Resources Research, 32(11), 3367-3374. Rodríguez-Iturbe, I., Ijjasz-Vasquez, E. J., Bras, R. L., & Tarboton, D. G. (1992). Power law distributions of discharge mass and energy in river basins. Water Resources Research, 28(4), 1089-1093.

  13. Mortality due to respiratory diseases in the elderly after influenza vaccination campaigns in the Federal District, Brazil, 1996-2009 *

    PubMed Central

    Scoralick, Francisca Magalhães; Piazzolla, Luciana Paganini; Pires, Liana Laura; Neri, Cleudsom; de Paula, Wladimir Kummer

    2013-01-01

    OBJECTIVE: To compare mortality rates due to respiratory diseases among elderly individuals residing in the Federal District of Brasília, Brazil, prior to and after the implementation of a national influenza vaccination campaign. METHODS: This was an ecological time series analysis. Data regarding the population of individuals who were over 60 years of age between 1996 and 2009 were obtained from official databases. The variables of interest were the crude mortality rate (CMR), the mortality rate due to the respiratory disease (MRRD), and the proportional mortality ratio (PMR) for respiratory diseases. We performed a qualitative analysis of the data for the period prior to and after the implementation of the vaccination campaign (1996-1999 and 2000-2009, respectively). RESULTS: The CMR increased with advancing age. Over the course of the study period, we observed reductions in the CMR in all of the age brackets studied, particularly among those aged 80 years or older. Reductions in the MRRD were also found in all of the age groups, especially in those aged 80 years or older. In addition, there was a decrease in the PMR for respiratory diseases in all age groups throughout the study period. The most pronounced decrease in the PMR for respiratory diseases in the ≥ 70 year age bracket occurred in 2000 (immediately following the implementation of the national vaccination campaign); in 2001, that rate increased in all age groups, despite the greater adherence to the vaccination campaign in comparison with that recorded for 2000. CONCLUSIONS: Influenza vaccination appears to have a positive impact on the prevention of mortality due to respiratory diseases, particularly in the population aged 70 or over. PMID:23670505

  14. La prise en charge des morsures de chien chez les enfants

    PubMed Central

    Sabhaney, Vikram; Goldman, Ran D.

    2012-01-01

    Résumé Question Une fillette de 4 ans jouait avec le chien de ses voisins. Le chien s’est excité et a mordu la jeune fille à l’avant-bras, y laissant une plaie punctiforme. À cause cette blessure, elle s’est présentée à mon bureau. Devrais-je la traiter avec des antibiotiques? Quel antibiotique faut-il utiliser et pendant combien de temps? Réponse L’administration d’antibiotiques prophylactiques est indiquée lorsqu’on a procédé à une suture primitive de la morsure, que la plaie est de gravité modérée à sévère, qu’elle est punctiforme (particulièrement s’il y a eu pénétration de l’os, de la gaine tendineuse ou de l’articulation), pour les morsures au visage, aux mains, aux pieds ou aux parties génitales ou lorsque les victimes sont immunodéprimées ou souffrent d’asplénisme. L’antibiotique de première intention est l’amoxicilline-clavulanate. La prophylaxie appropriée antitétanique et contre la rage devrait faire partie des soins chez un patient qui a été mordu par un chien, tout comme le débridement local et le nettoyage complet de la plaie.

  15. Developmental expression of vascular endothelial growth factor receptor 3 and vascular endothelial growth factor C in forebrain.

    PubMed

    Ward, M C; Cunningham, A M

    2015-09-10

    Increased understanding of the neurovascular niche suggests that development of the central nervous system (CNS) and its vasculature is coordinated through shared regulatory factors. These include the vascular endothelial growth factor (VEGF) family, reported to promote neuroproliferation and neuroprotection in addition to angiogenesis via its receptors VEGFR1-3. VEGFR3, a mediator of lymphangiogenesis, is expressed in murine and rat brain from early gestation, has been associated with neural progenitors and neurons (Choi et al., 2010) and oligodendroglia (Le Bras et al., 2006) in the developing cortex and is reported to mediate adult neurogenesis in the subventricular zone (SVZ) (Calvo et al., 2011). The early expression pattern of VEGFR3 protein and its cellular associations has not as yet been comprehensively reported. We describe the temporal expression of VEGFR3 protein at a cellular level and its close association with its VEGFC ligand, determined by double-labeling immunohistochemistry in the developing rat brain from embryonic day (E) 13 to postnatal day (P) 23. We found high expression of VEGFR3 in the ventricular zone and along radial glia in early gestation in association with neural stem cells and neuroblasts. Similar expression patterns were seen in the immature olfactory bulb and optic cup. In later development we found less expression by neural progenitors in proliferative regions including the SVZ and dentate gyrus of the hippocampus. In contrast, VEGFR3 expression increased with development in the cortex in neurons and astrocytes, and appeared in the emerging population of oligodendroglial progenitors. High expression in ventricular ependyma, choroid plexus and pigmented retinal epithelium was noted from E18. VEGFC ligand was found in association with VEGFR3 throughout development, with highest expression in embryonic stages. Our findings suggest an important role for VEGFC/VEGFR3 signaling in neuronal proliferation in early forebrain development

  16. Seasonality of the activity pattern of Callithrix penicillata (Primates, Callitrichidae) in the cerrado (scrub savanna vegetation).

    PubMed

    Vilela, S L; de Faria, D S

    2004-05-01

    Two wild groups of Callithrix penicillata, the Black Pincelled Marmoset, were observed from January to September 1998, in two areas, one an area of dense scrub savanna vegetation (cerrado) and the other, a semidecidual woodland (cerradão), both within the boundaries of the Ecological Reserve of IBGE (Brazilian Institute of Geography and Statistics), in an environmentally protected area, the APA (Portuguese abbreviation for "environmental protected area") Gama/Cabeça-de-Veado, Brasília, DF. The behavioral data collected during the rainy (January 15 to April 15) and dry season (June 1 to September 15) were compared. Because of the proximity to the Reserve facilities, the group from the dense scrub savanna vegetation (CD) was submitted to antropic impacts different from the group in the semidecidual woodland (CE), which was using as territory an area that had been suffering from man-made fires every two years as part of a long-term experimental project on fire impacts. The behavioral data was quantified by instantaneous cross-section ("scan sampling") every ten minutes with records of locomotion, rest, foraging for insects, use of exudate, and feeding. During the whole year, the greatest percentage of time spent by CE and CD was in foraging for insects, with 44% and 39%, respectively. It was evident when comparing the data for the two seasons that, for both groups, foraging for insects was more intense during the dry season, possibly to complement the shortage of food, and locomotion increased during the rainy season. The greater the availability and distribution of fruit in the areas, the greater the locomotion of the groups to obtain these resources. None of the other behavioral patterns, including the use of exudates, presented significant differences between the two seasons. Both groups foraged more frequently during the dry season and locomoted more during the rainy one. PMID:15462311

  17. Use of GIS for Earthquakes in Brazil

    NASA Astrophysics Data System (ADS)

    Franca, G. S.; Algarte, K. T.; Assumpcao, M.; Barbosa, J. R.; Roig, H. L.; Pascual, M. F.; Vasconcelos, A. E.; Ferreira, J. M.; Ribotta, L. C.; do Nascimento, A. F.; Pavao, C. G.

    2011-12-01

    We present geoprocessing techniques to monitor and analyse earthquakes in Brazil. We constructed a georeferenced database called SIGSIBRA using PostgreSQL + PostGIS softwares, and fed by information from the SISBRA earthquake catalog, IBGE geographical data and CPRM geological data. The SISBRA catalog was built from the book "Sismicidade Brasileira" (Berrocal et al, 1984), updated with the Brazilian seismic bulletins from the Brazilian Geophysical Journal up to 1995, and especially with the data from seismographic monitoring activities of the University of Brasília-SIS/UnB, the Federal University of Rio Grande do Norte-UFRN, the University of Sao Paulo-USP and the Institute for Technological Research (IPT). Earthquakes occur in Brazil with moderate to low magnitudes. Besides natural earthquakes, seismic activity triggered by water dams must also be monitored. With the growing number and size of Brazilian dams (because of the many rivers, favorable topography and "clean" energy) concern with reservoir triggered seismicity is expected to increase. Approval for the construction of a hydropower plant requires seismic hazard assesmment prepared by an interdisciplinary team, with a large contribution of geoprocessing specialists. Therefore, it is important to study the characteristics of this seismicity, so that these professionals can avoid or mitigate potential environmental and social harm to communities on the margins of large dams. Thus the SIGSIBRA system can generate spatial analysis of its events, such as intensity estimation of "Kernel" points distribution; spatial statistics; spatial autocorrelation (Morans I) and correlations with geological structures, making it possible to characterize important aspects of the Brazilian seismicity. Finally, we show the statistical analysis of the database through the program ZMAP and estimate the intraplate seismogenic zones in Brazil.

  18. Farmyard Manure and Fertilizer Effects on Seed Potato (Solanum tuberosum L.) Yield in Green House Production

    NASA Astrophysics Data System (ADS)

    László, M.

    2009-04-01

    Nowadays is widely well know that the potato is an important vegetable crop at Brazíl. It is grown on about 173.000 ha, with total yield of 2.6 million tons year-1. The average yield is 15 t ha-1. This level is very low because degeneration of crop is rapid under high temperature and high viruses pressure. Therefore seed potato propagation and production is principal on consumption potato production. This is why we found it necessary to develop it. The latossolo vermelho soil-farmyard manure- burnt rice straw-fertilizer 4N:14P:8K greenhouse pot trial was set up at the National Vegetable Crops Research Center, Brasília-DF, Brazíl in 1990. The methods of the experiments were soil x farmyard manure x burnt rice straw, soil x 4N:14P:8K fertilizer and soil x farmyard manure x burnt rice straw x 4N:14P:8K fertilizer on randomized block design in total 29 combination of treatments in 5, 5 and 3 repetitions with in a total parcel of 116. According to chemical analysis of the a., soil, b., farmyard manure and c., burnt rice straw the agrochemistry parameters were as follows (estimated datas): a., latossolo vermelho soil: CaCO3 0.3-0.7%, humo 0.9-1.0%, pH (H2O) 5.3, pH (KCl) 4.5, AL- P2O5 3.2-3.5 mg kg-1, AL- K2O 180 mg kg-1, Mg (KCl) 70 mg kg-1, EDTA-Zn 0.5-0.8 mg kg-1, EDTA-Cu 0.5-0.6 mg kg-1, b., farmyard manure: N 1.8 g kg-1, P2O5 2.0 g kg-1, K2O 4.0 g kg-1, c., burnt rice straw: N 0.8 g kg-1, P2O5 7.0 g kg-1, K2O 4.5 g kg-1. The experimental datas were estimated by analysis of variance, ANOVA and MANOVA. The main conclusions were as follows: 1. Mixture of 80% latossolo vermelho, 10% burnt rice straw and 10% farmyard manure were shown best performance on seed potato productivity. The piece of tubers with a 0-20 mm (consumption seeds) was increased by 77%. 2. Total seed potato number was reached maximum at 10.8 g pot-1 4N:14P:8K fertilizer regarding to average of treatments with a 33%. 3. Dry biomassa production plant-1 was decreased by high dose of 4N:14P:8K

  19. Neandertal nasal structures and upper respiratory tract "specialization".

    PubMed

    Franciscus, R G

    1999-02-16

    Schwartz and Tattersall [Schwartz, J. H. & Tattersall, I. (1996) Proc. Natl. Acad. Sci. USA 93, 10852-10854] have argued for a previously unrecognized suite of autapomorphies in the internal nasal region of Neandertals that make them unique, not only among hominids, but possibly among all other terrestrial mammals. These purported autapomorphies include (i) the development of an internal nasal margin bearing a well developed and vertically oriented medial projection; (ii) a pronounced medial swelling of the lateral nasal wall into the posterior nasal cavity; and (iii) the lack of an ossified roof over the lacrimal groove. In addition, Laitman et al. [Laitman, J. T., Reidenberg, J. S., Marquez, S. & Gannon, P. J. (1996) Proc. Natl. Acad. Sci. USA 93, 10543-10545] pointed to these features as evidence for upper respiratory tract specializations among the Neandertals, indicating potential differences in behavior compared with modern humans. Critically reviewing the anatomical basis for Schwartz and Tattersall's contentions reveals several serious problems with their analysis, including (i) reliance on specimens with damaged, incomplete, or, in some cases, entirely absent relevant anatomy; (ii) failure to consider primary vs. secondary spatial consequences in nasal trait conceptualization; and (iii) failure to consider actual ranges of variation in these traits in both fossil and recent humans. Accordingly, the unique phylogenetic and adaptive "specializations" attributed to Neandertal internal nasal structures are unwarranted. PMID:9990106

  20. Edge ratio and community structure in networks

    NASA Astrophysics Data System (ADS)

    Cafieri, Sonia; Hansen, Pierre; Liberti, Leo

    2010-02-01

    A hierarchical divisive algorithm is proposed for identifying communities in complex networks. To that effect, the definition of community in the weak sense of Radicchi [Proc. Natl. Acad. Sci. U.S.A. 101, 2658 (2004)] is extended into a criterion for a bipartition to be optimal: one seeks to maximize the minimum for both classes of the bipartition of the ratio of inner edges to cut edges. A mathematical program is used within a dichotomous search to do this in an optimal way for each bipartition. This includes an exact solution of the problem of detecting indivisible communities. The resulting hierarchical divisive algorithm is compared with exact modularity maximization on both artificial and real world data sets. For two problems of the former kind optimal solutions are found; for five problems of the latter kind the edge ratio algorithm always appears to be competitive. Moreover, it provides additional information in several cases, notably through the use of the dendrogram summarizing the resolution. Finally, both algorithms are compared on reduced versions of the data sets of Girvan and Newman [Proc. Natl. Acad. Sci. U.S.A. 99, 7821 (2002)] and of Lancichinetti [Phys. Rev. E 78, 046110 (2008)]. Results for these instances appear to be comparable.

  1. General topology meets model theory, on and

    PubMed Central

    Malliaris, Maryanthe; Shelah, Saharon

    2013-01-01

    Cantor proved in 1874 [Cantor G (1874) J Reine Angew Math 77:258–262] that the continuum is uncountable, and Hilbert’s first problem asks whether it is the smallest uncountable cardinal. A program arose to study cardinal invariants of the continuum, which measure the size of the continuum in various ways. By Gödel [Gödel K (1939) Proc Natl Acad Sci USA 25(4):220–224] and Cohen [Cohen P (1963) Proc Natl Acad Sci USA 50(6):1143–1148], Hilbert’s first problem is independent of ZFC (Zermelo-Fraenkel set theory with the axiom of choice). Much work both before and since has been done on inequalities between these cardinal invariants, but some basic questions have remained open despite Cohen’s introduction of forcing. The oldest and perhaps most famous of these is whether “,” which was proved in a special case by Rothberger [Rothberger F (1948) Fund Math 35:29–46], building on Hausdorff [Hausdorff (1936) Fund Math 26:241–255]. In this paper we explain how our work on the structure of Keisler’s order, a large-scale classification problem in model theory, led to the solution of this problem in ZFC as well as of an a priori unrelated open question in model theory. PMID:23836659

  2. Magnetic Tests For Magnetosome Chains In Martian Meteorite ALH84001

    NASA Astrophysics Data System (ADS)

    Weiss, B. P.; Kim, S.; Kirschvink, J. L.; Sankaran, M.; Kobayashi, A.; Komeili, A.

    2003-12-01

    Transmission electron microscopy studies have been used to argue that magnetites in carbonates from Martian meteorite ALH84001 have a composition and morphology indistinguishable from that of magnetotactic bacteria and their magnetofossils (1). It has even been claimed from scanning electron microscopy imaging that some ALH84001 magnetites are aligned in chains (2). If true, this would provide dramatic support for the magnetofossil hypothesis because alignment in chains is perhaps the most distinctive of the six crystallographic properties thought to be collectively unique to magnetosomes. The leading alternative hypothesis is that the ALH84001 magnetites are the inorganic products of shock-heating of the carbonates (3, 4). Here we use three rock magnetic techniques-low-temperature cycling, the Moskowitz test (5), and ferromagnetic resonance (FMR)-to demonstrate that most or all of the magnetites in ALH84001 are unusually pure and fine-grained but are not arranged in magnetosome chains. 1. K. L. Thomas-Keprta et al., Geochim. Cosmochim. Acta 64, 4049-4081 (2000). 2. I. E. Friedmann, J. Wierzchos, C. Ascaso, M. Winklhofer, Proc. Natl. Acad. Sci. USA 98, 2176-2181 (2001). 3. D. C. Golden et al., Am. Mineral. 83, 370-375 (2001). 4. D. J. Barber, E. R. D. Scott, Proc. Natl. Acad. Sci. USA 99, 6556-6561 (2002). 5. B. M. Moskowitz, R. B. Frankel, D. A. Bazylinski, Earth Planet. Sci. Lett. 120, 283-300 (1993).

  3. Significance of endangered and threatened plant natural products in the control of human disease

    PubMed Central

    Ibrahim, Mohamed Ali; Na, MinKyun; Oh, Joonseok; Schinazi, Raymond F.; McBrayer, Tami R.; Whitaker, Tony; Doerksen, Robert J.; Newman, David J.; Zachos, Louis G.; Hamann, Mark T.

    2013-01-01

    One in five of the world’s plant species is threatened with extinction according to the 2010 first global analysis of extinction risk. Tilman et al. predicted a massive ecological change to terrestrial plants within the next 50–100 y, accompanied by an increase in the number of global plant species facing extinction [Tilman D, et al. (2001) Proc Natl Acad Sci USA 98(10):5433–5440]. Most of the drug-producing plant families contain endangered species never previously studied for their utility to human health, which strongly validates the need to prioritize protection and assessment of these fragile and endangered groups [Zhu F, et al. (2011) Proc Natl Acad Sci USA 108(31):12943–12948]. With little prior attention given to endangered and rare plant species, this report provides strong justification for conservation of the rare plant Diplostephium rhododendroides Hieron., as well as other potential drug-producing endangered species in this and other groups. PMID:24082148

  4. Advanced Communications Architecture Demonstration Made Significant Progress

    NASA Technical Reports Server (NTRS)

    Carek, David Andrew

    2004-01-01

    Simulation for a ground station located at 44.5 deg latitude. The Advanced Communications Architecture Demonstration (ACAD) is a concept architecture to provide high-rate Ka-band (27-GHz) direct-to-ground delivery of payload data from the International Space Station. This new concept in delivering data from the space station targets scientific experiments that buffer data onboard. The concept design provides a method to augment the current downlink capability through the Tracking Data Relay Satellite System (TDRSS) Ku-band (15-GHz) communications system. The ACAD concept pushes the limits of technology in high-rate data communications for space-qualified systems. Research activities are ongoing in examining the various aspects of high-rate communications systems including: (1) link budget parametric analyses, (2) antenna configuration trade studies, (3) orbital simulations (see the preceding figure), (4) optimization of ground station contact time (see the following graph), (5) processor and storage architecture definition, and (6) protocol evaluations and dependencies.

  5. Tendências De Teses e Dissertações Sobre Educação em Astronomia No Brasil

    NASA Astrophysics Data System (ADS)

    Bretones, Paulo Sergio; Megid Neto, Jorge

    2005-07-01

    Apresentam-se os resultados de uma pesquisa do tipo estado da arte sobre teses e dissertações defendidas no Brasil e relativas ao ensino de Astronomia, com objetivo de identificar essa produção e conhecer as principais tendências da pesquisa nesse campo. Foram localizadas 13 dissertações de mestrado e 3 teses de doutorado, as quais foram estudadas em função dos seguintes aspectos: isntituição, ano de defesa, nível escolar abrangido no estudo, foco temático do estudo e gênero de trabalho acadêmico. Pretende-se assim colaborar com a divulgação ampla da produção acadêmica na área. Ao mesmo tempo o estudo possibilita, a partir de investigações decorrentes, apontar as contribuições dessa produção para o ensino e sinalizar com necessidades a serem supridas por futuras pesquisas.

  6. Neandertal nasal structures and upper respiratory tract “specialization”

    PubMed Central

    Franciscus, Robert G.

    1999-01-01

    Schwartz and Tattersall [Schwartz, J. H. & Tattersall, I. (1996) Proc. Natl. Acad. Sci. USA 93, 10852–10854] have argued for a previously unrecognized suite of autapomorphies in the internal nasal region of Neandertals that make them unique, not only among hominids, but possibly among all other terrestrial mammals. These purported autapomorphies include (i) the development of an internal nasal margin bearing a well developed and vertically oriented medial projection; (ii) a pronounced medial swelling of the lateral nasal wall into the posterior nasal cavity; and (iii) the lack of an ossified roof over the lacrimal groove. In addition, Laitman et al. [Laitman, J. T., Reidenberg, J. S., Marquez, S. & Gannon, P. J. (1996) Proc. Natl. Acad. Sci. USA 93, 10543–10545] pointed to these features as evidence for upper respiratory tract specializations among the Neandertals, indicating potential differences in behavior compared with modern humans. Critically reviewing the anatomical basis for Schwartz and Tattersall’s contentions reveals several serious problems with their analysis, including (i) reliance on specimens with damaged, incomplete, or, in some cases, entirely absent relevant anatomy; (ii) failure to consider primary vs. secondary spatial consequences in nasal trait conceptualization; and (iii) failure to consider actual ranges of variation in these traits in both fossil and recent humans. Accordingly, the unique phylogenetic and adaptive “specializations” attributed to Neandertal internal nasal structures are unwarranted. PMID:9990106

  7. The chimeric VirA-tar receptor protein is locked into a highly responsive state.

    PubMed

    Turk, S C; van Lange, R P; Sonneveld, E; Hooykaas, P J

    1993-09-01

    The wild-type VirA protein is known to be responsive not only to phenolic compounds but also to sugars via the ChvE protein (G. A. Cangelosi, R. G. Ankenbauer, and E. W. Nester, Proc. Natl. Acad. Sci. USA 87:6708-6712, 1990, and N. Shimoda, A. Toyoda-Yamamoto, J. Nagamine, S. Usami, M. Katayama, Y. Sakagami, and Y. Machida, Proc. Natl. Acad. Sci. USA 87:6684-6688, 1990). It is shown here that the mutant VirA(Ser-44, Arg-45) protein and the chimeric VirA-Tar protein are no longer responsive to sugars and the ChvE protein. However, whereas the chimeric VirA-Tar protein was found to be locked in a highly responsive state, the VirA(Ser-44, Arg-45) mutant protein appeared to be locked in a low responsive state. This difference turned out to be important for tumorigenicity of the host strains in virulence assays on Kalanchoë daigremontiana. PMID:8366057

  8. Accurate force spectroscopy in tapping mode atomic force microscopy in liquids

    NASA Astrophysics Data System (ADS)

    Xu, Xin; Melcher, John; Raman, Arvind

    2010-01-01

    Existing force spectroscopy methods in tapping mode atomic force microscopy (AFM) such as higher harmonic inversion [M. Stark, R. W. Stark, W. M. Heckl, and R. Guckenberger, Proc. Natl. Acad. Sci. U.S.A. 99, 8473 (2002)] or scanning probe acceleration microscopy [J. Legleiter, M. Park, B. Cusick, and T. Kowalewski, Proc. Natl. Acad. Sci. U.S.A. 103, 4813 (2006)] or integral relations [M. Lee and W. Jhe, Phys. Rev. Lett. 97, 036104 (2006); S. Hu and A. Raman, Nanotechnology 19, 375704 (2008); H. Hölscher, Appl. Phys. Lett. 89, 123109 (2006); A. J. Katan, Nanotechnology 20, 165703 (2009)] require and assume as an observable the tip dynamics in a single eigenmode of the oscillating microcantilever. We demonstrate that this assumption can distort significantly the extracted tip-sample interaction forces when applied to tapping mode AFM with soft cantilevers in liquid environments. This exception is due to the fact that under these conditions the second eigenmode is momentarily excited and the observed tip dynamics clearly contains contributions from the fundamental and second eigenmodes. To alleviate this problem, a simple experimental method is proposed to screen the second eigenmode contributions in the observed tip deflection signal to allow accurate tip-sample force reconstruction in liquids. The method is implemented experimentally to reconstruct interaction forces on polymer, bacteriorhodopsin membrane, and mica samples in buffer solutions.

  9. Transdominant genetic analysis of a growth control pathway

    PubMed Central

    Caponigro, Giordano; Abedi, Majid R.; Hurlburt, Anthony P.; Maxfield, Andrew; Judd, Weston; Kamb, Alexander

    1998-01-01

    Genetic selections that use proteinaceous transdominant inhibitors encoded by DNA libraries to cause mutant phenocopies may facilitate genetic analysis in traditionally nongenetic organisms. We performed a selection for random short peptides and larger protein fragments (collectively termed “perturbagens”) that inhibit the yeast pheromone response pathway. Peptide and protein fragment perturbagens that permit cell division in the presence of pheromone were recovered. Two perturbagens were derived from proteins required for pheromone response, and an additional two were derived from proteins that may negatively influence the pheromone response pathway. Furthermore, three known components of the pathway were identified as probable perturbagen targets based on physical interaction assays. Thus, by selection for transdominant inhibitors of pheromone response, multiple pathway components were identified either directly as gene fragments or indirectly as the likely targets of specific perturbagens. These results, combined with the results of previous work [Holzmayer, T. A., Pestov, D. G. & Roninson, I. B. (1992) Nucl. Acids. Res. 20, 711–717; Whiteway, M., Dignard, D. & Thomas, D. Y. (1992) Proc. Natl. Acad. Sci. USA 89, 9410–9414; and Gudkov, A. V., Kazarov, A. R., Thimmapaya, R., Axenovich, S. A., Mazo, I. A. & Roninson, I. B. (1994) Proc. Natl. Acad. Sci. USA 91, 3744–3748], suggest that transdominant genetic analysis of the type described here will be broadly applicable. PMID:9636180

  10. Boolean networks with veto functions

    NASA Astrophysics Data System (ADS)

    Ebadi, Haleh; Klemm, Konstantin

    2014-08-01

    Boolean networks are discrete dynamical systems for modeling regulation and signaling in living cells. We investigate a particular class of Boolean functions with inhibiting inputs exerting a veto (forced zero) on the output. We give analytical expressions for the sensitivity of these functions and provide evidence for their role in natural systems. In an intracellular signal transduction network [Helikar et al., Proc. Natl. Acad. Sci. USA 105, 1913 (2008), 10.1073/pnas.0705088105], the functions with veto are over-represented by a factor exceeding the over-representation of threshold functions and canalyzing functions in the same system. In Boolean networks for control of the yeast cell cycle [Li et al., Proc. Natl. Acad. Sci. USA 101, 4781 (2004), 10.1073/pnas.0305937101; Davidich et al., PLoS ONE 3, e1672 (2008), 10.1371/journal.pone.0001672], no or minimal changes to the wiring diagrams are necessary to formulate their dynamics in terms of the veto functions introduced here.

  11. Acadia National Park Climate Change Scenario Planning Workshop summary

    USGS Publications Warehouse

    Star, Jonathan; Fisichelli, Nicholas; Bryan, Alexander; Babson, Amanda; Cole-Will, Rebecca; Miller-Rushing, Abraham J.

    2016-01-01

    This report summarizes outcomes from a two-day scenario planning workshop for Acadia National Park, Maine (ACAD). The primary objective of the workshop was to help ACAD senior leadership make management and planning decisions based on up-to-date climate science and assessments of future uncertainty. The workshop was also designed as a training program, helping build participants' capabilities to develop and use scenarios. The details of the workshop are given in later sections. The climate scenarios presented here are based on published global climate model output. The scenario implications for resources and management decisions are based on expert knowledge distilled through scientist-manager interaction during workgroup break-out sessions at the workshop. Thus, the descriptions below are from these small-group discussions in a workshop setting and should not be taken as vetted research statements of responses to the climate scenarios, but rather as insights and examinations of possible futures (Martin et al. 2011, McBride et al. 2012).

  12. Viscosity Solutions for the One-Body Liouville Equation in Yang-Mills Charged Bianchi Models with Non-Zero Mass

    NASA Astrophysics Data System (ADS)

    Ayissi, Raoul Domingo; Noutchegueme, Norbert; Etoua, Remy Magloire; Tchagna, Hugues Paulin Mbeutcha

    2015-09-01

    Recently in 2005, Briani and Rampazzo (Nonlinear Differ Equ Appl 12:71-91, 2005) gave, using results of Crandall and Lions (Ill J Math 31:665-688, 1987), Ishii (Indiana Univ Math J 33: 721-748, 1984, Bull Fac Sci Eng 28: 33-77, 1985) and Ley (Adv Diff Equ 6:547-576, 2001) a density approach to Hamilton-Jacobi equations with t-measurable Hamiltonians. In this paper we show, using an important result of Briani and Rampazzo (Nonlinear Differ Equ Appl 12:71-91, 2005) the existence and uniqueness of viscosity solutions to the one-body Liouville relativistic equation in Yang-Mills charged Bianchi space times with non-zero mass. To our knowledge, the method used here is original and thus, totally different from those used in Alves (C R Acad Sci Paris Sér A 278:1151-1154, 1975), Choquet-Bruhat and Noutchegueme (C R Acad Sci Paris Sér I 311, 1973), Choquet-Bruhat and Noutchegueme (Ann Inst Henri Poincaré 55:759-787, 1991), Choquet-Bruhat and Noutchegueme (Pitman Res Notes Math Ser 253:52-71, 1992), Noutchegueme and Noundjeu (Ann Inst Henri Poincaré 1:385-404, 2000), Wollman (J Math Anal Appl 127:103-121, 1987) and Choquet-Bruhat (Existence and uniqueness for the Einstein-Maxwell-Liouville system. Volume dedicated to Petrov, Moscow, 1971) who have studied the same equation.

  13. Methane concentrations in water wells unrelated to proximity to existing oil and gas wells in northeastern Pennsylvania.

    PubMed

    Siegel, Donald I; Azzolina, Nicholas A; Smith, Bert J; Perry, A Elizabeth; Bothun, Rikka L

    2015-04-01

    Recent studies in northeastern Pennsylvania report higher concentrations of dissolved methane in domestic water wells associated with proximity to nearby gas-producing wells [ Osborn et al. Proc. Natl. Acad. Sci. U. S. A. 2011 , 108 , 8172 ] and [ Jackson et al. Proc. Natl. Acad. Sci. U. S. A. , 2013 , 110 , 11250 ]. We test this possible association by using Chesapeake Energy's baseline data set of over 11,300 dissolved methane analyses from domestic water wells, densely arrayed in Bradford and nearby counties (Pennsylvania), and near 661 pre-existing oil and gas wells. The majority of these, 92%, were unconventional wells, drilled with horizontal legs and hydraulically fractured. Our data set is hundreds of times larger than data sets used in prior studies. In contrast to prior findings, we found no statistically significant relationship between dissolved methane concentrations in groundwater from domestic water wells and proximity to pre-existing oil or gas wells. Previous analyses used small sample sets compared to the population of domestic wells available, which may explain the difference in prior findings compared to ours. PMID:25764141

  14. Reexamination of magnetic isotope and field effects on adenosine triphosphate production by creatine kinase

    PubMed Central

    Crotty, Darragh; Silkstone, Gary; Poddar, Soumya; Ranson, Richard; Prina-Mello, Adriele; Wilson, Michael T.; Coey, J. M. D.

    2012-01-01

    The influence of isotopically enriched magnesium on the creatine kinase catalyzed phosphorylation of adenosine diphosphate is examined in two independent series of experiments where adenosine triphosphate (ATP) concentrations were determined by a luciferase-linked luminescence end-point assay or a real-time spectrophotometric assay. No increase was observed between the rates of ATP production with natural Mg, 24Mg, and 25Mg, nor was any significant magnetic field effect observed in magnetic fields from 3 to 1,000 mT. Our results are in conflict with those reported by Buchachenko et al. [J Am Chem Soc 130:12868–12869 (2008)], and they challenge these authors’ general claims that a large (two- to threefold) magnetic isotope effect is “universally observable” for ATP-producing enzymes [Her Russ Acad Sci 80:22–28 (2010)] and that “enzymatic phosphorylation is an ion-radical, electron-spin-selective process” [Proc Natl Acad Sci USA 101:10793–10796 (2005)]. PMID:22198842

  15. Adult pallium transcriptomes surprise in not reflecting predicted homologies across diverse chicken and mouse pallial sectors

    PubMed Central

    Belgard, T. Grant; Montiel, Juan F.; Wang, Wei Zhi; García-Moreno, Fernando; Ponting, Chris P.; Molnár, Zoltán

    2013-01-01

    The thorniest problem in comparative neurobiology is the identification of the particular brain region of birds and reptiles that corresponds to the mammalian neocortex [Butler AB, Reiner A, Karten HJ (2011) Ann N Y Acad Sci 1225:14–27; Wang Y, Brzozowska-Prechtl A, Karten HJ (2010) Proc Natl Acad Sci USA 107(28):12676–12681]. We explored which genes are actively transcribed in the regions of controversial ancestry in a representative bird (chicken) and mammal (mouse) at adult stages. We conducted four analyses comparing the expression patterns of their 5,130 most highly expressed one-to-one orthologous genes that considered global patterns of expression specificity, strong gene markers, and coexpression networks. Our study demonstrates transcriptomic divergence, plausible convergence, and, in two exceptional cases, conservation between specialized avian and mammalian telencephalic regions. This large-scale study potentially resolves the complex relationship between developmental homology and functional characteristics on the molecular level and settles long-standing evolutionary debates. PMID:23878249

  16. Adult pallium transcriptomes surprise in not reflecting predicted homologies across diverse chicken and mouse pallial sectors.

    PubMed

    Belgard, T Grant; Montiel, Juan F; Wang, Wei Zhi; García-Moreno, Fernando; Margulies, Elliott H; Ponting, Chris P; Molnár, Zoltán

    2013-08-01

    The thorniest problem in comparative neurobiology is the identification of the particular brain region of birds and reptiles that corresponds to the mammalian neocortex [Butler AB, Reiner A, Karten HJ (2011) Ann N Y Acad Sci 1225:14-27; Wang Y, Brzozowska-Prechtl A, Karten HJ (2010) Proc Natl Acad Sci USA 107(28):12676-12681]. We explored which genes are actively transcribed in the regions of controversial ancestry in a representative bird (chicken) and mammal (mouse) at adult stages. We conducted four analyses comparing the expression patterns of their 5,130 most highly expressed one-to-one orthologous genes that considered global patterns of expression specificity, strong gene markers, and coexpression networks. Our study demonstrates transcriptomic divergence, plausible convergence, and, in two exceptional cases, conservation between specialized avian and mammalian telencephalic regions. This large-scale study potentially resolves the complex relationship between developmental homology and functional characteristics on the molecular level and settles long-standing evolutionary debates. PMID:23878249

  17. Return of the living dead: Re-reading Pierre Flourens' contributions to neurophysiology and literature.

    PubMed

    Levinson, Sharman

    2013-01-01

    Historians of neurophysiology remember Marie Jean Pierre Flourens (1794-1867) for his experimental approach to nineteenth-century debates on cortical localization and, in particular, for his successful attacks on Frantz Joseph Gall's (1758-1828) phrenology (Gall and Spurzheim, 1810-19). Whereas Gall and his colleague, Johann Gaspar Spurzheim (1776-1832), posited correlations between features of the skull and brain development and claimed to have localized character traits, competencies and temperaments in specific cortical regions, Flourens advocated cerebral equipotentiality and provided empirical as well as philosophical grounds for his theories. Flourens has also been recognized for his contributions to the understanding of the cerebellum's role in the coordination of movement, the localization of a respiratory center in the medulla oblongata, the relationship between the semicircular canals and balance, the role of the periosteum in bone growth and regeneration, and finally, the anesthetic properties of chloroform. Less known to historians of neuroscience is the fact that Pierre Flourens was not only a neurophysiologist and Secrétaire Perpetuel of the French Académie des Sciences, he was also a member of the Académie Française, France's most prestigious literary academy. Examining Flourens' contributions as a writer and, at the same time, a prime target for criticism and caricature from journalists, yields a particularly interesting example of the problematic relations between different genres of science writing and their respective publics in mid-nineteenth-century France. PMID:24290264

  18. The roles of language processing in a spoken language interface.

    PubMed Central

    Hirschman, L

    1995-01-01

    This paper provides an overview of the colloquium's discussion session on natural language understanding, which followed presentations by M. Bates [Bates, M. (1995) Proc. Natl. Acad. Sci. USA 92, 9977-9982] and R. C. Moore [Moore, R. C. (1995) Proc. Natl. Acad. Sci. USA 92, 9983-9988]. The paper reviews the dual role of language processing in providing understanding of the spoken input and an additional source of constraint in the recognition process. To date, language processing has successfully provided understanding but has provided only limited (and computationally expensive) constraint. As a result, most current systems use a loosely coupled, unidirectional interface, such as N-best or a word network, with natural language constraints as a postprocess, to filter or resort the recognizer output. However, the level of discourse context provides significant constraint on what people can talk about and how things can be referred to; when the system becomes an active participant, it can influence this order. But sources of discourse constraint have not been extensively explored, in part because these effects can only be seen by studying systems in the context of their use in interactive problem solving. This paper argues that we need to study interactive systems to understand what kinds of applications are appropriate for the current state of technology and how the technology can move from the laboratory toward real applications. PMID:7479811

  19. Pierre Ambroise-Thomas: a loyal friend and a strong supporter of tropical medicine in Brazil.

    PubMed

    Daniel-Ribeiro, Cláudio Tadeu

    2016-01-01

    Our colleagues at the Sociedade Brasileira de Medicina Tropical have been informed of the demise of Professor Pierre Ambroise-Thomas (1937-2014). However, considering that the tribute we paid to him in 2015 - at the 20th anniversary of the Seminário Laveran & Deane sobre Malária - is equally true today, it is worth sharing it with the readers of the RSBMT, in recognition of his many virtues. Pierre Ambroise-Thomas (MD in 1963 and DSc in 1969) was Honorary Professor of Parasitology and Tropical Medicine at the Faculté de Médecine de Grenoble (France), Honorary President of the Académie Nationale de Médecine, member of the Académie Nationale de Pharmacie and Officier dans l'Ordre de La Légion d'Honneur. In addition to his important contributions to tropical medicine and parasitology, working in France during his long and productive career (50 years and 300 publications), Ambroise-Thomas became an admirer and supporter of Brazilian activities related to research, teaching and information in Tropical Medicine. PMID:27598625

  20. Le Carbonifère du Maroc central : les formations de Migoumess, de Tirhela et d'Idmarrach. Lithologie, biostratigraphie et conséquences géodynamiquesThe Carboniferous formations of Migoumess, Tirhela and Idmarrach (central Morocco): lithology, biostratigraphy and geodynamic consequences

    NASA Astrophysics Data System (ADS)

    Berkhli, Mostafa; Vachard, Daniel

    2002-01-01

    New biostratigraphical data based on foraminifers, algae and pseudo-algae indicate that the limestone pebbles of the channelized polygenic conglomerates of the Migoumess formation contain Late Visean (V3b γ-V3c) assemblages. That confirms the Westphalian age attributed to this formation by Hollard [Zdt. Geol. Ges. 129 (1978) 495-512]. The Tournaisian age assigned to it by palynology [C. R. Acad. Sci. Paris, série II 310 (1990) 1573-1576] cannot be retained. The Tirhela formation, Late Visean and Serpukhovian (E1) in age, is coeval with the Akerchi formation [Berkhli, thèse d'État, 1999; Berkhli et al., J. Afr. Earth Sci. (accepté)]. The Idmarrach formation, mapped as a thrust sheet [C. R. Acad. Sci. Paris, série II 310 (1990) 1573-1576], is dated as Serpukhovian (E1) and its thrusting is consequently post-Serpukhovian. Palaeogeographic and geodynamic consequences are listed. To cite this article: M. Berkhli, D. Vachard, C. R. Geoscience 334 (2002) 67-72

  1. [Louis XIV's Ginseng: Shaping of Knowledge on an Herbal Medicine in the Late 17th and the Early 18th Century France].

    PubMed

    Lee, Hye-Min

    2016-04-01

    This article aims to investigate the shaping of knowledge and discourse on ginseng, especially among physicians and botanists, since its introduction to France from the 17th century until the early 18th century. In France, knowledge on herbal medicine, including that of ginseng, was shaped under the influence of the modern state's policy and institution: mercantilism and the Académie royale des sciences. The knowledge of herbal medicine developed as an important part of the mercantilist policy supported systematically by the Académie. The East Asian ginseng, renowned as a panacea, was first introduced into France in the 17th century, initially in a roundabout way through transportation and English and Dutch publications of travel tales from various foreign countries. The publication activity was mainly conducted by Thévenot company with the intention to meet the needs of French mercantilism promoted by Colbert. It also implied interests on medicine in order to bolster the people's health. The Thévenot company's activity thus offered vital information on plants and herbs abroad, one of which was ginseng. Furthermore, with Louis XIV's dispatching of the Jesuit missionaries to East Asia, the Frenchmen were able to directly gather information on ginseng. These information became a basis for research of the Académie. In the Académie, founded in 1666 by Colbert, the king's physicians and botanists systematically and collectively studied on exotic plants and medical herbs including ginseng. They were also key figures of the Jardin du Roi. These institutions bore a striking contrast to the faculty of medicine at the University of Paris which has been a center of the traditional Galenic medicine. The research of the Académie on ginseng was greatly advanced, owing much to the reports and samples sent from China and Canada by Jartoux, Sarrazin, and Lapitau. From the early 18th century, the conservative attitude of the University of Paris, which was a stronghold of

  2. Unraveling Cholesterol Catabolism in Mycobacterium tuberculosis: ChsE4-ChsE5 α2β2 Acyl-CoA Dehydrogenase Initiates β-Oxidation of 3-Oxo-cholest-4-en-26-oyl CoA

    PubMed Central

    2016-01-01

    The metabolism of host cholesterol by Mycobacterium tuberculosis (Mtb) is an important factor for both its virulence and pathogenesis, although how and why cholesterol metabolism is required is not fully understood. Mtb uses a unique set of catabolic enzymes that are homologous to those required for classical β-oxidation of fatty acids but are specific for steroid-derived substrates. Here, we identify and assign the substrate specificities of two of these enzymes, ChsE4-ChsE5 (Rv3504-Rv3505) and ChsE3 (Rv3573c), that carry out cholesterol side chain oxidation in Mtb. Steady-state assays demonstrate that ChsE4-ChsE5 preferentially catalyzes the oxidation of 3-oxo-cholest-4-en-26-oyl CoA in the first cycle of cholesterol side chain β-oxidation that ultimately yields propionyl-CoA, whereas ChsE3 specifically catalyzes the oxidation of 3-oxo-chol-4-en-24-oyl CoA in the second cycle of β-oxidation that generates acetyl-CoA. However, ChsE4-ChsE5 can catalyze the oxidation of 3-oxo-chol-4-en-24-oyl CoA as well as 3-oxo-4-pregnene-20-carboxyl-CoA. The functional redundancy of ChsE4-ChsE5 explains the in vivo phenotype of the igr knockout strain of Mycobacterium tuberculosis; the loss of ChsE1-ChsE2 can be compensated for by ChsE4-ChsE5 during the chronic phase of infection. The X-ray crystallographic structure of ChsE4-ChsE5 was determined to a resolution of 2.0 Å and represents the first high-resolution structure of a heterotetrameric acyl-CoA dehydrogenase (ACAD). Unlike typical homotetrameric ACADs that bind four flavin adenine dinucleotide (FAD) cofactors, ChsE4-ChsE5 binds one FAD at each dimer interface, resulting in only two substrate-binding sites rather than the classical four active sites. A comparison of the ChsE4-ChsE5 substrate-binding site to those of known mammalian ACADs reveals an enlarged binding cavity that accommodates steroid substrates and highlights novel prospects for designing inhibitors against the committed β-oxidation step in the first

  3. Active compensation of aperture discontinuities for WFIRST-AFTA: analytical and numerical comparison of propagation methods and preliminary results with a WFIRST-AFTA-like pupil

    NASA Astrophysics Data System (ADS)

    Mazoyer, Johan; Pueyo, Laurent; Norman, Colin; N'Diaye, Mamadou; van der Marel, Roeland P.; Soummer, Rémi

    2016-03-01

    The new frontier in the quest for the highest contrast levels in the focal plane of a coronagraph is now the correction of the large diffraction artifacts introduced at the science camera by apertures of increasing complexity. Indeed, the future generation of space- and ground-based coronagraphic instruments will be mounted on on-axis and/or segmented telescopes; the design of coronagraphic instruments for such observatories is currently a domain undergoing rapid progress. One approach consists of using two sequential deformable mirrors (DMs) to correct for aberrations introduced by secondary mirror structures and segmentation of the primary mirror. The coronagraph for the WFIRST-AFTA mission will be the first of such instruments in space with a two-DM wavefront control system. Regardless of the control algorithm for these multiple DMs, they will have to rely on quick and accurate simulation of the propagation effects introduced by the out-of-pupil surface. In the first part of this paper, we present the analytical description of the different approximations to simulate these propagation effects. In Appendix A, we prove analytically that in the special case of surfaces inducing a converging beam, the Fresnel method yields high fidelity for simulations of these effects. We provide numerical simulations showing this effect. In the second part, we use these tools in the framework of the active compensation of aperture discontinuities (ACAD) technique applied to pupil geometries similar to WFIRST-AFTA. We present these simulations in the context of the optical layout of the high-contrast imager for complex aperture telescopes, which will test ACAD on a optical bench. The results of this analysis show that using the ACAD method, an apodized pupil Lyot coronagraph, and the performance of our current DMs, we are able to obtain, in numerical simulations, a dark hole with a WFIRST-AFTA-like. Our numerical simulation shows that we can obtain contrast better than 2×10-9 in

  4. A Global Scale Scenario for Prebiotic Chemistry: Silica-Based Self-Assembled Mineral Structures and Formamide

    PubMed Central

    2016-01-01

    The pathway from simple abiotically made organic compounds to the molecular bricks of life, as we know it, is unknown. The most efficient geological abiotic route to organic compounds results from the aqueous dissolution of olivine, a reaction known as serpentinization (Sleep, N.H., et al. (2004) Proc. Natl. Acad. Sci. USA 101, 12818–12822). In addition to molecular hydrogen and a reducing environment, serpentinization reactions lead to high-pH alkaline brines that can become easily enriched in silica. Under these chemical conditions, the formation of self-assembled nanocrystalline mineral composites, namely silica/carbonate biomorphs and metal silicate hydrate (MSH) tubular membranes (silica gardens), is unavoidable (Kellermeier, M., et al. In Methods in Enzymology, Research Methods in Biomineralization Science (De Yoreo, J., Ed.) Vol. 532, pp 225–256, Academic Press, Burlington, MA). The osmotically driven membranous structures have remarkable catalytic properties that could be operating in the reducing organic-rich chemical pot in which they form. Among one-carbon compounds, formamide (NH2CHO) has been shown to trigger the formation of complex prebiotic molecules under mineral-driven catalytic conditions (Saladino, R., et al. (2001) Biorganic & Medicinal Chemistry, 9, 1249–1253), proton irradiation (Saladino, R., et al. (2015) Proc. Natl. Acad. Sci. USA, 112, 2746–2755), and laser-induced dielectric breakdown (Ferus, M., et al. (2015) Proc Natl Acad Sci USA, 112, 657–662). Here, we show that MSH membranes are catalysts for the condensation of NH2CHO, yielding prebiotically relevant compounds, including carboxylic acids, amino acids, and nucleobases. Membranes formed by the reaction of alkaline (pH 12) sodium silicate solutions with MgSO4 and Fe2(SO4)3·9H2O show the highest efficiency, while reactions with CuCl2·2H2O, ZnCl2, FeCl2·4H2O, and MnCl2·4H2O showed lower reactivities. The collections of compounds forming inside and outside the tubular

  5. A Global Scale Scenario for Prebiotic Chemistry: Silica-Based Self-Assembled Mineral Structures and Formamide.

    PubMed

    Saladino, Raffaele; Botta, Giorgia; Bizzarri, Bruno Mattia; Di Mauro, Ernesto; Garcia Ruiz, Juan Manuel

    2016-05-17

    The pathway from simple abiotically made organic compounds to the molecular bricks of life, as we know it, is unknown. The most efficient geological abiotic route to organic compounds results from the aqueous dissolution of olivine, a reaction known as serpentinization (Sleep, N.H., et al. (2004) Proc. Natl. Acad. Sci. USA 101, 12818-12822). In addition to molecular hydrogen and a reducing environment, serpentinization reactions lead to high-pH alkaline brines that can become easily enriched in silica. Under these chemical conditions, the formation of self-assembled nanocrystalline mineral composites, namely silica/carbonate biomorphs and metal silicate hydrate (MSH) tubular membranes (silica gardens), is unavoidable (Kellermeier, M., et al. In Methods in Enzymology, Research Methods in Biomineralization Science (De Yoreo, J., Ed.) Vol. 532, pp 225-256, Academic Press, Burlington, MA). The osmotically driven membranous structures have remarkable catalytic properties that could be operating in the reducing organic-rich chemical pot in which they form. Among one-carbon compounds, formamide (NH2CHO) has been shown to trigger the formation of complex prebiotic molecules under mineral-driven catalytic conditions (Saladino, R., et al. (2001) Biorganic & Medicinal Chemistry, 9, 1249-1253), proton irradiation (Saladino, R., et al. (2015) Proc. Natl. Acad. Sci. USA, 112, 2746-2755), and laser-induced dielectric breakdown (Ferus, M., et al. (2015) Proc Natl Acad Sci USA, 112, 657-662). Here, we show that MSH membranes are catalysts for the condensation of NH2CHO, yielding prebiotically relevant compounds, including carboxylic acids, amino acids, and nucleobases. Membranes formed by the reaction of alkaline (pH 12) sodium silicate solutions with MgSO4 and Fe2(SO4)3·9H2O show the highest efficiency, while reactions with CuCl2·2H2O, ZnCl2, FeCl2·4H2O, and MnCl2·4H2O showed lower reactivities. The collections of compounds forming inside and outside the tubular membrane are

  6. On uniqueness and stability of Sobolev's solution in scattering by wedges

    NASA Astrophysics Data System (ADS)

    Komech, A. I.; Merzon, A. E.; la Paz Méndez, J. E. De

    2015-10-01

    We prove that the solution of the scattering problem of pulses, constructed by Sobolev (Proc Seismol Inst Acad Sci URSS 41:1-15, 1934), coincides with the solution obtained by our method of complex characteristics. The coincidence holds for the DD- and NN-boundary conditions. The method of complex characteristics has been developed by Komech and Merzon in 2002-2007. Its main advantage is that it provides (a) the existence and uniqueness of the solutions in suitable functional classes and (b) the limiting amplitude principle. The uniqueness in the Sobolev approach was not considered. Our result means that Sobolev's solution belongs to our functional classes and agrees with the limiting amplitude principle.

  7. 5p Deletions: Current Knowledge and Future Directions

    PubMed Central

    Nguyen, Joanne M.; Qualmann, Krista J.; Okashah, Rebecca; Reilly, Amysue; Alexeyev, Mikhail F.; Campbell, Dennis J.

    2016-01-01

    Disorders resulting from 5p deletions (5p–) were first recognized by Lejeune et al. in 1963 [Lejeune et al. (1963); C R Hebd Seances Acad Sci 257:3098-3102]. 5p– is caused by partial or total deletion of the short arm of chromosome 5. The most recognizable phenotype is characterized by a high-pitched cry, dysmorphic features, poor growth, and developmental delay. This report reviews 5p– disorders and their molecular basis. Hemizygosity for genes located within this region have been implicated in contributing to the phenotype. A review of the genes on 5p which may be dosage sensitive is summarized. Because of the growing knowledge of these specific genes, future directions to explore potential targeted therapies for individuals with 5p– are discussed. PMID:26235846

  8. Dielectric function for doped graphene layer with barium titanate

    NASA Astrophysics Data System (ADS)

    Martinez Ramos, Manuel; Garces Garcia, Eric; Magana, Fernado; Vazquez Fonseca, Gerardo Jorge

    2015-03-01

    The aim of our study is to calculate the dielectric function for a system formed with a graphene layer doped with barium titanate. Density functional theory, within the local density approximation, plane-waves and pseudopotentials scheme as implemented in Quantum Espresso suite of programs was used. We considered 128 carbon atoms with a barium titanate cluster of 11 molecules as unit cell with periodic conditions. The geometry optimization is achieved. Optimization of structural configuration is performed by relaxation of all atomic positions to minimize their total energies. Band structure, density of states and linear optical response (the imaginary part of dielectric tensor) were calculated. We thank Dirección General de Asuntos del Personal Académico de la Universidad Nacional Autónoma de México, partial financial support by Grant IN-106514 and we also thank Miztli Super-Computing center the technical assistance.

  9. Penetration of Action Potentials During Collision in the Median and Lateral Giant Axons of Invertebrates

    NASA Astrophysics Data System (ADS)

    Gonzalez-Perez, Alfredo; Budvytyte, Rima; Mosgaard, Lars D.; Nissen, Søren; Heimburg, Thomas

    2014-07-01

    The collisions of two simultaneously generated impulses in the giant axons of both earthworms and lobsters propagating in orthodromic and antidromic direction are investigated. The experiments have been performed on the extracted ventral cords of Lumbricus terrestris and the abdominal ventral cord of a lobster, Homarus americanus, by using external stimulation and recording. The collision of two nerve impulses of orthodromic and antidromic propagation did not result in the annihilation of the two signals, contrary to the common notion that is based on the existence of a refractory period in the well-known Hodgkin-Huxley theory. However, the results are in agreement with the electromechanical soliton theory for nerve-pulse propagation, as suggested by Heimburg and Jackson [On Soliton Propagation in Biomembranes and Nerves, Proc. Natl. Acad. Sci. U.S.A. 102, 9790 (2005).].

  10. How are static magnetic fields detected biologically?

    NASA Astrophysics Data System (ADS)

    Finegold, Leonard

    2009-03-01

    There is overwhelming evidence that life, from bacteria to birds to bats, detects magnetic fields, using the fields for orientation or navigation. Indeed there are recent reports (based on Google Earth imagery) that cattle and deer align themselves with the earth's magnetic field. [1]. The development of frog and insect eggs are changed by high magnetic fields, probably through known physical mechanisms. However, the mechanisms for eukaryotic navigation and alignment are not clear. Persuasive published models will be discussed. Evidence, that static magnetic fields might produce therapeutic effects, will be updated [2]. [4pt] [1] S. Begall, et al., Proc Natl Acad Sci USA, 105:13451 (2008). [0pt] [2] L. Finegold and B.L. Flamm, BMJ, 332:4 (2006).

  11. Automated shimming of B0 for spectroscopic imaging

    NASA Astrophysics Data System (ADS)

    Tropp, James; Derby, Kevin A.; Hawryszko, Christine; Sugiura, Satoshi; Yamagata, Hitoshi

    A method for automated shimming of B0 in whole body imaging magnets is demonstrated. The method employs spectroscopic imaging [ T. R. Brown, B. M. Kincaid, and K. Ugurbil, Proc. Natl. Acad. Sci. USA, 79, 3532, 1982 ] of 1H to map the B0 field of the region of interest with the subject in situ. Correction currents for the shims, based on prior measurement of shim fields versus shim currents, are then calculated and applied by computer. The chief application of the method is shimming for multivoxel spectroscopy examinations in vivo wherein it is shown to produce marked improvement of 31P spectra from spectroscopic imaging exams of brain and calf muscle, in normal and diseased subjects.

  12. Controlling Viral Capsid Assembly with Templating

    PubMed Central

    Hagan, Michael F.

    2009-01-01

    We develop coarse-grained models that describe the dynamic encapsidation of functionalized nanoparticles by viral capsid proteins. We find that some forms of cooperative interactions between protein subunits and nanoparticles can dramatically enhance rates and robustness of assembly, as compared to the spontaneous assembly of subunits into empty capsids. For large core-subunit interactions, subunits adsorb onto core surfaces en masse in a disordered manner, and then undergo a cooperative rearrangement into an ordered capsid structure. These assembly pathways are unlike any identified for empty capsid formation. Our models can be directly applied to recent experiments in which viral capsid proteins assemble around the functionalized inorganic nanoparticles [Sun et al., Proc. Natl. Acad. Sci (2007) 104, 1354]. In addition, we discuss broader implications for understanding the dynamic encapsidation of single-stranded genomic molecules during viral replication and for developing multicomponent nanostructured materials. PMID:18643099

  13. Calculation of the wetting parameter from a cluster model in the framework of nanothermodynamics.

    PubMed

    García-Morales, V; Cervera, J; Pellicer, J

    2003-06-01

    The critical wetting parameter omega(c) determines the strength of interfacial fluctuations in critical wetting transitions. In this Brief Report, we calculate omega(c) from considerations on critical liquid clusters inside a vapor phase. The starting point is a cluster model developed by Hill and Chamberlin in the framework of nanothermodynamics [Proc. Natl. Acad. Sci. USA 95, 12779 (1998)]. Our calculations yield results for omega(c) between 0.52 and 1.00, depending on the degrees of freedom considered. The findings are in agreement with previous experimental results and give an idea of the universal dynamical behavior of the clusters when approaching criticality. We suggest that this behavior is a combination of translation and vortex rotational motion (omega(c)=0.84). PMID:16241275

  14. Fractional Hamiltonian monodromy from a Gauss-Manin monodromy

    NASA Astrophysics Data System (ADS)

    Sugny, D.; Mardešić, P.; Pelletier, M.; Jebrane, A.; Jauslin, H. R.

    2008-04-01

    Fractional Hamiltonian monodromy is a generalization of the notion of Hamiltonian monodromy, recently introduced by [Nekhoroshev, Sadovskií, and Zhilinskií, C. R. Acad. Sci. Paris, Ser. 1 335, 985 (2002); Nekhoroshev, Sadovskií, and Zhilinskií, Ann. Henri Poincare 7, 1099 (2006)] for energy-momentum maps whose image has a particular type of nonisolated singularities. In this paper, we analyze the notion of fractional Hamiltonian monodromy in terms of the Gauss-Manin monodromy of a Riemann surface constructed from the energy-momentum map and associated with a loop in complex space which bypasses the line of singularities. We also prove some propositions on fractional Hamiltonian monodromy for 1:-n and m :-n resonant systems.

  15. On the ability of the Viking gas chromatograph–mass spectrometer to detect organic matter

    PubMed Central

    Biemann, Klaus

    2007-01-01

    A recent paper by Navarro-Gonzalez et al. [Navarro-Gonzalez R, Navarro KF, de la Rosa J, Iniguez E, Molina P, Miranda LD, Morales P, Cienfuegos E, Coll P, Raulin F, et al. (2006) Proc Natl Acad Sci USA 103:16089–16094] claims to show that the Viking GCMS (gas chromatograph–mass spectrometer) experiment, which carried out a search for organic matter at the surface of Mars in 1976, “may have been blind to low levels of organics.” To rebut this assertion, the Viking experiment, test data, and results on Mars are reviewed, and the fallacies in the design, execution, and interpretation of the new experiments presented by Navarro-Gonzalez et al. are critically examined. PMID:17548829

  16. On a question of Gross

    NASA Astrophysics Data System (ADS)

    Banerjee, Abhijit

    2007-03-01

    Using the notion of weighted sharing of sets we prove two uniqueness theorems which improve the results proved by Fang and Qiu [H. Qiu, M. Fang, A unicity theorem for meromorphic functions, Bull. Malaysian Math. Sci. Soc. 25 (2002) 31-38], Lahiri and Banerjee [I. Lahiri, A. Banerjee, Uniqueness of meromorphic functions with deficient poles, Kyungpook Math. J. 44 (2004) 575-584] and Yi and Lin [H.X. Yi, W.C. Lin, Uniqueness theorems concerning a question of Gross, Proc. Japan Acad. Ser. A 80 (2004) 136-140] and thus provide an answer to the question of Gross [F. Gross, Factorization of meromorphic functions and some open problems, in: Proc. Conf. Univ. Kentucky, Lexington, KY, 1976, in: Lecture Notes in Math., vol. 599, Springer, Berlin, 1977, pp. 51-69], under a weaker hypothesis.

  17. Once more: The continuous spectrum of ideal magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Goedbloed, J. P.

    1998-09-01

    A controversy on the existence of continuous spectra of ideal magnetohydrodynamics in addition to the well-known Alfvén and slow continua, dating back to a conjecture by Grad [Proc. Natl. Acad. Sci. USA 70, 3377 (1973)] and revived by Lashmore-Davies, Thyagaraja, and Cairns [Phys. Plasmas 4, 3243 (1997)], is once more resolved by demonstrating that the resolvent operator is bounded in the relevant domain: There are no additional continua. In addition, the solution of the initial value problem is constructed in terms of the three-dimensional Green's dyadic, which is free of apparent singularities and clearly exhibits the classical continua as δ functions on the diagonal. This construction provides the connection with the proper and improper normal modes and shows that the local dynamics on the magnetic surfaces is described by the classical continua.

  18. Thermodynamics of information processing based on enzyme kinetics: An exactly solvable model of an information pump.

    PubMed

    Cao, Yuansheng; Gong, Zongping; Quan, H T

    2015-06-01

    Motivated by the recent proposed models of the information engine [Proc. Natl. Acad. Sci. USA 109, 11641 (2012)] and the information refrigerator [Phys. Rev. Lett. 111, 030602 (2013)], we propose a minimal model of the information pump and the information eraser based on enzyme kinetics. This device can either pump molecules against the chemical potential gradient by consuming the information to be encoded in the bit stream or (partially) erase the information initially encoded in the bit stream by consuming the Gibbs free energy. The dynamics of this model is solved exactly, and the "phase diagram" of the operation regimes is determined. The efficiency and the power of the information machine is analyzed. The validity of the second law of thermodynamics within our model is clarified. Our model offers a simple paradigm for the investigating of the thermodynamics of information processing involving the chemical potential in small systems. PMID:26172671

  19. Structure of common pili from Escherichia coli.

    PubMed Central

    McMichael, J C; Ou, J T

    1979-01-01

    Several important properties of the common pili from Escherichia coli are discussed. These pili were resistant to the gentle Folin-Ciocalteau reagent methods for protein detection and were not readily solubilized by sodium dodecyl sulfate. They were found to contain a reducing sugar but not peptidoglycan. The pilin had multiple conformations in sodium dodecyl sulfate solution, and the appearance of multiple bands on sodium dodecyl sulfate gels did not necessarily indicate heterogeneity of the preparation. The ilus subunit was found to be a different protein than outer membrane III, which has the same apparent molecular weight. In addition, we conformed the results of Brinton (Trans. N.Y. Acad. Sci 27:1003-1054, 1965): that there is a dramatic change in the properties of pili after they are heated at pH values below 2. Images PMID:37233

  20. The Murray Springs Clovis site, Pleistocene extinction, and the question of extraterrestrial impact

    PubMed Central

    Haynes, C. Vance; Boerner, J.; Domanik, K.; Lauretta, D.; Ballenger, J.; Goreva, J.

    2010-01-01

    Some of the evidence for the recent hypothesis of an extraterrestrial impact that caused late Pleistocene megafaunal extinctions [Firestone et al. (2007) Proc Natl Acad Sci USA 104:16016–16021] was based upon samples collected at Murray Springs, a Clovis archaeological site in southeastern Arizona. Here we describe sampling and analyses of magnetic separates from within, above, and below the lower Younger Dryas boundary (LYDB) black mat at Murray Springs, as well as radiation measurements from the LYDB at Murray Springs and two other well-stratified Clovis sites. The main magnetic fraction at Murray Springs is maghemite. Magnetic microspherules have terrestrial origins but also occur as cosmic dust particles. We failed to find iridium or radiation anomalies. The evidence for massive biomass burning at Murray Springs is addressed and found to be lacking. We could not substantiate some of the claims by Firestone and others, but our findings do not preclude a terminal Pleistocene cosmic event. PMID:20160115

  1. Scald-Induced Necrobiosis Lipoidica in a Patient with Diabetes Mellitus and Psoriasis.

    PubMed

    Ito, Hoshiko; Imamura, Sadao

    2016-01-01

    The Koebner phenomenon (KP) was first introduced by Heinrich Koebner in the 1870s to describe the appearance of psoriatic lesions following trauma in psoriasis patients. KP has since been defined in numerous diseases, including necrobiosis lipoidica diabeticorum (NLD). Since most Koebnerized dermatological lesions can localise to a site of previous trauma, Weiss et al. (Eur Acad Dermatol Venereol 2002;16:241-248) classified them into four categories (I-IV) according to the Boyd-Nelder classification (Int J Dermatol 1990;29:401-410) system. In this system, necrobiosis lipoidica is classified as category III, which includes diseases that occasionally localise at the site of trauma. We report a case of NLD that developed after scald in a psoriasis patient. NLD after trauma has often been reported, but this is the first case of NLD that coincidentally occurred at a scald site in a psoriasis patient. PMID:26889139

  2. [Nuclear arms and medical responsibility].

    PubMed

    Firket, H

    1999-01-01

    The medical profession would be unable to cope with the millions of simultaneous casualities of a nuclear war. Such a war between developed countries becomes less likely, but new countries equip themselves, with nuclear weapons, using the violation of the Non-Proliferation Treaty by the great powers as an excuse. The danger of nuclear war is spreading with the consequences one can imagine. A world movement, including military experts, political, moral and scientific leaders and representative national medical groups, among them the World Medical Association, press governments to negotiate a comprehensive abolition treaty. The "Académie royale de Médecine de Belgique" joining moral prestige to an authoritative expertise, should take a stand on the problem. PMID:10687249

  3. Physical constraints on charge transport through bacterial nanowires

    PubMed Central

    Polizzi, Nicholas F.; Skourtis, Spiros S.

    2012-01-01

    Extracellular appendages of the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 were recently shown to sustain currents of 1010 electrons per second over distances of 0.5 microns [El-Naggar et al., Proc. Natl. Acad. Sci. U. S. A., 2010, 107, 18127]. However, the identity of the charge localizing sites and their organization along the “nanowire” remain unknown. We use theory to predict redox cofactor separation distances that would permit charge flow at rates of 1010 electrons per second over 0.5 microns for voltage biases of ≤1V, using a steady-state analysis governed by a non-adiabatic electron transport mechanism. We find the observed currents necessitate a multi-step hopping transport mechanism, with charge localizing sites separated by less than 1 nm and reorganization energies that rival the lowest known in biology. PMID:22470966

  4. Simple combined model for nonlinear excitations in DNA.

    PubMed

    Hien, D L; Nhan, N T; Ngo, V Thanh; Viet, N A

    2007-08-01

    We propose a simple model for DNA denaturation bases on the pendulum model of Englander [Proc. Natl. Acad. Sci. U.S.A. 77, 7222 (1980)] and the microscopic model of Peyrard and Bishop [Phys. Rev. Lett. 62, 2755 (1989)], so-called "combined model." The main parameters of our model are the coupling constant k along each strand, the mean stretching y* of the hydrogen bonds, the ratio of the damping constant and driven force gamma/F. We show that both the length L of unpaired bases and the velocity v of kinks depend on not only the coupling constant k but also the temperature T. Our results are in good agreement with previous works. PMID:17930079

  5. Influence of disorder on viscosity of undercooled melts

    NASA Astrophysics Data System (ADS)

    Avramov, I.

    1991-09-01

    The influence of disorder on shear viscosity of undercooled melts is described by the formula η=η0ṡexp(θ/T )a. It is shown that this expression reproduces the existing experimental data with a reasonable accuracy for a broad range of substances of various nature (silicates, borates, germanates, phosphates, Se, glucose, glycerin, As2Se3, etc.). Angell and Sichina [Ann. NY Acad. Sci. 279, 53 (1976)] distinguish between ``strong'' and ``fragile'' liquids on the basis of their heat capacity. The present model provides a physical ground for such classification. Also the isostructural viscosity of glasses is easily described. The present approach gives a natural explanation to the empirical rule of Bimen and Kauzmann.

  6. Geometric measure of entanglement and applications to bipartite and multipartite quantum states

    SciTech Connect

    Wei, T.-C.; Goldbart, Paul M.

    2003-10-01

    The degree to which a pure quantum state is entangled can be characterized by the distance or angle to the nearest unentangled state. This geometric measure of entanglement, already present in a number of settings [A. Shimony, Ann. NY. Acad. Sci. 755, 675 (1995); H. Barnum and N. Linden, J. Phys. A: Math. Gen. 34, 6787 (2001)], is explored for bipartite and multipartite pure and mixed states. The measure is determined analytically for arbitrary two-qubit mixed states and for generalized Werner and isotropic states, and is also applied to certain multipartite mixed states. In particular, a detailed analysis is given for arbitrary mixtures of three-qubit Greenberger-Horne-Zeilinger, W, and inverted-W states. Along the way, we point out connections of the geometric measure of entanglement with entanglement witnesses and with the Hartree approximation method.

  7. Three-qubit thermal entanglement via entanglement swapping on two-qubit Heisenberg XY chains

    SciTech Connect

    Kao, Zi Chong; Ng, Jezreel; Yeo, Ye

    2005-12-15

    In this paper, we consider the generation of a three-qubit Greenberger-Horne-Zeilinger-like thermal state by applying the entanglement swapping scheme of Zukowski et al. [Ann. N. Y. Acad. Sci. 755, 91 (1995)] to three pairs of two-qubit Heisenberg XY chains. The quality of the resulting three-qubit entanglement is studied by analyzing the teleportation fidelity, when it is used as a resource in the teleportation protocol of Karlsson et al. [Phys. Rev. A 58, 4394 (1998)]. We show that even though thermal noise in the original two-qubit states is amplified by the entanglement swapping process, we are still able to achieve nonclassical fidelities for the anisotropic Heisenberg XY chains at finitely higher and higher temperatures by adjusting the strengths of an external magnetic field. This has a positive implication on the solid-state realization of a quantum computer.

  8. An extension of the steepest descent method for Riemann-Hilbert problems: the small dispersion limit of the Korteweg-de Vries (KdV) equation.

    PubMed

    Deift, P; Venakides, S; Zhou, X

    1998-01-20

    This paper extends the steepest descent method for Riemann-Hilbert problems introduced by Deift and Zhou in a critical new way. We present, in particular, an algorithm, to obtain the support of the Riemann-Hilbert problem for leading asymptotics. Applying this extended method to small dispersion KdV (Korteweg-de Vries) equation, we (i) recover the variational formulation of P. D. Lax and C. D. Levermore [(1979) Proc. Natl. Acad. Sci. USA76, 3602-3606] for the weak limit of the solution, (ii) derive, without using an ansatz, the hyperelliptic asymptotic solution of S. Venakides that describes the oscillations; and (iii) are now able to compute the phase shifts, integrating the modulation equations exactly. The procedure of this paper is a version of fully nonlinear geometrical optics for integrable systems. With some additional analysis the theory can provide rigorous error estimates between the solution and its computed asymptotic expression. PMID:11038618

  9. An Englishman abroad: Charles Blagden's visit to Paris in 1783.

    PubMed

    Fauque, Danielle M E

    2008-12-20

    Once the preliminaries of peace had been signed in January 1783, after the war of American independence, exchanges between British and French men of science resumed their normal course. On a visit to Paris in 1783, the francophile Charles Blagden (with the encouragement of Joseph Banks) made a number of contacts that fostered relations between the Royal Society and the Académie royale des sciences. In the course of this and several subsequent visits to France, Blagden became especially intimate with the chemist Claude-Louis Berthollet. His correspondence, now in the Royal Society, is a rich source for our understanding of some of the leading scientific debates of the day, in particular concerning the nature of water, which forms the main subject of this article. PMID:19244920

  10. Plant biotechnology for food security and bioeconomy.

    PubMed

    Clarke, Jihong Liu; Zhang, Peng

    2013-09-01

    This year is a special year for plant biotechnology. It was 30 years ago, on January 18 1983, one of the most important dates in the history of plant biotechnology, that three independent groups described Agrobacterium tumefaciens-mediated genetic transformation at the Miami Winter Symposium, leading to the production of normal, fertile transgenic plants (Bevan et al. in Nature 304:184-187, 1983; Fraley et al. in Proc Natl Acad Sci USA 80:4803-4807, 1983; Herrera-Estrella et al. in EMBO J 2:987-995, 1983; Vasil in Plant Cell Rep 27:1432-1440, 2008). Since then, plant biotechnology has rapidly advanced into a useful and valuable tool and has made a significant impact on crop production, development of a biotech industry and the bio-based economy worldwide. PMID:23860797

  11. Ion flow through a membrane: effect of chemical reaction on time dependence.

    PubMed Central

    Hays, T R; Lin, S H; Eyring, H

    1978-01-01

    The membrane model previously described [Hays, T.R., Buckwalter, C.Q., Lin S.H. & Eyring, H. (1978) Proc. Natl. Acad. Sci. USA 75, 1612-1615] for ion flow through a membrane is expanded to include the effect of binding of the mobile ion at the occupiable sites in the membrane. Two different effects were investigated: alteration of the association-dissociation rates at constant equilibrium constant and alteration of the equilibrium constant at constant dissociation constant. Increasing the rates of association and dissociation initially causes an increased slowing of the relaxation to the final steady state, though ultimately the curves for the faster rates cross those for the slower states. Increasing the equilibrium constant causes a greater delay in the relaxation curve, with the curves for different equilibrium constants not crossing. Overall, the effect of binding is not very great unless the equilibrium constant for binding is quite large. PMID:276852

  12. A Science Superior to Music: Joseph Sauveur and the Estrangement between Music and Acoustics

    NASA Astrophysics Data System (ADS)

    Fix, Adam

    2015-09-01

    The scientific revolution saw a shift from the natural philosophy of music to the science of acoustics. Joseph Sauveur (1653-1716), an early pioneer in acoustics, determined that science as understood in the eighteenth century could not address the fundamental problems of music, particularly the problem of consonance. Building on Descartes, Mersenne, and Huygens especially, Sauveur drew a sharp divide between sound and music, recognizing the former as a physical phenomenon obeying mechanical and mathematical principles and the latter as an inescapably subjective and unquantifiable perception. While acoustics grew prominent in the Académie des sciences, music largely fell out of the scientific discourse, becoming primarily practiced art rather than natural philosophy. This study illuminates what was considered proper science at the dawn of the Enlightenment and why one particular branch of natural philosophy—music—did not make the cut.

  13. Asymptotic properties of a HIV-1 infection model with time delay

    NASA Astrophysics Data System (ADS)

    Li, Dan; Ma, Wanbiao

    2007-11-01

    Based on some important biological meanings, a class of more general HIV-1 infection models with time delay is proposed in the paper. In the HIV-1 infection model, time delay is used to describe the time between infection of uninfected target cells and the emission of viral particles on a cellular level as proposed by Herz et al. [A.V.M. Herz, S. Bonhoeffer, R.M. Anderson, R.M. May, M.A. Nowak, Viral dynamics in vivo: Limitations on estimates of intracellular delay and virus decay, Proc. Natl. Acad. Sci. USA 93 (1996) 7247-7251]. Then, the effect of time delay on stability of the equilibria of the HIV-1 infection model has been studied and sufficient criteria for local asymptotic stability of the infected equilibrium and global asymptotic stability of the viral free equilibrium are given.

  14. Electron spin resonance dating of human teeth from Toca da Santa shelter of São Raimundo Nonato, Piauí, Brazil

    NASA Astrophysics Data System (ADS)

    Kinoshita, A.; Figueiredo, A. M. G.; Felice, G. D.; Lage, M. C. S. M.; Guidon, N.; Baffa, O.

    2008-02-01

    Results of the dating of fossil human teeth excavated from a shelter in the surroundings areas of the Serra da Capivara National Park, São Raimundo Nonato, Piauí, Brazil are presented. This shelter was partially excavated to search for more data that could improve the archaeological context of the Garrincho’s limestone hill sites, where the Toca do Gordo do Garrincho shelter provided two human teeth dated by conventional C-14 in (12,170 ± 40) yBP (years before present) and calibrated age (2 Sigma, 95% probability) 15,245 14,690 yBP (Beta 136204) [E. Peyre, C. Guérin, N. Guidon, I. Coppens, CR Acad. Sci. Paris, Sciences de la terre et des planètes/ Earth & Planetary Sciences 327 (1998) 335, [1

  15. Information filtering via biased heat conduction.

    PubMed

    Liu, Jian-Guo; Zhou, Tao; Guo, Qiang

    2011-09-01

    The process of heat conduction has recently found application in personalized recommendation [Zhou et al., Proc. Natl. Acad. Sci. USA 107, 4511 (2010)], which is of high diversity but low accuracy. By decreasing the temperatures of small-degree objects, we present an improved algorithm, called biased heat conduction, which could simultaneously enhance the accuracy and diversity. Extensive experimental analyses demonstrate that the accuracy on MovieLens, Netflix, and Delicious datasets could be improved by 43.5%, 55.4% and 19.2%, respectively, compared with the standard heat conduction algorithm and also the diversity is increased or approximately unchanged. Further statistical analyses suggest that the present algorithm could simultaneously identify users' mainstream and special tastes, resulting in better performance than the standard heat conduction algorithm. This work provides a creditable way for highly efficient information filtering. PMID:22060533

  16. Information filtering via biased heat conduction

    NASA Astrophysics Data System (ADS)

    Liu, Jian-Guo; Zhou, Tao; Guo, Qiang

    2011-09-01

    The process of heat conduction has recently found application in personalized recommendation [Zhou , Proc. Natl. Acad. Sci. USA PNASA60027-842410.1073/pnas.1000488107107, 4511 (2010)], which is of high diversity but low accuracy. By decreasing the temperatures of small-degree objects, we present an improved algorithm, called biased heat conduction, which could simultaneously enhance the accuracy and diversity. Extensive experimental analyses demonstrate that the accuracy on MovieLens, Netflix, and Delicious datasets could be improved by 43.5%, 55.4% and 19.2%, respectively, compared with the standard heat conduction algorithm and also the diversity is increased or approximately unchanged. Further statistical analyses suggest that the present algorithm could simultaneously identify users' mainstream and special tastes, resulting in better performance than the standard heat conduction algorithm. This work provides a creditable way for highly efficient information filtering.

  17. An item-oriented recommendation algorithm on cold-start problem

    NASA Astrophysics Data System (ADS)

    Qiu, Tian; Chen, Guang; Zhang, Zi-Ke; Zhou, Tao

    2011-09-01

    Based on a hybrid algorithm incorporating the heat conduction and probability spreading processes (Proc. Natl. Acad. Sci. U.S.A., 107 (2010) 4511), in this letter, we propose an improved method by introducing an item-oriented function, focusing on solving the dilemma of the recommendation accuracy between the cold and popular items. Differently from previous works, the present algorithm does not require any additional information (e.g., tags). Further experimental results obtained in three real datasets, RYM, Netflix and MovieLens, show that, compared with the original hybrid method, the proposed algorithm significantly enhances the recommendation accuracy of the cold items, while it keeps the recommendation accuracy of the overall and the popular items. This work might shed some light on both understanding and designing effective methods for long-tailed online applications of recommender systems.

  18. Identification of a putative yeast homolog of the mammalian beta chains of the clathrin-associated protein complexes.

    PubMed Central

    Kirchhausen, T

    1990-01-01

    The clathrin-associated protein complexes are heterotetrameric structures believed to interact with clathrin and with membrane components of mammalian coated pits and coated vesicles. I have identified a yeast homolog of the mammalian beta-type large chains, suggesting the existence in yeast cells of clathrin-associated protein complexes. A sequence comparison between the putative yeast beta-type chain and its mammalian counterparts shows that their amino-terminal domains are related over their entire length and that their carboxyl-terminal domains diverge completely. This observation is consistent with our earlier proposal (T. Kurchhausen et al., Proc. Natl. Acad. Sci. USA 86:2612-2616, 1989) for the bifunctional-domain organization of the large chains, in which the invariant amino-terminal region interacts with conserved proteins of the coat while the variable carboxyl-terminal domain interacts with different membrane components of coated pits and coated vesicles. PMID:2122239

  19. Nonadditive entropy reconciles the area law in quantum systems with classical thermodynamics.

    PubMed

    Caruso, Filippo; Tsallis, Constantino

    2008-08-01

    The Boltzmann-Gibbs-von Neumann entropy of a large part (of linear size L ) of some (much larger) d -dimensional quantum systems follows the so-called area law (as for black holes), i.e., it is proportional to Ld-1. Here we show, for d=1,2 , that the (nonadditive) entropy Sq satisfies, for a special value of q not equal to 1, the classical thermodynamical prescription for the entropy to be extensive, i.e., Sq proportional variant Ld. Therefore, we reconcile with classical thermodynamics the area law widespread in quantum systems. Recently, a similar behavior was exhibited in mathematical models with scale-invariant correlations [C. Tsallis, M. Gell-Mann, and Y. Sato, Proc. Natl. Acad. Sci. U.S.A.102 15377 (2005)]. Finally, we find that the system critical features are marked by a maximum of the special entropic index q. PMID:18850781

  20. « Les fleurs du MAL » une méthode d'ondelettes adaptive de lignes arbitraires I : problèmes de convection diffusion

    NASA Astrophysics Data System (ADS)

    Ren, Xiaoan; Xanthis, Leonidas S.

    2004-01-01

    Baudelaire's 'les fleurs du mal' refers to various new developments ('les fleurs') of the method ofarbitrarylines ( mal), since it was first published (in C. R. Acad. Sci. Paris, Sér. I, in 1991). Here we revisit the basic mal (semi-discretization) methodology for stationary convection-diffusion problems and develop an adaptive, wavelet-based solver that is capable of capturing the thin layers that arise in such problems. We show the efficacy and high accuracy of the wavelet-mal solver by applying it to a challenging 2D problem involving both boundary and interior layers. To cite this article: X. Ren, L.S. Xanthis, C. R. Mecanique 332 (2004).

  1. Temperature derivative spectroscopy to monitor the autoxidation decay of cytochromes P450.

    PubMed

    Luthra, Abhinav; Denisov, Ilia G; Sligar, Stephen G

    2011-07-01

    Temperature derivative spectroscopy (TDS), a type of relaxation spectroscopy, is a powerful tool to study protein dynamics (Berendzen, J.; Braunstein, D. Proc. Natl. Acad. Sci. U. S. A. 1990, 87, 1). We developed the version of temperature derivative spectroscopy to monitor kinetics of autoxidation of cytochromes P450 and applied it to study the properties of the oxy-ferrous complex of a human membrane bound P450, CYP19A1 (aromatase), and that of a bacterial soluble P450, CYP101 when bound with their most common substrates, androstenedione (AD) and camphor, respectively. TDS extends the panel of methods that can be used to monitor heme protein kinetics, providing a rapid measurement technique and enabling measurement of the autoxidation rate over a wide range of temperatures, yielding the activation energy as well as absolute reaction rate in a single experiment. PMID:21615185

  2. PARTNeR: A Tool for Outreach and Teaching Astronomy

    NASA Astrophysics Data System (ADS)

    Gallego, Juan Ángel Vaquerizo; Fuertes, Carmen Blasco

    PARTNeR is an acronym for Proyecto Académico con el Radio Telescopio de NASA en Robledo (Academic Project with the NASA Radio Telescope at Robledo). It is intended for general Astronomy outreach and, in particular, radioastronomy, throughout Spanish educational centres. To satisfy this target, a new educational material has been developed in 2007 to help not only teachers but also students. This material supports cross curricular programs and provides with the possibility of including Astronomy in related subjects like Physics, Chemistry, Technology, Mathematics or even English language. In this paper, the material that has been developed will be shown in detail and how it can be adapted to the disciplines from 4th year ESO (Enseñanza Secundaria Obligatoria-Compulsory Secondary Education) to High School. The pedagogic results obtained for the first year it has been implemented with students in classrooms will also be presented.

  3. Gaming and Religion: The Impact of Spirituality and Denomination.

    PubMed

    Braun, Birgit; Kornhuber, Johannes; Lenz, Bernd

    2016-08-01

    A previous investigation from Korea indicated that religion might modulate gaming behavior (Kim and Kim in J Korean Acad Nurs 40:378-388, 2010). Our present study aimed to investigate whether a belief in God, practicing religious behavior and religious denomination affected gaming behavior. Data were derived from a Western cohort of young men (Cohort Study on Substance Use Risk Factors, n = 5990). The results showed that a stronger belief in God was associated with lower gaming frequency and smaller game addiction scale scores. In addition, practicing religiosity was related to less frequent online and offline gaming. Finally, Christians gamed less frequently and had lower game addiction scale scores than subjects without religious denomination. In the future, these results could prove useful in developing preventive and therapeutic strategies for the Internet gaming disorder. PMID:26590569

  4. Hubble's diagram and cosmic expansion

    PubMed Central

    Kirshner, Robert P.

    2004-01-01

    Edwin Hubble's classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168–173]. The chief result, that a galaxy's distance is proportional to its redshift, is so well known and so deeply embedded into the language of astronomy through the Hubble diagram, the Hubble constant, Hubble's Law, and the Hubble time, that the article itself is rarely referenced. Even though Hubble's distances have a large systematic error, Hubble's velocities come chiefly from Vesto Melvin Slipher, and the interpretation in terms of the de Sitter effect is out of the mainstream of modern cosmology, this article opened the way to investigation of the expanding, evolving, and accelerating universe that engages today's burgeoning field of cosmology. PMID:14695886

  5. Targeted and robust amplification of mitochondrial DNA in the presence of nuclear-encoded mitochondrial pseudogenes using Φ29 DNA polymerases.

    PubMed

    Wolff, Jonci N

    2014-01-01

    Accidental co-amplification of nuclear-encoded mitochondrial pseudogenes (numts) in mitochondrial DNA (mtDNA) analyses is a common problem in biological and medical research alike [Yao et al., J Med Genet 45:769-772, 2008; Song et al., Proc Natl Acad Sci U S A 105:13486-13491, 2008]. A wealth of strategies have been developed to evade the contamination of mtDNA data sets with numts, but time- and cost-effective protocols of general applicability are scarce [Wolff et al., PLoS One 7:e37142, 2012]. The protocol presented here closes this gap by combining serial dilution with standard and rolling circle DNA amplification. This strategy leads to selective enrichment of mtDNA and removal of nuclear DNA (nuDNA) from template solutions, enabling mtDNA analyses in a virtually numt-free environment. PMID:24823783

  6. Competencias en ética biocéntrica

    PubMed Central

    Stepke, Fernando Lolas

    2013-01-01

    Resumen Este artículo explora el origen y la conceptualización de la bioética en tanto ética biocéntrica, definida por el pionero Fritz Jahr como un imperativo hipotético que llama a respetar la vida en todas sus formas. Tras describirla como proceso social, procedimiento técnico y producto académico, se enumeran y comentan algunas competencias que debieran presidir el empleo del discurso bioético en cualquier punto del complejo social “investigación médica”: miembros de comités de ética de investigación, investigadores, empresarios, administradores. Cada uno de estos grupos, en su “cultura epistémica” propia, define y explicita los principios básicos en tanto expresión de valores y leyes generales. PMID:23459767

  7. Is There an Optimal Level of Open-Endedness in Prebiotic Evolution?

    NASA Astrophysics Data System (ADS)

    Markovitch, Omer; Sorek, Daniel; Lui, Leong Ting; Lancet, Doron; Krasnogor, Natalio

    2012-10-01

    In this paper we explore the question of whether there is an optimal set up for a putative prebiotic system leading to open-ended evolution (OEE) of the events unfolding within this system. We do so by proposing two key innovations. First, we introduce a new index that measures OEE as a function of the likelihood of events unfolding within a universe given its initial conditions. Next, we apply this index to a variant of the graded autocatalysis replication domain (GARD) model, Segre et al. (P Natl Acad Sci USA 97(8):4112-4117, 2000; Markovitch and Lancet Artif Life 18(3), 2012), and use it to study - under a unified and concise prebiotic evolutionary framework - both a variety of initial conditions of the universe and the OEE of species that evolve from them.

  8. Is there an optimal level of open-endedness in prebiotic evolution?

    PubMed

    Markovitch, Omer; Sorek, Daniel; Lui, Leong Ting; Lancet, Doron; Krasnogor, Natalio

    2012-10-01

    In this paper we explore the question of whether there is an optimal set up for a putative prebiotic system leading to open-ended evolution (OEE) of the events unfolding within this system. We do so by proposing two key innovations. First, we introduce a new index that measures OEE as a function of the likelihood of events unfolding within a universe given its initial conditions. Next, we apply this index to a variant of the graded autocatalysis replication domain (GARD) model, Segre et al. (P Natl Acad Sci USA 97(8):4112-4117, 2000; Markovitch and Lancet Artif Life 18(3), 2012), and use it to study--under a unified and concise prebiotic evolutionary framework--both a variety of initial conditions of the universe and the OEE of species that evolve from them. PMID:23114973

  9. Preface

    NASA Astrophysics Data System (ADS)

    Hart, Stan; Basu, Asish

    Publication of this monograph will coincide, to a precision of a few per mil, with the centenary of Henri Becquerel's discovery of "radiations actives" (C. R. Acad. Sci., Feb. 24, 1896). In 1896 the Earth was only 40 million years old according to Lord Kelvin. Eleven years later, Boltwood had pushed the Earth's age past 2000 million years, based on the first U/Pb chemical dating results. In exciting progression came discovery of isotopes by J. J. Thomson in 1912, invention of the mass spectrometer by Dempster (1918) and Aston (1919), the first measurement of the isotopic composition of Pb (Aston, 1927) and the final approach, using Pb-Pb isotopic dating, to the correct age of the Earth: close—2.9 Ga (Gerling, 1942), closer—3.0 Ga (Holmes, 1949) and closest—4.50 Ga (Patterson, Tilton and Inghram, 1953).

  10. Earth Processes: Reading the Isotopic Code

    NASA Astrophysics Data System (ADS)

    Basu, Asish; Hart, Stan

    Publication of this monograph will coincide, to a precision of a few per mil, with the centenary of Henri Becquerel's discovery of "radiations actives" (C. R. Acad. Sci., Feb. 24, 1896). In 1896 the Earth was only 40 million years old according to Lord Kelvin. Eleven years later, Boltwood had pushed the Earth's age past 2000 million years, based on the first U/Pb chemical dating results. In exciting progression came discovery of isotopes by J. J. Thomson in 1912, invention of the mass spectrometer by Dempster (1918) and Aston (1919), the first measurement of the isotopic composition of Pb (Aston, 1927) and the final approach, using Pb-Pb isotopic dating, to the correct age of the Earth: close—2.9 Ga (Gerling, 1942), closer—3.0 Ga (Holmes, 1949) and closest—4.50 Ga (Patterson, Tilton and Inghram, 1953).

  11. ADAR proteins: structure and catalytic mechanism.

    PubMed

    Goodman, Rena A; Macbeth, Mark R; Beal, Peter A

    2012-01-01

    Since the discovery of the adenosine deaminase (ADA) acting on RNA (ADAR) family of proteins in 1988 (Bass and Weintraub, Cell 55:1089-1098, 1988) (Wagner et al. Proc Natl Acad Sci U S A 86:2647-2651, 1989), we have learned much about their structure and catalytic mechanism. However, much about these enzymes is still unknown, particularly regarding the selective recognition and processing of specific adenosines within substrate RNAs. While a crystal structure of the catalytic domain of human ADAR2 has been solved, we still lack structural data for an ADAR catalytic domain bound to RNA, and we lack any structural data for other ADARs. However, by analyzing the structural data that is available along with similarities to other deaminases, mutagenesis and other biochemical experiments, we have been able to advance the understanding of how these fascinating enzymes function. PMID:21769729

  12. Genealogical theory for random mating populations with two sexes.

    PubMed

    Pollak, Edward

    2006-07-01

    Consider a random mating population that has N(m) males and N(f) females in each generation. Let us assume that at time 0 a random sample of n copies of a gene is taken from this population. Then, for models introduced by Wright [Evolution in Mendelian populations, Genetics 16 (1931) 97; Inbreeding and homozygosis, Proc. Nat. Acad. Wash. 19 (1933) 420; Evolution and the Genetics of Populations, The Theory of Gene Frequencies, vol. II, The University of Chicago, Chicago and London, 1969.], it is possible to obtain generalizations of the haploid theory of genealogical processes developed by Felsenstein . It is conjectured that these hold generally, regardless of the effective population size, if n

  13. Spin-dependent electron transport in protein-like single-helical molecules

    PubMed Central

    Guo, Ai-Min; Sun, Qing-Feng

    2014-01-01

    We report on a theoretical study of spin-dependent electron transport through single-helical molecules connected by two nonmagnetic electrodes, and explain the experiment of significant spin-selective phenomenon observed in α-helical protein and the contradictory results between the protein and single-stranded DNA. Our results reveal that the α-helical protein is an efficient spin filter and the spin polarization is robust against the disorder. These results are in excellent agreement with recent experiments [Mishra D, et al. (2013) Proc Natl Acad Sci USA 110(37):14872–14876; Göhler B, et al. (2011) Science 331(6019):894–897] and may facilitate engineering of chiral-based spintronic devices. PMID:25071198

  14. Evolution of new functions de novo and from preexisting genes.

    PubMed

    Andersson, Dan I; Jerlström-Hultqvist, Jon; Näsvall, Joakim

    2015-06-01

    How the enormous structural and functional diversity of new genes and proteins was generated (estimated to be 10(10)-10(12) different proteins in all organisms on earth [Choi I-G, Kim S-H. 2006. Evolution of protein structural classes and protein sequence families. Proc Natl Acad Sci 103: 14056-14061] is a central biological question that has a long and rich history. Extensive work during the last 80 years have shown that new genes that play important roles in lineage-specific phenotypes and adaptation can originate through a multitude of different mechanisms, including duplication, lateral gene transfer, gene fusion/fission, and de novo origination. In this review, we focus on two main processes as generators of new functions: evolution of new genes by duplication and divergence of pre-existing genes and de novo gene origination in which a whole protein-coding gene evolves from a noncoding sequence. PMID:26032716

  15. Challenges to reestablishment of free-ranging populations of black-footed ferrets

    USGS Publications Warehouse

    Biggins, D.E.; Godbey, J.L.

    2003-01-01

    The black-footed ferret (Mustela nigripes) of North America is critically endangered due in part to its extreme specialization on formerly stable and abundant prairie dogs (Cynomys). Its close relative, the Siberian polecat (M. eversmannii) seems to have been subjected to a varying environment that was not conducive to specialization. One source of environmental variation in Asian steppes was plague (caused by Yersina pestis), which was absent from North America. Introduction of plague to North America presents serious challenges to ferret recovery. Partial solutions to other biological and political problems have been found, resulting in improved production in captivity, increased survival post-release, and thriving populations in plague-free South Dakota. ?? 2003 Acade??mie des sciences. Published by E??ditions scientifiques et me??dicales Elsevier SAS. All rights reserved.

  16. The Murray Springs Clovis site, Pleistocene extinction, and the question of extraterrestrial impact.

    PubMed

    Haynes, C Vance; Boerner, J; Domanik, K; Lauretta, D; Ballenger, J; Goreva, J

    2010-03-01

    Some of the evidence for the recent hypothesis of an extraterrestrial impact that caused late Pleistocene megafaunal extinctions [Firestone et al. (2007) Proc Natl Acad Sci USA 104:16016-16021] was based upon samples collected at Murray Springs, a Clovis archaeological site in southeastern Arizona. Here we describe sampling and analyses of magnetic separates from within, above, and below the lower Younger Dryas boundary (LYDB) black mat at Murray Springs, as well as radiation measurements from the LYDB at Murray Springs and two other well-stratified Clovis sites. The main magnetic fraction at Murray Springs is maghemite. Magnetic microspherules have terrestrial origins but also occur as cosmic dust particles. We failed to find iridium or radiation anomalies. The evidence for massive biomass burning at Murray Springs is addressed and found to be lacking. We could not substantiate some of the claims by Firestone and others, but our findings do not preclude a terminal Pleistocene cosmic event. PMID:20160115

  17. The Condensation Phase Transition in Random Graph Coloring

    NASA Astrophysics Data System (ADS)

    Bapst, Victor; Coja-Oghlan, Amin; Hetterich, Samuel; Raßmann, Felicia; Vilenchik, Dan

    2016-01-01

    Based on a non-rigorous formalism called the "cavity method", physicists have put forward intriguing predictions on phase transitions in diluted mean-field models, in which the geometry of interactions is induced by a sparse random graph or hypergraph. One example of such a model is the graph coloring problem on the Erdős-Renyi random graph G( n, d/ n), which can be viewed as the zero temperature case of the Potts antiferromagnet. The cavity method predicts that in addition to the k-colorability phase transition studied intensively in combinatorics, there exists a second phase transition called the condensation phase transition (Krzakala et al. in Proc Natl Acad Sci 104:10318-10323, 2007). In fact, there is a conjecture as to the precise location of this phase transition in terms of a certain distributional fixed point problem. In this paper we prove this conjecture for k exceeding a certain constant k 0.

  18. Finite Time Extinction for Stochastic Sign Fast Diffusion and Self-Organized Criticality

    NASA Astrophysics Data System (ADS)

    Gess, Benjamin

    2015-04-01

    We prove finite time extinction for stochastic sign fast diffusion equations driven by linear multiplicative space-time noise, corresponding to the Bak-Tang-Wiesenfeld model for self-organized criticality. This solves a problem posed and left open in several works: (Barbu, Methods Appl Sci 36:1726-1733, 2013; Röckner and Wang, J Lond Math Soc (2) 87:545-560, 2013; Barbu et al. J Math Anal Appl 389:147-164, 2012; Barbu and Röckner, Comm Math Phys 311:539-555, 2012; Barbu et al., Comm Math Phys 285:901-923, 2009, C R Math Acad Sci Paris 347(1-2):81-84, 2009). The highly singular-degenerate nature of the drift in interplay with the stochastic perturbation causes the need for new methods in the analysis of mass diffusion, and several new estimates and techniques are introduced.

  19. Physical analysis of light-scattering changes in bovine photoreceptor membrane suspensions.

    PubMed Central

    Michel-Villaz, M; Brisson, A; Chapron, Y; Saibil, H

    1984-01-01

    We have used electron microscopy and model calculations to analyze the physical basis of light-scattering signals from suspensions of photoreceptor membranes. These signals have previously been used to probe interactions between photoactivated rhodopsin (R*) and the peripheral membrane enzyme, GTP-binding protein (G) (Kühn et al., 1981, Proc. Natl. Acad. Sci. USA., 78:6873-6877). Although there is no unique physical interpretation of these signals, we have shown in this study that they were qualitatively unchanged when the rod outer segment fragments (containing stacked disks) were fragmented by sonication or osmotic shock to produce spherical disk membrane vesicles. An exact treatment of the scattering process for spherical vesicles enabled us to evaluate the effects of changing membrane thickness, refractive index, or vesicle diameter. We present a particular redistribution of mass upon R*-G interaction that fits the experimental data. Images FIGURE 4 PMID:6498278

  20. The Observation of Highly Ordered Domains in Membranes with Cholesterol

    SciTech Connect

    Armstrong, Clare L; Marquardt, Drew; Dies, Hannah; Kucerka, Norbert; Yamani, Zahra; Harroun, Thad; Katsaras, John; Shi, A-C; Rheinstadter, Maikel C

    2013-01-01

    Rafts, or functional domains, are transient nano- or mesoscopic structures in the exoplasmic leaflet of the plasma membrane, and are thought to be essential for many cellular processes. Using neutron diffraction and computer modelling, we present evidence for the existence of highly ordered lipid domains in the cholesterol-rich (32.5 mol%) liquid-ordered (lo) phase of dipalmitoylphosphatidylcholine membranes. The liquid ordered phase in one-component lipid membranes has previously been thought to be a homogeneous phase. The presence of highly ordered lipid domains embedded in a disordered lipid matrix implies non-uniform distribution of cholesterol between the two phases. The experimental results are in excellent agreement with recent computer simulations of DPPC/cholesterol complexes [Meinhardt, Vink and Schmid (2013). Proc Natl Acad Sci USA 110(12): 4476 4481], which reported the existence of nanometer size lo domains in a liquid disordered lipid environment.

  1. Alternative approach to community detection in networks.

    PubMed

    Medus, A D; Dorso, C O

    2009-06-01

    The problem of community detection is relevant in many disciplines of science and modularity optimization is the widely accepted method for this purpose. It has recently been shown that this approach presents a resolution limit by which it is not possible to detect communities with sizes smaller than a threshold, which depends on the network size. Moreover, it might happen that the communities resulting from such an approach do not satisfy the usual qualitative definition of commune; i.e., nodes in a commune are more connected among themselves than to nodes outside the commune. In this paper we present a different method for community detection in complex networks. We define merit factors based on the weak and strong community definitions formulated by Radicchi [Proc. Natl. Acad. Sci. U.S.A. 101, 2658 (2004)] and we show that these local definitions avoid the resolution limit problem found in the modularity optimization approach. PMID:19658568

  2. Nano-Optics for Chemical and Materials Characterization

    NASA Astrophysics Data System (ADS)

    Beversluis, Michael; Stranick, Stephan

    2007-03-01

    Light microscopy can provide non-destructive, real-time, three-dimensional imaging with chemically-specific contrast, but diffraction frequently limits the resolution to roughly 200 nm. Recently, structured illumination techniques have allowed fluorescence imaging to reach 50 nm resolution [1]. Since these fluorescence techniques were developed for use in microbiology, a key challenge is to take the resolution-enhancing features and apply them to contrast mechanisms like vibrational spectroscopy (e.g., Raman and CARS microscopy) that provide morphological and chemically specific imaging.. We are developing a new hybrid technique that combines the resolution enhancement of structured illumination microscopy with scanning techniques that can record hyperspectral images with 100 nm spatial resolution. We will show such superresolving images of semiconductor nanostructures and discuss the advantages and requirements for this technique. Referenence: 1. M. G. L. Gustafsson, P. Natl. Acad. Sci. USA 102, 13081-13086 (2005).

  3. Particle ordering in inertially focused microfluidic flows

    NASA Astrophysics Data System (ADS)

    Humphry, Katherine; Kulkarni, Pandurang; di Carlo, Dino; Edd, Jon; Toner, Mehmet; Morris, Jeffrey; Weitz, David; Stone, Howard

    2008-11-01

    We study inertially driven focusing of particles [1], which has recently been exploited in a controlled fashion in microfluidic devices [2]. In particular, we characterize the focusing as a function of particle and channel Reynolds number by reporting particle position in directions perpendicular to the flow, and a large distance from the fluid inlet. Focusing of dilute suspensions leads to a linear arrangement of particles whose spacing is primarily a function of concentration and channel aspect ratio. All results are compared with simulations, which provide mechanistic insights into particle behavior.[1] G. Segré and A. Silberberg, Nature 189, 209 (1961). [2] D. Di Carlo, D. Irimia, R. G. Tompkins, and M. Toner, Proc. Nat. Acad. Sci. U.S.A. 104, 18892 (2007).

  4. Crystal Structure in the Vivo-Assembled Bacillus subtilis Spx/RNA Polymerase alpha Subunit C-Terminal Domain Complex

    SciTech Connect

    Lamour, V.; Westblade, L; Campbell, E; Darst, S

    2009-01-01

    The Bacillus subtilis Spx protein is a global transcription factor that interacts with the C-terminal domain of the RNA polymerase {alpha} subunit ({alpha}CTD) and regulates transcription of genes involved in thiol-oxidative stress, sporulation, competence, and organosulfur metabolism. Here we determined the X-ray crystal structure of the Spx/{alpha}CTD complex from an entirely new crystal form than previously reported [Newberry, K.J., Nakano, S., Zuber, P., Brennan, R.G., 2005. Crystal structure of the Bacillus subtilis anti-alpha, global transcriptional regulator, Spx, in complex with the alpha C-terminal domain of RNA polymerase. Proc. Natl. Acad. Sci. USA 102, 15839-15844]. Comparison of the previously reported sulfate-bound complex and our sulfate-free complex reveals subtle conformational changes that may be important for the role of Spx in regulating organosulfur metabolism.

  5. Spectral tripartitioning of networks.

    PubMed

    Richardson, Thomas; Mucha, Peter J; Porter, Mason A

    2009-09-01

    We formulate a spectral graph-partitioning algorithm that uses the two leading eigenvectors of the matrix corresponding to a selected quality function to split a network into three communities in a single step. In so doing, we extend the recursive bipartitioning methods developed by Newman [M. E. J. Newman, Proc. Natl. Acad. Sci. U.S.A. 103, 8577 (2006); Phys. Rev. E 74, 036104 (2006)] to allow one to consider the best available two-way and three-way divisions at each recursive step. We illustrate the method using simple "bucket brigade" examples and then apply the algorithm to examine the community structures of the coauthorship graph of network scientists and of U. S. Congressional networks inferred from roll call voting similarities. PMID:19905184

  6. Composition fluctuations, correlated response, and protein solvation in membranes

    NASA Astrophysics Data System (ADS)

    McConnell, Harden

    2010-05-01

    Membrane composition fluctuations are deduced from the deuterium NMR relaxation data of S. L. Veatch et al. [Proc. Natl. Acad. Sci. U.S.A. 104, 17650 (2007)]. A theoretical model for these fluctuations is used to determine the parameters of a correlation function. A fluctuation-response relation is then derived to infer the response of a lipid bilayer membrane to perturbations, such as the presence of a protein. The energy of the correlated response is shown to decrease as a bilayer miscibility critical point is approached from higher temperatures. Near the critical temperature the low energy of the composition response facilitates the lipid solvation of membrane proteins and minimizes lipid-mediated nonspecific protein-protein interactions. This facilitated lipid solvation of membrane proteins may be the basis of reports that at the growth temperature, the lipids of animal cell membranes have compositions such that they are within ˜10° of a miscibility critical point.

  7. Intermediate binding of phycocyanobilin to the lyase, CpeS1, and transfer to apoprotein.

    PubMed

    Tu, Jun-Ming; Kupka, Michaela; Böhm, Stephan; Plöscher, Matthias; Eichacker, Lutz; Zhao, Kai-Hong; Scheer, Hugo

    2008-01-01

    The phycobilin: Cysteine-84-phycobiliprotein lyase, CpeS1, catalyzes phycocyanobilin (PCB) and phycoerythrobilin attachment to nearly all cysteine-84 (consensus sequence) binding sites of phycoerythrin, phycoerythrocyanin, phycocyanin and allophycocyanin (Zhao et al. (2007) Proc Natl Acad Sci 104:14300-14305). We now show that CpeS1 can bind PCB, as assayed by Ni(2+) chelating affinity chromatography. Binding is rapid, and the chromophore is bound in an extended conformation similar to that in phycobiliproteins but only poorly fluorescent. Upon addition of apo-biliproteins, the chromophore is transferred to the latter much slower ( approximately 1 h), indicating that chromophorylated CpeS1 is an intermediate in the enzymatic reaction. In addition, imidazole is bound to PCB, as shown by mass spectroscopy of tryptic digests of the intermediate CpeS1-PCB complex. PMID:17912606

  8. Method to find community structures based on information centrality

    NASA Astrophysics Data System (ADS)

    Fortunato, Santo; Latora, Vito; Marchiori, Massimo

    2004-11-01

    Community structures are an important feature of many social, biological, and technological networks. Here we study a variation on the method for detecting such communities proposed by Girvan and Newman and based on the idea of using centrality measures to define the community boundaries [M. Girvan and M. E. J. Newman, Proc. Natl. Acad. Sci. U.S.A. 99, 7821 (2002)]. We develop an algorithm of hierarchical clustering that consists in finding and removing iteratively the edge with the highest information centrality. We test the algorithm on computer generated and real-world networks whose community structure is already known or has been studied by means of other methods. We show that our algorithm, although it runs to completion in a time O(n4) , is very effective especially when the communities are very mixed and hardly detectable by the other methods.

  9. Using PET H2O15 brain imaging to study the functional-anatomical correlates of non-human primate communication.

    PubMed

    Gil-da-Costa, Ricardo; Braun, Allen; Martin, Alex

    2006-03-01

    In this article, we describe methods for using oxygen-15 water (H2O15) positron emission tomography (PET) to explore the functional neuroanatomy of cognition in awake, non-human primates. The discussion is based on a recent study designed to identify regions in the monkey brain associated with perceiving auditory stimuli, and species-specific calls, in particular [Gil-da-Costa et al., Proc. Natl. Acad. Sci. USA 101 (2004) 17516-17521]. Details are provided concerning critical aspects of the experimental paradigm, including pre-scanning habituation sessions to acclimate the animals to the PET scanner environment, and details of a pilot study to determine the auditory stimulus parameters necessary to produce robust activity in brain regions known to process auditory information (belt and parabelt regions of monkey auditory cortex). Methods for acquiring and analyzing PET data to identify significant regions of brain activity in single animals are also presented. PMID:16466931

  10. INCLUSIÓN DE LA ÉTICA Y BIOÉTICA EN LA FORMACIÓN DE PRE Y POSGRADO DEL CIRUJANO-DENTISTA EN PERÚ

    PubMed Central

    Rupaya, Carmen Rosa García

    2009-01-01

    Se revisan aspectos de la inclusión de la ética y bioética en la formación de pre y posgrado del cirujano-dentista en Perú. Desde el punto de vista de la formación del docente, se analiza la presencia de normatividad ética en la investigación científica que genera la universidad, así como los conocimientos y actitudes vinculados con la ética y bioética en la formación del odontólogo. Se concluye que es un compromiso fomentar un cambio de paradigma, a través de un movimiento masivo que involucre los ámbitos familiar, profesional y académico, con el n de integrar la reflexión ética en nuestro diario proceder. PMID:19946384

  11. Earthquake triggering and large-scale geologic storage of carbon dioxide

    PubMed Central

    Zoback, Mark D.; Gorelick, Steven M.

    2012-01-01

    Despite its enormous cost, large-scale carbon capture and storage (CCS) is considered a viable strategy for significantly reducing CO2 emissions associated with coal-based electrical power generation and other industrial sources of CO2 [Intergovernmental Panel on Climate Change (2005) IPCC Special Report on Carbon Dioxide Capture and Storage. Prepared by Working Group III of the Intergovernmental Panel on Climate Change, eds Metz B, et al. (Cambridge Univ Press, Cambridge, UK); Szulczewski ML, et al. (2012) Proc Natl Acad Sci USA 109:5185–5189]. We argue here that there is a high probability that earthquakes will be triggered by injection of large volumes of CO2 into the brittle rocks commonly found in continental interiors. Because even small- to moderate-sized earthquakes threaten the seal integrity of CO2 repositories, in this context, large-scale CCS is a risky, and likely unsuccessful, strategy for significantly reducing greenhouse gas emissions. PMID:22711814

  12. Induction of entropic segregation: the first step is the hardest.

    PubMed

    Minina, Elena; Arnold, Axel

    2014-08-21

    In confinement, overlapping polymers experience entropic segregating forces that tend to demix them. This plays a role during cell replication, where it facilitates the segregation of daughter chromosomes. It has been argued that these forces are strong enough to explain chromosome segregation in elongated bacteria such as E. coli without the need for additional active mechanisms [S. Jun and B. Mulder, Proc. Natl. Acad. Sci. U. S. A., 2006, 103, 12388]. However, entropic segregation can only set in after the initial symmetry has been broken. We demonstrate that the timescale for this induction phase is exponentially growing in the chain length, while the actual segregation time scales only quadratically in the chain length. Thus the induction quickly becomes the dominating, slow process, and makes entropic segregation much less efficient than previously thought. The slow induction might also explain the long delay in chromosome segregation observed in experiments on E. coli. PMID:24974935

  13. Earthquake triggering and large-scale geologic storage of carbon dioxide.

    PubMed

    Zoback, Mark D; Gorelick, Steven M

    2012-06-26

    Despite its enormous cost, large-scale carbon capture and storage (CCS) is considered a viable strategy for significantly reducing CO(2) emissions associated with coal-based electrical power generation and other industrial sources of CO(2) [Intergovernmental Panel on Climate Change (2005) IPCC Special Report on Carbon Dioxide Capture and Storage. Prepared by Working Group III of the Intergovernmental Panel on Climate Change, eds Metz B, et al. (Cambridge Univ Press, Cambridge, UK); Szulczewski ML, et al. (2012) Proc Natl Acad Sci USA 109:5185-5189]. We argue here that there is a high probability that earthquakes will be triggered by injection of large volumes of CO(2) into the brittle rocks commonly found in continental interiors. Because even small- to moderate-sized earthquakes threaten the seal integrity of CO(2) repositories, in this context, large-scale CCS is a risky, and likely unsuccessful, strategy for significantly reducing greenhouse gas emissions. PMID:22711814

  14. Alternative perspective on the control of transpiration by radiation.

    PubMed

    Mott, Keith A; Peak, David

    2011-12-01

    Stomatal responses to light are important determinants for plant water use efficiency and for general circulation models, but a mechanistic understanding of these responses remains elusive. A recent study [Pieruschka R, Huber G, Berry JA (2010) Proc Natl Acad Sci USA 107:13372-13377] concluded that stomata respond to total absorbed radiation rather than red and blue light as previously thought. We tested this idea by reexamining stomatal responses to red and blue light and to IR radiation. We show that responses to red and blue light are not consistent with a response to total absorbed radiation and that apparent stomatal responses to IR radiation are explainable as experimental artifacts. In addition, our data and analysis provide a method for accurately determining the internal temperature of a leaf. PMID:22106306

  15. In vitro formation of multimeric DNA structures mediated by purified simian virus 40 chromatin.

    PubMed Central

    Waldeck, W; Zentgraf, H; Sauer, G

    1982-01-01

    Simian virus 40 chromatin was incubated after purification by sucrose density-gradient centrifugation with various circular double-stranded DNA substrates. Monomeric rings were converted in the presence of Mg2+ to structures possessing a higher degree of complexity. Dimeric catenanes, as well as multimeric linear structures and concatemers, were generated, indicating that recombination events had occurred in vitro involving covalent linkage between different DNA molecules. Furthermore, apparently fused dimeric rings were observed. Their structures suggest that they may be recombination intermediates such as those described in a prokaryotic system [Potter, H. & Dressler, D. (1976) Proc. Natl. Acad. Sci. USA 73, 3000-3004]. Recombination did not take place between heterologous DNA substrates, as exclusively homologous multimeric DNA structures were observed. Images PMID:6280162

  16. Hydrodynamic collective effects of active proteins in biological membranes.

    PubMed

    Koyano, Yuki; Kitahata, Hiroyuki; Mikhailov, Alexander S

    2016-08-01

    Lipid bilayers forming biological membranes are known to behave as viscous two-dimensional fluids on submicrometer scales; usually they contain a large number of active protein inclusions. Recently, it was shown [A. S. Mikhailov and R. Kapral, Proc. Natl. Acad. Sci. USA 112, E3639 (2015)PNASA60027-842410.1073/pnas.1506825112] that such active proteins should induce nonthermal fluctuating lipid flows leading to diffusion enhancement and chemotaxislike drift for passive inclusions in biomembranes. Here, a detailed analytical and numerical investigation of such effects is performed. The attention is focused on the situations when proteins are concentrated within lipid rafts. We demonstrate that passive particles tend to become attracted by active rafts and are accumulated inside them. PMID:27627343

  17. Differential conductance and defect states in the heavy-fermion superconductor CeCoIn5

    NASA Astrophysics Data System (ADS)

    Van Dyke, John S.; Davis, J. C. Séamus; Morr, Dirk K.

    2016-01-01

    We demonstrate that the electronic band structure extracted from quasiparticle interference spectroscopy [Nat. Phys. 9, 468 (2013), 10.1038/nphys2671] and the theoretically computed form of the superconducting gaps [Proc. Natl. Acad. Sci. USA 111, 11663 (2014), 10.1073/pnas.1409444111] can be used to understand the d I /d V line shape measured in the normal and superconducting state of CeCoIn5 [Nat. Phys. 9, 474 (2013), 10.1038/nphys2672]. In particular, the d I /d V line shape, and the spatial structure of defect-induced impurity states, reflects the existence of multiple superconducting gaps of dx2-y2 symmetry. These results strongly support a recently proposed microscopic origin of the unconventional superconducting state.

  18. A generalized front marching algorithm for the solution of the eikonal equation

    NASA Astrophysics Data System (ADS)

    Covello, Paul; Rodrigue, Garry

    2003-07-01

    A new front marching algorithm for solving the eikonal equation is presented. An important property of the algorithm is that it can be used on nodes that are located on highly distorted grids or on nodes that are randomly located. When the nodes are located on an orthogonal grid, the method is first-order accurate and is shown to be a generalization of the front marching algorithm in (Proc. Natl. Acad. Sci. 93 (4) (1996) 1591). The accuracy of the method is also shown to be dependent on the principle curvature of the wave front solution. Numerical results on a variety of node configurations as well as on shadow, nonconvex and nondifferentiable solutions are presented.

  19. Compatibility between shape equation and boundary conditions of lipid membranes with free edges.

    PubMed

    Tu, Z C

    2010-02-28

    Only some special open surfaces satisfying the shape equation of lipid membranes can be compatible with the boundary conditions. As a result of this compatibility, the first integral of the shape equation should vanish for axisymmetric lipid membranes, from which two theorems of nonexistence are verified: (i) there is no axisymmetric open membrane being a part of torus satisfying the shape equation; (ii) there is no axisymmetric open membrane being a part of a biconcave discodal surface satisfying the shape equation. Additionally, the shape equation is reduced to a second-order differential equation while the boundary conditions are reduced to two equations due to this compatibility. Numerical solutions to the reduced shape equation and boundary conditions agree well with the experimental data [A. Saitoh et al., Proc. Natl. Acad. Sci. U.S.A. 95, 1026 (1998)]. PMID:20192294

  20. Exo-planet Direct Imaging with On-Axis and/or Segmented Apertures in Space: Adaptive Compensation of Aperture Discontinuities

    NASA Astrophysics Data System (ADS)

    Soummer, Remi

    Capitalizing on a recent breakthrough in wavefront control theory for obscured apertures made by our group, we propose to demonstrate a method to achieve high contrast exoplanet imaging with on-axis obscured apertures. Our new algorithm, which we named Adaptive Compensation of Aperture Discontinuities (ACAD), provides the ability to compensate for aperture discontinuities (segment gaps and/or secondary mirror supports) by controlling deformable mirrors in a nonlinear wavefront control regime not utilized before but conceptually similar to the beam reshaping used in PIAA coronagraphy. We propose here an in-air demonstration at 1E- 7 contrast, enabled by adding a second deformable mirror to our current test-bed. This expansion of the scope of our current efforts in exoplanet imaging technologies will enabling us to demonstrate an integrated solution for wavefront control and starlight suppression on complex aperture geometries. It is directly applicable at scales from moderate-cost exoplanet probe missions to the 2.4 m AFTA telescopes to future flagship UVOIR observatories with apertures potentially 16-20 m. Searching for nearby habitable worlds with direct imaging is one of the top scientific priorities established by the Astro2010 Decadal Survey. Achieving this ambitious goal will require 1e-10 contrast on a telescope large enough to provide angular resolution and sensitivity to planets around a significant sample of nearby stars. Such a mission must of course also be realized at an achievable cost. Lightweight segmented mirror technology allows larger diameter optics to fit in any given launch vehicle as compared to monolithic mirrors, and lowers total life-cycle costs from construction through integration & test, making it a compelling option for future large space telescopes. At smaller scales, on-axis designs with secondary obscurations and supports are less challenging to fabricate and thus more affordable than the off-axis unobscured primary mirror designs

  1. Presence of Both Photosystems in Guard Cells of Vicia faba L

    PubMed Central

    Outlaw, William H.; Mayne, Berger C.; Zenger, Vincent E.; Manchester, Jill

    1981-01-01

    A new procedure is reported for high-yield isolation of guard cell protoplasts from Vicia faba L. Delayed light emission and P700 content plus absorption and fluorescence emission spectra of these protoplast extracts are reported. It is concluded that both photosystems are present. The presence of photosystem II and the absence of the reductive-step enzyme of the Calvin-Benson Cycle (Outlaw WH Jr, J Manchester, CH DiCamelli, DD Randall, B Rapp, GM Veith 1979 Proc Natl Acad Sci USA 76: 6371-6375) in a cell has no precedent in the literature. It is speculated that noncyclic photosynthetic electron flow is an environmental sensor which causes stomata to remain open in light. Images PMID:16661609

  2. Characterization of the heartworm Acanthocheilonema spirocauda (Leidy, 1858) Anderson, 1992 (Nematoda: Onchocercidae) in Scandinavia.

    PubMed

    Leidenberger, Sonja; Boström, Sven

    2008-12-01

    The heartworm Acanthocheilonema spirocauda (Leidy, Proc Acad Nat Sci Philadelphia 10:110-112, 1858) Anderson, 1992 is described from material collected from harbour seals in Scandinavia and compared with types and other specimens described by Anderson (Can J Zool 37:481-493, 1959) from harbour seals in eastern USA. Most morphometric characters of the material from USA fall within the ranges established for the Scandinavian one. Some intraspecific variability in the organisation of papillae on the male tail was detected among the Scandinavian specimens. Differences between the specimens from Scandinavia and Eastern USA are also found in the organisation of papillae on the tail of males and females. An excretory pore was not discernible, but a clearly hemizonid-like structure is described. For the first time, scanning electron micrographs present external morphological structures of the species. PMID:18762981

  3. Configurations of an Articulated Arm and Singularities of Special Multi-Flags

    NASA Astrophysics Data System (ADS)

    Pelletier, Fernand; Slayman, Mayada

    2014-06-01

    P. Mormul has classified the singularities of special multi-flags in terms of "EKR class" encoded by sequences j_1,dots, j_k of integers (see [Singularity Theory Seminar, Warsaw University of Technology, Vol. 8, 2003, 87-100] and [Banach Center Publ., Vol. 65, Polish Acad. Sci., Warsaw, 2004, 157-178]). However, A.L. Castro and R. Montgomery have proposed in I>Israel J. Math. 192 (2012), 381-427] a codification of singularities of multi-flags by RC and RVT codes. The main results of this paper describe a decomposition of each ''EKR'' set of depth 1 in terms of RVT codes as well as characterize such a set in terms of configurations of an articulated arm. Indeed, an analogue description for some ''EKR'' sets of depth 2 is provided. All these results give rise to a complete characterization of all ''EKR'' sets for 1≤ k≤ 4.

  4. 1H-NMR study of the three low temperature phases of DPPC-water systems.

    PubMed

    Trahms, L; Klabe, W D; Boroske, E

    1983-06-01

    The three phases of dipalmitoylphosphatidylcholine-water dispersions, occurring below the main transition are studied by a moment analysis of 1H-nuclear magnetic resonance (NMR) spectra. The subtransition, recently detected by Chen, S. C., J. M. Sturtevant, and B. J. Gaffney, 1980, Pro. Natl. Acad. Sci. USA, 77:5060-5063, is characterized by a sharp drop in the second moment at 12 degrees C as a result of increasing the temperature. Interesting features of this phase transition are a hysteresis of 11 K and extremely slow kinetics. It is interpreted as the onset of a flip-flop of the hydrocarbon chains about their long axis. At the pretransition, this type of motion is assumed to change into a fast rotation. The proposed models for the three phases are confirmed by computer calculations of theoretical values for the second and fourth moments of the corresponding NMR signals. PMID:6688190

  5. Formaldehyde photodissociation: Dependence on total angular momentum and rotational alignment of the CO product

    SciTech Connect

    Farnum, John D.; Zhang, Xiubin; Bowman, Joel M.

    2007-04-07

    Quasiclassical trajectory calculations are reported to investigate the effects of rotational excitation of formaldehyde on the branching ratios of the fragmentation products, H{sub 2}+CO and H+HCO. The results of tens of thousands of trajectories show that increased rotational excitation causes suppression of the radical channel and enhancement of the molecular channel. Decomposing the molecular channel into ''direct'' and ''roaming'' channels shows that increased rotation switches from suppressing to enhancing the roaming products across our chosen energy range. However, decomposition into these pathways is difficult because the difference between them does not appear to have a distinct boundary. A vector correlation investigation of the CO rotation shows different characteristics in the roaming versus direct channels and this difference is a potentially useful signature of the roaming mechanism, as first speculated by Kable and Houston in their experimental study of photodissociation of acetaldehyde [P. L. Houston and S. H. Kable, Proc. Nat. Acad. Sci. 103, 16079 (2006)].

  6. Note: Recombination of H{sup +} and OH{sup -} ions along water wires

    SciTech Connect

    Lee, Song Hi; Rasaiah, Jayendran C.

    2013-07-21

    Transport and recombination of hydrogen and hydroxide ions along a hydrogen-bonded water wire are studied by molecular dynamics simulation using a dissociating model for water. The results are compared with a recent CP-MD study of neutralization in bulk water [A. Hassanali, M. K. Prakrash, H. Eshet, and M. Parrinello, Proc. Natl. Acad. Sci. U.S.A. 108, 20410 (2011)]. The translocation of H{sup +} and OH{sup -} along the wire is faster than in the bulk water, followed by compression of the water wire when two water molecules separate the transported ions. Neutralization occurs with the concerted transfer of three protons as in the bulk water, followed by energy dissipation along the water chain.

  7. Entanglement properties of positive operators with ranges in completely entangled subspaces

    NASA Astrophysics Data System (ADS)

    Sengupta, R.; Arvind, Singh, Ajit Iqbal

    2014-12-01

    We prove that the projection on a completely entangled subspace S of maximum dimension obtained by Parthasarathy [K. R. Parthasarathy, Proc. Indian Acad. Sci. Math. Sci. 114, 365 (2004), 10.1007/BF02829441] in a multipartite quantum system is not positive under partial transpose. We next show that a large number of positive operators with a range in S also have the same property. In this process we construct an orthonormal basis for S and provide a theorem to link the constructions of completely entangled subspaces due to Parthasarathy (as cited above), Bhat [B. V. R. Bhat, Int. J. Quantum Inf. 4, 325 (2006), 10.1142/S0219749906001797], and Johnston [N. Johnston, Phys. Rev. A 87, 064302 (2013), 10.1103/PhysRevA.87.064302].

  8. Content-based network model with duplication and divergence

    NASA Astrophysics Data System (ADS)

    Şengün, Yasemin; Erzan, Ayşe

    2006-06-01

    We construct a minimal content-based realization of the duplication and divergence model of genomic networks introduced by Wagner [Proc. Natl. Acad. Sci. 91 (1994) 4387] and investigate the scaling properties of the directed degree distribution and clustering coefficient. We find that the content-based network exhibits crossover between two scaling regimes, with log-periodic oscillations for large degrees. These features are not present in the original gene duplication model, but inherent in the content-based model of Balcan and Erzan. The scaling form of the degree distribution of the content-based model turns out to be robust under duplication and divergence, with some re-adjustment of the scaling exponents, while the out-clustering coefficient goes over from a weak power-law dependence on the degree, to an exponential decay under mutations which include splitting and merging of strings.

  9. [Competence in biocentric ethics.

    PubMed

    Stepke, Fernando Lolas

    2012-07-01

    ResumenEste artículo explora el origen y la conceptualización de la bioética en tanto ética biocéntrica, definida por el pionero Fritz Jahr como un imperativo hipotético que llama a respetar la vida en todas sus formas. Tras describirla como proceso social, procedimiento técnico y producto académico, se enumeran y comentan algunas competencias que debieran presidir el empleo del discurso bioético en cualquier punto del complejo social "investigación médica": miembros de comités de ética de investigación, investigadores, empresarios, administradores. Cada uno de estos grupos, en su "cultura epistémica" propia, define y explicita los principios básicos en tanto expresión de valores y leyes generales. PMID:23459767

  10. The Observation of Highly Ordered Domains in Membranes with Cholesterol

    PubMed Central

    Armstrong, Clare L.; Marquardt, Drew; Dies, Hannah; Kučerka, Norbert; Yamani, Zahra; Harroun, Thad A.; Katsaras, John; Shi, An-Chang; Rheinstädter, Maikel C.

    2013-01-01

    Rafts, or functional domains, are transient nano- or mesoscopic structures in the exoplasmic leaflet of the plasma membrane, and are thought to be essential for many cellular processes. Using neutron diffraction and computer modelling, we present evidence for the existence of highly ordered lipid domains in the cholesterol-rich (32.5 mol%) liquid-ordered () phase of dipalmitoylphosphatidylcholine membranes. The liquid ordered phase in one-component lipid membranes has previously been thought to be a homogeneous phase. The presence of highly ordered lipid domains embedded in a disordered lipid matrix implies non-uniform distribution of cholesterol between the two phases. The experimental results are in excellent agreement with recent computer simulations of DPPC/cholesterol complexes [Meinhardt, Vink and Schmid (2013). Proc Natl Acad Sci USA 110(12): 4476–4481], which reported the existence of nanometer size domains in a liquid disordered lipid environment. PMID:23823623

  11. LA BIOÉTICA COMO QUEHACER FILOSÓFICO

    PubMed Central

    Ferrer, Jorge José

    2009-01-01

    El artículo examina el estatuto epistemológico de la bioética como disciplina académica. El autor sostiene que el estatuto epistemológico de un discurso lo determina la pregunta fundamental que se plantea y la respuesta que se busca, focos integradores del discurso. En el caso de la bioética, la pregunta fundamental es de índole moral. La bioética es pues una disciplina ética que tiene su hogar epistemológico en la filosofía. El autor también defiende el concepto de “éticas aplicadas”. Sugiere finalmente que el método de la bioética, sobre todo la que se hace desde nuestras latitudes, debería adoptar el círculo hermenéutico como metodología para su filosofar. PMID:20463860

  12. Eight years of bioethics

    PubMed Central

    Moreno-Exebio, Luis

    2012-01-01

    Este trabajo presenta la experiencia que significó el paso por el Programa Internacional de Formación en Ética de la investigación biomédica y psicosocial del Centro Interdisciplinario de Estudios en Bioética de la Universidad de Chile (2003–2004) y algunas reflexiones respecto de la integración de lo aprendido en mi posterior labor en comités de ética y programas académicos de ética de investigación. Asimismo, en la elaboración de regulaciones que permitan una mejor evaluación ética y científica. PMID:23172984

  13. The J gene of bacteriophage phi X174: in vitro analysis of J protein function.

    PubMed Central

    Hamatake, R K; Aoyama, A; Hayashi, M

    1985-01-01

    The J protein of phi X174 is a small, highly basic protein and is a component of the phage capsid. We have investigated the role of J protein during single-stranded viral DNA synthesis and phage morphogenesis by using an in vitro system composed of purified viral and host components (Aoyama et al., Proc. Natl. Acad. Sci. U.S.A. 80:4195-4199, 1983). The characterization of the products made in the presence and absence of J protein shows that J protein is not required for viral DNA synthesis, but is required for the packaging of DNA into infectious phage. The ability of J protein to bind to double-stranded DNA as well as single-stranded DNA and other interactions with DNA suggest a model in which J protein binds to double-stranded, replicative form DNA and enters the phage prohead by remaining bound to viral DNA as it is encapsidated. PMID:3157804

  14. Scald-Induced Necrobiosis Lipoidica in a Patient with Diabetes Mellitus and Psoriasis

    PubMed Central

    Ito, Hoshiko; Imamura, Sadao

    2016-01-01

    The Koebner phenomenon (KP) was first introduced by Heinrich Koebner in the 1870s to describe the appearance of psoriatic lesions following trauma in psoriasis patients. KP has since been defined in numerous diseases, including necrobiosis lipoidica diabeticorum (NLD). Since most Koebnerized dermatological lesions can localise to a site of previous trauma, Weiss et al. (Eur Acad Dermatol Venereol 2002;16:241–248) classified them into four categories (I–IV) according to the Boyd-Nelder classification (Int J Dermatol 1990;29:401–410) system. In this system, necrobiosis lipoidica is classified as category III, which includes diseases that occasionally localise at the site of trauma. We report a case of NLD that developed after scald in a psoriasis patient. NLD after trauma has often been reported, but this is the first case of NLD that coincidentally occurred at a scald site in a psoriasis patient. PMID:26889139

  15. Large-scale Individual-based Models of Pandemic Influenza Mitigation Strategies

    NASA Astrophysics Data System (ADS)

    Kadau, Kai; Germann, Timothy; Longini, Ira; Macken, Catherine

    2007-03-01

    We have developed a large-scale stochastic simulation model to investigate the spread of a pandemic strain of influenza virus through the U.S. population of 281 million people, to assess the likely effectiveness of various potential intervention strategies including antiviral agents, vaccines, and modified social mobility (including school closure and travel restrictions) [1]. The heterogeneous population structure and mobility is based on available Census and Department of Transportation data where available. Our simulations demonstrate that, in a highly mobile population, restricting travel after an outbreak is detected is likely to delay slightly the time course of the outbreak without impacting the eventual number ill. For large basic reproductive numbers R0, we predict that multiple strategies in combination (involving both social and medical interventions) will be required to achieve a substantial reduction in illness rates. [1] T. C. Germann, K. Kadau, I. M. Longini, and C. A. Macken, Proc. Natl. Acad. Sci. (USA) 103, 5935-5940 (2006).

  16. Solid-state NMR of the Yersinia pestis outer membrane protein Ail in lipid bilayer nanodiscs sedimented by ultracentrifugation.

    PubMed

    Ding, Yi; Fujimoto, L Miya; Yao, Yong; Marassi, Francesca M

    2015-04-01

    Solid-state NMR studies of sedimented soluble proteins has been developed recently as an attractive approach for overcoming the size limitations of solution NMR spectroscopy while bypassing the need for sample crystallization or precipitation (Bertini et al. Proc Natl Acad Sci USA 108(26):10396-10399, 2011). Inspired by the potential benefits of this method, we have investigated the ability to sediment lipid bilayer nanodiscs reconstituted with a membrane protein. In this study, we show that nanodiscs containing the outer membrane protein Ail from Yersinia pestis can be sedimented for solid-state NMR structural studies, without the need for precipitation or lyophilization. Optimized preparations of Ail in phospholipid nanodiscs support both the structure and the fibronectin binding activity of the protein. The same sample can be used for solution NMR, solid-state NMR and activity assays, facilitating structure-activity correlation experiments across a wide range of timescales. PMID:25578899

  17. Interactions of Avocado (Persea americana) Cytochrome P-450 with Monoterpenoids

    PubMed Central

    Hallahan, David L.; Nugent, Jonathan H. A.; Hallahan, Beverly J.; Dawson, Glenn W.; Smiley, Diane W.; West, Jevon M.; Wallsgrove, Roger M.

    1992-01-01

    The microsomal fraction of avocado (Persea americana) mesocarp is a rich source of cytochrome P-450 active in the demethylation of xenobiotics. Cytochrome P-450 from this tissue has been purified and well characterized at the molecular level (DP O'Keefe, KJ Leto [1989] Plant Physiol 89: 1141-1149; KR Bozak, H Yu, R Sirevag, RE Christoffersen [1990] Proc Natl Acad Sci USA 87: 3904-3908). Despite this extensive characterization, the role of the enzyme in vivo was not established. Optical and electron paramagnetic resonance binding studies described here suggest that the monoterpenoids, nerol and geraniol, are substrates of avocado cytochrome P-450 (spectral dissociation constant of 7.2 and 35 micromolar, respectively). Avocado microsomes have been shown to catalyze the hydroxylation of these monoterpenoids, and both nerol and geraniol have been shown to inhibit the activity of avocado cytochrome P-450 toward the artificial substrate 7-ethoxycoumarin, with nerol a competitive inhibitor of this activity. PMID:16668790

  18. Lalande: his life (1732-1807) and works

    NASA Astrophysics Data System (ADS)

    Débarbat, Suzanne

    2005-05-01

    Lalande, born in Bourg-en-Bresse, made his first studies at the Jesuit College, later in Paris, attending Delisle's and Lemonnier's courses. He went to Berlin in 1751 for the determination of the lunar parallax, with Lacaille being in South Africa. Among the observatories in Paris, at the end of XVIIIth century, were the ones remaining to the Navy, the Royal Observatory, and the observatory named after the Military school. Being nominated as the head of this last observatory, Lalande asked his "nephew" to observe positions of stars, having in view a large catalogue. Together with other observers, he and hist wife obtained places for about 50,000 such objects, the so-called Lalande's Catalogue. Lalande is also famous for his writings, mostly his book whose title in French is "Astronomie" published in three editions. He was a member of the Académie des Sciences and of the Bureau des Longitudes.

  19. Dynamical Transition of Protein-Hydration Water

    NASA Astrophysics Data System (ADS)

    Doster, W.; Busch, S.; Gaspar, A. M.; Appavou, M.-S.; Wuttke, J.; Scheer, H.

    2010-03-01

    Thin layers of water on biomolecular and other nanostructured surfaces can be supercooled to temperatures not accessible with bulk water. Chen et al. [Proc. Natl. Acad. Sci. U.S.A. 103, 9012 (2006)]PNASA60027-842410.1073/pnas.0602474103 suggested that anomalies near 220 K observed by quasielastic neutron scattering can be explained by a hidden critical point of bulk water. Based on more sensitive measurements of water on perdeuterated phycocyanin, using the new neutron backscattering spectrometer SPHERES, and an improved data analysis, we present results that show no sign of such a fragile-to-strong transition. The inflection of the elastic intensity at 220 K has a dynamic origin that is compatible with a calorimetric glass transition at 170 K. The temperature dependence of the relaxation times is highly sensitive to data evaluation; it can be brought into perfect agreement with the results of other techniques, without any anomaly.

  20. Differential conductance and defect states in the heavy-fermion superconductor CeCoIn5

    DOE PAGESBeta

    John S. Van Dyke; Davis, James C.; Morr, Dirk K.

    2016-01-22

    We demonstrate that the electronic band structure extracted from quasiparticle interference spectroscopy [Nat. Phys. 9, 468 (2013)] and the theoretically computed form of the superconducting gaps [Proc. Natl. Acad. Sci. USA 111, 11663 (2014)] can be used to understand the dI/dV line shape measured in the normal and superconducting state of CeCoIn5 [Nat. Phys. 9, 474 (2013)]. In particular, the dI/dV line shape, and the spatial structure of defect-induced impurity states, reflects the existence of multiple superconducting gaps of dx2–y2 symmetry. As a result, these results strongly support a recently proposed microscopic origin of the unconventional superconducting state.

  1. A cylinder-to-sphere Fourier view factor model for azimuthal asymmetry studies in cylindrical hohlraums

    NASA Astrophysics Data System (ADS)

    Giorla, J.; Poggi, F.; Paillard, D.

    2002-01-01

    This work addresses the analytical calculation of the irradiation coming from a cylindrical surface to a spherical one. This exact solution of the x-ray transport equation allows one to connect the emitted and the received fluxes, expanded as Fourier modes, by coefficients called Fourier view factors. Such a calculation is well suited to a symmetry study in the Laser Megajoule configuration [P.-A. Holstein, M. André, M. Casanova et al., C. R. Acad. Sci. Paris 1, 693 (2000)] where a cylindrical hohlraum and a spherical capsule are irradiated. Indeed, this 60 quad laser system induces an azimuthal asymmetry of the hohlraum lighting depending on the laser focal spot size. Thus, the Fourier view factors allow one to express the modes of the capsule irradiation as functions of the elliptic spot dimensions.

  2. Antiviral activity of squalamine: Role of electrostatic membrane binding

    NASA Astrophysics Data System (ADS)

    Beckerman, Bernard; Qu, Wei; Mishra, Abhijit; Zasloff, Michael; Wong, Gerard; Luijten, Erik

    2012-02-01

    Recent workootnotetextM. Zasloff et al., Proc. Nat. Acad. Sci. (USA) 108, 15978 (2011). has demonstrated that squalamine, a molecule found in the liver of sharks, exhibits broad-spectrum antiviral properties. It has been proposed that this activity results from the charge-density matching of squalamine and phospholipid membranes, causing squalamine to bind to membranes and displace proteins such as Rac1 that are crucial for the viral replication cycle. Here we investigate this hypothesis by numerical simulation of a coarse-grained model for the competition between Rac1 and squalamine in binding affinity to a flat lipid bilayer. We perform free-energy calculations to test the ability of squalamine to condense stacked bilayer systems and thereby displace bulkier Rac1 molecules. We directly compare our findings to small-angle x-ray scattering results for the same setup.

  3. Treating leukemia at the risk of inducing severe anemia.

    PubMed

    Chen, Wendy S; Zhu, Helen He; Feng, Gen-Sheng

    2016-05-01

    Anemia is a frequently observed adverse effect in cancer patients who receive chemotherapy or drugs designed to block specific oncogenic signaling pathways, although the underlying mechanisms are poorly understood. An article first published online (Zhu HH, Luo X, Zhang K, et al. Proc Natl Acad Sci USA 2015;112:13342-13347) presented data indicating that cell type-specific pathway cross-talk is likely an important mechanism to consider. Shp2 and Pten, two master regulators of central cytoplasmic signaling pathways, oppose each other in myeloproliferation and leukemogenesis, but cooperate in promoting erythropoiesis. Thus, genetic ablation or pharmacologic inhibition of Shp2 suppresses the leukemogenic effect of Pten loss, yet simultaneously induces severe anemia in mice with Pten deficiency in blood cells. PMID:26826310

  4. EDITORIAL Proceedings of the XIV International Conference on Small-Angle Scattering, SAS-2009

    NASA Astrophysics Data System (ADS)

    Ungar, Goran; Heenan, Richard

    2010-10-01

    There are 52 papers in these Proceedings. The papers are divided into 10 thematic sections and a section for invited papers and reviews. The sections and the respective section editors are given below. Section Editor(s) Invited Papers and Reviews Peter Griffiths, Wim Bras, Rudolf Winter Beamlines and Instrumentation Elliot Gilbert, Wim Bras, Nigel Rhodes Theory, Data processing and Modelling Jan Skov Pedersen, Carlo Knupp Biological Systems and Membranes Richard Heenan, Cameron Neylon Ceramics, Glasses and Porous Materials Rudolf Winter Colloids and Solutions Peter Griffiths Hierarchical Structures and Fibres Steve Eichhorn, Karen Edler Metallic and Magnetic Systems Armin Hoell Polymers Patrick Fairclough Time resolved Diffraction, Kinetic and Dynamical Studies João Cabral, Christoph Rau We are grateful to all section editors and the many anonymous referees for their invaluable effort which made the publication of the Proceedings possible. The refereeing process was strict and thorough, some papers were rejected and most were improved. The resulting compendium gives a good overview of recent developments in small-angle X-ray and neutron scattering theory, application, methods of analysis and instrumentation. Thus it should be a useful source of reference for a number of years to come. The papers are a good reflection of the material presented at the meeting. Because of the general high quality of the articles, it was difficult to decide which to highlight and be fair to all contributors. The following in particular have caught the attention of the editors. Highlighted papers A statistical survey of publications reporting the application of SAXS and SANS by Aldo Craievich (paper 012003) is recommended reading for anyone needing convincing about the vibrancy of this scientific field and the ever expanding use of these techniques. Two aspects of coherent X-ray scattering, made available by the advent of the 3rd generation synchrotron sources, are discussed in the

  5. Skin Cancer in the Crosshairs: Highlights from the Biennial Scientific Retreat of International Transplant Skin Cancer Collaborative and Skin Care in Organ Transplant Recipients Europe.

    PubMed

    Sinnya, Sudipta; Zwald, Fiona O; Colegio, Oscar R

    2015-08-01

    The International Transplant Skin Cancer Collaborative (ITSCC) is an organization comprising of physicians; transplant surgeons and basic science research scientists dedicated in providing optimal care and ongoing research advancements in solid organ transplant recipients to improve patient outcome and quality of life. As medical advances occur, it is anticipated that the sheer number of solid organ transplantations occurring worldwide will continue to increase. The long-term medication associated immunosuppression improves graft survival, but as a consequence, these individuals become increasingly susceptible to various cutaneous malignancies, lymphoproliferative disorders and infections. Squamous cell carcinoma is the most frequently encountered skin cancer and increases 65- to 250-fold [Jensen et al., Skin cancer in kidney and heart transplant recipients and different long-term immunosuppressive therapy regimens. J Am Acad Dermatol. 1999;40:177-186; Lindelöf et al., Incidence of skin cancer in 5356 patients following organ transplantation. Br J Dermatol. 2000; 143:513-519]. However, the rates of basal cell carcinoma, Merkel cell carcinoma and melanoma also increase in organ transplant recipients leading to significant morbidity as well as mortality [Berg and Otley. Skin cancer in organ transplant recipients: epidemiology, pathogenesis, and management. J Am Acad Dermatol. 2002; 47:1-20]. In October 2014, the International Transplant Skin Cancer Collaborative and its equivalent European counterpart, Skin Care in Organ Transplant Recipients Europe held its 10th biennial meeting in Essex, MA to discuss the clinical conundrums and the evolving research pertinent to the field. This meeting report provides a synthesis of all the clinical and research data presented at the 4-day meeting. PMID:27500228

  6. Biochemical and Genetic Investigation of Initial Reactions in Aerobic Degradation of the Bile Acid Cholate in Pseudomonas sp. Strain Chol1▿

    PubMed Central

    Birkenmaier, Antoinette; Holert, Johannes; Erdbrink, Henrike; Moeller, Heiko M.; Friemel, Anke; Schoenenberger, René; Suter, Marc J.-F.; Klebensberger, Janosch; Philipp, Bodo

    2007-01-01

    Bile acids are surface-active steroid compounds with toxic effects for bacteria. Recently, the isolation and characterization of a bacterium, Pseudomonas sp. strain Chol1, growing with bile acids as the carbon and energy source was reported. In this study, initial reactions of the aerobic degradation pathway for the bile acid cholate were investigated on the biochemical and genetic level in strain Chol1. These reactions comprised A-ring oxidation, activation with coenzyme A (CoA), and β-oxidation of the acyl side chain with the C19-steroid dihydroxyandrostadienedione as the end product. A-ring oxidizing enzyme activities leading to Δ1,4-3-ketocholyl-CoA were detected in cell extracts and confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Cholate activation with CoA was demonstrated in cell extracts and confirmed with a chemically synthesized standard by LC-MS/MS. A transposon mutant with a block in oxidation of the acyl side chain accumulated a steroid compound in culture supernatants which was identified as 7α,12α-dihydroxy-3-oxopregna-1,4-diene-20-carboxylate (DHOPDC) by nuclear magnetic resonance spectroscopy. The interrupted gene was identified as encoding a putative acyl-CoA-dehydrogenase (ACAD). DHOPDC activation with CoA in cell extracts of strain Chol1 was detected by LC-MS/MS. The growth defect of the transposon mutant could be complemented by the wild-type ACAD gene located on the plasmid pBBR1MCS-5. Based on these results, the initiating reactions of the cholate degradation pathway leading from cholate to dihydroxyandrostadienedione could be reconstructed. In addition, the first bacterial gene encoding an enzyme for a specific reaction step in side chain degradation of steroid compounds was identified, and it showed a high degree of similarity to genes in other steroid-degrading bacteria. PMID:17693490

  7. Synaptic plasticity with discrete state synapses

    NASA Astrophysics Data System (ADS)

    Abarbanel, Henry D. I.; Talathi, Sachin S.; Gibb, Leif; Rabinovich, M. I.

    2005-09-01

    Experimental observations on synaptic plasticity at individual glutamatergic synapses from the CA3 Shaffer collateral pathway onto CA1 pyramidal cells in the hippocampus suggest that the transitions in synaptic strength occur among discrete levels at individual synapses [C. C. H. Petersen , Proc. Natl. Acad. Sci. USA 85, 4732 (1998); O’Connor, Wittenberg, and Wang, D. H. O’Connor , Proc. Natl. Acad. Sci. USA (to be published); J. M. Montgomery and D. V. Madison, Trends Neurosci. 27, 744 (2004)]. This happens for both long term potentiation (LTP) and long term depression (LTD) induction protocols. O’Connor, Wittenberg, and Wang have argued that three states would account for their observations on individual synapses in the CA3-CA1 pathway. We develop a quantitative model of this three-state system with transitions among the states determined by a competition between kinases and phosphatases shown by D. H. O’Connor , to be determinant of LTP and LTD, respectively. Specific predictions for various plasticity protocols are given by coupling this description of discrete synaptic α -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor ligand gated ion channel conductance changes to a model of postsynaptic membrane potential and associated intracellular calcium fluxes to yield the transition rates among the states. We then present various LTP and LTD induction protocols to the model system and report the resulting whole cell changes in AMPA conductance. We also examine the effect of our discrete state synaptic plasticity model on the synchronization of realistic oscillating neurons. We show that one-to-one synchronization is enhanced by the plasticity we discuss here and the presynaptic and postsynaptic oscillations are in phase. Synaptic strength saturates naturally in this model and does not require artificial upper or lower cutoffs, in contrast to earlier models of plasticity.

  8. PNAS Plus: Independent evaluation of conflicting microspherule results from different investigations of the Younger Dryas impact hypothesis

    NASA Astrophysics Data System (ADS)

    LeCompte, Malcolm A.; Goodyear, Albert C.; Demitroff, Mark N.; Batchelor, Dale; Vogel, Edward K.; Mooney, Charles; Rock, Barrett N.; Seidel, Alfred W.

    2012-10-01

    Firestone et al. sampled sedimentary sequences at many sites across North America, Europe, and Asia [Firestone RB, et al. (2007) Proc Natl Acad Sci USA 106:16016-16021]. In sediments dated to the Younger Dryas onset or Boundary (YDB) approximately 12,900 calendar years ago, Firestone et al. reported discovery of markers, including nanodiamonds, aciniform soot, high-temperature melt-glass, and magnetic microspherules attributed to cosmic impacts/airbursts. The microspherules were explained as either cosmic material ablation or terrestrial ejecta from a hypothesized North American impact that initiated the abrupt Younger Dryas cooling, contributed to megafaunal extinctions, and triggered human cultural shifts and population declines. A number of independent groups have confirmed the presence of YDB spherules, but two have not. One of them [Surovell TA, et al. (2009) Proc Natl Acad Sci USA 104:18155-18158] collected and analyzed samples from seven YDB sites, purportedly using the same protocol as Firestone et al., but did not find a single spherule in YDB sediments at two previously reported sites. To examine this discrepancy, we conducted an independent blind investigation of two sites common to both studies, and a third site investigated only by Surovell et al. We found abundant YDB microspherules at all three widely separated sites consistent with the results of Firestone et al. and conclude that the analytical protocol employed by Surovell et al. deviated significantly from that of Firestone et al. Morphological and geochemical analyses of YDB spherules suggest they are not cosmic, volcanic, authigenic, or anthropogenic in origin. Instead, they appear to have formed from abrupt melting and quenching of terrestrial materials.

  9. Evidence for an intense solar outburst in prehistory

    NASA Astrophysics Data System (ADS)

    Peratt, A. L.; Yao, W. F.

    2008-10-01

    A past intense solar outburst and its effect on Earth was proposed by Gold (1962 Pontificiae Acad. Sci. Scr. Varia 25 159) who, along with others, based his hypotheses on strong astronomical and geophysical evidence. The discovery that objects from the Neolithic or Early Bronze Age carry patterns associated with high-current Z-pinches, as would result from an intense plasma impinging Earth, provides a possible insight into the origin and meaning of these ancient symbols produced by humans. Peratt (2003 Trans. Plasma Sci. 31 1192) dealt with the comparison of graphical and radiation data from high-current Z-pinches to petroglyphs, geoglyphs and megaliths. Peratt (2007 Trans. Plasma Sci. 35 778) focused primarily, but not exclusively, on petroglyphs of some 84 different morphologies; pictures found in laboratory experiments and carved on rock. These corresponded to mankind's visual observations of ancient aurora as might be produced if the solar wind had increased at times between one and two orders of magnitude, millennia ago (Gold 1962 Pontificiae Acad. Sci. Scr. Varia 25 159). In Peratt (2007 Trans. Plasma Sci. 35 778), the data were given on the source of light and its temporal change from a current-increasing Z-pinch or dense plasma focus aurora. Orientation and field-of-view data are given as surveyed and contributed from 139 countries, from sites and fields containing several millions of these objects, the latest data coming from a 300 km survey along the Orinoco river basin in Venezuela. In this paper, we include additional petroglyph figures derivable from experiment and computer. This information allows a reconstruction of the auroral form presumably associated with extreme geomagnetic storms and shows, based on existent geophysical evidence, relativistic electron flow inward at Earth's south polar axis and hypervelocity proton impacts around the north polar axis.

  10. Biomineral formation as a biosignature for microbial activities Precambrian cherts

    NASA Astrophysics Data System (ADS)

    Rincón Tomás, Blanca; Mühlen, Dominik; Hoppert, Michael; Reitner, Joachim

    2015-04-01

    In recent anoxic sediments manganese(II)carbonate minerals (e.g., rhodochrosite, kutnohorite) derive mainly from the reduction of manganese(IV) compounds by microbial anaerobic respiration. Small particles of rhodochrosite in stromatolite-like features in the Dresser chert Fm (Pilbara supergroup, W-Australia), associated with small flakes of kerogen, account for biogenic formation of the mineral in this early Archaean setting. Contrastingly, the formation of huge manganese-rich (carbonate) deposits requires effective manganese redox cycling, also conducted by various microbial processes, mainly requiring conditions of the early and late Proterozoic (Kirschvink et al., 2000; Nealson and Saffrani 1994). However, putative anaerobic pathways like microbial nitrate-dependent manganese oxidation (Hulth et al., 1999), anoxygenic photosynthesis (Johnson et al., 2013) and oxidation in UV light may facilitate manganese cycling even in a reducing atmosphere. Thus manganese redox cycling might have been possible even before the onset of oxygenic photosynthesis. Hence, there are several ways how manganese carbonates could have been formed biogenically and deposited in Precambrian sediments. Thus, the minerals may be suitable biosignatures for microbial redox processes in many respects. The hyperthermophilic archaeon Pyrobaculum islandicum produces rhodochrosite during growth on hydrogen and organic compounds and may be a putative model organism for the reduction of Mn(IV). References Hulth S, Aller RC, Gilbert F. (1999) Geochim Cosmochim Acta, 63, 49-66. Johnson JE, Webb SM, Thomas K, Ono S, Kirschvink JL, Fischer WW. (2013) Proc Natl Acad Sci USA, 110, 11238-11243. Kirschvink JL, Gaidos EJ, Bertani LE, Beukes NJ, Gutzmer J, Maepa LN, Steinberger LE. (2000) Proc Natl Acad Sci USA, 97, 1400-1405. Nealson KH, Saffarini D. (1994). Annu Rev Microbiol, 48, 311-343.

  11. Study of minima of the fluctuations of the order parameter of seismicity using GCMT catalogue in global scale.

    NASA Astrophysics Data System (ADS)

    Christopoulos, Stavros-Richard G.; Sarlis, Nicholas V.; Skordas, Efthimios S.

    2016-04-01

    It has been recently shown [1,2] that earthquakes of magnitude M greater or equal to 7 are globally correlated. The identification of this correlation became possible when studying the variance κ1 of natural time which has been proposed as an order parameter for seismicity[3,4]. In the present study, we focus on the behaviour of the fluctuations of κ1 before major earthquakes using the Global Centroid Moment Tensor catalogue for a magnitude threshold Mthres=5.0 as in Ref.[5]. Natural time analysis reveals that distinct minima of the fluctuations κ1of seismicity appear within almost five and a half months on average before all major earthquakes of magnitude larger than M8.4. This phenomenon corroborates the recent finding [6] that similar minima of seismicity order parameter fluctuations had been observed before all major shallow earthquakes in Japan. Finally, we examine the statistical significance of the results by using ROC graphs [7,8] and the proposed prediction method has a p-value to occur by chance well below 0.1%. The hit rate is 100% with a false alarm rate only 6.67%. An attempt to lower the target earthquake magnitude threshold will be also presented. REFERENCES [1] N. V. Sarlis, Phys. Rev. E 84, 022101 (2011). [2] N. V. Sarlis and S.-R. G. Christopoulos, Chaos 22, 023123 (2012) [3] P. A. Varotsos, N. V. Sarlis, and E. S. Skordas, Practica of Athens Acad. 76, 294 (2001). [4] P. A. Varotsos, N. V. Sarlis, and E. S. Skordas, Phys. Rev. E 66, 011902 (2002). [5] N.V. Sarlis, S.-R. G. Christopoulos, and E. S. Skordas, Chaos 25, 063110 (2015) [6] N. V. Sarlis et al., Proc. Natl. Acad. Sci. U.S.A. 110, 13734 (2013) [7] T. Fawcett, Pattern Recognit. Lett. 27, 861 (2006). [8] N. V. Sarlis and S.-R. G. Christopoulos, Comput. Phys. Commun. 185, 1172 (2014).

  12. Mechanism of cooperative behaviour in systems of slow and fast molecular motors.

    PubMed

    Larson, Adam G; Landahl, Eric C; Rice, Sarah E

    2009-06-28

    Two recent theoretical advances have described cargo transport by multiple identical motors and by multiple oppositely directed, but otherwise identical motors [M. J. Muller, S. Klumpp and R. Lipowsky, Proc. Natl. Acad. Sci. U. S. A., 2008, 105(12), 4609-4614; S. Klumpp and R. Lipowsky, Proc. Natl. Acad. Sci. U. S. A., 2005, 102(48), 17284-17289]. Here, we combine a similar theoretical approach with a simple experiment to describe the behaviour of a system comprised of slow and fast molecular motors having the same directionality. We observed the movement of microtubules by mixtures of slow and fast kinesin motors attached to a glass coverslip in a classic sliding filament assay. The motors are identical, except that the slow ones contain five point mutations that collectively reduce their velocity approximately 15-fold without compromising maximal ATPase activity. Our results indicate that a small fraction of fast motors are able to accelerate the dissociation of slow motors from microtubules. Because of this, a sharp, highly cooperative transition occurs from slow to fast microtubule movement as the relative number of fast motors in the assay is increased. Microtubules move at half-maximal velocity when only 15% of the motors in the assay are fast. Our model indicates that this behaviour depends primarily on the relative motor velocities and the asymmetry between their forward and backward dissociation forces. It weakly depends on the number of motors and their processivity. We predict that movement of cargoes bound to two types of motors having very different velocities will be dominated by one or the other motor. Therefore, cargoes can potentially undergo abrupt changes in movement in response to regulatory mechanisms acting on only a small fraction of motors. PMID:19506764

  13. Effects of the cFMS kinase inhibitor 5-(3-methoxy-4-((4-methoxybenzyl)oxy)benzyl)pyrimidine-2,4-diamine (GW2580) in normal and arthritic rats.

    PubMed

    Conway, James G; Pink, Heather; Bergquist, Mandy L; Han, Bajin; Depee, Scott; Tadepalli, Sarva; Lin, Peiyuan; Crumrine, R Christian; Binz, Jane; Clark, Richard L; Selph, Jeffrey L; Stimpson, Stephen A; Hutchins, Jeff T; Chamberlain, Stanley D; Brodie, Thomas A

    2008-07-01

    The cFMS (cellular homolog of the V-FMS oncogene product of the Susan McDonough strain of feline sarcoma virus) (Proc Natl Acad Sci U S A 83:3331-3335, 1986) kinase inhibitor 5-(3-methoxy-4-((4-methoxybenzyl)oxy)benzyl)pyrimidine-2,4-diamine (GW2580) inhibits colony-stimulating factor (CSF)-1-induced monocyte growth and bone degradation in vitro and inhibits CSF-1 signaling through cFMS kinase in 4-day models in mice (Proc Natl Acad Sci U S A 102:16078, 2005). In the present study, the kinase selectivity of GW2580 was further characterized, and the effects of chronic treatment were evaluated in normal and arthritic rats. GW2580 selectively inhibited cFMS kinase compared with 186 other kinases in vitro and completely inhibited CSF-1-induced growth of rat monocytes, with an IC(50) value of 0.2 microM. GW2580 dosed orally at 25 and 75 mg/kg 1 and 5 h before the injection of lipopolysaccharide inhibited tumor necrosis factor-alpha production by 60 to 85%, indicating a duration of action of at least 5 h. In a 21-day adjuvant arthritis model, GW2580 dosed twice a day (b.i.d.) from days 0 to 21, 7 to 21, or 14 to 21 inhibited joint connective tissue and bone destruction as assessed by radiology, histology and bone mineral content measurements. In contrast, GW2580 did not affect ankle swelling in the adjuvant model nor did it affect ankle swelling in a model where local arthritis is reactivated by peptidoglycan polysaccharide polymers. GW2580 administered to normal rats for 21 days showed no effects on tissue histology and only modest changes in serum clinical chemistry and blood hematology. In conclusion, GW2580 was effective in preserving joint integrity in the adjuvant arthritis model while showing minimal effects in normal rats. PMID:18434589

  14. Metabolic Heritability at Birth: Implications for Chronic Disease Research

    PubMed Central

    Ryckman, Kelli K.; Smith, Caitlin J.; Jelliffe-Pawlowski, Laura L; Momany, Allison M.; Berberich, Stanton L.; Murray, Jeffrey C.

    2014-01-01

    Recent genome-wide association studies of the adult human metabolome have identified genetic variants associated with relative levels of several acylcarnitines, which are important clinical correlates for chronic conditions such as type 2 diabetes and obesity. We have previously shown that these same metabolite levels are highly heritable at birth; however, no studies to our knowledge have examined genetic associations with these metabolites measured at birth. Here, we examine, in 743 newborns, 58 single nucleotide polymorphisms (SNPs) in 11 candidate genes previously associated with differing relative levels of short-chain acylcarnitines in adults. Six SNPs (rs2066938, rs3916, rs3794215, rs555404, rs558314, rs1799958) in the short chain acyl-CoA dehydrogenase gene (ACADS) were associated with neonatal C4 levels. Most significant was the G allele of rs2066938, which was associated with significantly higher levels of C4 (P=1.5×10−29). This SNP explains 25% of the variation in neonatal C4 levels, which is similar to the variation previously reported in adult C4 levels. There were also significant (P<1×10−4) associations between neonatal levels of C5-OH and SNPs in the solute carrier family 22 genes (SLC22A4 and SLC22A5) and the 3-methylcrotonyl-CoA carboxylase 1 gene (MCCC1). We have replicated, in newborns, SNP associations between metabolic traits and the ACADS and SLC22A4 genes observed in adults. This research has important implications not only for the identification of rare inborn errors of metabolism but also for personalized medicine and early detection of later life risks for chronic conditions. PMID:24850141

  15. Anomalous behavior of water inside the SecY translocon.

    PubMed

    Capponi, Sara; Heyden, Matthias; Bondar, Ana-Nicoleta; Tobias, Douglas J; White, Stephen H

    2015-07-21

    The heterotrimeric SecY translocon complex is required for the cotranslational assembly of membrane proteins in bacteria and archaea. The insertion of transmembrane (TM) segments during nascent-chain passage through the translocon is generally viewed as a simple partitioning process between the water-filled translocon and membrane lipid bilayer, suggesting that partitioning is driven by the hydrophobic effect. Indeed, the apparent free energy of partitioning of unnatural aliphatic amino acids on TM segments is proportional to accessible surface area, which is a hallmark of the hydrophobic effect [Öjemalm K, et al. (2011) Proc Natl Acad Sci USA 108(31):E359-E364]. However, the apparent partitioning solvation parameter is less than one-half the value expected for simple bulk partitioning, suggesting that the water in the translocon departs from bulk behavior. To examine the state of water in a SecY translocon complex embedded in a lipid bilayer, we carried out all-atom molecular-dynamics simulations of the Pyrococcus furiosus SecYE, which was determined to be in a "primed" open state [Egea PF, Stroud RM (2010) Proc Natl Acad Sci USA 107(40):17182-17187]. Remarkably, SecYE remained in this state throughout our 450-ns simulation. Water molecules within SecY exhibited anomalous diffusion, had highly retarded rotational dynamics, and aligned their dipoles along the SecY transmembrane axis. The translocon is therefore not a simple water-filled pore, which raises the question of how anomalous water behavior affects the mechanism of translocon function and, more generally, the partitioning of hydrophobic molecules. Because large water-filled cavities are found in many membrane proteins, our findings may have broader implications. PMID:26139523

  16. Two-photon fluorescence coincidence analysis: rapid measurements of enzyme kinetics.

    PubMed Central

    Heinze, Katrin G; Rarbach, Markus; Jahnz, Michael; Schwille, Petra

    2002-01-01

    Dual-color fluorescence cross-correlation analysis is a powerful tool for probing interactions of different fluorescently labeled molecules in aqueous solution. The concept is the selective observation of coordinated spontaneous fluctuations in two separate detection channels that unambiguously reflect the existence of physical or chemical linkages among the different fluorescent species. It has previously been shown that the evaluation of cross-correlation amplitudes, i.e., coincidence factors, is sufficient to extract essential information about the kinetics of formation or cleavage of chemical or physical bonds. Confocal fluorescence coincidence analysis (CFCA) (Winkler et al., Proc. Natl. Acad. Sci. U.S.A. 96:1375-1378, 1999) emphasizes short analysis times and simplified data evaluation and is thus particularly useful for screening applications or measurements on live cells where small illumination doses need to be applied. The recent use of two-photon fluorescence excitation has simplified dual- or multicolor measurements by enabling the simultaneous excitation of largely different dye molecules by a single infra-red laser line (Heinze et al., Proc. Natl. Acad. Sci. U.S.A. 97:10377-10382, 2000). It is demonstrated here that a combination of CFCA with two-photon excitation allows for minimization of analysis times for multicomponent systems down to some hundreds of milliseconds, while preserving all known advantages of two-photon excitation. By introducing crucial measurement parameters, experimental limits for the reduction of sampling times are discussed for the special case of distinguishing positive from negative samples in an endonucleolytic cleavage assay. PMID:12202390

  17. Chemical Analysis of a "Miller-Type" Complex Prebiotic Broth. Part I: Chemical Diversity, Oxygen and Nitrogen Based Polymers

    NASA Astrophysics Data System (ADS)

    Wollrab, Eva; Scherer, Sabrina; Aubriet, Frédéric; Carré, Vincent; Carlomagno, Teresa; Codutti, Luca; Ott, Albrecht

    2016-06-01

    In a famous experiment Stanley Miller showed that a large number of organic substances can emerge from sparking a mixture of methane, ammonia and hydrogen in the presence of water (Miller, Science 117:528-529, 1953). Among these substances Miller identified different amino acids, and he concluded that prebiotic events may well have produced many of Life's molecular building blocks. There have been many variants of the original experiment since, including different gas mixtures (Miller, J Am Chem Soc 77:2351-2361, 1955; Oró Nature 197:862-867, 1963; Schlesinger and Miller, J Mol Evol 19:376-382, 1983; Miyakawa et al., Proc Natl Acad Sci 99:14,628-14,631, 2002). Recently some of Miller's remaining original samples were analyzed with modern equipment (Johnson et al. Science 322:404-404, 2008; Parker et al. Proc Natl Acad Sci 108:5526-5531, 2011) and a total of 23 racemic amino acids were identified. To give an overview of the chemical variety of a possible prebiotic broth, here we analyze a "Miller type" experiment using state of the art mass spectrometry and NMR spectroscopy. We identify substances of a wide range of saturation, which can be hydrophilic, hydrophobic or amphiphilic in nature. Often the molecules contain heteroatoms, with amines and amides being prominent classes of molecule. In some samples we detect ethylene glycol based polymers. Their formation in water requires the presence of a catalyst. Contrary to expectations, we cannot identify any preferred reaction product. The capacity to spontaneously produce this extremely high degree of molecular variety in a very simple experiment is a remarkable feature of organic chemistry and possibly prerequisite for Life to emerge. It remains a future task to uncover how dedicated, organized chemical reaction pathways may have arisen from this degree of complexity.

  18. 3D-CANVENT: An interactive mine ventilation simulator

    SciTech Connect

    Hardcastle, S.G.

    1995-12-31

    3D-CANVENT is a software package that integrates advanced computer aided design (ACAD) true 3D graphics with a mine ventilation simulator. The package runs as a Windows{trademark} application to access its printer drivers environment and does not need third party CAD software. It is composed of two primary modules: DMVENT and MINEDESIGNER. DMVENT is a traditional Fortran coded Hardy-Cross iterative ventilation network solver written in 1980 with thermodynamic capabilities. This module is relatively unchanged with the traditional data input options for branch type, specified or calculated resistances, fixed flows, and fixed or variable pressure fans. MINEDESIGNER is the graphics engine that optimizes the ventilation design process. It performs the front-end transformation of input data entered in the graphical interface into the correct format for the solver. At the back-end it reconverts the historically standard tabular data output from the solver into an easily viewed graphical format. ACAD features of MINEDESIGNER are used to generate a 3D wire-frame node and branch network of the mine`s ventilation system. The network can be displayed in up to 4 views orientated to XYZ planes or a 3D view. AU the views have zoom, pan, slice and rotate options. The graphical interface efficiently permits data entry and editing via a mouse with pick-and-point item selection. Branches can be found or added with {open_quotes}search{close_quotes} and {open_quotes}join{close_quotes} options. Visual interpretation is enhanced by the 16 colour options for branches and numerous graphical attributes. Network locations are readily identified by alpha-numeric names for branches, junctions and fans, and also the logical numbering of junctions. The program is also readily expandable for pollutant simulation and control/monitoring applications.

  19. Deep Sequencing Reveals Novel Genetic Variants in Children with Acute Liver Failure and Tissue Evidence of Impaired Energy Metabolism

    PubMed Central

    Valencia, C. Alexander; Wang, Xinjian; Wang, Jin; Peters, Anna; Simmons, Julia R.; Moran, Molly C.; Mathur, Abhinav; Husami, Ammar; Qian, Yaping; Sheridan, Rachel; Bove, Kevin E.; Witte, David; Huang, Taosheng; Miethke, Alexander G.

    2016-01-01

    Background & Aims The etiology of acute liver failure (ALF) remains elusive in almost half of affected children. We hypothesized that inherited mitochondrial and fatty acid oxidation disorders were occult etiological factors in patients with idiopathic ALF and impaired energy metabolism. Methods Twelve patients with elevated blood molar lactate/pyruvate ratio and indeterminate etiology were selected from a retrospective cohort of 74 subjects with ALF because their fixed and frozen liver samples were available for histological, ultrastructural, molecular and biochemical analysis. Results A customized next-generation sequencing panel for 26 genes associated with mitochondrial and fatty acid oxidation defects revealed mutations and sequence variants in five subjects. Variants involved the genes ACAD9, POLG, POLG2, DGUOK, and RRM2B; the latter not previously reported in subjects with ALF. The explanted livers of the patients with heterozygous, truncating insertion mutations in RRM2B showed patchy micro- and macrovesicular steatosis, decreased mitochondrial DNA (mtDNA) content <30% of controls, and reduced respiratory chain complex activity; both patients had good post-transplant outcome. One infant with severe lactic acidosis was found to carry two heterozygous variants in ACAD9, which was associated with isolated complex I deficiency and diffuse hypergranular hepatocytes. The two subjects with heterozygous variants of unknown clinical significance in POLG and DGUOK developed ALF following drug exposure. Their hepatocytes displayed abnormal mitochondria by electron microscopy. Conclusion Targeted next generation sequencing and correlation with histological, ultrastructural and functional studies on liver tissue in children with elevated lactate/pyruvate ratio expand the spectrum of genes associated with pediatric ALF. PMID:27483465

  20. Cell-Demanded VEGF Release via Nanocapsules Elicits Different Receptor Activation Dynamics and Enhanced Angiogenesis.

    PubMed

    Zhu, Suwei; Segura, Tatiana

    2016-06-01

    Although the delivery of vascular endothelial growth factor (VEGF) with extended release profiles has consistently shown beneficial therapeutic effects compared with bolus delivery, [Martino, M. M., F. Tortelli, M. Mochizuki, S. Traub, D. Ben-David, G. A. Kuhn, R. Muller, E. Livne, S. A. Eming, and J. A. Hubbell. Sci. Transl. Med. 3(100):100ra189, 2011; Martino, M. M., P. S. Briquez, A. Ranga, M. P. Lutolf, and J. A. Hubbell. Proc. Natl. Acad. Sci. USA. 110(12):4563-4568, 2013; Amiram, M., K. M. Luginbuhl, X. Li, M. N. Feinglos, and A. Chilkoti. Proc. Natl. Acad. Sci. USA. 110(8):2792-2797, 2013] it remains unclear if the reason is solely due to the physical availability and the reduced degradation of the protein. Here we studied the activation of VEGF receptor 2 (VR-2) by sustained released VEGF compared with bolus delivered VEGF to unveil that sustained delivery system alters the dynamics of receptor activation and affects the actions of cells between sprouting and proliferation. We utilized a protein nanocapsule delivery strategy that releases VEGF as mediated by extracellular proteases. These protein nanocapsules were synthesized through an aqueous assembly of a nanogel-peptide shell around the protein, leading to one to two proteins encapsulated per nanocapsule. Receptor activation studies revealed differential dynamics of receptor activation for slowly released VEGF compared with bolus delivered VEGF. As expected sustained released VEGF via nanocapsules resulted in enhanced vascular sprouting in vitro and in vivo. These studies demonstrate the physical presentation of VEGF, in this case of a slow release with time, can affect its molecular mechanism of actions and cause alterations in cellular responses and therapeutic outcomes. PMID:26940611

  1. Jensen's inequality for filtration consistent nonlinear expectation without domination condition

    NASA Astrophysics Data System (ADS)

    Fan, Sheng-Jun

    2008-09-01

    In this paper, the general filtration consistent nonlinear expectation defined on the integrable variable space is considered, based on the results in [F. Coquet, Y. Hu, J. Memin, S. Peng, Filtration consistent nonlinear expectations and related g-expectation, Probab. Theory Related Fields 123 (2002) 1-27]. Under a natural continuous assumption for the nonlinear expectation, which weakens the domination assumption in [F. Coquet, Y. Hu, J. Memin, S. Peng, Filtration consistent nonlinear expectations and related g-expectation, Probab. Theory Related Fields 123 (2002) 1-27], the author obtains the necessary and sufficient conditions under which Jensen's inequality for filtration consistent nonlinear expectation holds in general, respectively on scalar function and bivariate function. These two results generalize the known results on Jensen's inequality for g-expectation in [Z. Chen, R. Kulperger, L. Jiang, Jensen's inequality for g-expectation: Part 1, C. R. Acad. Sci. Paris Ser. I 337 (11) (2003) 725-730; Z. Chen, R. Kulperger, L. Jiang, Jensen's inequality for g-expectation: Part 2, C. R. Acad. Sci. Paris Ser. I 337 (12) (2003) 797-800; L. Jiang, On Jensen's inequality of bivariate function for g-expectation, J. Shandong Univ. 38 (5) (2003) 13-22 (in Chinese); L. Jiang, Z. Chen, On Jensen's inequality for g-expectation, Chinese Ann. Math. Ser. B 25 (3) (2004) 401-412; L. Jiang, Jensen's inequality for backward stochastic differential equation, Chinese Ann. Math. Ser. B 27 (5) (2006) 553-564; S. Fan, Jensen's inequality for g-expectation on convex (concave) function, Chinese Ann. Math. Ser. A 27 (5) (2006) 635-644 (in Chinese)].

  2. CNVs leading to fusion transcripts in individuals with autism spectrum disorder

    PubMed Central

    Holt, Richard; Sykes, Nuala H; Conceição, Inês C; Cazier, Jean-Baptiste; Anney, Richard JL; Oliveira, Guiomar; Gallagher, Louise; Vicente, Astrid; Monaco, Anthony P; Pagnamenta, Alistair T

    2012-01-01

    There is strong evidence that rare copy number variants (CNVs) have a role in susceptibility to autism spectrum disorders (ASDs). Much research has focused on how CNVs mediate a phenotypic effect by altering gene expression levels. We investigated an alternative mechanism whereby CNVs combine the 5′ and 3′ ends of two genes, creating a ‘fusion gene'. Any resulting mRNA with an open reading frame could potentially alter the phenotype via a gain-of-function mechanism. We examined 2382 and 3096 rare CNVs from 996 individuals with ASD and 1287 controls, respectively, for potential to generate fusion transcripts. There was no increased burden in individuals with ASD; 122/996 cases harbored at least one rare CNV of this type, compared with 179/1287 controls (P=0.89). There was also no difference in the overall frequency distribution between cases and controls. We examined specific examples of such CNVs nominated by case–control analysis and a candidate approach. Accordingly, a duplication involving REEP1-POLR1A (found in 3/996 cases and 0/1287 controls) and a single occurrence CNV involving KIAA0319-TDP2 were tested. However, no fusion transcripts were detected by RT-PCR. Analysis of additional samples based on cell line availability resulted in validation of a MAPKAPK5-ACAD10 fusion transcript in two probands. However, this variant was present in controls at a similar rate and is unlikely to influence ASD susceptibility. In summary, although we find no evidence that fusion-gene generating CNVs lead to ASD susceptibility, discovery of a MAPKAPK5-ACAD10 transcript with an estimated frequency of ∼1/200 suggests that gain-of-function mechanisms should be considered in future CNVs studies. PMID:22549408

  3. Skin Cancer in the Crosshairs

    PubMed Central

    Sinnya, Sudipta; Zwald, Fiona O.; Colegio, Oscar R.

    2015-01-01

    Abstract The International Transplant Skin Cancer Collaborative (ITSCC) is an organization comprising of physicians; transplant surgeons and basic science research scientists dedicated in providing optimal care and ongoing research advancements in solid organ transplant recipients to improve patient outcome and quality of life. As medical advances occur, it is anticipated that the sheer number of solid organ transplantations occurring worldwide will continue to increase. The long-term medication associated immunosuppression improves graft survival, but as a consequence, these individuals become increasingly susceptible to various cutaneous malignancies, lymphoproliferative disorders and infections. Squamous cell carcinoma is the most frequently encountered skin cancer and increases 65- to 250-fold [Jensen et al., Skin cancer in kidney and heart transplant recipients and different long-term immunosuppressive therapy regimens. J Am Acad Dermatol. 1999;40:177-186; Lindelöf et al., Incidence of skin cancer in 5356 patients following organ transplantation. Br J Dermatol. 2000; 143:513-519]. However, the rates of basal cell carcinoma, Merkel cell carcinoma and melanoma also increase in organ transplant recipients leading to significant morbidity as well as mortality [Berg and Otley. Skin cancer in organ transplant recipients: epidemiology, pathogenesis, and management. J Am Acad Dermatol. 2002; 47:1-20]. In October 2014, the International Transplant Skin Cancer Collaborative and its equivalent European counterpart, Skin Care in Organ Transplant Recipients Europe held its 10th biennial meeting in Essex, MA to discuss the clinical conundrums and the evolving research pertinent to the field. This meeting report provides a synthesis of all the clinical and research data presented at the 4-day meeting.

  4. Geometric origin of scaling in large traffic networks.

    PubMed

    Popović, Marko; Štefančić, Hrvoje; Zlatić, Vinko

    2012-11-16

    Large scale traffic networks are an indispensable part of contemporary human mobility and international trade. Networks of airport travel and cargo ship movements are invaluable for the understanding of human mobility patterns [R. Guimera et al., Proc. Natl. Acad. Sci. U.S.A. 102, 7794 (2005))], epidemic spreading [V. Colizza et al., Proc. Natl. Acad. Sci. U.S.A. 103, 2015 (2006)], global trade [International Maritime Organization, http://www.imo.org/], and spread of invasive species [G. M. Ruiz et al., Nature (London) 408, 49 (2000)]. Different studies [M. Barthelemy, Phys. Rept. 499, 1 (2011)] point to the universal character of some of the exponents measured in such networks. Here we show that exponents which relate (i) the strength of nodes to their degree and (ii) weights of links to degrees of nodes that they connect have a geometric origin. We present a simple robust model which exhibits the observed power laws and relates exponents to the dimensionality of 2D space in which traffic networks are embedded. We show that the relation between weight strength and degree is s(k)~k(3/2), the relation between distance strength and degree is s(d)(k)~k(3/2), and the relation between weight of link and degrees of linked nodes is w(ij)~(k(i)k(j))(1/2) on the plane 2D surface. We further analyze the influence of spherical geometry, relevant for the whole planet, on exact values of these exponents. Our model predicts that these exponents should be found in future studies of port networks and it imposes constraints on more refined models of port networks. PMID:23215527

  5. The Mishin mission, December 1962 - December 1993

    NASA Astrophysics Data System (ADS)

    Vick, Charles P.

    1994-09-01

    Despite the large amount of information that has now emerged on the Soviet manned Lunar effort, many unanswered questions remain about hardware and poorly defined historical related questions. Only about 45% of the full program story had been told and officially released as of the end of 1993. Much of the program still remains secret, but thanks to seven direct meetings with retired General Chief Designer Acad. V. P. Mishin many hardware questions have been answered. It has now become possible to define the L3 spacecraft hardware details precisely. Three of the drawings were, by request, signed by Acad. V. P. Mishin even though they were still undergoing revisions. He had specified changes which have been completed and registered copies for himself. Subsequent changes were made in the light of actual photographs of the hardware and discussions with the individual component designers for precise working understanding of the details. This proved critical in understanding the docking systems design configuration details. The results is a series of drawings on the Soviet manned Lunar program hardware reflecting many years of research, though only part of the total series of drawings that have been developed on the programmes physical layout. Detail diagrams for the following systems are presented. (1) The Soviet Manned Lunar Landing Spacecraft L-3 and Manned Circumnavigation Spacecraft Zond 7K-L1; (2) The N1 Soviet Manned Lunar Program booster systems layout for the L3 payload; (3) The N1-L3 competitors UR-700, UR-700M (UR 900) and R-56. The N1-L3 featured for comparison is the 1969 design variant. Also shown is Proton LK-1 that evolved to Proton Zoned SL-12; and (4) N1-L3 and the N1-L3M compared with the Saturn-V and the G-1-e design concept.

  6. Anomalous behavior of water inside the SecY translocon

    PubMed Central

    Capponi, Sara; Heyden, Matthias; Bondar, Ana-Nicoleta; Tobias, Douglas J.; White, Stephen H.

    2015-01-01

    The heterotrimeric SecY translocon complex is required for the cotranslational assembly of membrane proteins in bacteria and archaea. The insertion of transmembrane (TM) segments during nascent-chain passage through the translocon is generally viewed as a simple partitioning process between the water-filled translocon and membrane lipid bilayer, suggesting that partitioning is driven by the hydrophobic effect. Indeed, the apparent free energy of partitioning of unnatural aliphatic amino acids on TM segments is proportional to accessible surface area, which is a hallmark of the hydrophobic effect [Öjemalm K, et al. (2011) Proc Natl Acad Sci USA 108(31):E359–E364]. However, the apparent partitioning solvation parameter is less than one-half the value expected for simple bulk partitioning, suggesting that the water in the translocon departs from bulk behavior. To examine the state of water in a SecY translocon complex embedded in a lipid bilayer, we carried out all-atom molecular-dynamics simulations of the Pyrococcus furiosus SecYE, which was determined to be in a “primed” open state [Egea PF, Stroud RM (2010) Proc Natl Acad Sci USA 107(40):17182–17187]. Remarkably, SecYE remained in this state throughout our 450-ns simulation. Water molecules within SecY exhibited anomalous diffusion, had highly retarded rotational dynamics, and aligned their dipoles along the SecY transmembrane axis. The translocon is therefore not a simple water-filled pore, which raises the question of how anomalous water behavior affects the mechanism of translocon function and, more generally, the partitioning of hydrophobic molecules. Because large water-filled cavities are found in many membrane proteins, our findings may have broader implications. PMID:26139523

  7. Calorie restriction reduces the incidence of myeloid leukemia induced by a single whole-body radiation in C3H/He mice.

    PubMed

    Yoshida, K; Inoue, T; Nojima, K; Hirabayashi, Y; Sado, T

    1997-03-18

    Dietary restriction, especially caloric restriction, is a major modifier in experimental carcinogenesis and is known to decrease significantly the incidence of neoplasms. Gross and Dreyfuss [Gross, L. & Dreyfuss, Y. (1984) Proc. Natl. Acad. Sci. USA 81, 7596-7598; Gross, L. & Dreyfuss, Y. (1986) Proc. Natl. Acad. Sci. USA 83, 7928-7931] reported that a 36% restriction in caloric intake dramatically decreased the radiation-induced solid tumors and/or leukemias. Their protocol predominantly produced lymphatic neoplasms. It is of interest to observe the effect of caloric restriction on radiation-induced myeloid leukemia, because the disease was observed to have been increased in the survivors of the atomic bombs in Hiroshima and Nagasaki. The spontaneous incidence of myeloid leukemia in C3H/He male mice is 1%, and the incidence increased to 23.3% when 3 Gy of whole-body x-ray irradiation was given. However, the incidence of myeloid leukemia was found to be significantly decreased by caloric restriction; it was reduced to 7.9% and 10.7% when restriction was started before (6 weeks old) and after (10 weeks old) irradiation, respectively. In addition, the onset of the myeloid leukemia in both restricted groups was prolonged to a greater extent as compared with the control diet group. Caloric restriction demonstrated a significant prolongation of the life span in the groups on a restricted diet after having been exposed to irradiation, either before or after dietary restriction, in comparison with mice that were only irradiated. PMID:9122244

  8. The origin of the supernumerary subunits and assembly factors of complex I: A treasure trove of pathway evolution.

    PubMed

    Elurbe, Dei M; Huynen, Martijn A

    2016-07-01

    We review and document the evolutionary origin of all complex I assembly factors and nine supernumerary subunits from protein families. Based on experimental data and the conservation of critical residues we identify a spectrum of protein function conservation between the complex I representatives and their non-complex I homologs. This spectrum ranges from proteins that have retained their molecular function but in which the substrate specificity may have changed or have become more specific, like NDUFAF5, to proteins that have lost their original molecular function and critical catalytic residues like NDUFAF6. In between are proteins that have retained their molecular function, which however appears unrelated to complex I, like ACAD9, or proteins in which amino acids of the active site are conserved but for which no enzymatic activity has been reported, like NDUFA10. We interpret complex I evolution against the background of molecular evolution theory. Complex I supernumerary subunits and assembly factors appear to have been recruited from proteins that are mitochondrial and/or that are expressed when complex I is active. Within the evolution of complex I and its assembly there are many cases of neofunctionalization after gene duplication, like ACAD9 and TMEM126B, one case of subfunctionalization: ACPM1 and ACPM2 in Yarrowia lipolytica, and one case in which a complex I protein itself appears to have been the source of a new protein from another complex: NDUFS6 gave rise to cytochrome c oxidase subunit COX4/COX5b. Complex I and its assembly can therewith be regarded as a treasure trove for pathway evolution. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt. PMID:27048931

  9. Chemical Analysis of a "Miller-Type" Complex Prebiotic Broth: Part I: Chemical Diversity, Oxygen and Nitrogen Based Polymers.

    PubMed

    Wollrab, Eva; Scherer, Sabrina; Aubriet, Frédéric; Carré, Vincent; Carlomagno, Teresa; Codutti, Luca; Ott, Albrecht

    2016-06-01

    In a famous experiment Stanley Miller showed that a large number of organic substances can emerge from sparking a mixture of methane, ammonia and hydrogen in the presence of water (Miller, Science 117:528-529, 1953). Among these substances Miller identified different amino acids, and he concluded that prebiotic events may well have produced many of Life's molecular building blocks. There have been many variants of the original experiment since, including different gas mixtures (Miller, J Am Chem Soc 77:2351-2361, 1955; Oró Nature 197:862-867, 1963; Schlesinger and Miller, J Mol Evol 19:376-382, 1983; Miyakawa et al., Proc Natl Acad Sci 99:14,628-14,631, 2002). Recently some of Miller's remaining original samples were analyzed with modern equipment (Johnson et al. Science 322:404-404, 2008; Parker et al. Proc Natl Acad Sci 108:5526-5531, 2011) and a total of 23 racemic amino acids were identified. To give an overview of the chemical variety of a possible prebiotic broth, here we analyze a "Miller type" experiment using state of the art mass spectrometry and NMR spectroscopy. We identify substances of a wide range of saturation, which can be hydrophilic, hydrophobic or amphiphilic in nature. Often the molecules contain heteroatoms, with amines and amides being prominent classes of molecule. In some samples we detect ethylene glycol based polymers. Their formation in water requires the presence of a catalyst. Contrary to expectations, we cannot identify any preferred reaction product. The capacity to spontaneously produce this extremely high degree of molecular variety in a very simple experiment is a remarkable feature of organic chemistry and possibly prerequisite for Life to emerge. It remains a future task to uncover how dedicated, organized chemical reaction pathways may have arisen from this degree of complexity. PMID:26508401

  10. Silent information regulator 2 family of NAD- dependent histone/protein deacetylases generates a unique product, 1-O-acetyl-ADP-ribose.

    PubMed

    Tanner, K G; Landry, J; Sternglanz, R; Denu, J M

    2000-12-19

    Conflicting reports have suggested that the silent information regulator 2 (SIR2) protein family employs NAD(+) to ADP-ribosylate histones [Tanny, J. C., Dowd, G. J., Huang, J., Hilz, H. & Moazed, D. (1999) Cell 99, 735-745; Frye, R. A. (1999) Biochem. Biophys. Res. Commun. 260, 273-279], deacetylate histones [Landry, J., Sutton, A., Tafrov, S. T., Heller, R. C., Stebbins, J., Pillus, L. & Sternglanz, R. (2000) Proc. Natl. Acad. Sci. USA 97, 5807-5811; Smith, J. S., Brachmann, C. B., Celic, I., Kenna, M. A., Muhammad, S., Starai, V. J., Avalos, J. L., Escalante-Semerena, J. C., Grubmeyer, C., Wolberger, C. & Boeke, J. D. (2000) Proc. Natl. Acad. Sci. USA 97, 6658-6663], or both [Imai, S., Armstrong, C. M., Kaeberlein, M. & Guarente, L. (2000) Nature (London) 403, 795-800]. Uncovering the true enzymatic function of SIR2 is critical to the basic understanding of its cellular function. Therefore, we set out to authenticate the reaction products and to determine the intrinsic catalytic mechanism. We provide direct evidence that the efficient histone/protein deacetylase reaction is tightly coupled to the formation of a previously unidentified acetyl-ADP-ribose product (1-O-acetyl-ADP ribose). One molecule of NAD(+) and one molecule of acetyl-lysine are readily catalyzed to one molecule of deacetylated lysine, nicotinamide, and 1-O-acetyl-ADP-ribose. A unique reaction mechanism involving the attack of enzyme-bound acetate or the direct attack of acetyl-lysine on an oxocarbenium ADP-ribose intermediate is proposed. We suggest that the reported histone/protein ADP-ribosyltransferase activity is a low-efficiency side reaction that can be explained through the partial uncoupling of the intrinsic deacetylation and acetate transfer to ADP-ribose. PMID:11106374

  11. A proposed essential gene discovery pipeline: a Campylobacter jejuni case study.

    PubMed

    Reuter, Mark; Gaskin, Duncan J H; Metris, Aline

    2015-01-01

    Genes required for an organism's growth and survival are termed essential and represent potential intervention targets. Following in the footsteps of the genomics era, the "next-gen" genomic era provides vast amounts of genetic information. Sequencing of a representative bacterial pathogen genome has been superseded by sequencing of whole strain collections, whether from environmental or clinical sources (Harris et al., Science 327:469-474, 2010; Lewis et al., J Hosp Infect 75:37-41, 2010; Beres et al., Proc Natl Acad Sci U S A 107:4371-4376, 2010; Qi et al., PLoS Pathog 5:e1000580, 2009; He et al., Proc Natl Acad Sci U S A 107:7527-7532, 2010; Barrick et al., Nature 461:1243-1247, 2009; Sheppard et al., Mol Ecol 22:1051-1064, 2013). However, the challenge of using this information to gain biological insight remains. Nonetheless, this information, in combination with experimental data from the literature, can serve as the framework for gaining a better understanding of an organism's biology. Generic metabolic pathways have long been known, and a number of websites (e.g., KEGG and BioCyc) attempt to map information from genome annotation to metabolic pathways (Kanehisa et al., Nucleic Acids Res 40:D109-D114, 2010; Karp et al., Nucleic Acids Res 33:6083-6089, 2005). Extending this analysis to incorporate metabolic flux models further allows in silico prediction of potential essential genes. Such efforts are of value, either to highlight novel generic antimicrobials or to seek novel treatments for non-paradigm organisms. Such in silico approaches are attractive as they can highlight pathways and genes that would otherwise only be identified by costly and time-consuming laboratory methods. PMID:25636619

  12. Structural analysis of the Creignish Hills Mylonite Zone, Cape Breton Island, Nova Scotia: implications for Neoproterozoic core complex development along the northern Gondwanan margin?

    NASA Astrophysics Data System (ADS)

    Wessel, Zachary R.; Nance, R. Damian; Keppie, J. Duncan; Murphy, J. Brendan

    2005-04-01

    Late Neoproterozoic ductile shear zones that juxtapose low-grade over high-grade assemblages are characteristic features of parts of the peri-Gondwanan terranes of the Canadian Appalachians. One such ductile shear zone, in the Creignish Hills of Cape Breton Island, Nova Scotia, brings low-grade platformal metasedimentary rocks of the George River Metamorphic Suite into contact with underlying high-grade rocks of the Bras d’Or Gneiss. The low-grade assemblage includes quartzite, marble, schist, and phyllite with interlayered felsic volcanogenic units and mafic flows, whereas the high-grade unit comprises low-pressure, high-temperature gneiss and migmatite, including pelitic paragneiss of likely volcanogenic origin. The ductile shear zone between the two assemblages (Creignish Hills Mylonite Zone) envelopes the high-grade rocks in the form of a WNW-plunging antiform. The structural dome is truncated to the east against Carboniferous strata by high-angle faulting. Kinematic indicators within the mylonite, including asymmetric porphyroclasts, fractured veins, S C fabrics, and folded mylonitic foliation, suggest a broadly top-to-the-southeast (dextral) sense of shear, while the presence of gneissic granitoid sheets that are broadly concordant but locally cross-cut and are folded about the mylonitic foliation, suggest that mylonitization was accompanied by partial melting and syntectonic intrusion. Monazite from the gneiss and zircon from the granitoid sheets have yielded near-identical U Pb ages of ca. 550 Ma. Juxtaposition of low-grade over high-grade assemblages in several peri-Gondwanan basement blocks in central Cape Breton Island suggests that the Creignish Hills Mylonite Zone is part of a series of regional low-angle detachments with a core complex geometry. Similar ductile shear zones with easterly components of shear and low-angle pre-Carboniferous orientations also place low-grade over high-grade rocks in southern New Brunswick and the Cobequid Highlands of

  13. Spectral analysis of hydrological time series of a river basin in southern Spain

    NASA Astrophysics Data System (ADS)

    Luque-Espinar, Juan Antonio; Pulido-Velazquez, David; Pardo-Igúzquiza, Eulogio; Fernández-Chacón, Francisca; Jiménez-Sánchez, Jorge; Chica-Olmo, Mario

    2016-04-01

    Spectral analysis has been applied with the aim to determine the presence and statistical significance of climate cycles in data series from different rainfall, piezometric and gauging stations located in upper Genil River Basin. This river starts in Sierra Nevada Range at 3,480 m a.s.l. and is one of the most important rivers of this region. The study area has more than 2.500 km2, with large topographic differences. For this previous study, we have used more than 30 rain data series, 4 piezometric data series and 3 data series from gauging stations. Considering a monthly temporal unit, the studied period range from 1951 to 2015 but most of the data series have some lacks. Spectral analysis is a methodology widely used to discover cyclic components in time series. The time series is assumed to be a linear combination of sinusoidal functions of known periods but of unknown amplitude and phase. The amplitude is related with the variance of the time series, explained by the oscillation at each frequency (Blackman and Tukey, 1958, Bras and Rodríguez-Iturbe, 1985, Chatfield, 1991, Jenkins and Watts, 1968, among others). The signal component represents the structured part of the time series, made up of a small number of embedded periodicities. Then, we take into account the known result for the one-sided confidence band of the power spectrum estimator. For this study, we established confidence levels of <90%, 90%, 95%, and 99%. Different climate signals have been identified: ENSO, QBO, NAO, Sun Spot cycles, as well as others related to sun activity, but the most powerful signals correspond to the annual cycle, followed by the 6 month and NAO cycles. Nevertheless, significant differences between rain data series and piezometric/flow data series have been pointed out. In piezometric data series and flow data series, ENSO and NAO signals could be stronger than others with high frequencies. The climatic peaks in lower frequencies in rain data are smaller and the confidence

  14. The Temporal Variation Analysis Of Cananéia GPS Station Coordinates

    NASA Astrophysics Data System (ADS)

    de Abreu, M. A.; da Fonseca, E. S.

    2007-05-01

    The objective of this paper is present the results obtained in the data processing of NEIA GPS permanent station, which belongs to the Brazilian Network of Continuous Monitoring of GPS System (RBMC), and to analyze the variations suffered of a time series of the station coordinates. The data had been collected in a double frequency GPS geodesic receiver, with 15 seconds rate of collection. The period analyzed was from January 2002 to April 2006. The data was processed with Bernese V.5.0 software and the AUSPOS on-line service, using differential method. In the Bernese processing was used the fiducial station PARA (Curitiba/Brazil) and for the AUSPOS processing was used BRAZ (Brasília - Brazil), LPGS (La Plata/Argentina) and UNSA (Salta/Argentina), these stations are in the same lithospherical plate. In the both processing's was used a propagation model of planimetric speed to detect NEIA station movement. After the processing's, it were made the difference between the calculated and the fiducial coordinates of NEIA station in the latitude, longitude and geodetic height. The displacement analysis at NEIA station, show variations of its coordinates caused by the South American Plate movement. The Bernese processing results show a displacement around 1,25 cm/year in the North direction and 0,30 cm/year in the West direction. The planimetric resultant vector displacement for NEIA station is about 1,30 cm/year in the Northwest direction. On the other hand, the AUSPOS processing service presented approximately 1,03 cm/year displacement in the North direction for latitude and for longitude an inverse displacements can be verified for the two sessions (first session: 0 to 12 hour and the second session 12 to 24 hour), 0,10 cm/year in West direction and -0,10 cm/year in East direction, respectively. Although, for the geometric height the Bernese and AUSPOS processing results, presents different signals. In the first session the results from Bernese processing present a -0

  15. The Experience Of The Meteorological Support By The National Institute Of Meteorology During The XV Pan-american Games

    NASA Astrophysics Data System (ADS)

    Seabra, M.; Gonçalves, P.; Braga, A.; Raposo, R.; Ito, E.; Gadelha, A.; Dallantonia, A.

    2008-05-01

    The XV Pan-American Games were organized in Rio de Janeiro city during 13 to 29 July, 2007 with a participation of 5.662 athletes of 42 countries . The Ministry of Sports requested INMET to provide meteorological support to the games, with the exception of the water sports only, which fell under the responsibility of the Brazilian Navy. The meteorological activities should follow the same pattern experienced during the Olympic Games of Sydney in Australia in the year of 2000, and of Athens in Greece in 2004, with a forecast center entirely dedicated to the event. NMET developed a website with detailed information oriented to the athletes and organizing committee and to the general public. The homepage had 3 different option of idioms (Portuguese, English and Spanish). After choosing the idiom, the user could consult the meteorological data, to each competition place, and to the Pan- American Village, every 15 minutes, containing weather forecast bulletin, daily synoptic analysis, the last 10 satellite image and meteograms. Besides observed data verified "in situ" INMET supplied forecast generated by High Resolution Model (MBAR) with 7km grid resolution especially set up for the games. INMET installed 7 automatic meteorological stations near the competition places, which supplied temperature , relative humidity , atmospheric pressure, wind (direction and intensity), radiation and precipitation every 15 minutes. Those information were relayed by satellite to INMET headquarters located in Brasília and soon after they were published in the website. To help the Brazilian Olympic Committee - COB, the athletes, their technical commission and the public in general, meteorological bulletins were emitted daily. The forecast was done together with the Navy and also with INMET's 6th District located in Rio de Janeiro, and responsible for the forecast statewide. This forecast was then placed at the INMET's website. Both the 3 days weather forecast and Meteorological Alert were

  16. Processus mis en jeu dans l'evolution morpho-dynamique de Roberts Bank (Delta du Fraser): Observation et modelisation hydrodynamiques et sedimentaires

    NASA Astrophysics Data System (ADS)

    Meule, Samuel

    Roberts Bank couvre le delta intertidal entre le bras principal du fleuve Fraser et la pointe du Cap Roberts en Colombie Britannique, Canada. Sous la pression du developpement urbain et la modification du regime sedimentaire, cette plage de sable fin est soumise a une erosion significative. L'identification des forces hydrodynamiques, leur importance et leur interaction permettent de determiner les zones de transport, et donc la stabilite de Roberts Bank. Deux periodes de mesures associees a des phases de modelisation de la houle et des courants ont ete effectuees lors de ce travail. La premiere periode de mesure, entre le 29 juin et le 8 juillet 2001, a permis l'identification de processus hydrodynamiques et sedimentaires associes aux forts courants de maree presents le long de Roberts Bank. La seconde phase de mesure, entre le 1er mars et le 26 mars 2002, a permis d'etudier les processus de remise en suspension associes a la houle. Des phases de modelisation ont ete menees a partir des connaissances acquises sur le terrain, afin d'affiner la comprehension des processus sedimentaires et notamment les interactions houle - courant - sediment. Les mecanismes, mis en evidence dans cette etude, participent au faconnage de Roberts Bank, contribuent a son erosion et a la mise en place de nouvelles structures sedimentaires. Les courants de flot de maree vont initier la creation de nuages de resuspension de sediment depuis le fond. En eau peu profonde, la composante " onshore" du courant de maree induit un transport a la cote, tandis qu'en eau plus profonde une faible composante " offshore" du courant peut favoriser un transport au large le long de la pente. Les chenaux, les dunes subaquatiques et les surfaces d'erosion affleurantes fournissent une rugosite de fond suffisante a la generation de turbulence et donc de nuages de sediment en suspension. Lors de la maree de jusant, les sediments resuspendus en eau peu profonde, sont transportes vers le large a partir d

  17. Interactions between soil moisture and Atmospheric Boundary Layer at the Brazilian savana-type vegetation Cerrado

    NASA Astrophysics Data System (ADS)

    Pinheiro, L. R.; Siqueira, M. B.

    2013-05-01

    Before the large people influx and development of the central part of Brazil in the sixties, due to new capital Brasília, Cerrado, a typical Brazilian savanna-type vegetation, used to occupy about 2 million km2, going all the way from the Amazon tropical forest, in the north of the country, to the edges of what used to be of the Atlantic forest in the southeast. Today, somewhat 50% of this area has given place to agriculture, pasture and managed forests. It is forecasted that, at the current rate of this vegetation displacement, Cerrado will be gone by 2030. Understanding how Cerrado interacts with the atmosphere and how this interaction will be modified with this land-use change is a crucial step towards improving predictions of future climate-change scenarios. Cerrado is a vegetation adapted to a climate characterized by two very distinct seasons, a wet season (Nov-Mar) and dry season (May-Ago), with April and October being transitions between seasons. Typically, based on measurements in a weather station located in Brasilia, 75% of precipitation happens in the wet-season months and only 5% during dry-season. Under these circumstances, it is clear that the vegetation will have to cope with long periods of water stress. In this work we studied using numerical simulations, the interactions between soil-moisture, responsible for the water stress, with the Atmospheric Boundary Layer (ABL). The numerical model comprises of a Soil-Vegetation-Atmosphere model where the biophysical processes are represented with a big-leaf approach. Soil water is estimated with a simple logistic model and with water-stress effects on stomatal conductance are parameterized from local measurements of simultaneous latent-heat fluxes and soil moisture. ABL evolution is calculate with a slab model that considers independently surface and entrainment fluxes of sensible- and latent- heat. Temperature tropospheric lapse-rate is taken from soundings at local airport. Simulations of 30-day dry

  18. Using Uranium-Series Isotopes to Quantify Volcanic Soil Formation Rates Under a Tropical Climate: Basse-Terre, Guadeloupe

    NASA Astrophysics Data System (ADS)

    Pereyra, Y.; Ma, L.; Sak, P. B.; Gaillardet, J.; Buss, H. L.; Brantley, S. L.

    2014-12-01

    U-series isotopes fractionate during chemical weathering and their activity ratios have been used to determine timescales and rates of soil formation. Such soil formation rates are measured at soil profile scale and provide an important link to compare chemical weathering rates measured across different spatial scales. We analyzed U-series isotope compositions in a ~12m deep soil profile in Basse-Terre Island of French Guadeloupe. The tropical Bras David watershed is developed on andesitic pyroclastic flows. Field observations have shown heterogeneity in color and texture in this profile. However, major element chemistry and mineralogy show some general depth trends. First, Al, Fe, and Ti show a depletion profile relative to Th from 12m to 4m depth, an addition from 4m to 2m, and depletion from 2m to the surface. Second, mobile elements such as Ca, Mg, and Sr have undergone intensive weathering, therefore show almost complete depletion even in the deep profile, and an addition profile near the surface. This addition trend is most likely related to atmospheric dust and marine aerosol signatures. Finally, K, Mn, and Si show a partial depletion profile at depth. The main minerals present throughout the soil profile are halloysite and gibbsite. 238U/232Th ratios in this profile ranged from 0.374 to 1.696, while the 230Th/232Th ratios ranged from 0.367 to 1.701. A decrease of (238U/232Th) in the deep soil profile from 12m to 4m depth is observed, and an increase in the shallow profile from 4m to the surface. The (230Th /232Th) ratios showed a similar trend as (238U/232Th). Marine aerosols and atmospheric dust are responsible for the addition of U in shallow soils while intensive chemical weathering is responsible for the loss of U at depth. U-series chemical weathering model suggests that the weathering duration from 12m to 4m depth is about 250kyr, with a weathering advancing rate of ~30 m/Ma. The rate is also about one order of magnitude lower than the weathering rate

  19. Bone Tissue Response to Porous and Functionalized Titanium and Silica Based Coatings

    PubMed Central

    Chaudhari, Amol; Braem, Annabel; Vleugels, Jozef; Martens, Johan A.; Naert, Ignace; Cardoso, Marcio Vivan; Duyck, Joke

    2011-01-01

    Background Topography and presence of bio-mimetic coatings are known to improve osseointegration. The objective of this study was to evaluate the bone regeneration potential of porous and osteogenic coatings. Methodology Six-implants [Control (CTR); porous titanium coatings (T1, T2); thickened titanium (Ti) dioxide layer (TiO2); Amorphous Microporous Silica (AMS) and Bio-active Glass (BAG)] were implanted randomly in tibiae of 20-New Zealand white rabbits. The animals were sacrificed after 2 or 4 weeks. The samples were analyzed histologically and histomorphometrically. In the initial bone-free areas (bone regeneration areas (BRAs)), the bone area fraction (BAF) was evaluated in the whole cavity (500 µm, BAF-500), in the implant vicinity (100 µm, BAF-100) and further away (100–500 µm, BAF-400) from the implant. Bone-to-implant contact (BIC-BAA) was measured in the areas where the implants were installed in contact to the host bone (bone adaptation areas (BAAs)) to understand and compare the bone adaptation. Mixed models were used for statistical analysis. Principal Findings After 2 weeks, the differences in BAF-500 for different surfaces were not significant (p>0.05). After 4 weeks, a higher BAF-500 was observed for BAG than CTR. BAF-100 for AMS was higher than BAG and BAF-400 for BAG was higher than CTR and AMS. For T1 and AMS, the bone regeneration was faster in the 100-µm compared to the 400-µm zone. BIC-BAA for AMS and BAG was lower after 4 than 2 weeks. After 4 weeks, BIC-BAA for BAG was lower than AMS and CTR. Conclusions BAG is highly osteogenic at a distance from the implant. The porous titanium coatings didn't stimulate bone regeneration but allowed bone growth into the pores. Although AMS didn't stimulate higher bone response, it has a potential of faster bone growth in the vicinity compared to further away from the surface. BIC-BAA data were inconclusive to understand the bone adaptation. PMID:21935382

  20. Response of the ionospheric F-region in the Brazilian sector during the super geomagnetic storm in April 2000 observed by GPS

    NASA Astrophysics Data System (ADS)

    de Abreu, A. J.; Sahai, Y.; Fagundes, P. R.; Becker-Guedes, F.; de Jesus, R.; Guarnieri, F. L.; Pillat, V. G.

    2010-06-01

    The response of the ionospheric F-region in the equatorial and low latitude regions in the Brazilian sector during the super geomagnetic storm on 06-07 April 2000 has been studied in the present investigation. The geomagnetic storm reached a minimum Dst of -288 nT at 0100 UT on 07 April. In this paper, we present vertical total electron content (VTEC) and phase fluctuations (in TECU/min) from GPS observations obtained at Imperatriz (5.5°S, 47.5°W; IMPZ), Brasília (15.9°S, 47.9°W; BRAZ), Presidente Prudente (22.12°S, 51.4°W; UEPP), and Porto Alegre (30.1°S, 51.1°W; POAL) during the period 05-08 April. Also, several GPS-based TEC maps are presented from the global GPS network, showing widespread and drastic TEC changes during the different phases of the geomagnetic storm. In addition, ion density measurements on-board the satellite Defense Meteorological Satellite Program (DMSP) F15 orbiting at an altitude of 840 km and the first Republic of China satellite (ROCSAT-1) orbiting at an altitude of 600 km are presented. The observations indicate that one of the orbits of the DMSP satellite is fairly close to the 4 GPS stations and both the DMSP F15 ion-density plots and the phase fluctuations from GPS observations show no ionospheric irregularities in the Brazilian sector before 2358 UT on the night of 06-07 April 2000. During the fast decrease of Dst on 06 April, there is a prompt penetration of electric field of magnetospheric origin resulting in decrease of VTEC at IMPZ, an equatorial station and large increase in VTEC at POAL, a low latitude station. This resulted in strong phase fluctuations on the night of 06-07 April, up to POAL. During the daytime on 07 April during the recovery phase, the VTEC observations show positive ionospheric storm at all the GPS stations, from IMPZ to POAL, and the effect increasing from IMPZ to POAL. This is possibly linked to the equatorward directed meridional wind. During the daytime on 08 April (the recovery phase continues

  1. Response of the Ionospheric F-region in the Brazilian sector during the super geomagnetic storm in April 2000 observed by GPS

    NASA Astrophysics Data System (ADS)

    de Abreu, Alessandro; Sahai, Yogeshwar; Fagundes, Paulo Roberto; Becker-Guedes, Fabio; de Jesus, Rodolfo; Guarnieri, Fernando; Pillat, Valdir G.

    The response of the ionospheric F-region in the equatorial and low latitude regions in the Brazilian sector during the super geomagnetic storm on 06-07 April 2000 has been studied in the present investigation. The geomagnetic storm reached a minimum Dst of -288 nT at 0100 UT on 07 April. In this paper, we present vertical total electron content (VTEC) and phase fluctuations (in TECU/min) from GPS observations obtained at Imperatriz (5.5o S, 47.5o W; IMPZ), Brasé (15.9o S, 47.9o W; BRAZ), Presidente Prudente (22.12o S, 51.4o W; UEPP), ılia and Porto Alegre (30.1o S, 51.1o W; POAL) during the period 05 to 08 April. Also, several GPS-based TEC maps are presented from the global GPS network, showing widespread and drastic TEC changes during the different phases of the geomagnetic storm. In addition, ion density measurements on-board the satellite Defense Meteorological Satellite Program (DMSP) F15 orbiting at an altitude of 840 km and the first Republic of China satellite (ROCSAT-1) orbiting at an altitude of 600 km are presented. The observations indicate that one of the orbits of the DMSP satellite is fairly close to the 4 GPS stations and both the DMSP F15 ion-density plots and the phase fluctuations from GPS observations show no ionospheric irregularities in the Brazilian sector before 2358 UT on the night of 06-07 April 2000. During the fast decrease of Dst on 06 April, there is a prompt penetration of electric field of magnetospheric origin resulting in decrease of VTEC at IMPZ, an equatorial station and large increase in VTEC at POAL, a low latitude station. This resulted in strong phase fluctuations on the night of 06-07 April, up to POAL. During the daytime on 07 April during the recovery phase, the VTEC observations show positive ionospheric storm at all the GPS stations, from IMPZ to POAL, and the effect increasing from IMPZ to POAL. This is possibly linked to the equatorward directed meridional wind. During the daytime on 08 April (the recovery phase

  2. Pilomatricome: étude de 22 cas

    PubMed Central

    Nasreddine, Fatima Zahra; Hali, Fouzia; Chiheb, Soumiya

    2016-01-01

    Le pilomatricome est une tumeur cutanée fréquente et bénigne du follicule pileux chez l'enfant. C'est une tumeur annexielle souvent méconnue et confondue avec d'autres lésions cutanées. Les localisations habituelles sont la tête et le cou. Le but de ce travail est de rapporter une série de 22 cas comportant des formes inhabituelles colligées au service de dermatologie sur une période allant de Janvier 2006 jusqu'au Mai 2015. L’étude a concerné 16 femmes et 6 hommes. La moyenne d’âge était de 23,3 ans (4-80 ans). La localisation cervico faciale a été observée dans 12 cas, 2 patients avaient des localisations multiples, un garçon de 4ans avait une localisation au niveau fronto-temporal et une fillette de 14 ans avait une localisation au niveau du visage et de l'avant-bras, et un patient de 48 ans avait une localisation sous unguéale. L'aspect clinique était typique dans tous les cas avec des nodules sous cutanés de consistance pierreuse. Tous les patients ont bénéficié d'une exérèse des nodules sous anesthésie locale. L’étude histologique était en faveur d'un épithélioma momifié de Malherbe d'exérèse complète sans signes de malignité. Aucun patient n'a présenté de rechute. L'originalité de notre étude réside dans la présence de localisations exceptionnelles au niveau latéro-vertébral, des membres et sous-unguéale, l’âge de survenue inhabituel à 80 ans et la présence de localisations multiples signalées chez 2 enfants. PMID:27516819

  3. Lymphœdème unilatéral du membre supérieur au cours d'une polyarthrite rhumatoïde

    PubMed Central

    Bouomrani, Salem; Nouma, Hanène; Slama, Alaeddine; Chebbi, Safouane; Neffoussi, Marwa; Fara, Afef; Beji, Maher

    2015-01-01

    Les lymphœdèmes chroniques et localisés des membres ne sont qu'exceptionnellement signalés au cours de la polyarthrite rhumatoïde (PR). Nous rapportons l'observation d'une patiente âgée de 63 ans ayant une PR diagnostiquée depuis dix ans et traitée par hydroxychloroquine, prednisone et méthotrexate avec une bonne évolution fût explorée pour une tuméfaction du membre supérieur gauche évoluant depuis deux ans. À l'examen clinique on notait un membre infiltré en totalité, indolore, élastique et recouvert d'une peau tendue, luisante mais d'aspect normal. Le reste de l'examen somatique était sans particularités. La biologie ne montrait pas d'anomalies. L'imagerie médicale (radiographies-X standards des os de l'avant bras et du thorax, scanner-X thoracique, échographie des parties molles et du creux axillaire, doppler artériel et veineux du membre atteint et écho-mammographie) se révélait normale. La lympho-scintigraphie concluait à l'absence de visualisation du réseau lymphatique superficiel gauche. Le diagnostic de lymphœdème secondaire associé à la PR était retenu devant la négativité du bilan étiologique. Une kinésithérapie de drainage lymphatique fût prescrite en association à des assauts cortisoniques mais l'amélioration n’était que partielle. Parmi les manifestations extra articulaires de la PR, les lymphœdèmes chroniques localisés des membres restent inhabituels et souvent méconnus. Leurs mécanismes physiopathologiques sont mal élucidés et leur traitement ne fait pas encore l'unanimité. Ils gardent en revanche une implication pronostique fonctionnelle majeure. PMID:26448809

  4. Impacts of Dust on Tropical Volcanic Soil Formation: Insights from Strontium and Uranium-Series Isotopes in Soils from Basse-Terre Island, French Guadeloupe

    NASA Astrophysics Data System (ADS)

    Pereyra, Y.; Ma, L.; Sak, P. B.; Gaillardet, J.; Buss, H. L.; Brantley, S. L.

    2015-12-01

    Dust inputs play an important role in soil formation, especially for thick soils developed on tropical volcanic islands. In these regions, soils are highly depleted due to intensive chemical weathering, and mineral nutrients from dusts have been known to be important in sustaining soil fertility and productivity. Tropical volcanic soils are an ideal system to study the impacts of dust inputs on the ecosystem. Sr and U-series isotopes are excellent tracers to identify sources of materials in an open system if the end-members have distinctive isotope signatures. These two isotope systems are particularly useful to trace the origin of atmospheric inputs into soils and to determine rates and timescales of soil formation. This study analyzes major elemental concentrations, Sr and U-series isotope ratios in highly depleted soils in the tropical volcanic island of Basse-Terre in French Guadeloupe to determine atmospheric input sources and identify key soil formation processes. We focus on three soil profiles (8 to 12 m thick) from the Bras-David, Moustique Petit-Bourg, and Deshaies watersheds; and on the adjacent rivers to these sites. Results have shown a significant depletion of U, Sr, and major elements in the deep profile (12 to 4 m) attributed to rapid chemical weathering. The top soil profiles (4 m to the surface) all show addition of elements such as Ca, Mg, U, and Sr due to atmospheric dust. More importantly, the topsoil profiles have distinct Sr and U-series isotope compositions from the deep soils. Sr and U-series isotope ratios of the top soils and sequential extraction fractions confirm that the sources of the dust are from the Saharan dessert, through long distance transport from Africa to the Caribbean region across the Atlantic Ocean. During the transport, some dust isotope signatures may also have been modified by local volcanic ashes and marine aerosols. Our study highlights that dusts and marine aerosols play important roles in element cycles and

  5. Hydrological changes due to land-use change from Brazilian savanna to managed Eucalyptus

    NASA Astrophysics Data System (ADS)

    Siqueira, M. B.; Mota, F. C. M.

    2014-12-01

    Before the large people influx and development of the central part of Brazil in the sixties, due to new capital Brasília, Cerrado, a typical Brazilian savanna-type vegetation, used to occupy about 2 million km2, going from the Amazon tropical forest, in the north, to the edges of what used to be the Atlantic forest in the southeast. Today, somewhat 50% of this area has given place to agriculture, pasture and managed forests. Understanding how Cerrado interacts with the atmosphere and how this interaction will be modified with this land-use change is a crucial step towards improving predictions of future climate-change scenarios. Cerrado is a vegetation adapted to a climate characterized by two distinct seasons, a wet season (Nov-Mar) and dry season (May-Ago), with April and October being transitions between seasons. Typically, 75% of precipitation happens in the wet-season months and only 5% during dry-season. In this study, it is investigated the potential impacts of the substitution of Cerrado to the eco-hydrological characteristics of the region. The focus here is Eucalyptus plantation which have increased substantially in the last decade due to government incentives. Two eddy-covariance (EC) systems were installed, one in an undisturbed Cerrado Stricto area and other in a recently-established Eucalyptus plantation. The two areas are 1,400m apart and are subjected to the same meteorology and similar edaphic conditions. Besides instrumentation typical of EC towers, a soil-moisture profiling system were installed in each site. Data from the towers will be used to parameterized a Soil-Vegetation-Atmosphere (SVAT) model to simulate hydrological and atmospheric boundary layer (ABL) processes in order to understand how the two vegetation cover modulates the exchange of mass and energy between the biosphere and atmosphere. Simulations of 30-day dry down from saturation to complete water stress were performed and were analyzed on how ABL respond to soil moisture

  6. Chagas disease: current epidemiological trends after the interruption of vectorial and transfusional transmission in the Southern Cone countries.

    PubMed

    Moncayo, Alvaro

    2003-07-01

    Chagas disease, named after Carlos Chagas who first described it in 1909, exists only on the American Continent. It is caused by a parasite, Trypanosoma cruzi, transmitted to humans by blood-sucking triatomine bugs and by blood transfusion. Chagas disease has two successive phases, acute and chronic. The acute phase lasts 6 to 8 weeks. After several years of starting the chronic phase, 20% to 35% of the infected individuals, depending on the geographical area will develop irreversible lesions of the autonomous nervous system in the heart, esophagus, colon and the peripheral nervous system. Data on the prevalence and distribution of Chagas disease improved in quality during the 1980's as a result of the demographically representative cross-sectional studies carried out in countries where accurate information was not available. A group of experts met in Bras lia in 1979 and devised standard protocols to carry out countrywide prevalence studies on human T. cruzi infection and triatomine house infestation. Thanks to a coordinated multi-country program in the Southern Cone countries the transmission of Chagas disease by vectors and by blood transfusion has been interrupted in Uruguay in1997, in Chile in 1999, and in 8 of the 12 endemic states of Brazil in 2000 and so the incidence of new infections by T. cruzi in the whole continent has decreased by 70%. Similar control multi-country initiatives have been launched in the Andean countries and in Central America and rapid progress has been recorded to ensure the interruption of the transmission of Chagas disease by 2005 as requested by a Resolution of the World Health Assembly approved in 1998. The cost-benefit analysis of the investments of the vector control program in Brazil indicate that there are savings of US$17 in medical care and disabilities for each dollar spent on prevention, showing that the program is a health investment with good return. Since the inception in 1979 of the Steering Committee on Chagas Disease

  7. Les garrots de prélèvement, un drame chez le nourrisson: à propos de 3 cas

    PubMed Central

    Ouangré, Edgar; Bazongo, Moussa; Ouédraogo, Isso; Zida, Maurice; Ouedraogo, Daouda; Sanou, Adama; Bonkoungou, Gilbert Patindé; Doamba, Rodrigue Namékinsba; Zongo, Nayi; Traore, Si Simon

    2016-01-01

    Le délai pour la levée d'un garrot sur un membre est limité, tout retard, surtout après la 3ème heure expose à un risque d'amputation de celui-ci. Notre objectif a été de rapporter trois cas de gangrène ischémique de membre par oubli d'un garrot après un prélèvement sanguin, afin d'interpeler le personnel soignant sur ses dangers. Il s'est agi de trois nourrissons dont deux de 3 mois et un de 5 mois, reçus aux urgences viscérales du CHU-Yalgado Ouédraogo pour tuméfaction du membre thoracique gauche. Dans leurs antécédents, on a noté une pose de garrot pour prélèvement de sang qui a été oublié pendant 24 heures dans deux cas et 48 heures dans un cas. L'examen avait retrouvé un œdème diffus associé à un sphacèle du membre supérieur remontant jusqu'au 1/3 moyen du bras; une abolition des pouls ulnaire et radial ainsi que de la sensibilité de la main dans 2 cas. Dans un cas les signes étaient atténués. Le diagnostic de gangrène ischémique de membre a été retenu dans tous les cas. La biologie réalisée était normale. En urgence, il a été réalisé une amputation trans-humérale dans 2 cas et un débridement associé à une amputation de quatre doigts dans un cas. L’évolution a été simple dans tous les cas. La gangrène sèche iatrogène de membre par garrot en milieu hospitalier ne devrait pas se concevoir. Cela passe par la rigueur dans l'administration des soins et une surveillance régulière et attentive des patients. PMID:27217892

  8. Great Historical Events That Were Significantly Affected by the Weather. Part 11: Meteorological Aspects of the Battle of Waterloo.

    NASA Astrophysics Data System (ADS)

    Neumann, J.

    1993-03-01

    The Waterloo Campaign extended from 15 to 18 June 1815, with the decisive Battle of Waterloo taking place on the 18th. The campaign involved the "Army of the North" of Napoleon on the one hand, and the Anglo-Dutch and Prussian armies on the other. The latter were commanded, respectively, by the Duke of Wellington and Prince Blücher. A shallow but active low and associated warm and cold fronts crossed the battle area on the 16th and 17th.The weather had important effects on the battles. On the 16th, in a battle between part of the French army and part of the Prussian army, at the village of Ligny, about 40 km south-southeast of Brussels, thunderstorms connected with the passage of the aforementioned warm front made the use of muskets impracticable.However, the most important weather effects developed on the 17th and during the night from the 17th to the 18th. Violent thunderstorms occurred early in the afternoon of the 17th close to Ligny, while Napoleon was in the process of attacking the Anglo-Dutch force at Quatre Bras. The rains turned the ground into a quagmire, making it impossible for the French artillery and cavalry, and even for the infantry, to move across the fields in extended order, as required by the emperor. The French advance was so greatly slowed down that Wellington was able to withdraw his lighter force to a better position near Waterloo. Thus, the Anglo-Dutch force was almost completely preserved for the decisive battle of the next day.The rainshowers of the 17th and the night from the 17th to the 18th softened the ground to an extent that, on the morning of the 18th, Napoleon and his artillery experts judged that the battle-the Battle of Waterloo-could not be started before a late hour of the forenoon [1130 local standard time (LST)]. Until the arrival of the Prussian force, about 1600 LST and later, the battle tended to go in favor of the French, but the Prussians turned the tide of the fighting.The paper quotes judgments of military

  9. Efeito do Solo do Materias Organicos E do Adubo Formula 4N:14P:8K Para Producao DA Batata (Solanum tuberosum L.) Semente Pre-Basica no Casa de Vegetacao

    NASA Astrophysics Data System (ADS)

    László, Márton

    2010-05-01

    Widely well know that the potato is an important vegetable crop at Brazíl. Plant grown on about 173.000 ha, with total yield of 2.6 million tons year-1. The average yield is about 15 t ha-1. This level is very low because degeneration of crop is rapid under high temperature and high viruses pressure. Therefore seed potato propagation and production is principal on consumption potato production. This is why we found it necessary to develop it. The latossolo vermelho soil-farmyard manure- burnt rice straw-fertilizer 4N:14P:8K greenhouse pot trial was set up at the National Vegetable Crops Research Center, Brasília-DF, Brazíl in 1990. The methods of the experiments were soil x farmyard manure x burnt rice straw, soil x 4N:14P:8K fertilizer and soil x farmyard manure x burnt rice straw x 4N:14P:8K fertilizer on randomized block design in total 29 combination of treatments in 5, 5 and 3 repetitions with in a total parcel of 116. According to chemical analysis of the a., soil, b., farmyard manure and c., burnt rice straw the agrochemistry parameters were as follows: a., latossolo vermelho soil: CaCO3 0.3-0.7%, humo 0.9-1.0%, pH (H2O) 5.3, pH (KCl) 4.5, AL- P2O5 3.2-3.5 mg kg-1, AL- K2O 180 mg kg-1, Mg (KCl) 70 mg kg-1, EDTA-Zn 0.5-0.8 mg kg-1, EDTA-Cu 0.5-0.6 mg kg-1, b., farmyard manure: N 1.8 g kg-1, P2O5 2.0 g kg-1, K2O 4.0 g kg-1, c., burnt rice straw: N 0.8 g kg-1, P2O5 7.0 g kg-1, K2O 4.5 g kg-1. The experimental datas were estimated by analysis of variance, ANOVA and MANOVA. The main conclusions were as follows: 1. Mixture of 80% latossolo vermelho, 10% burnt rice straw and 10% farmyard manure were shown best performance on seed potato productivity. The piece of tubers with a 0-20 mm (consumption seeds) was increased by 77%. 2. Total seed potato number was reached maximum at 10.8 g pot-1 4N:14P:8K fertilizer regarding to average of treatments with a 33%. 3. Dry biomassa production plant-1 was decreased by high dose of 4N:14P:8K fertilizer (18.0 g pot-1) with a

  10. EDITORIAL Proceedings of the XIV International Conference on Small-Angle Scattering, SAS-2009

    NASA Astrophysics Data System (ADS)

    Ungar, Goran; Heenan, Richard

    2010-10-01

    There are 52 papers in these Proceedings. The papers are divided into 10 thematic sections and a section for invited papers and reviews. The sections and the respective section editors are given below. Section Editor(s) Invited Papers and Reviews Peter Griffiths, Wim Bras, Rudolf Winter Beamlines and Instrumentation Elliot Gilbert, Wim Bras, Nigel Rhodes Theory, Data processing and Modelling Jan Skov Pedersen, Carlo Knupp Biological Systems and Membranes Richard Heenan, Cameron Neylon Ceramics, Glasses and Porous Materials Rudolf Winter Colloids and Solutions Peter Griffiths Hierarchical Structures and Fibres Steve Eichhorn, Karen Edler Metallic and Magnetic Systems Armin Hoell Polymers Patrick Fairclough Time resolved Diffraction, Kinetic and Dynamical Studies João Cabral, Christoph Rau We are grateful to all section editors and the many anonymous referees for their invaluable effort which made the publication of the Proceedings possible. The refereeing process was strict and thorough, some papers were rejected and most were improved. The resulting compendium gives a good overview of recent developments in small-angle X-ray and neutron scattering theory, application, methods of analysis and instrumentation. Thus it should be a useful source of reference for a number of years to come. The papers are a good reflection of the material presented at the meeting. Because of the general high quality of the articles, it was difficult to decide which to highlight and be fair to all contributors. The following in particular have caught the attention of the editors. Highlighted papers A statistical survey of publications reporting the application of SAXS and SANS by Aldo Craievich (paper 012003) is recommended reading for anyone needing convincing about the vibrancy of this scientific field and the ever expanding use of these techniques. Two aspects of coherent X-ray scattering, made available by the advent of the 3rd generation synchrotron sources, are discussed in the

  11. Efeito do Solo do Materias Organicos E do Adubo Formula 4N:14P:8K Para Producao DA Batata (Solanum tuberosum L.) Semente Pre-Basica no Casa de Vegetacao

    NASA Astrophysics Data System (ADS)

    László, Márton

    2010-05-01

    Widely well know that the potato is an important vegetable crop at Brazíl. Plant grown on about 173.000 ha, with total yield of 2.6 million tons year-1. The average yield is about 15 t ha-1. This level is very low because degeneration of crop is rapid under high temperature and high viruses pressure. Therefore seed potato propagation and production is principal on consumption potato production. This is why we found it necessary to develop it. The latossolo vermelho soil-farmyard manure- burnt rice straw-fertilizer 4N:14P:8K greenhouse pot trial was set up at the National Vegetable Crops Research Center, Brasília-DF, Brazíl in 1990. The methods of the experiments were soil x farmyard manure x burnt rice straw, soil x 4N:14P:8K fertilizer and soil x farmyard manure x burnt rice straw x 4N:14P:8K fertilizer on randomized block design in total 29 combination of treatments in 5, 5 and 3 repetitions with in a total parcel of 116. According to chemical analysis of the a., soil, b., farmyard manure and c., burnt rice straw the agrochemistry parameters were as follows: a., latossolo vermelho soil: CaCO3 0.3-0.7%, humo 0.9-1.0%, pH (H2O) 5.3, pH (KCl) 4.5, AL- P2O5 3.2-3.5 mg kg-1, AL- K2O 180 mg kg-1, Mg (KCl) 70 mg kg-1, EDTA-Zn 0.5-0.8 mg kg-1, EDTA-Cu 0.5-0.6 mg kg-1, b., farmyard manure: N 1.8 g kg-1, P2O5 2.0 g kg-1, K2O 4.0 g kg-1, c., burnt rice straw: N 0.8 g kg-1, P2O5 7.0 g kg-1, K2O 4.5 g kg-1. The experimental datas were estimated by analysis of variance, ANOVA and MANOVA. The main conclusions were as follows: 1. Mixture of 80% latossolo vermelho, 10% burnt rice straw and 10% farmyard manure were shown best performance on seed potato productivity. The piece of tubers with a 0-20 mm (consumption seeds) was increased by 77%. 2. Total seed potato number was reached maximum at 10.8 g pot-1 4N:14P:8K fertilizer regarding to average of treatments with a 33%. 3. Dry biomassa production plant-1 was decreased by high dose of 4N:14P:8K fertilizer (18.0 g pot-1) with a

  12. Facteurs prédictifs de succès des étudiants en première année de médecine à l'université de Parakou

    PubMed Central

    Adoukonou, Thierry; Tognon-Tchegnonsi, Francis; Mensah, Emile; Allodé, Alexandre; Adovoekpe, Jean-Marie; Gandaho, Prosper; Akpona, Simon

    2016-01-01

    Introduction Plusieurs facteurs dont les notes obtenues au BAC peuvent influencer les performances académiques des étudiants en première année de médecine. L'objectif de cette étude était d’évaluer la relation entre les résultats des étudiants au BAC et le succès en première année de médecine. Méthodes Nous avons réalisé une étude analytique ayant inclus l'ensemble des étudiants régulièrement inscrits en première année à la Faculté de Médecine de l'université de Parakou durant l'année académique 2010-2011. Les données concernant les notes par discipline et mention obtenue au BAC ont été collectées. Une analyse multivariée utilisant la régression logistique et la régression linéaire multiple a permis d’établir les meilleurs prédicteurs du succès et de la moyenne de l’étudiant en fin d'année. Le logiciel SPSS version 17.0 a été utilisé pour l'analyse des données et un p<0,05 a été considéré comme statistiquement significatif. Résultats Parmi les 414 étudiants régulièrement inscrits les données de 407 ont pu être exploitées. Ils étaient âgés de 15 à 31 ans; 262 (64,4%) étaient de sexe masculin. 98 étaient admis avec un taux de succès de 23,7%. Le sexe masculin, la note obtenue en mathématiques, en sciences physiques, la moyenne au BAC et la mention étaient associés au succès en fin d'année mais en analyse multivariée seule une note en sciences physiques > 15/20 était associée au succès (OR: 2,8 [1,32- 6,00]). Pour la moyenne générale obtenue en fin d'année seule une mention bien obtenue au BAC était associée (coefficient de l'erreur standard: 0,130 Bêta =0,370 et p=0,00001). Conclusion Les meilleurs prédicateurs du succès en première année étaient une bonne moyenne en sciences physiques au BAC et une mention bien. La prise en compte de ces éléments dans le recrutement des étudiants en première année pourrait améliorer les résultats académiques. PMID:27313819

  13. The Missing Memory of Canadian Sociology: Reflexive Government and "the Social Science".

    PubMed

    Curtis, Bruce

    2016-05-01

    The modest literature on the history of Canadian Sociology takes the appearance of a named academic discipline as its object. Canadian Sociology is held to have had some precursors in the 1880s, but really to appear only in the 1920s. It is described as a foreign import and as an activity first of intellectual speculation and moral reform. Observational and analytic practice are absent before 1880. The activities of state agents and government departments in the social field are not discussed. This article offers a richer account through an examination of the larger field from which Sociology was extracted, "the social science," which was practiced actively in colonial Canada from the early nineteenth century. The social science shaped and was itself shaped by colonial conditions. The article outlines three interrelated moments in social science to carry its claims: inventory-making, the emergence of "population-thinking," and "reflexive government." Attending to the social science underlines the complex and convoluted relations of sociology with state power. Les rares oeuvrages académiques portant sur l'histoire de la sociologie canadienne prend pour objet l'apparition du terme dans le contexte universitaire. Dans cet optique, ils signalent certains précurseurs de la sociologie canadienne dès les années 1880, mais en fait ils affirment que cette discipline n'apparaît que dans les années 1920. Cette discipline est présentée comme une importation académique et, d'abord et avant tout, comme de la spéculation intellectuelle et comme un projet de réforme morale. D'après cette vision, les pratiques d'observation et d'analyse sociales ne semblent pas exister avant 1880, et les acteurs politiques et administratifs sont absents du terrain. Notre article propose un examen plus riche du vaste champ duquel la sociologie académique fut arrachée: activement pratiquée au Canada à l'époque coloniale dès le début du XIXe si

  14. Extreme events of 2012, 2013 and 2014 linked to planetary wave resonance

    NASA Astrophysics Data System (ADS)

    Petoukhov, Vladimir; Coumou, Dim; Rahmstorf, Stefan; Stadtherr, Lisa; Kornhuber, Kai; Petri, Stefan; Schellnhuber, Hans Joachim

    2016-04-01

    Croatia. We have analysed this event in some detail and demonstrate a linkage to planetary wave resonance (Stadtherr et al., in revision). References Coumou D, Petoukhov V, Rahmstorf S, Petri S, and Schellnhuber HJ (2014) Quasi-resonant circulation regimes and hemispheric synchronization of extreme weather in boreal summer. Proc Natl Acad Sci USA 111: 12331-12336. Petoukhov V, Rahmstorf S, Petri S, Schellnhuber HJ (2013) Quasiresonant amplification of planetary waves and recent Northern Hemisphere weather extremes. Proc Natl Acad Sci USA 110(14): 5336-5341. Petoukhov V, Petri S, Rahmstorf S, Coumou D, Kornhuber K, Schellnhuber HJ (submitted) The role of quasi-resonant planetary wave dynamics in recent boreal spring-to-autumn extreme events. Proc Natl Acad Sci USA. Stadtherr L, Coumou D, Petoukhov V, Petri S, Rahmstorf S (in revision) Record Balkan floods of 2014 linked to planetary wave resonance. Science Advances.

  15. Farmyard Manure and Fertilizer Effects on Seed Potato (Solanum tuberosum L.) Yield in Green House Production

    NASA Astrophysics Data System (ADS)

    László, M.

    2009-04-01

    Nowadays is widely well know that the potato is an important vegetable crop at Brazíl. It is grown on about 173.000 ha, with total yield of 2.6 million tons year-1. The average yield is 15 t ha-1. This level is very low because degeneration of crop is rapid under high temperature and high viruses pressure. Therefore seed potato propagation and production is principal on consumption potato production. This is why we found it necessary to develop it. The latossolo vermelho soil-farmyard manure- burnt rice straw-fertilizer 4N:14P:8K greenhouse pot trial was set up at the National Vegetable Crops Research Center, Brasília-DF, Brazíl in 1990. The methods of the experiments were soil x farmyard manure x burnt rice straw, soil x 4N:14P:8K fertilizer and soil x farmyard manure x burnt rice straw x 4N:14P:8K fertilizer on randomized block design in total 29 combination of treatments in 5, 5 and 3 repetitions with in a total parcel of 116. According to chemical analysis of the a., soil, b., farmyard manure and c., burnt rice straw the agrochemistry parameters were as follows (estimated datas): a., latossolo vermelho soil: CaCO3 0.3-0.7%, humo 0.9-1.0%, pH (H2O) 5.3, pH (KCl) 4.5, AL- P2O5 3.2-3.5 mg kg-1, AL- K2O 180 mg kg-1, Mg (KCl) 70 mg kg-1, EDTA-Zn 0.5-0.8 mg kg-1, EDTA-Cu 0.5-0.6 mg kg-1, b., farmyard manure: N 1.8 g kg-1, P2O5 2.0 g kg-1, K2O 4.0 g kg-1, c., burnt rice straw: N 0.8 g kg-1, P2O5 7.0 g kg-1, K2O 4.5 g kg-1. The experimental datas were estimated by analysis of variance, ANOVA and MANOVA. The main conclusions were as follows: 1. Mixture of 80% latossolo vermelho, 10% burnt rice straw and 10% farmyard manure were shown best performance on seed potato productivity. The piece of tubers with a 0-20 mm (consumption seeds) was increased by 77%. 2. Total seed potato number was reached maximum at 10.8 g pot-1 4N:14P:8K fertilizer regarding to average of treatments with a 33%. 3. Dry biomassa production plant-1 was decreased by high dose of 4N:14P:8K

  16. Coupled Modeling of Fault Poromechanics During Geologic CO2 Storage

    NASA Astrophysics Data System (ADS)

    Jha, B.; Hager, B. H.; Juanes, R.

    2012-12-01

    through faults in realistic CO2 injection scenarios. B. Aagaard et al., "Pylith User Manual version 1.6.1, Computational Infrastructure for Geodynamics," (2011). J. T. Birkholzer and Q. Zhou, Int. J. Greenh. Gas Control 3:745-756 (2009). F. Cappa, and J. Rutqvist, Geophys. Res. Lett. 38, L17313 (2011). O. Coussy, "Mechanics of Porous Continua", John Wiley & Sons, (1995) J. Kim, H. A. Tchelepi, and R. Juanes, Soc. Pet. Eng. J. 16, 249 (2011). M. L. Szulczewski et al., Proc. Natl. Acad. Sci. USA 109:5185-5189 (2012). M. D. Zoback and S. M. Gorelick, Proc. Natl. Acad. Sci. USA, 109: 10164-10168 (2012). Displacement field in a synthetic reservoir with a CO2 injection well, a brine relieve well, and a fault. Notice the slip on the fault.

  17. Conformon-driven biopolymer shape changes in cell modeling.

    PubMed

    Ji, Sungchul; Ciobanu, Gabriel

    2003-07-01

    Conceptual models of the atom preceded the mathematical model of the hydrogen atom in physics in the second decade of the 20th century. The computer modeling of the living cell in the 21st century may follow a similar course of development. A conceptual model of the cell called the Bhopalator was formulated in the mid-1980s, along with its twin theories known as the conformon theory of molecular machines and the cell language theory of biopolymer interactions [Ann. N.Y. Acad. Sci. 227 (1974) 211; BioSystems 44 (1997) 17; Ann. N.Y. Acad. Sci. 870 (1999a) 411; BioSystems 54 (2000) 107; Semiotica 138 (1-4) (2002a) 15; Fundamenta Informaticae 49 (2002b) 147]. The conformon theory accounts for the reversible actions of individual biopolymers coupled to irreversible chemical reactions, while the cell language theory provides a theoretical framework for understanding the complex networks of dynamic interactions among biopolymers in the cell. These two theories are reviewed and further elaborated for the benefit of both computational biologists and computer scientists who are interested in modeling the living cell and its functions. One of the critical components of the mechanisms of cell communication and cell computing has been postulated to be space- and time-organized teleonomic (i.e. goal-directed) shape changes of biopolymers that are driven by exergonic (free energy-releasing) chemical reactions. The generalized Franck-Condon principle is suggested to be essential in resolving the apparent paradox arising when one attempts to couple endergonic (free energy-requiring) biopolymer shape changes to the exergonic chemical reactions that are catalyzed by biopolymer shape changes themselves. Conformons, defined as sequence-specific mechanical strains of biopolymers first invoked three decades ago to account for energy coupling in mitochondria, have been identified as shape changers, the agents that cause shape changes in biopolymers. Given a set of space- and time

  18. Modeling of optical spectra of the light-harvesting CP29 antenna complex of photosystem II--part II.

    PubMed

    Feng, Ximao; Kell, Adam; Pieper, Jörg; Jankowiak, Ryszard

    2013-06-01

    Until recently, it was believed that the CP29 protein from higher plant photosystem II (PSII) contains 8 chlorophylls (Chl's) per complex (Ahn et al. Science 2008, 320, 794-797; Bassi et al. Proc. Natl. Acad. Sci. U.S.A. 1999, 96, 10056-10061) in contrast to the 13 Chl's revealed by the recent X-ray structure (Pan et al. Nat. Struct. Mol. Biol. 2011, 18, 309-315). This disagreement presents a constraint on the interpretation of the underlying electronic structure of this complex. To shed more light on the interpretation of various experimental optical spectra discussed in the accompanying paper (part I, DOI 10.1021/jp4004328 ), we report here calculated low-temperature (5 K) absorption, fluorescence, hole-burned (HB), and 300 K circular dichroism (CD) spectra for CP29 complexes with a different number of pigments. We focus on excitonic structure and the nature of the low-energy state using modeling based on the X-ray structure of CP29 and Redfield theory. We show that the lowest energy state is mostly contributed to by a612, a611, and a615 Chl's. We suggest that in the previously studied CP29 complexes from spinach (Pieper et al. Photochem. Photobiol.2000, 71, 574-589) two Chl's could have been lost during the preparation/purification procedure, but it is unlikely that the spinach CP29 protein contains only eight Chl's, as suggested by the sequence homology-based study (Bassi et al. Proc. Natl. Acad. Sci. U.S.A.1999, 96, 10056-10061). The likely Chl's missing in wild-type (WT) CP29 complexes studied previously (Pieper et al. Photochem. Photobiol. 2000, 71, 574-589) include a615 and b607. This is why the nonresonant HB spectra shown in that reference were ~1 nm blue-shifted with the low-energy state mostly localized on about one Chl a (i.e., a612) molecule. Pigment composition of CP29 is discussed in the context of light-harvesting and excitation energy transfer. PMID:23662835

  19. The Noble Gas Fingerprint in a UK Unconventional Gas Reservoir

    NASA Astrophysics Data System (ADS)

    McKavney, Rory; Gilfillan, Stuart; Györe, Domokos; Stuart, Fin

    2016-04-01

    helium and neon isotopic signatures exhibit a small but resolvable mantle input previously unseen onshore in the United Kingdom. We will outline the potential sources of this mantle input. 1. Osborn et al. (2011). Proc. Natl. Acad. Sci. U. S. A. 108, 10.1073/pnas.1100682108 2. Baldassare et al. (2014). Am. Assoc. Pet. Geol. Bull. 98, 10.1306/06111312178 3 .Ballentine et al. (2002). Rev. Min. Geochem. 47, 10.2138/rmg.2002.47.13 4. Gilfillan & Wilkinson (2011). Int. J. 5, 10.1016/j.ijggc.2011.08.008 5. Darrah et al. (2014). Proc. Natl. Acad. Sci. 111, 10.1073/pnas.1322107111

  20. The role of genomics in conservation and reproductive sciences.

    PubMed

    Johnson, Warren E; Koepfli, Klaus

    2014-01-01

    maintaining functional ecosystems, evolutionary process and will impact future food supplies, human health, biomaterial development and geopolitics (Myers and Knoll Proc Natl Acad Sci U S A 98:5389-5392, 2001; Templeton et al. Proc Natl Acad Sci U S A 98:5426-5432, 2001). Therefore, conservation of genetic diversity is a social, cultural, scientific, and economic prerogative and is the key to adaptation in the uncertain future of a human-dominated environment. Once lost, genetic resources are nearly impossible to regain, increasing the urgency of fundamental global approaches (e.g. www.cbd.int/sp/targets ).In this chapter we provide a review of current research and recent advances in biotechnology and genomic approaches for animal conservation and the management of genetic resources, with an emphasis on reproductive sciences. It is intended to provide information and insights for research and to provoke thoughts on how to take advantage of these opportunities. PMID:25091907

  1. An HIV gp120-CD4 Immunogen Does Not Elicit Autoimmune Antibody Responses in Cynomolgus Macaques.

    PubMed

    Schwartz, Jennifer A; Prado, Ilia; Misamore, Johnathan; Weiss, Deborah; Francis, Jesse; Pal, Ranajit; Huaman, Maria; Cristillo, Anthony; Lewis, George K; Gallo, Robert C; DeVico, Anthony L; Fouts, Timothy R

    2016-07-01

    A promising concept for human immunodeficiency virus (HIV) vaccines focuses immunity on the highly conserved transition state structures and epitopes that appear when the HIV glycoprotein gp120 binds to its receptor, CD4. We are developing chimeric antigens (full-length single chain, or FLSC) in which gp120 and CD4 sequences are flexibly linked to allow stable intrachain complex formation between the two moieties (A. DeVico et al., Proc Natl Acad Sci U S A 104:17477-17482, 2007, doi:10.1073/pnas.0707399104; T. R. Fouts et al., J Virol 74:11427-11436, 2000, doi:10.1128/JVI.74.24.11427-11436.2000). Proof of concept studies with nonhuman primates show that FLSC elicited heterologous protection against simian-human immunodeficiency virus (SHIV)/simian immunodeficiency virus (SIV) (T. R. Fouts et al., Proc Natl Acad Sci U S A 112:E992-E999, 2016, doi:10.1073/pnas.1423669112), which correlated with antibodies against transition state gp120 epitopes. Nevertheless, advancement of any vaccine that comprises gp120-CD4 complexes must consider whether the CD4 component breaks tolerance and becomes immunogenic in the autologous host. To address this, we performed an immunotoxicology study with cynomolgus macaques vaccinated with either FLSC or a rhesus variant of FLSC containing macaque CD4 sequences (rhFLSC). Enzyme-linked immunosorbent assay (ELISA) binding titers, primary CD3(+) T cell staining, and temporal trends in T cell subset frequencies served to assess whether anti-CD4 autoantibody responses were elicited by vaccination. We find that immunization with multiple high doses of rhFLSC did not elicit detectable antibody titers despite robust responses to rhFLSC. In accordance with these findings, immunized animals had no changes in circulating CD4(+) T cell counts or evidence of autoantibody reactivity with cell surface CD4 on primary naive macaque T cells. Collectively, these studies show that antigens using CD4 sequences to stabilize transition state gp120 structures

  2. Polymorphism of epsomite (MgSO4.7H2O) up to 50 kbar from powder neutron diffraction.

    NASA Astrophysics Data System (ADS)

    Wood, I. G.; Fortes, A. D.; Vocadlo, L.

    2006-12-01

    Hydrated sulfate salts are important evaporite minerals on the Earth, and on Mars too, as well as being a candidate rock-forming mineral inside the icy moons of the outer solar system. In order to be able to model the interiors of these icy moons, we are carrying out a program of investigation of epsomite and related hydrates at high pressure. Previously, we have studied deuterated epsomite to 5.5 kbar in a gas pressure cell, and observed no phase changes [1]. Here we report the results of work to extend that pressure range by an order of magnitude, to 50 kbar. Such pressures are applicable to the deep interiors of large icy moons (likely core-mantle pressures are 15-20 kbar, and core pressures in large undifferentiated objects would be 35-40 kbar. Such pressures are also in the lower range expected due to impact shock. Our aim in this experiment was to investigate the possible high-pressure polymorphism and dehydration reported by earlier workers [2,3]. At room temperature, we observed a series of polymorphic phase transitions upon compression which are broadly in agreement with existing piston-cylinder observations. Epsomite appears to undergo one or two very sluggish transition below 15 kbar. Above this pressure, we observe a phase which is stable up to 28 kbar, and is probably the phase IV reported by Livshits et al. [3]. Most recently, we have attempted to recover phase IV to ambient pressure so that we may collect data at a greater range of scattering angles. Phase IV appears to amorphise above ~ 30 kbar. We report the state of our work on the high-pressure phases of epsomite, and plans for future investigations. References [1] Fortes. A. D, et al. (2006) Eur. J. Min. 18(4), 449-462. [2] Bridgman, P. W. (1948a) Proc. Am. Acad. Arts Sci. 76, 71-87, & Bridgman, P. W. (1948b) Proc. Am. Acad. Arts Sci. 76, 89-99: [3] Livshits, L. D. et al. (1963) Russ. J. Inorg. Chem. 8, 676-678.

  3. The Evolution of Sterol Biosynthesis in Bacteria: In Situ Fluorescence Localization of Sterols in the Nucleoid Bacterium Gemmata obscuriglobus

    NASA Astrophysics Data System (ADS)

    Budin, M.; Jorgenson, T. L.; Pearson, A.

    2004-12-01

    acquired the ability to produce sterols for a specialized function related to their nuclear membrane. 1. Brocks, J.J., et al., Science 285:1033-36 (1999). 2. Bird, C.W., et al., Nature 230:473-74 (1971). 3. Bode, H.B., et al., Mol. Microbiol. 47:471-81 (2003). 4. Pearson, A., et al., Proc. Natl. Acad. Sci. USA 100:15352-57 (2003). 5. Fuerst, J.A. and R.I. Webb, Proc. Natl. Acad. Sci. USA 88:8184-88 (1991).

  4. Temporal Correlations In Natural Time Analysis and Tsallis Non Extensive Statistical Mechanics

    NASA Astrophysics Data System (ADS)

    Sarlis, N. V.; Varotsos, P.; Skordas, E. S.

    2015-12-01

    Upon analyzing the seismic catalog in a new time domain termed natural time[1-3] and employing a sliding natural time window comprising a number of events that would occur in a few months, we find that the fluctuations β of the order parameter of seismicity[4] show a minimum βmin a few months before major earthquakes (EQs)[5,6]. Such a minimum appears simultaneously[7] with the initiation of Seismic Electric Signals activity[8] being the first time in which two geophysical observables of different nature exhibit simultaneous anomalous behavior before major EQs. In addition, we show[9] that each precursory βmin is preceded as well as followed by characteristic changes of temporal correlations between EQ magnitudes identified by the celebrated Detrended Fluctuation Analysis of magnitude time series. We indicate that Tsallis non extensive statistical mechanics[10], in the frame of which kappa distributions arise[11], can capture temporal correlations between EQ magnitudes if complemented with natural time analysis [12]. References P.A. Varotsos, N.V. Sarlis, and E.S. Skordas, Phys Rev E, 66 (2002) 011902. P.A. Varotsos et al., Phys Rev E 72 (2005) 041103. Varotsos P. A., Sarlis N. V. and Skordas E. S., Natural Time Analysis: The new view of time. (Springer-Verlag, Berlin Heidelberg) 2011. N. V. Sarlis, E. S. Skordas and P. A. Varotsos, EPL 91 (2010) 59001. N. V. Sarlis et al., Proc Natl Acad Sci USA 110 (2013) 13734. N. V. Sarlis et al., Proc Natl Acad Sci USA 112 (2015) 986. P. A. Varotsos et al., Tectonophysics, 589 (2013) 116. P. Varotsos and M. Lazaridou, Tectonophysics 188 (1991) 321. P. A. Varotsos, N. V. Sarlis, and E. S. Skordas, J Geophys Res Space Physics, 119 (2014), 9192, doi: 10.1002/2014JA0205800. C. Tsallis, J Stat Phys 52 (1988) 479. G. Livadiotis, and D. J. McComas, J Geophys Res 114 (2009) A11105, doi:10.1029/2009JA014352. N. V. Sarlis, E. S. Skordas and P. A. Varotsos, Phys Rev E 82 (2010) 021110.

  5. Shikimic Acid Ozonolysis is Influenced by its Physical State

    NASA Astrophysics Data System (ADS)

    Steimer, S.; Krieger, U. K.; Lampimäki, M.; Peter, T.; Ammann, M.

    2013-12-01

    behavior regarding the ozone gas phase concentration. Microspectroscopy showed that the speed at which the characteristic double bond peak of shikimic acid disappeared was humidity dependent. The measured humidity dependence supports the hypothesis that the uptake coefficient is highly dependent on the diffusion coefficients of ozone and/or shikimic acid in the organic film. [1] Nature, 2010, 467, 824-827. [2] Proc. Natl. Acad. Sci. U. S. A., 2011, 108, 11003-11008. [3] Proc. Natl. Acad. Sci. U. S. A., 2012, 109, 17354-17359.

  6. Deuterium labeling for neutron structure-function-dynamics analysis.

    PubMed

    Meilleur, Flora; Weiss, Kevin L; Myles, Dean A A

    2009-01-01

    Neutron scattering and diffraction provide detailed information on the structure and dynamics of biological materials across time and length scales that range from picoseconds to nanoseconds and from 1 to 10,000 A, respectively. The particular sensitivity of neutrons to the isotopes of hydrogen makes selective deuterium labeling of biological systems an essential tool for maximizing the return from neutron scattering experiments. In neutron protein crystallography, the use of fully deuterated protein crystals improves the signal-to-noise ratio of the data by an order of magnitude and enhances the visibi-lity of the molecular structure (Proc Natl Acad Sci U S A 97:3872-3877, 2000; Acta Crystallogr D Biol Crystallogr 61:1413-1417, 2005; Acta Crystallogr D Biol Crystallogr 61:539-544, 2005). In solution and surface scattering experiments, the incorporation of deuterium-labeled subunits or components into complex assemblies or structures makes it possible to deconvolute the scattering of the labeled and unlabeled subunits and to determine their relative dispositions within the complex (J Mol Biol 93:255-265, 1975). With multiple labeling patterns, it is also possible to reconstruct the locations of multiple subunits in ternary and higher-order complexes (Science 238:1403-1406, 1987; J Mol Biol 271:588-601, 1997; J Biol Chem 275:14432-14439, 2000; Biochemistry 42:7790-7800, 2003). In inelastic neutron scattering experiments, which probe hydrogen dynamics in biological materials, the application of site, residue, or region-specific hydrogen-deuterium-labeling patterns can be used to distinguish and highlight the specific dynamics within a system (Proc Natl Acad Sci U S A 95:4970-4975, 1998).Partial, selective, or fully deuterated proteins can be readily produced by endogenous expression of recombinant proteins in bacterial systems that are adapted to growth in D(2)O solution and using selectively deuterated carbon sources. Adaptation can be achieved either by gradual

  7. Porosome: the secretory NanoMachine in cells.

    PubMed

    Jena, Bhanu P

    2013-01-01

    Cells synthesize and store within membranous sacs products such as hormones, growth factors, neurotransmitters, or digestive enzymes, for release on demand. As recently as just 15 years ago, it was believed that during cell secretion, membrane-bound secretory vesicles completely merge at the cell plasma membrane resulting in the diffusion of intravesicular contents to the cell exterior and the compensatory retrieval of the excess membrane by endocytosis. This explanation, however, failed to explain the generation of partially empty vesicles observed in electron micrographs following secretion. Logically therefore, in a 1993 News and Views article in the journal Nature, Prof. Erwin Neher wrote "It seems terribly wasteful that, during the release of hormones and neurotransmitters from a cell, the membrane of a vesicle should merge with the plasma membrane to be retrieved for recycling only seconds or minutes later." The discovery of permanent secretory portals or nanomachines at the cell plasma membrane called POROSOMES, where membrane-bound secretory vesicles transiently dock and fuse to release intravesicular contents to the cell exterior, has finally resolved this conundrum. Following this discovery, the composition of the porosome, its structure and dynamics visualized with high-resolution imaging techniques atomic force and electron microscopy, and its functional reconstitution into artificial lipid membrane have provided a molecular understanding of cell secretion. In agreement, it has been demonstrated that "secretory granules are recaptured largely intact after stimulated exocytosis in cultured endocrine cells" (Proc Natl Acad Sci U S A 100:2070-2075, 2003); that "single synaptic vesicles fuse transiently and successively without loss of identity" (Nature 423:643-647, 2003); and that "zymogen granule exocytosis is characterized by long fusion pore openings and preservation of vesicle lipid identity" (Proc Natl Acad Sci U S A 101:6774-6779, 2004). It made no

  8. Identification of the in vitro phosphorylation sites on Gs alpha mediated by pp60c-src.

    PubMed

    Moyers, J S; Linder, M E; Shannon, J D; Parsons, S J

    1995-01-15

    Overexpression of pp60c-src in mouse fibroblasts potentiates both agonist-induced signalling through beta-adrenergic receptors and cyclic AMP accumulation in response to cholera toxin [Bushman, Wilson, Luttrell, Moyers and Parsons (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 7462-7466; Moyers, Bouton and Parsons (1993) Mol. Cell. Biol. 13, 2391-2400]. In reconstitution experiments in vitro, phosphorylation of Gs alpha by immune-complexed pp60c-src resulted in enhanced rates of receptor-mediated guanosine 5'-[gamma-thio]triphosphate (GTP[S]) binding and GTP hydrolysis [Hausdorff, Pitcher, Luttrell, Linder, Kurose, Parsons, Caron and Lefkowitz (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 5720-5724]. These results suggest that one mechanism by which pp60c-src affects signalling through the beta-adrenergic receptor is by phosphorylation and functional alteration of the G protein. To elucidate how phosphorylation of Gs alpha might affect its function, we subjected phosphorylated, recombinant Gs alpha to tryptic phosphopeptide analysis. Phosphotryptic peptides were purified by h.p.l.c. and analysed by Edman degradation to determine the cycle numbers at which radiolabelled phosphotyrosine was released. Candidate peptides that contained Tyr residues at the corresponding positions were synthesized, phosphorylated in vitro by pp60c-src, and their migrations in two-dimensional electrophoresis/t.l.c. were compared with those of tryptic phosphopeptides from intact Gs alpha. We report here that Gs alpha is phosphorylated on two residues by pp60c-src, namely, Tyr-37 and Tyr-377. Tyr-37 lies near the site of beta gamma binding in the N-terminus, within a region postulated to modulate GDP dissociation and activation by GTP [Johnson, Dhanasekaran, Gupta, Lowndes, Vaillancourt and Ruoho (1991) J. Cell Biochem. 47, 136-146], while Tyr-377 is located in the extreme C-terminus, within a region of Gs alpha important for receptor interaction [Sullivan, Miller, Masters, Beiderman, Heideman and

  9. Low frequency electromagnetic signals in the atmosphere caused by geodynamics and solar activity

    NASA Astrophysics Data System (ADS)

    Novik, Oleg; Ruzhin, Yuri; Ershov, Sergey; Volgin, Max; Smirnov, Fedor

    Due to the composed structure of the medium and large portions of energy transferred, a seismic excitation in the oceanic or continental lithosphere disturbs all types of geophysical fields. To investigate the problem of electromagnetic (EM) forcing on the atmosphere from the seismically activated lithosphere, we have formulated two mathematical models of interaction of fields of different physical nature resulting in arising of the low-frequency (from 0.1 to 10 Hz by amplitude of a few hundreds of pT) EM signals in the atmosphere. First we have considered the EM field generation in the moving oceanic lithosphere and then in the moving continental one. For both cases, the main physical principles and geological data were applied for formulation of the model and characteristics of the computed signals of different nature agree with measurements of other authors. On the basis of the 2D model of the seismo-hydro-EM-temperature interaction in a lithosphere-Ocean-atmosphere domain, a block-scheme of a multisensory vertically distributed (from a seafloor up to the ionosphere) tsunami precursors’ detection system is described. On the basis of the 3D model of the seismo-EM interaction in a lithosphere-atmosphere domain, we explain effect of location of the future seismic epicenter area (obtained by Prof. Kopytenko, Yu. A. from Inst. IZMIRAN of Russian Acad. Sci. and co-authors) as the result of the magnetic field measurements in the atmosphere near the earth’s surface. We believe that the biosphere effects of forcing on the atmosphere may not be ignored. We formulate the result of our measurements with the system of micro-voltmeters: low-frequency EM disturbances of the atmosphere caused by solar activity (namely, geomagnetic storms with the geomagnetic index values K = 5 and K = 6), are decreasing temporarily the coherence of oscillations of the electric potentials of different points on the surface of a head, i.e. the coherence of the human brain EM processes. We are

  10. Role of NAD+ and ADP-Ribosylation in the Maintenance of the Golgi Structure

    PubMed Central

    Mironov, Alexander; Colanzi, Antonino; Silletta, Maria Giuseppina; Fiucci, Giusy; Flati, Silvio; Fusella, Aurora; Polishchuk, Roman; Mironov, Alexander; Tullio, Giuseppe Di; Weigert, Roberto; Malhotra, Vivek; Corda, Daniela; Matteis, Maria Antonietta De; Luini, Alberto

    1997-01-01

    We have investigated the role of the ADP- ribosylation induced by brefeldin A (BFA) in the mechanisms controlling the architecture of the Golgi complex. BFA causes the rapid disassembly of this organelle into a network of tubules, prevents the association of coatomer and other proteins to Golgi membranes, and stimulates the ADP-ribosylation of two cytosolic proteins of 38 and 50 kD (GAPDH and BARS-50; De Matteis, M.A., M. DiGirolamo, A. Colanzi, M. Pallas, G. Di Tullio, L.J. McDonald, J. Moss, G. Santini, S. Bannykh, D. Corda, and A. Luini. 1994. Proc. Natl. Acad. Sci. USA. 91:1114–1118; Di Girolamo, M., M.G. Silletta, M.A. De Matteis, A. Braca, A. Colanzi, D. Pawlak, M.M. Rasenick, A. Luini, and D. Corda. 1995. Proc. Natl. Acad. Sci. USA. 92:7065–7069). To study the role of ADP-ribosylation, this reaction was inhibited by depletion of NAD+ (the ADP-ribose donor) or by using selective pharmacological blockers in permeabilized cells. In NAD+-depleted cells and in the presence of dialized cytosol, BFA detached coat proteins from Golgi membranes with normal potency but failed to alter the organelle's structure. Readdition of NAD+ triggered Golgi disassembly by BFA. This effect of NAD+ was mimicked by the use of pre–ADP- ribosylated cytosol. The further addition of extracts enriched in native BARS-50 abolished the ability of ADP-ribosylated cytosol to support the effect of BFA. Pharmacological blockers of the BFA-dependent ADP-ribosylation (Weigert, R., A. Colanzi, A. Mironov, R. Buccione, C. Cericola, M.G. Sciulli, G. Santini, S. Flati, A. Fusella, J. Donaldson, M. DiGirolamo, D. Corda, M.A. De Matteis, and A. Luini. 1997. J. Biol. Chem. 272:14200–14207) prevented Golgi disassembly by BFA in permeabilized cells. These inhibitors became inactive in the presence of pre–ADP-ribosylated cytosol, and their activity was rescued by supplementing the cytosol with a native BARS-50–enriched fraction. These results indicate that ADP-ribosylation plays a role in the

  11. Sea-level variability in tide-gauge and geological records: An empirical Bayesian analysis (Invited)

    NASA Astrophysics Data System (ADS)

    Kopp, R. E.; Hay, C.; Morrow, E.; Mitrovica, J. X.; Horton, B.; Kemp, A.

    2013-12-01

    melt [5]. We end by presenting preliminary results from such an analysis. [1] Sallenger et al. (2012), Nat. Clim. Change 2: 884-888. [2] Kopp (in press),Geophys. Res. Lett. [3] Engelhart and Horton (2011), Quat. Sci. Rev. 54: 12-25. [4] Kemp et al. (2011), Proc. Natl. Acad. Sci. 108: 11017-11022. [5] Hay et al. (2013). Proc. Natl. Acad. Sci. 110: 3692-3699.

  12. 3-D Raman Imagery and Atomic Force Microscopy of Ancient Microscopic Fossils

    NASA Astrophysics Data System (ADS)

    Schopf, J.

    2003-12-01

    al. (2001) Proc. Nat. Acad. Sci. USA 98: 823-826. (2) Schopf, J.W. et al. (2002) Nature 416:73-76. (3) Schopf, J.W. (2003) 7th Exobiol. PI Symp. (NASA Ames): 57. (4) Kempe, A. et al. (2002) Proc. Nat. Acad. Sci. USA 99: 9117-9120.

  13. Alfred Vulpian and Jean-Martin Charcot in each other's shadow? From Castor and Pollux at La Salpêtrière to neurology forever.

    PubMed

    Bogousslavsky, Julien; Walusinski, Olivier; Moulin, Thierry

    2011-01-01

    While Alfred Vulpian (1826-1887) is not completely forgotten, he cannot match the uninterrupted celebrity which Jean-Martin Charcot (1825-1893) still enjoys today. After becoming interne (residents) at the same institute in 1848, both were involved in shaping the cradle of what would become modern neurology. Both started work as chiefs at a La Salpêtrière service on January 1, 1862, making common rounds and studies, with several common publications. While their friendship remained 'for life', as stated by Charcot at Vulpian's funeral, their career paths differed. Vulpian progressed quicker and higher, being appointed full professor and elected at the Académie Nationale de Médecine and the Académie des Sciences several years before Charcot, as well as becoming dean of the Paris Faculty of Medicine. These positions also enabled him to support his friend Charcot in getting appointed full clinical professor and becoming the first holder of the chair of Clinique des Maladies du Système Nerveux in 1882. Before studying medicine, Vulpian had worked in physiology with Pierre Flourens, and his career always remained balanced between physiology and neurology, with remarkable papers. He introduced Charcot to optic microscopy during their La Salpêtrière years, indirectly helping him to become his successor to the chair of pathological anatomy in 1872. While Vulpian succeeded so well in local medical affairs, Charcot spent his time building up a huge clinical service and a teaching 'school' at La Salpêtrière, which he never left for over 31 years until his death. This 'school' progressively became synonymous with clinical neurology itself and perpetuated the master's memory for decades. Vulpian never had such support, although Jules Déjerine was his pupil and Joseph Babinski was his interne before becoming Charcot's chef de clinique (chief of staff) in 1885. This unusual switch in Parisian medicine contributed to Charcot's unaltered celebrity over more than a century

  14. The Cloud Paradigm: Geostable molecules as proxies for surface oxygenation

    NASA Astrophysics Data System (ADS)

    Summons, R. E.; Hallmann, C.

    2011-12-01

    before the great oxidation event. Science 317, 1903-1906. (2007). Bosak T. et al., Morphological record of oxygenic photosynthesis in conical stromatolites. Proc. Natl. Acad. Sci. USA 106:10939-10943 (2009). Kopp, R.E. et al.,The Paleoproterozoic snowball Earth: A climate disaster triggered by the evolution of oxygenic photosynthesis. Proc. Natl. Acad. Sci. USA 102: 11131-11136 (2005). Waldbauer J.R. et al. Late Archean molecular fossils from the Transvaal Supergroup record the antiquity of microbial diversity and aerobiosis. Precambrian Research 169, 28-47 (2008).

  15. Evidence for altered ion transport in Saccharomyces cerevisiae overexpressing human MDR 1 protein.

    PubMed

    Fritz, F; Howard, E M; Hoffman, M M; Roepe, P D

    1999-03-30

    Recently [Hoffman, M. M., and Roepe, P. D. (1997) Biochemistry 36, 11153-11168] we presented evidence for a novel Na+- and Cl--dependent H+ transport process in LR73/hu MDR 1 CHO transfectants that likely explains pHi, volume, and membrane potential changes in eukaryotic cells overexpressing the hu MDR 1 protein. To further explore this process, we have overexpressed human MDR 1 protein in yeast strain 9.3 following a combination of approaches used previously [Kuchler, K., and Thorner, J. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 2302-2306; Ruetz, S., et al. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 11588-11592]. Thus, a truncated hu MDR 1 cDNA was cloned behind a tandem array of sterile 6 (Ste6) and alchohol dehydrogenase (Adh) promoters to create the yeast expression vector pFF1. Valinomycin resistance of intact cells and Western blot analysis with purified yeast plasma membranes confirmed the overexpression of full length, functional, and properly localized hu MDR 1 protein in independently isolated 9.3/pFF1 colonies. Interestingly, relative valinomycin resistance and growth of the 9.3/hu MDR 1 strains are found to strongly depend on the ionic composition of the growth medium. Atomic absorption reveals significant differences in intracellular K+ for 9.3/hu MDR 1 versus control yeast. Transport assays using [3H]tetraphenylphosphonium ([3H]TPP+) reveal perturbations in membrane potential for 9.3/hu MDR 1 yeast that are stimulated by KCl and alkaline pHex. ATPase activity of purified plasma membrane fractions from yeast strains and LR73/hu MDR 1 CHO transfectants constructed previously [Hoffman, M. M., et al. (1996) J. Gen. Physiol. 108, 295-313] was compared. MDR 1 ATPase activity exhibits a higher pH optimum and different salt dependencies, relative to yeast H+ ATPase. Inside-out plasma membrane vesicles (ISOV) fabricated from 9.3/hu MDR 1 and control strains were analyzed for formation of H+ gradients +/- verapamil. Similar pharmacologic profiles are found for

  16. Discussions about the Nature of Science in a Course on the History of Astronomy. (Spanish Title: Discusiones sobre la Naturaleza de la Ciencia en un Curso sobre Historia de la Astronomía.) Discussões sobre a Natureza da Ciência em um Curso sobre a História da Astronomia

    NASA Astrophysics Data System (ADS)

    Pires de Andrade, Victória Flório; L'Astorina, Bruno

    2010-07-01

    There are an increasing number of researches in science education that affirm the importance of discussions on the "nature of science" in basic education level as well as in teacher training. The history of science applied to education is a way to contextualize epistemological discussions, allowing both the understanding of scientific content and learning about science concepts. We present some reasonably consensual definitions on the nature of science that have been widely discussed by the academic community. We show also some episodes in the history of astronomy which can lead to discussions involving some aspects of the nature of science, and how they can do it. Hay un número creciente de investigaciones en la enseñanza de las ciencias que afirman la importancia de debates sobre la "naturaleza de la ciencia" en la educación básica y formación del profesorado. La historia de la ciencia aplicada a la educación es una manera de contextualizar los debates de la epistemología, lo que permite tanto la comprensión de los contenidos científicos como el aprendizaje de conceptos científicos. En esto trabajo, presentamos algunas definiciones bastante consensuales sobre la naturaleza de la ciencia que han sido ampliamente discutidas por la comunidad académica y mostramos cómo algunos episodios en la historia de la astronomía pueden llevar a discusiones sobre algunos aspectos de la naturaleza de la ciencia. Há um número crescente de pesquisas na área de ensino de ciências que afirmam a importância de discussões sobre a "natureza da ciência" na educação básica e na formação de professores. A história da ciência aplicada ao ensino é uma maneira de contextualizar discussões epistemológicas, permitindo tanto a compreensão de conteúdos científicos quanto o aprendizado de noções sobre as ciências. Neste trabalho apresentamos algumas definições razoavelmente consensuais sobre a natureza da ciência que foram amplamente discutidas pela

  17. Variation of Slope-Area Relationship Caused by a Catastrophic Landslide

    NASA Astrophysics Data System (ADS)

    Tseng, Chih-Ming; Lin, Ching-Weei; Dalla Fontana, Giancarlo; Tarolli, Paolo

    2013-04-01

    significantly changed the earth surface. References Montgomery, D.R., Foufoula-Georgiou, E., 1993. Channel network source representation using digital elevation models. Water Resour. Res. 29, 3925-3934. Lin, C.W., Chang, W.S., Liu, S.H., Tsai, T.T., Lee, S.P., Tsang, Y.C., Shieh, C.L., Tseng, C.M., 2011. Landslides triggered by the 7 August 2009 Typhoon Morakot in Southern Taiwan. Engineering Geology 123, 3-12. Tarolli, P., Dalla Fontana, G., 2009. Hillslope-to-valley transition morphology: new opportunities from high resolution DTMs, Geomorphology, 113, 47-56, doi:10.1016/j.geomorph.2009.02.006. Tsou, C.-Y., Feng, Z.-Y., Chigira, M., 2011. Catastrophic landslide induced by Typhoon Morakot, Shiaolin, Taiwan. Geomorphology 127, 166-178, doi:10.1016/j.geomorph.2010.12.013. Tucker, G.E., Bras, R.L., 1998. Hillslope processes, drainage density, and landscape morphology. Water Resour. Res. 34, 2751-2764. Wu, C. H., Chen, S. C., Chou, H. T., (2011). Geomorphologic characteristics of catastrophic landslides during typhoon Morakot in the Kaoping Watershed, Taiwan, Engineering Geology 123(1-2), 13-21, doi: 10.1016/j.enggeo.2011.04.018.

  18. GRID integration of oceanographic remote instrumentation

    NASA Astrophysics Data System (ADS)

    Salon, S.; Bolzon, G.; Mauri, E.; Poulain, P.-M.

    2009-04-01

    OGS. The main goal of DORII is the deployment of an eInfrastructure for those scientific communities where ICT technology and the concept of GRID is perceived as a big opportunity to boost their research but that, at present, results not fully exploited. The oceanographic community may greatly benefit from the resources being offered by the GRID technology, in particular concerning the data driven control/interaction workflow and the post-processing/visualization issues that characterize the remote instruments. [1] N.C. Flemming, S. Vallerga, N. Pinardi, H.W.A. Behrens, G. Manzella, D. Prandle and J.H. Stel (eds), Operational Oceanography - Implementation at the European and Regional Scales, Elsevier Oceanography Vol. 66. Elsevier, Amsterdam (2002). [2] http://poseidon.ogs.trieste.it/sire/medargo [3] P.-M. Poulain, R. Barbanti, J. Font, A. Cruzado, C. Millot, I. Gertman, A. Griffa, A. Molcard, V. Rupolo, S. Le Bras and L. Petit de la Villeon, MedArgo: a drifting profiler program in the Mediterranean Sea, Ocean Science 3, 379-395 (2007). [4] http://www.dorii.eu/home

  19. The Development of Plasma Thrusters and Its Importance for Space Technology and Science Education at University of Brasilia

    NASA Astrophysics Data System (ADS)

    Ferreira, Jose Leonardo; Calvoso, Lui; Gessini, Paolo; Ferreira, Ivan

    Since 2004 The Plasma Physics Laboratory of University of Brasilia (Brazil) is developing Hall Plasma Thurusters for Satellite station keeping and orbit control. The project is supported by CNPq, CAPES, FAP DF and from The Brazillian Space Agency-AEB. The project is part of The UNIESPAÇO Program for Space Activities Development in Brazillian Universities. In this work we are going to present the highlights of this project together with its vital contribution to include University of Brasilia in the Brazillian Space Program. Electric propulsion has already shown, over the years, its great advantages in being used as main and secondary thruster system of several space mission types. Between the many thruster concepts, one that has more tradition in flying real spacecraft is the Hall Effect Thruster (HET). These thrusters, first developed by the USSR in the 1960s, uses, in the traditional design, the radial magnetic field and axial electric field to trap electrons, ionize the gas and accelerate the plasma to therefore generate thrust. In contrast to the usual solution of using electromagnets to generate the magnetic field, the research group of the Plasma Physics Laboratory of University of Brasília has been working to develop new models of HETs that uses combined permanent magnets to generate the necessary magnetic field, with the main objective of saving electric power in the final system design. Since the beginning of this research line it was developed and implemented two prototypes of the Permanent Magnet Hall Thruster (PMHT). The first prototype, called P-HALL1, was successfully tested with the using of many diagnostics instruments, including, RF probe, Langmuir probe, Ion collector and Ion energy analyzer. The second prototype, P-HALL2, is currently under testing, and it’s planned the increasing of the plasma diagnostics and technology analysis, with the inclusion of a thrust balance, mass spectroscopy and Doppler broadening. We are also developing an

  20. Revealing provenance of quartz-rich sandstones using detrital quartz and zircon as source rock indicators: an example from the Cambrian of NW Argentina

    NASA Astrophysics Data System (ADS)

    Augustsson, Carita; Rüsing, Tobias; Adams, Christopher J.; Zimmermann, Udo; Chmiel, Hannah; Kocabayoǧlu, Mert; Büld, Mareike; Berndt, Jasper; Kooijman, Ellen

    2010-05-01

    represent first-cycle sand. In the stratigraphically upper parts (Campanario and Chalhualmayoc formations), the majority of quartz grains are of plutonic origin, whereas few are volcanic. Here, zircons of 550-700 Ma age are dominant. These zircons can partly be traced to igneous rocks of the Sierras Pampeanas. Presently unexposed or eroded rocks around the Mesón Group basin may have contributed further detritus. Alternatively, the Goiás Massif of the Brasília belt in central Brazil may have been an important source area. In that case, the far-travelled zircon grains probably were transported over the Río de la Plata Craton considering the presence of Transamazonian-aged grains (ca. 2 Ga). A higher degree of roundness and multiple growth zones in grains with inherited Transamazonian age suggest that these quartz-rich arenites represent multi-cycle sand. Our study shows that quartz-rich sandstones with a similar petrographic and whole-rock chemical composition throughout a studied sedimentary sequence may contain vital information about detrital transportation path changes.

  1. PREFACE Proceedings of the XIV International Conference on Small-Angle Scattering, SAS-2009

    NASA Astrophysics Data System (ADS)

    King, Stephen; Terrill, Nicholas

    2010-10-01

    scientific heart of the conference comprised 10 plenary sessions, interspersed by 39 'themed' parallel sessions, 2 poster sessions, an afternoon tour of Diamond and ISIS, and a week-long exhibition. There were 144 contributed oral presentations and 308 poster presentations across a total of 21 themes. Over half of all presentations fell under 6 themes: biological systems, colloids and solutions, instrumentation, kinetic and time-resolved measurements, polymers, and surfaces and interfaces. The importance of SAS techniques to the study of biology, materials science and soft matter/nanoscience is clear. The plenary presentations, which covered topics as diverse as advanced analysis techniques, biology, green chemistry, materials science and surfaces, were delivered by Frank Bates, Minnesota, USA, Peter Fratzl, MPI Golm, Germany, Buxing Han, Bejing, China, Julia Kornfield, CIT, USA, Jan Skov Pedersen, Aarhus, Denmark, Moonhor Ree, Pohang, Korea, Mitsuhiro Shibayama, Tokyo, Japan, Robert Thomas, Oxford, UK, Jill Trewhella, Sydney, Australia, and Thomas Zemb, ICSM Bagnols, France. Instigated by representatives of the Belgian and Dutch SAS communities one parallel session was dedicated to a tribute for Michel Koch, the pioneer of so many novel applications of SAXS, who retired after 30 years at the EMBL Hamburg in late 2006. With a supporting cast that included Wim Bras, ESRF, France, Tony Ryan, Sheffield, UK and Joe Zaccai, ILL,France, and watched by former colleague André Gabriel, Michel treated the audience to a fascinating - and at times light-hearted - retrospective of the evolution of synchrotron SAXS. Another parallel session was devoted to the work of the canSAS (Collective Action for Nomadic Small-Angle Scatterers) network of large-facility representatives and instrument scientists in areas such as data file formats, intensity calibration and software development. For further information see http://www.smallangles.net/wgwiki/index.php/canSAS_Working_Groups. A total of

  2. Recent studies on UV radiation in Brazil

    NASA Astrophysics Data System (ADS)

    Correa, M. P.; Ceballos, J. C.; Moregula, A.; Okuno, E.; Fausto, A.; Mol, A.; Santos, J. C.

    2009-04-01

    < 11) and Extreme (UVI ≥ 11). Under clear-sky conditions it has been constantly high in all the Brazilian territories. Maximum UVI recorded: São Paulo (2005-2008): 17.2; Itajubá: 15.5; and Ilhéus: 13.6. Even during winter, measurements constantly reach values around UVI = 6. São Paulo is appreciably touched for these high UV radiation levels to have a population very exposed during its quotidian. In the popular culture, an urban site is not popularly considered as a sunny place. In other words, for a large part of the Brazilian population, São Paulo or Itajubá are perceived as places where the risk to the sun overexposure is relatively low. These recent results are being used as basis for educational programs to teach the population about precautions to be taken during sun exposure. Acknowledgments: This study was supported by FAPEMIG (Minas Gerais, Brazil), FAPESP (São Paulo, Brazil) and CNPq (Brasília, Brazil).

  3. A multi-resolution analysis of lidar-DTMs to identify geomorphic processes from characteristic topographic length scales

    NASA Astrophysics Data System (ADS)

    Sangireddy, H.; Passalacqua, P.; Stark, C. P.

    2013-12-01

    processes. Also, we explore the variability in hillslope length scales as a function of hillslope diffusivity coefficients and critical shear stress in natural landscapes and show that we can infer signatures of dominant geomorphic processes by analyzing characteristic topographic length scales present in topography. References: Beven, K. and Kirkby, M. J.: A physically based variable contributing area model of basin hydrology, Hydrol. Sci. Bull., 24, 43-69, 1979 Howard, A. D. (1994). A detachment-limited model of drainage basin evolution.Water resources research, 30(7), 2261-2285. Passalacqua, P., Do Trung, T., Foufoula Georgiou, E., Sapiro, G., & Dietrich, W. E. (2010). A geometric framework for channel network extraction from lidar: Nonlinear diffusion and geodesic paths. Journal of Geophysical. Research: Earth Surface (2003-2012), 115(F1). Sangireddy, H., Passalacqua, P., Stark, C.P.(2012). Multi-resolution estimation of lidar-DTM surface flow metrics to identify characteristic topographic length scales, EP13C-0859: AGU Fall meeting 2012. Stark, C. P., & Stark, G. J. (2001). A channelization model of landscape evolution. American Journal of Science, 301(4-5), 486-512. Tucker, G. E., Catani, F., Rinaldo, A., & Bras, R. L. (2001). Statistical analysis of drainage density from digital terrain data. Geomorphology, 36(3), 187-202.

  4. Quantifying rind formation and chemical weathering rates in weathering clasts with uranium-series isotopes: a case study from Basse-Terre Island, Guadeloupe

    NASA Astrophysics Data System (ADS)

    Ma, L.; Chabaux, F. J.; Pelt, E.; Granet, M.; Sak, P. B.; Gaillardet, J.; Lebedeva, M.; Brantley, S. L.

    2011-12-01

    Weathering of tropical volcanic islands is rapid because of the reactive nature of the volcanic rock and the hot humid climate. In the tropics, rock fragments in the regolith zone commonly form alteration rinds. Weathering rinds are excellent samples to understand key chemical weathering processes. To quantify rock weathering rates in a tropical climate and to understand the environmental factors that control these rates, we combined a novel U-series isotopic technique with chemical and electron microprobe analyses to study weathering rinds formed at Basse-Terre Island, Guadeloupe. U-series isotopes and element concentrations were analyzed in a basaltic/andesitic weathering rind collected from the Bras David watershed on Basse-Terre Island. From the clast, core and rind samples were obtained by drilling along two linear profiles. Elemental profiles reveal that elemental loss varies in the order of Ca, Na, Sr > K, Mg, Rb > Mn > Si > Ba > Al > Fe, and Ti =0 across the core-rind interface, consistent with relative reactivity of phases in the clast from plagioclase ≈ pyroxene ≈ glass matrix > apatite > ilmenite. Elemental profiles also reveal conservative behavior of Th and external addition of U into the rind during clast weathering. Measured (234U/238U) activity ratios of the rind samples (1.001 to 1.031) are mostly higher than the core samples (average at ~1.003). Measured (238U/232Th) and (230Th/232Th) activity ratios of the core and rind samples range from 0.973 to 1.817, and 0.971 to 1.375, respectively. Most importantly, both (238U/232Th) and (230Th/232Th) activity ratios increase systematically from the core into the weathering rind for the two profiles. The elemental profiles and electronic microprobe observations suggest that weathering reactions include dissolution of pyroxene, plagioclase, and glass matrix, and formation of Fe oxyhydroxides, gibbsite and minor kaolinite. The dissolution of plagioclase leads to significant porosity growth within the rind

  5. Geostatistical Sampling Methods for Efficient Uncertainty Analysis in Flow and Transport Problems

    NASA Astrophysics Data System (ADS)

    Liodakis, Stylianos; Kyriakidis, Phaedon; Gaganis, Petros

    2015-04-01

    surface of a M-dimensional, unit radius hyper-sphere, (ii) relocating the N points on a representative set of N hyper-spheres of different radii, and (iii) transforming the coordinates of those points to lie on N different hyper-ellipsoids spanning the multivariate Gaussian distribution. The above method is applied in a dimensionality reduction context by defining flow-controlling points over which representative sampling of hydraulic conductivity is performed, thus also accounting for the sensitivity of the flow and transport model to the input hydraulic conductivity field. The performance of the various stratified sampling methods, LH, SL, and ME, is compared to that of SR sampling in terms of reproduction of ensemble statistics of hydraulic conductivity and solute concentration for different sample sizes N (numbers of realizations). The results indicate that ME sampling constitutes an equally if not more efficient simulation method than LH and SL sampling, as it can reproduce to a similar extent statistics of the conductivity and concentration fields, yet with smaller sampling variability than SR sampling. References [1] Gutjahr A.L. and Bras R.L. Spatial variability in subsurface flow and transport: A review. Reliability Engineering & System Safety, 42, 293-316, (1993). [2] Helton J.C. and Davis F.J. Latin hypercube sampling and the propagation of uncertainty in analyses of complex systems. Reliability Engineering & System Safety, 81, 23-69, (2003). [3] Switzer P. Multiple simulation of spatial fields. In: Heuvelink G, Lemmens M (eds) Proceedings of the 4th International Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences, Coronet Books Inc., pp 629?635 (2000).

  6. Localization of genes encoding three distinct flavin-containing monooxygenases to human chromosome 1q

    SciTech Connect

    Shephard, E.A.; Fox, M.F.; Povey, S. ); Dolphin, C.T.; Phillips, I.R.; Smith, R. )

    1993-04-01

    The authors have used the polymerase chain reaction to map the gene encoding human flavin-containing monooxygenase (FMO) form II (N. Lomri, Q. Gu, and J. R. Cashman, 1992, Proc. Natl. Acad. Sci. USA 89: 1685--1689) to chromosome 1. They propose the designation FMO3 for this gene as it is the third FMO gene to be mapped. The two other human FMO genes identified to date, FMO1 and FMO2, are also located on chromosome 1 (C. Dolphin, E. A. Shephard, S. Povey, C. N. A. Palmer, D. M. Ziegler, R. Ayesh, R. L. Smith, and 1. R. Phillips, 1991, J. Biol. Chem. 266: 12379--12385; C. Dolphin, E. A. Shephard, S. F. Povey, R. L. Smith, and I. R. Phillips, 1992, Biochem. J. 286: 261--267). The localization of FMO1, FMO2, and FMO3 has been refined to the long arm of chromosome 1. Analysis of human metaphase chromosomes by in situ hybridization confirmed the mapping of FMO1 and localized this gene more precisely to 1 q23-q25. 28 refs., 3 figs., 2 tabs.

  7. Absence of geochemical evidence for an impact event at the Bølling–Allerød/Younger Dryas transition

    PubMed Central

    Paquay, François S.; Goderis, Steven; Ravizza, Greg; Vanhaeck, Frank; Boyd, Matthew; Surovell, Todd A.; Holliday, Vance T.; Haynes, C. Vance; Claeys, Philippe

    2009-01-01

    High concentrations of iridium have been reported in terrestrial sediments dated at 12.9 ka and are interpreted to support an extraterrestrial impact event as the cause of the observed extinction in the Rancholabrean fauna, changes in the Paleoindian cultures, and the onset of the Younger Dryas cooling [Firestone RB, et al. (2007) Proc Natl Acad Sci USA 104:16016–16021]. Here, we report platinum group element (PGE: Os, Ir, Ru, Rh, Pt, Pd), gold (Au) concentrations, and 187Os/188Os ratios in time-equivalent terrestrial, lacustrine, and marine sections to seek robust evidence of an extraterrestrial contribution. First, our results do not reproduce the previously reported elevated Ir concentrations. Second, 187Os/188Os isotopic ratios in the sediment layers investigated are similar to average crustal values, indicating the absence of a significant meteoritic Os contribution to these sediments. Third, no PGE anomalies distinct from crustal signatures are present in the marine record in either the Gulf of California (DSDP 480, Guaymas Basin) or the Cariaco Basin (ODP 1002C). Our data show no evidence of an extraterrestrial (ET)-PGE enrichment anomaly in any of the investigated depositional settings investigated across North America and in one section in Belgium. The lack of a clear ET-PGE signature in this sample suite is inconsistent with the impact of a large chondritic projectile at the Bølling–Allerød/Younger Dryas transition. PMID:20007789

  8. Binding isotherms of sodium dodecyl sulfate to protein polypeptides with special reference to SDS-polyacylamide gel electrophoresis.

    PubMed

    Takagi, T; Tsujii, K; Shirahama, K

    1975-05-01

    To clarify the mode of interaction between sodium dodecyl sulfate (SDS) and protein polypeptides with special reference to SDS-polyacrylamide gel electrophoresis, the binding of SDS to several protein polypeptides was investigated by the equilibrium dialysis technique. Each of the binding isotherms was characterized by the presence of two phases: an initial gradual increase in the amount of binding to 0.3-0.6 g/g (first phase) and a subsequent steep increase to 1.2-1.5 g/g (second phase). The binding was completed at a concentration of SDS below the critical micelle concentration. Throughout the first and second phases, the isotherms obtained were different for each kind of protein. On the basis of experiments with bovine serum albumin and ribonuclease (EC 3.1.4.22], the isotherms were profoundly affected by the method used for modification of the sulfhydryl groups. The claim of Reynolds and Tanford (Proc. Natl, Acad. Sci. U.S., 66, 1002 (1970)) that the isotherms are virtually identical for many kinds of proteins was not supported by the present data. Changes in the gross and local conformations were examined with reference to the isotherms by measurements of CD spectrum, free boundary electrophoresis, and gel filtration. The results obtained were collectively interpreted based on the model of SDS-protein polypeptide complexes proposed by the present authors (J. Biochem., 75, 309 (1974)). PMID:1158859

  9. Understanding the similarity in thermophoresis between single- and double-stranded DNA or RNA

    NASA Astrophysics Data System (ADS)

    Reichl, Maren; Herzog, Mario; Greiss, Ferdinand; Wolff, Manuel; Braun, Dieter

    2015-06-01

    Thermophoresis is the movement of molecules in a temperature gradient. For aqueous solutions its microscopic basis is debated. Understanding thermophoresis for this case is, however, important since it proved very useful to detect the binding affinity of biomolecules and since thermophoresis could have played an important role in early molecular evolution. Here we discuss why the thermophoresis of single- and double-stranded oligonucleotides - DNA and RNA - is surprisingly similar. This finding is understood by comparing the spherical capacitor model for single-stranded species with the case of a rod-shaped model for double-stranded oligonucleotides. The approach describes thermophoresis of DNA and RNA with fitted effective charges consistent with electrophoresis measurements and explains the similarity between single- and double-stranded species. We could not confirm the sign change for the thermophoresis of single- versus double-stranded DNA in crowded solutions containing polyethylene glycol [Y. T. Maeda, T. Tlusty, and A. Libchaber, Proc. Natl. Acad. Sci. USA 109, 17972 (2012), 10.1073/pnas.1215764109], but find a salt-independent offset while the Debye length dependence still satisfies the capacitor model. Overall, the analysis documents the continuous progress in the microscopic understanding of thermophoresis.

  10. Ravens, New Caledonian crows and jackdaws parallel great apes in motor self-regulation despite smaller brains.

    PubMed

    Kabadayi, Can; Taylor, Lucy A; von Bayern, Auguste M P; Osvath, Mathias

    2016-04-01

    Overriding motor impulses instigated by salient perceptual stimuli represent a fundamental inhibitory skill. Such motor self-regulation facilitates more rational behaviour, as it brings economy into the bodily interaction with the physical and social world. It also underlies certain complex cognitive processes including decision making. Recently, MacLean et al. (MacLean et al. 2014 Proc. Natl Acad. Sci. USA 111, 2140-2148. (doi:10.1073/pnas.1323533111)) conducted a large-scale study involving 36 species, comparing motor self-regulation across taxa. They concluded that absolute brain size predicts level of performance. The great apes were most successful. Only a few of the species tested were birds. Given birds' small brain size-in absolute terms-yet flexible behaviour, their motor self-regulation calls for closer study. Corvids exhibit some of the largest relative avian brain sizes-although small in absolute measure-as well as the most flexible cognition in the animal kingdom. We therefore tested ravens, New Caledonian crows and jackdaws in the so-called cylinder task. We found performance indistinguishable from that of great apes despite the much smaller brains. We found both absolute and relative brain volume to be a reliable predictor of performance within Aves. The complex cognition of corvids is often likened to that of great apes; our results show further that they share similar fundamental cognitive mechanisms. PMID:27152224

  11. Cooperation between catalytic and DNA binding domains enhances thermostability and supports DNA synthesis at higher temperatures by thermostable DNA polymerases.

    PubMed

    Pavlov, Andrey R; Pavlova, Nadejda V; Kozyavkin, Sergei A; Slesarev, Alexei I

    2012-03-13

    We have previously introduced a general kinetic approach for comparative study of processivity, thermostability, and resistance to inhibitors of DNA polymerases [Pavlov, A. R., et al. (2002) Proc. Natl. Acad. Sci. U.S.A.99, 13510-13515]. The proposed method was successfully applied to characterize hybrid DNA polymerases created by fusing catalytic DNA polymerase domains with various sequence-nonspecific DNA binding domains. Here we use the developed kinetic analysis to assess basic parameters of DNA elongation by DNA polymerases and to further study the interdomain interactions in both previously constructed and new chimeric DNA polymerases. We show that connecting helix-hairpin-helix (HhH) domains to catalytic polymerase domains can increase thermostability, not only of DNA polymerases from extremely thermophilic species but also of the enzyme from a faculatative thermophilic bacterium Bacillus stearothermophilus. We also demonstrate that addition of Topo V HhH domains extends efficient DNA synthesis by chimerical polymerases up to 105 °C by maintaining processivity of DNA synthesis at high temperatures. We found that reversible high-temperature structural transitions in DNA polymerases decrease the rates of binding of these enzymes to the templates. Furthermore, activation energies and pre-exponential factors of the Arrhenius equation suggest that the mechanism of electrostatic enhancement of diffusion-controlled association plays a minor role in binding of templates to DNA polymerases. PMID:22320201

  12. Comparative hydrogen-deuterium exchange for a mesophilic vs thermophilic dihydrofolate reductase at 25 °C: identification of a single active site region with enhanced flexibility in the mesophilic protein.

    PubMed

    Oyeyemi, Olayinka A; Sours, Kevin M; Lee, Thomas; Kohen, Amnon; Resing, Katheryn A; Ahn, Natalie G; Klinman, Judith P

    2011-09-27

    The technique of hydrogen-deuterium exchange coupled to mass spectrometry (HDX-MS) has been applied to a mesophilic (E. coli) dihydrofolate reductase under conditions that allow direct comparison to a thermophilic (B. stearothermophilus) ortholog, Ec-DHFR and Bs-DHFR, respectively. The analysis of hydrogen-deuterium exchange patterns within proteolytically derived peptides allows spatial resolution, while requiring a series of controls to compare orthologous proteins with only ca. 40% sequence identity. These controls include the determination of primary structure effects on intrinsic rate constants for HDX as well as the use of existing 3-dimensional structures to evaluate the distance of each backbone amide hydrogen to the protein surface. Only a single peptide from the Ec-DHFR is found to be substantially more flexible than the Bs-DHFR at 25 °C in a region located within the protein interior at the intersection of the cofactor and substrate-binding sites. The surrounding regions of the enzyme are either unchanged or more flexible in the thermophilic DHFR from B. stearothermophilus. The region with increased flexibility in Ec-DHFR corresponds to one of two regions previously proposed to control the enthalpic barrier for hydride transfer in Bs-DHFR [Oyeyemi et al. (2010) Proc. Natl. Acad. Sci. U.S.A. 107, 10074]. PMID:21859100

  13. Spin-Exchange Optical Pumping of Solid Alkali Compounds

    NASA Astrophysics Data System (ADS)

    Patton, Brian; Ishikawa, Kiyoshi; Jau, Yuan-Yu; Happer, William

    2007-03-01

    Spin-exchange optical pumping of noble gases has been used for many years to create highly non-equilibrium spin populations, with applications ranging from fundamental physics[1] to medical imaging[2]. In this procedure, angular momentum is transferred from circularly-polarized laser light to the electron spins of an alkali vapor and ultimately to the nuclei of a gas such as ^3He or ^129Xe. Here we show experimentally that a similar process can be used to polarize the nuclei of a solid film of cesium hydride which coats the walls of an optical pumping cell. We present nuclear magnetic resonance (NMR) data which demonstrate that the nuclear polarization of ^133Cs in CsH can be enhanced above the Boltzmann limit in a 9.4-Tesla magnetic field. Possible spin-exchange mechanisms will be discussed, as well as the extension of this technique to other compounds. [1] T. W. Kornack, R. K. Ghosh, and M. V. Romalis, Phys. Rev. Lett. 95, 23080 (2005). [2] M. S. Conradi, D. A. Yablonskiy, et al., Acad. Radiol. 12, 1406 (2005).

  14. Self-consistent-field treatment of the dissociation of bound molecules in solution

    NASA Astrophysics Data System (ADS)

    Galindo, Carlos E.; Sokoloff, J. B.

    1993-10-01

    We present calculations of the dissociation of hydrogen-bonded molecules in solution, using a mean-field theory based on a variational method [N.R. Werthamer, in Rare Gas Solids, edited by M. L. Klein and J. A. Venables (Academic, New York, 1976), Vol. I, Chap. V]. The solvent is accounted for by a dielectric constant, and the effect of salt ions in solution on hydrogen bonding is treated by means of Soumpasis's potential of mean force [D. M. Soumpasis, Proc. Natl. Acad. Sci. USA 81, 5116 (1984)]. At high concentrations, the effect of salt ions on the interaction is dominated by an effective temperature-dependent interaction, which results from a position-dependent term in the entropy resulting from the hard-core volume exclusion. In addition to describing the dissociation transition, this procedure provides the temperature and electrolyte-concentration dependence of the vibrational spectrum. The sample calculation by Gao and Prohofsky [J. Chem. Phys. 80, 2242 (1984)] of two ammonia molecules bound together by a hydrogen bond in a vacuum is reconsidered in an ionic solution. Our method is also applied to the treatment of the hydrogen-bond dissociation of a pair of water molecules and of a hydrogen-bonded pair of negative point-charge ions. The latter is intended as a simple model for the dissociation of a single hydrogen-bonded base-pair unit of a DNA double helix.

  15. Understanding fast macroscale fracture from microcrack post mortem patterns

    NASA Astrophysics Data System (ADS)

    Scheibert, J.; Guerra, C.; Bonamy, D.; Dalmas, D.

    2012-04-01

    Dynamic crack propagation drives catastrophic solid failures. In many amorphous brittle materials, sufficiently fast crack growth involves small-scale, high-frequency microcracking damage localized near the crack tip [1]. The ultra-fast dynamics of microcrack nucleation, growth and coalescence is inaccessible experimentally and fast crack propagation was therefore studied only as a macroscale average. We will see how to overcome this limitation in polymethylmethacrylate, the archetype of brittle amorphous materials: We reconstructed the complete spatio-temporal microcracking dynamics, with micrometer / nanosecond resolution, through post mortem analysis of the fracture surfaces [2]. We found that all individual microcracks propagate at the same low, load-independent, velocity. Collectively, the main effect of microcracks is not to slow down fracture by increasing the energy required for crack propagation, as commonly believed, but on the contrary to boost the macroscale velocity through an acceleration factor selected on geometric grounds. Our results emphasize the key role of damage-related internal variables in the selection of macroscale fracture dynamics. [1] J. Scheibert, C. Guerra, F. Célarié, D. Dalmas, D. Bonamy, Phys. Rev. Lett. 104, 045501 (2010) [2] C. Guerra, J. Scheibert, D. Bonamy, D. Dalmas, Proc. Natl. Acad. Sci. USA 109, 390 (2012)

  16. Modelling the 2-kinase domain of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase on adenylate kinase.

    PubMed Central

    Bertrand, L; Vertommen, D; Depiereux, E; Hue, L; Rider, M H; Feytmans, E

    1997-01-01

    Simultaneous multiple alignment of available sequences of the bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase revealed several segments of conserved residues in the 2-kinase domain. The sequence of the kinase domain was also compared with proteins of known three-dimensional structure. No similarity was found between the kinase domain of 6-phosphofructo-2-kinase and 6-phosphofructo-1-kinase. This questions the modelling of the 2-kinase domain on bacterial 6-phosphofructo-1-kinase that has previously been proposed [Bazan, Fletterick and Pilkis (1989) Proc. Natl. Acad. Sci. U.S.A. 86, 9642-9646]. However, sequence similarities were found between the 2-kinase domain and several nucleotide-binding proteins, the most similar being adenylate kinase. A structural model of the 2-kinase domain based on adenylate kinase is proposed. It accommodates all the results of site-directed mutagenesis studies carried out to date on residues in the 2-kinase domain. It also allows residues potentially involved in catalysis and/or substrate binding to be predicted. PMID:9032445

  17. A three-dimensional statistical mechanical model of folding double-stranded chain molecules

    NASA Astrophysics Data System (ADS)

    Zhang, Wenbing; Chen, Shi-Jie

    2001-05-01

    Based on a graphical representation of intrachain contacts, we have developed a new three-dimensional model for the statistical mechanics of double-stranded chain molecules. The theory has been tested and validated for the cubic lattice chain conformations. The statistical mechanical model can be applied to the equilibrium folding thermodynamics of a large class of chain molecules, including protein β-hairpin conformations and RNA secondary structures. The application of a previously developed two-dimensional model to RNA secondary structure folding thermodynamics generally overestimates the breadth of the melting curves [S-J. Chen and K. A. Dill, Proc. Natl. Acad. Sci. U.S.A. 97, 646 (2000)], suggesting an underestimation for the sharpness of the conformational transitions. In this work, we show that the new three-dimensional model gives much sharper melting curves than the two-dimensional model. We believe that the new three-dimensional model may give much improved predictions for the thermodynamic properties of RNA conformational changes than the previous two-dimensional model.

  18. Proof of physical exchange of genes on the chromosomes.

    PubMed

    Coe, Edward; Kass, Lee B

    2005-05-10

    Seventy-five years ago, a convincing demonstration that the genes were physically aligned along the chromosome was lacking. Harriet Creighton (1909-2004) and Barbara McClintock (1902-1992) [Creighton, H. B. & McClintock, B. (1931) Proc. Natl. Acad. Sci. USA 17, 492-497] showed by an elegantly simple experiment in 1931 that exchange between genes was accompanied by exchange of cytological, i.e., physical, parts of chromosomes. The work has been acclaimed as one of the great experiments in biology. Creighton's doctoral dissertation under McClintock's mentorship provided the basis for the landmark paper, which was unique in merging cytological with genetic data. A companion paper by McClintock, printed and bound back-to-back with the joint paper, set the essential stage with data on the cytological and genetic features that Creighton applied. Following directly from this work, and leading to today's recognition that the genome is a graspable entity, was the knowledge that the genes could be studied as components of a linear structure, the chromosome. Here, we review the data surrounding the Creighton and McClintock paper and provide a perspective on the significance of their findings. PMID:15867161

  19. A comparison of auditory brainstem responses across diving bird species.

    PubMed

    Crowell, Sara E; Wells-Berlin, Alicia M; Carr, Catherine E; Olsen, Glenn H; Therrien, Ronald E; Yannuzzi, Sally E; Ketten, Darlene R

    2015-08-01

    There is little biological data available for diving birds because many live in hard-to-study, remote habitats. Only one species of diving bird, the black-footed penguin (Spheniscus demersus), has been studied in respect to auditory capabilities (Wever et al., Proc Natl Acad Sci USA 63:676-680, 1969). We, therefore, measured in-air auditory threshold in ten species of diving birds, using the auditory brainstem response (ABR). The average audiogram obtained for each species followed the U-shape typical of birds and many other animals. All species tested shared a common region of the greatest sensitivity, from 1000 to 3000 Hz, although audiograms differed significantly across species. Thresholds of all duck species tested were more similar to each other than to the two non-duck species tested. The red-throated loon (Gavia stellata) and northern gannet (Morus bassanus) exhibited the highest thresholds while the lowest thresholds belonged to the duck species, specifically the lesser scaup (Aythya affinis) and ruddy duck (Oxyura jamaicensis). Vocalization parameters were also measured for each species, and showed that with the exception of the common eider (Somateria mollisima), the peak frequency, i.e., frequency at the greatest intensity, of all species' vocalizations measured here fell between 1000 and 3000 Hz, matching the bandwidth of the most sensitive hearing range. PMID:26156644

  20. Photoinduced Electron Transfer in DNA: Charge Shift Dynamics Between 8-Oxo-Guanine Anion and Adenine.

    PubMed

    Zhang, Yuyuan; Dood, Jordan; Beckstead, Ashley A; Li, Xi-Bo; Nguyen, Khiem V; Burrows, Cynthia J; Improta, Roberto; Kohler, Bern

    2015-06-18

    Femtosecond time-resolved IR spectroscopy is used to investigate the excited-state dynamics of a dinucleotide containing an 8-oxoguanine anion at the 5'-end and neutral adenine at the 3'-end. UV excitation of the dinucleotide transfers an electron from deprotonated 8-oxoguanine to its π-stacked neighbor adenine in less than 1 ps, generating a neutral 8-oxoguanine radical and an adenine radical anion. These species are identified by the excellent agreement between the experimental and calculated IR difference spectra. The quantum efficiency of this ultrafast charge shift reaction approaches unity. Back electron transfer from the adenine radical anion to the 8-oxguanine neutral radical occurs in 9 ps, or approximately 6 times faster than between the adenine radical anion and the 8-oxoguanine radical cation (Zhang, Y. et al. Proc. Natl. Acad. Sci. U.S.A. 2014, 111, 11612-11617). The large asymmetry in forward and back electron transfer rates is fully rationalized by semiclassical nonadiabatic electron transfer theory. Forward electron transfer is ultrafast because the driving force is nearly equal to the reorganization energy, which is estimated to lie between 1 and 2 eV. Back electron transfer is highly exergonic and takes place much more slowly in the Marcus inverted region. PMID:25660103

  1. Studying the Replicative Life Span of Yeast Cells

    PubMed Central

    Sinclair, David A.

    2016-01-01

    The budding yeast Saccharomyces cerevisiae is a useful model for elucidating the pathways that control life span and the influence of environmental factors, such as calorie restriction (CR). For 75 years, CR has been studied for its ability to delay diseases of aging in mammals, from cancer to cardiovascular disease (McCay et al., Nutr Rev 33:241–243, 1975). In many other species, reducing calorie intake extends life span, including unicellular organisms (Jiang et al., FASEB J 14:2135–2137, 2000; Lin et al., Science 289:2126–2128, 2000), invertebrates (Rogina and Helfand, Proc Natl Acad Sci U S A 101:15998–16003, 2004), and rodents (Martín-Montalvo et al., Oncogene 30:505–520, 2011). Here we describe how to calorically restrict yeast cells, the methods used to determine the replicative life span (RLS) of budding yeast cells, how to selectively kill daughter cells using the mother enrichment program (MEP), how to measure recombination frequency at the rDNA locus, how to isolate large quantities of old cells, and how to analyze the circular forms of DNA known as extrachromosomal rDNA circles (ERCs), a cause of aging in S. cerevisiae (Petes, Cell 19:765–774, 1980; Sinclair and Guarente, Cell 91:1033–1042, 1997; Defossez et al., Mol Cell 3:447–455, 1999). PMID:23929097

  2. Multiple critical points and liquid liquid equilibria from the van der Waals like equations of state

    NASA Astrophysics Data System (ADS)

    Artemenko, Sergey; Lozovsky, Taras; Mazur, Victor

    2008-06-01

    The principal aim of this work is a comprehensive analysis of the phase diagram of water via the van der Waals like equations of state (EoSs) which are considered as superpositions of repulsive and attractive forces. We test more extensively the modified van der Waals EoS (MVDW) proposed by Skibinski et al (2004 Phys. Rev. E 69 061206) and refine this model by introducing instead of the classical van der Waals repulsive term a very accurate hard sphere EoS over the entire stable and metastable regions (Liu 2006 Preprint cond-mat/0605392). It was detected that the simplest form of MVDW EoS displays a complex phase behavior, including three critical points, and identifies four fluid phases (gas, low density liquid (LDL), high density liquid (HDL), and very high density liquid (VHDL)). Moreover the experimentally observed (Mallamace et al 2007 Proc. Natl Acad. Sci. USA 104 18387) anomalous behavior of the density of water in the deeply supercooled region (a density minimum) is reproduced by the MWDW EoS. An improvement of the repulsive part does not change the topological picture of the phase behavior of water in the wide range of thermodynamic variables. The new parameters set for second and third critical points are recognized by thorough analysis of experimental data for the loci of thermodynamic response function extrema.

  3. Role of interference in the photosynthetic heat engine

    NASA Astrophysics Data System (ADS)

    Xu, Y. Y.; Liu, J.

    2014-11-01

    The observation of quantum coherence in pigment-protein complexes has attracted considerable interest. One such endeavor entails applying a quantum heat engine to model the photosynthetic reaction center, but the definition of work used is inconsistent with that defined in quantum thermodynamics. Using the definition of work proposed in Weimer et al. [Europhys. Lett. 83, 30008 (2008), 10.1209/0295-5075/83/30008], we investigated two proposals for enhancing the performance of the photosynthetic reaction center. In proposal A, which is similar to that in Dorfman et al. [Proc. Natl. Acad. Sci. USA 110, 2746 (2013), 10.1073/pnas.1212666110], we found that the power and current-voltage characteristic of the heat engine can be increased by Fano interference but the efficiency cannot. In proposal B, which is similar to that in Creatore et al. [Phys. Rev. Lett. 111, 253601 (2013), 10.1103/PhysRevLett.111.253601], we found that the mechanism of strengthening the performance of the heat engine is invalid; i.e., the dipole-dipole interaction between two electron donors could not increase the power, efficiency, or current-voltage characteristic.

  4. Clonal reproduction in fungi

    PubMed Central

    Taylor, John W.; Hann-Soden, Christopher; Branco, Sara; Sylvain, Iman; Ellison, Christopher E.

    2015-01-01

    Research over the past two decades shows that both recombination and clonality are likely to contribute to the reproduction of all fungi. This view of fungi is different from the historical and still commonly held view that a large fraction of fungi are exclusively clonal and that some fungi have been exclusively clonal for hundreds of millions of years. Here, we first will consider how these two historical views have changed. Then we will examine the impact on fungal research of the concept of restrained recombination [Tibayrenc M, Ayala FJ (2012) Proc Natl Acad Sci USA 109 (48):E3305–E3313]. Using animal and human pathogenic fungi, we examine extrinsic restraints on recombination associated with bottlenecks in genetic variation caused by geographic dispersal and extrinsic restraints caused by shifts in reproductive mode associated with either disease transmission or hybridization. Using species of the model yeast Saccharomyces and the model filamentous fungus Neurospora, we examine intrinsic restraints on recombination associated with mating systems that range from strictly clonal at one extreme to fully outbreeding at the other and those that lie between, including selfing and inbreeding. We also consider the effect of nomenclature on perception of reproductive mode and a means of comparing the relative impact of clonality and recombination on fungal populations. Last, we consider a recent hypothesis suggesting that fungi thought to have the most severe intrinsic constraints on recombination actually may have the fewest. PMID:26195774

  5. Why Quantum Coherence Is Not Important in the Fenna-Matthews-Olsen Complex.

    PubMed

    Wilkins, David M; Dattani, Nikesh S

    2015-07-14

    We develop and present an improvement to the conventional technique for solving the Hierarchical Equations of Motion (HEOM), which can reduce the memory cost by up to 75% while retaining the same (or even better) convergence rate and accuracy. This allows for a full calculation of the population dynamics of the 24-site FMO trimer for long time scales with very little effort, and we present the first fully converged, exact results for the 7-site subsystem of the monomer, and for the full 24-site trimer. We then show where our exact 7-site results deviate from the approximation of Ishizaki and Fleming [A. Ishizaki and G. R. Fleming, Proc. Natl. Acad. Sci. U.S.A., 2009, 106, 17255]. Our exact results are then compared to calculations using the incoherent Förster theory, and it is found that the time scale of energy transfer is roughly the same, regardless of whether or not coherence is considered. This means that coherence is not likely to improve the efficiency of the transfer. In fact, the incoherent theory often tends to overpredict the rates of energy transfer, suggesting that, in some cases, quantum coherence may actually slow the photosynthetic process. PMID:26575775

  6. DNA binding properties of the Saccharomyces cerevisiae DAT1 gene product.

    PubMed

    Reardon, B J; Gordon, D; Ballard, M J; Winter, E

    1995-12-11

    The DAT1 gene of Saccharomyces cerevisiae encodes a DNA binding protein (Dat1p) that specifically recognizes the minor groove of non-alternating oligo(A).oligo(T) tracts. Sequence-specific recognition requires arginine residues found within three perfectly repeated pentads (G-R-K-P-G) of the Dat1p DNA binding domain [Reardon, B. J., Winters, R. S., Gordon, D., and Winter, E. (1993) Proc. Natl. Acad. Sci. USA 90, 11327-1131]. This report describes a rapid and simple method for purifying the Dat1p DNA binding domain and the biochemical characterization of its interaction with oligo(A).oligo(T) tracts. Oligonucleotide binding experiments and the characterization of yeast genomic Dat1p binding sites show that Dat1p specifically binds to any 11 base sequence in which 10 bases conform to an oligo(A).oligo(T) tract. Binding studies of different sized Dat1p derivatives show that the Dat1p DNA binding domain can function as a monomer. Competition DNA binding assays using poly(I).poly(C), demonstrate that the minor groove oligo(A).oligo(T) constituents are not sufficient for high specificity DNA binding. These data constrain the possible models for Dat1p/oligo(A).oligo(T) complexes, suggest that the DNA binding domain is in an extended structure when complexed to its cognate DNA, and show that Dat1p binding sites are more prevalent than previously thought. PMID:8532535

  7. Speculations on the origin of life and thermophily: Review of available information on reverse gyrase suggests that hyperthermophilic procaryotes are not so primitive

    NASA Astrophysics Data System (ADS)

    Forterre, Patrick; Confalonier, Fabrice; Charbonnier, Franck; Duguet, Michel

    1995-06-01

    All present-day hyperthermophiles studied so far (eitherBacteria orArchaea) contain a unique DNA topoisomerase, reverse gyrase, which probably helps to stabilize genomic DNA at high temperature. Herein the data relating this enzyme is reviewed and discussed from the perspective of the nature of the last detectable common ancestor and the origin of life. The sequence of the gene encoding reverse gyrase from an archaeon,Sulfolobus acidocaldarius, suggests that this enzyme contains both a helicase and a topoisomerase domains (Confalonieriet al.,Proc. Natl. Acad. Sci., 1993, 90, 4735). Accordingly, it has been proposed that reverse gyrase originated by the fusion of DNA helicase and DNA topoisomerase genes. If reverse gyrase is essential for life at high temperature, its composite structure suggests that DNA helicases and topoisomerases appeared independently and first evolved in a mesophilic world. Such scenario contradicts the hypothesis that a direct link connects present day hyperthermophiles to a hot origin of life. We discuss different patterns for the early cellular evolution in which reverse gyrase appeared either before the emergence of the last common ancestor ofArchaea, Bacteria andEucarya, or in a lineage common to the two procaryotic domains. The latter scenario could explain why all today hyperthermophiles are procaryotes.

  8. Humidity sensation, cockroaches, worms, and humans: are common sensory mechanisms for hygrosensation shared across species?

    PubMed

    Filingeri, Davide

    2015-08-01

    Although the ability to detect humidity (i.e., hygrosensation) represents an important sensory attribute in many animal species (including humans), the neurophysiological and molecular bases of such sensory ability remain largely unknown in many animals. Recently, Russell and colleagues (Russell J, Vidal-Gadea AG, Makay A, Lanam C, Pierce-Shimomura JT. Proc Natl Acad Sci USA 111: 8269-8274, 2014) provided for the first time neuromolecular evidence for the sensory integration of thermal and mechanical sensory cues which underpin the hygrosensation strategy of an animal (i.e., the free-living roundworm Caenorhabditis elegans) that lacks specific sensory organs for humidity detection (i.e., hygroreceptors). Due to the remarkable similarities in the hygrosensation transduction mechanisms used by hygroreceptor-provided (e.g., insects) and hygroreceptor-lacking species (e.g., roundworms and humans), the findings of Russell et al. highlight potentially universal mechanisms for humidity detection that could be shared across a wide range of species, including humans. PMID:25318766

  9. Humidity sensation, cockroaches, worms, and humans: are common sensory mechanisms for hygrosensation shared across species?

    PubMed Central

    2014-01-01

    Although the ability to detect humidity (i.e., hygrosensation) represents an important sensory attribute in many animal species (including humans), the neurophysiological and molecular bases of such sensory ability remain largely unknown in many animals. Recently, Russell and colleagues (Russell J, Vidal-Gadea AG, Makay A, Lanam C, Pierce-Shimomura JT. Proc Natl Acad Sci USA 111: 8269–8274, 2014) provided for the first time neuromolecular evidence for the sensory integration of thermal and mechanical sensory cues which underpin the hygrosensation strategy of an animal (i.e., the free-living roundworm Caenorhabditis elegans) that lacks specific sensory organs for humidity detection (i.e., hygroreceptors). Due to the remarkable similarities in the hygrosensation transduction mechanisms used by hygroreceptor-provided (e.g., insects) and hygroreceptor-lacking species (e.g., roundworms and humans), the findings of Russell et al. highlight potentially universal mechanisms for humidity detection that could be shared across a wide range of species, including humans. PMID:25318766

  10. Effect of protein kinase P on phosphorylations catalyzed by the epidermal growth factor.

    PubMed Central

    Abdel-Ghany, M; Kole, H K; Racker, E

    1987-01-01

    Protein kinase P (PK-P) activated by histones or certain other basic compounds has been purified previously from yeast [Yanagita, Y., Abdel-Ghany, M., Raden, D., Nelson, N. & Racker, E. (1987) Proc. Natl. Acad. Sci. USA 84, 925-929]. It is shown here that PK-P is present in solubilized membranes of A-431 carcinoma cells where it changes the epidermal growth factor (EGF) receptor kinase activity. Polylysine, a weak PK-P activator, inhibited the autophosphorylation of the EGF receptor both in the absence and presence of EGF. Increased PK-P activity induced by histone 1, a potent activator, gave rise to increased autophosphorylation of the EGF receptor as well as phosphorylation at tyrosine residues of numerous other endogenous membrane components. The stimulation by histone was particularly striking in the presence of EGF. A similar stimulation was achieved with polylysine and EGF on addition of yeast PK-P. However, addition of yeast PK-P in the presence of histone 1 markedly inhibited the EGF-stimulated phosphorylation of endogenous membrane proteins. We conclude from these results that the effect of PK-P on the EGF receptor takes place in three phases: at low levels PK-P inhibits the autophosphorylation, at intermediate levels it stimulates the autophosphorylation as well as the EGF-dependent phosphorylation of numerous other membrane proteins, and at high levels it inhibits the phosphorylation of these proteins. Images PMID:3501120

  11. Effects of Silver and Other Metals on the Cytoskeleton

    NASA Technical Reports Server (NTRS)

    Conrad, Gary W.

    1997-01-01

    Directly or indirectly, trace concentrations of silver ion (Ag(+)) stabilize microtubules (Conrad, A.H., et al. Cell Motil. & Cytoskel. 27:117-132), as does taxol (Conrad, A.H., et al. J. Exp. Zool. 262:154-165), an effect with major consequences for cellular shape changes and development. Polymerization of microtubules is gravity-sensitive (Tabony and Job, Proc. Natl. Acad. Sci. USA 89:6948-6952), so trace amounts of Ag(+) may alter cellular ability to respond to gravity. If Ag electrolysis is used to purify water on NASA space vehicles, plants and animals/astronauts will be exposed continuously to Ag(+), a regimen with unknown cellular and developmental consequences. Fertilized eggs of the marine mudsnail, Ilyanassa obsoleta, are the cells in which the effects of A(+) on microtubules were discovered. They distribute visible cytoplasmic contents according to gravity and contain cytoplasmic morphogenetic determinants for heart development. The objectives are to determine if the effects of Ag(+), AU(3+), (of biosensor relevance), or Gd(3+) (inhibitor of some stretch-activated ion channels) on the cytoskeleton (in the presence and absence of mechanical loading) will affect cellular responses to gravity.

  12. Massive production of farnesol-derived dicarboxylic acids in mice treated with the squalene synthase inhibitor zaragozic acid A.

    PubMed

    Vaidya, S; Bostedor, R; Kurtz, M M; Bergstrom, J D; Bansal, V S

    1998-07-01

    The zaragozic acids are potent inhibitors of squalene synthase. In vivo studies in mice confirmed our earlier observations that inhibition of squalene synthase by zaragozic acid A was accompanied by an increase in the incorporation of label from [3H]mevalonate into farnesyl-diphosphate (FPP)-derived isoprenoic acids (J. D. Bergstrom et al., 1993, Proc. Natl. Acad. Sci. USA 90, 80-84). Farnesyl-diphosphate-derived metabolites appear transiently in the liver. We were unable to detect any farnesol formation in the zaragozic acid-treated animals which indicates that FPP is readily converted to farnesoic acid and dicarboxylic acids in the liver. These metabolites were found to be produced only in the liver and not in the kidney. trans-3,7-Dimethyl-2-octaen-1,8-dioic acid and 3, 7-dimethyloctan-1,8-dioic acid were identified as the major end products of farnesyl-diphosphate metabolism in the urine of mice treated with zaragozic acid A. Quantitative analysis of these FPP-derived dicarboxylic acids by gas-liquid chromatography revealed that approximately 11 mg of total dicarboxylic acids is excreted per day into the urine of a mouse after 3 days of treatment with zaragozic acid A. PMID:9647670

  13. A theoretical estimation for the optimal network robustness measure R against malicious node attacks

    NASA Astrophysics Data System (ADS)

    Ma, Liangliang; Liu, Jing; Duan, Boping; Zhou, Mingxing

    2015-07-01

    In a recent work (Schneider C. M. et al., Proc. Natl. Acad. Sci. U.S.A., 108 (2011) 3838), Schneider et al. introduced an effective measure R to evaluate the network robustness against malicious attacks on nodes. Take R as the objective function, they used a heuristic algorithm to optimize the network robustness. In this paper, a theoretical analysis is conducted to estimate the value of R for different types of networks, including regular networks, WS networks, ER networks, and BA networks. The experimental results show that the theoretical value of R is approximately equal to that of optimized networks. Furthermore, the theoretical analysis also shows that regular networks are the most robust than other networks. To validate this result, a heuristic method is proposed to optimize the network structure, in which the degree distribution can be changed and the number of nodes and edges remains invariant. The optimization results show that the degree of most nodes in the optimal networks is close to the average degree, and the optimal network topology is close to regular networks, which confirms the theoretical analysis.

  14. Resilience and Controllability of Dynamic Collective Behaviors

    PubMed Central

    Komareji, Mohammad; Bouffanais, Roland

    2013-01-01

    The network paradigm is used to gain insight into the structural root causes of the resilience of consensus in dynamic collective behaviors, and to analyze the controllability of the swarm dynamics. Here we devise the dynamic signaling network which is the information transfer channel underpinning the swarm dynamics of the directed interagent connectivity based on a topological neighborhood of interactions. The study of the connectedness of the swarm signaling network reveals the profound relationship between group size and number of interacting neighbors, which is found to be in good agreement with field observations on flock of starlings [Ballerini et al. (2008) Proc. Natl. Acad. Sci. USA, 105: 1232]. Using a dynamical model, we generate dynamic collective behaviors enabling us to uncover that the swarm signaling network is a homogeneous clustered small-world network, thus facilitating emergent outcomes if connectedness is maintained. Resilience of the emergent consensus is tested by introducing exogenous environmental noise, which ultimately stresses how deeply intertwined are the swarm dynamics in the physical and network spaces. The availability of the signaling network allows us to analytically establish for the first time the number of driver agents necessary to fully control the swarm dynamics. PMID:24358209

  15. Resilience and controllability of dynamic collective behaviors.

    PubMed

    Komareji, Mohammad; Bouffanais, Roland

    2013-01-01

    The network paradigm is used to gain insight into the structural root causes of the resilience of consensus in dynamic collective behaviors, and to analyze the controllability of the swarm dynamics. Here we devise the dynamic signaling network which is the information transfer channel underpinning the swarm dynamics of the directed interagent connectivity based on a topological neighborhood of interactions. The study of the connectedness of the swarm signaling network reveals the profound relationship between group size and number of interacting neighbors, which is found to be in good agreement with field observations on flock of starlings [Ballerini et al. (2008) Proc. Natl. Acad. Sci. USA, 105: 1232]. Using a dynamical model, we generate dynamic collective behaviors enabling us to uncover that the swarm signaling network is a homogeneous clustered small-world network, thus facilitating emergent outcomes if connectedness is maintained. Resilience of the emergent consensus is tested by introducing exogenous environmental noise, which ultimately stresses how deeply intertwined are the swarm dynamics in the physical and network spaces. The availability of the signaling network allows us to analytically establish for the first time the number of driver agents necessary to fully control the swarm dynamics. PMID:24358209

  16. The Boussinesq Debate: Reversibility, Instability, and Free Will.

    PubMed

    Michael Mueller, Thomas

    2015-12-01

    In 1877, a young mathematician named Joseph Boussinesq presented a mémoire to the Académie des sciences which demonstrated that some differential equations may have more than one solution. Boussinesq linked this fact to indeterminism and to a possible solution to the free will versus determinism debate. Boussinesq's main interest was to reconcile his philosophical and religious views with science by showing that matter and motion do not suffice to explain all there is in the world. His argument received mixed criticism that addressed both his philosophical views and the scientific content of his work, pointing to the physical "realisticness" of multiple solutions. While Boussinesq proved to be able to face the philosophical criticism, the scientific objections became a serious problem, thus slowly moving the focus of the debate from the philosophical plane to the scientific one. This change of perspective implied a wide discussion on topics such as instability, the sensitivity to initial conditions, and the conservation of energy. The Boussinesq debate is an example of a philosophically motivated debate that transforms into a scientific one, an example of the influence of philosophy on the development of science. PMID:26554644

  17. Lilienfeld Prize Talk: New Results on Water in Bulk, Nanoconfined, and Biological Environments

    NASA Astrophysics Data System (ADS)

    Stanley, H. Eugene

    2008-04-01

    This talk will introduce some of the 63 unsolved mysteries of water, and will demonstrate some recent progress in solving them combining information provided by water in bulk, nanoconfined, and biological environments. In particular, we will present evidence from experiments designed to test the hypothesis that water displays ``polymorphism'' in that it can exist in two liquid different phases and display a novel liquid-liquid critical point. The concept of liquid polymorphism is also proving useful in understanding some of the anomalies of other liquids with local tetrahedral symmetry, such as silicon, silica, and carbon. In particular, the talk will discuss changes in dynamic transport properties [1], and water in biological environments, including a possible physical explanation for the phenomenon known as the protein glass transition [2]. [1] P. Kumar, S. V. Buldyrev, S. L. Becker, P. H. Poole, F. W. Starr, and H. E. Stanley, ``Relation between the Widom line and the Breakdown of the Stokes--Einstein Relation in Supercooled Water,'' Proc. Natl. Acad. Sci. USA 104, 9575-9579 (2007). [2] P. Kumar, Z. Yan, L. Xu, M. G. Mazza, S. V. Buldyrev, S.-H. Chen. S. Sastry, and H. E. Stanley, ``Glass Transition in Biomolecules and the Liquid-Liquid Critical Point of Water,'' Phys. Rev. Lett. 97, 177802 (2006).

  18. Can life history trade-offs explain the evolution of short stature in human pygmies? A response to Migliano et al. (2007).

    PubMed

    Becker, Noémie S A; Verdu, Paul; Hewlett, Barry; Pavard, Samuel

    2010-02-01

    Walker et al. ["Growth rates and life histories in twenty-two small-scale societies," Am. J. Hum. Biol. 18:295-311 (2006)] used life history theory to develop an innovative explanation for human diversity in stature. Short stature could have been selected for in some human populations as a result of the advantage of an earlier growth cessation and earlier reproduction in a context of high mortality. Migliano et al. ["Life history trade-offs explain the evolution of human pygmies," Proc. Natl. Acad. Sci. USA 104:20,216-20,219 (2007)] recently published an important article that tested this hypothesis to explain short stature in human pygmy populations. However innovative this work may be, we believe that some of the data and results presented are controversial if not questionable. As problematic points we note (1) the use of an arbitrary threshold of height (155 cm) to categorize populations into pygmies and nonpygmies; (2) the use of demographic data from Philippine pygmy groups that have experienced dramatic cultural and environmental changes in the last 20 years, and (3) the use of demographic data concerning African pygmy groups because good systematic data on these groups are not available. Finally, we report here mathematical errors and loopholes in the optimization model developed by Migliano and colleagues. In this paper we suggest alternative trade-offs that can be used to explain Migliano's results on more reliable bases. PMID:20504169

  19. Cell poking. Determination of the elastic area compressibility modulus of the erythrocyte membrane.

    PubMed Central

    Daily, B; Elson, E L; Zahalak, G I

    1984-01-01

    Cell poking, a new method for measuring mechanical properties of single cells was used to determine the elastic area compressibility modulus of osmotically swollen human erythrocytes. With this method we determined the force required to indent cells attached to a glass coverslip (Petersen, N.O., W. B. McConnaughey , and E. L. Elson , 1982, Proc. Natl. Acad. Sci. USA, 79:5327. Forces on the order of one millidyne and indentations on the order of one micron were detected. An analysis of these data in terms of a simplified mechanical model yielded the elastic area compressibility modulus. This analysis used a variational approach to minimize the isothermal elastic potential energy density function given by E. A. Evans and R. Skalak (Mechanics and Thermodynamics of Biomembranes, 1980, CRC Press, Boca Raton , FL). Measurements on swollen erythrocytes gave a range of values, depending in part on the osmotic conditions, of 17.9 +/- 8.2 to 34.8 +/- 12.0 mdyn /micron for the elastic area compressibility modulus at 25 degrees C. Fractional area expansion greater than 2.6 +/- 0.8% produced rapid cell lysis. These values were not corrected for the reversible movement of water across the cell membrane in response to hydrostatic pressure gradients. Our results agree reasonably with those obtained by Evans et al. (Evans, E.A., R. Waugh , and L. Melnick , 1976, Biophys. J., 16:585-595.) using micropipette aspiration under similar conditions. PMID:6722261

  20. The Solar Corona and a CME at the 2010 Total Eclipse

    NASA Astrophysics Data System (ADS)

    Pasachoff, Jay M.; Rusin, V.; Druckmüllerová, H.; Saniga, M.; Lu, M.; Malamut, C.; Seaton, D. B.; Golub, L.; Engell, A. J.; Hill, S. W.; Lucas, R.

    2011-05-01

    The 11 July 2010 total solar eclipse was observed on the ground from French Polynesia and, 83 minutes later, from Easter Island, and near-simultaneous images were made with spacecraft instruments including AIA/SDO, HMI/SDO, EUVI/STEREO, SWAP/PROBA2, EIT/SOHO, and LASCO/SOHO. We report on changes in the corona detectable with high-resolution image processing of the ground-based eclipse coronal imaging, including two CME's that were seen to evolve. We compare with the spacecraft images to give a complete depiction of coronal structure at the time of the eclipse, which corresponded to a low but rising phase of the solar-activity cycle. We acknowledge the support of NASA's MSFC NNX10AK47A, NSF REU AST-1005024 with DoD ASSURE, VEGA 2/0098/10 of the Slovak Acad. Sci, 205/09/1469 of the Czech Science Foundation, PRODEX C90345 of ESA/BELSPO, FP7/2007-2013/218816 SOTERIA, Lockheed Martin; for equipment: Nikon Professional Services, ASTELCO Systems GmbH (Germany), and National Geographic Society's Photographic Division; and colleagues Y.-M. Wang (NRL), S. Habbal (U. Hawaii), H. Lanteires (Tatakoto), and J. Kern (Carnegie Obs.).

  1. The motion of a single red blood cell in a capillary

    NASA Astrophysics Data System (ADS)

    Savin, Thierry; Mahadevan, L.

    2009-11-01

    The collective vaso-occlusive event in sickle cell disease induced by multiple red blood cells (RBC's) has recently been evoked and controlled in vitro using a microfluidic platform [1]. The increase in the cells' stiffness in this disease is believed to be a predominant factor at the onset of the occlusion. We report here the motion of a single swollen RBC in a capillary. We use a tapered glass capillary with inner diameter as low as 3 microns, and track the squeezed cell driven by a controlled pressure drop. This allows us to simultaneously measure the variations of the RBC velocity as a function of the pressure gradient and of the local capillary diameter in a single experiment. We show that under certain regimes of confinement, the velocity increases with the pressure head with a characteristic power-law. We analyze our findings in terms of a elasto-hydrodynamical model for soft lubrication.[4pt] [1] Higgins et al., Proc. Natl. Acad. Sci. U.S.A. 104: 20496 (2007).

  2. [On Academics and Academicians. Historical sketch].

    PubMed

    de Micheli-Serra, Alfredo

    2003-01-01

    First Academies originated in Italy at the beginnings of the Renaissance. Their works were of encyclopedic extent. Regarding to scientific academies, the first was the "Accademia dei Lincei" founded in Rome on August 17, 1603, due to the initiative of four young men; three naturalists and a physician. Later, several distiguished scientists were admitted, such as Giambattista della Porta, inventor of the dark chamber (1610) and Galileo Galilei (1611). This Academy sponsored the publication of a compendium of Francisco Hernández manuscripts, prepared by the Italian physician Antonio Nardo Recchi. Many years later, other scientific academies arose, such as the "Accademia del Cimento", established in 1657 in Florence and inspired by Galilean thought. In 1662, the "Royal Society" of London, was formally recognized, following Bacon's empirical line, and in 1666 the "Académie Royale des Sciences" was created in Paris, which followed the mechanicist orientation of Descartes. These scientific societies aspired to become centers of information and exchange ideas. Therefore, the "Philosophical Transactions" in London and the "Journal des Savants" in Paris began to be published in 1665. Both publications often included medical articles and notes. Regarding New Spain, the worthy "Academia médico-quirúrgica" of Puebla, mentioned since 1802, must be considered. In independent Mexico, two successive medical academies were established that paved the way for our National Academy of Medicine (1864). This society, since its birth, has been publishing the "Gaceta Médica de México", dean of the Mexican medical journals. PMID:12872422

  3. Quantifying the distribution of nanodiamonds in pre-Younger Dryas to recent age deposits along Bull Creek, Oklahoma Panhandle, USA

    PubMed Central

    Bement, Leland C.; Madden, Andrew S.; Carter, Brian J.; Simms, Alexander R.; Swindle, Andrew L.; Alexander, Hanna M.; Fine, Scott; Benamara, Mourad

    2014-01-01

    High levels of nanodiamonds (nds) have been used to support the transformative hypothesis that an extraterrestrial (ET) event (comet explosion) triggered Younger Dryas changes in temperature, flora and fauna assemblages, and human adaptations [Firestone RB, et al. (2007) Proc Natl Acad Sci USA 104(41):16016–16021]. We evaluate this hypothesis by establishing the distribution of nds within the Bull Creek drainage of the Beaver River basin in the Oklahoma panhandle. The earlier report of an abundance spike of nds in the Bull Creek I Younger Dryas boundary soil is confirmed, although no pure cubic diamonds were identified. The lack of hexagonal nds suggests Bull Creek I is not near any impact site. Potential hexagonal nds at Bull Creek were found to be more consistent with graphene/graphane. An additional nd spike is found in deposits of late Holocene through the modern age, indicating nds are not unique to the Younger Dryas boundary. Nd distributions do not correlate with depositional environment, pedogenesis, climate perturbations, periods of surface stability, or cultural activity. PMID:24449875

  4. Bertrand's paradox: a physical way out along the lines of Buffon's needle throwing experiment

    NASA Astrophysics Data System (ADS)

    Di Porto, P.; Crosignani, B.; Ciattoni, A.; Liu, H. C.

    2011-05-01

    Bertrand's paradox (Bertrand 1889 Calcul des Probabilités (Paris: Gauthier-Villars)) can be considered as a cautionary memento, to practitioners and students of probability calculus alike, of the possible ambiguous meaning of the term 'at random' when the sample space of events is continuous. It deals with the existence of different possible answers to the following question: what is the probability that a chord, drawn at random in a circle of radius R, is longer than the side R \\sqrt{3} of an inscribed equilateral triangle? Physics can help to remove the ambiguity by identifying an actual experiment, whose outcome is obviously unique and prescribes the physical variables to which the term 'random' can be correctly applied. In this paper, after briefly describing Bertrand's paradox, we associate it with an experiment, which is basically a variation of the famous Buffon's needle experiment (Buffon 1733 Histoire de l'Acad. Roy. des. Sciences pp 43-5 Buffon 1777 Histoire naturelle, générale et particulière Supplément 4 46) for estimating the value of π. Its outcome is compared with the analytic predictions of probability calculus, that is with the probability distribution of variables whose uniform distribution can be considered a sound implementation of complete randomness.

  5. Calreticulin Is a Receptor for Nuclear Export

    PubMed Central

    Holaska, James M.; Black, Ben E.; Love, Dona C.; Hanover, John A.; Leszyk, John; Paschal, Bryce M.

    2001-01-01

    In previous work, we used a permeabilized cell assay that reconstitutes nuclear export of protein kinase inhibitor (PKI) to show that cytosol contains an export activity that is distinct from Crm1 (Holaska, J.M., and B.M. Paschal. 1995. Proc. Natl. Acad. Sci. USA. 95: 14739–14744). Here, we describe the purification and characterization of the activity as calreticulin (CRT), a protein previously ascribed to functions in the lumen of the ER. We show that cells contain both ER and cytosolic pools of CRT. The mechanism of CRT-dependent export of PKI requires a functional nuclear export signal (NES) in PKI and involves formation of an export complex that contains RanGTP. Previous studies linking CRT to downregulation of steroid hormone receptor function led us to examine its potential role in nuclear export of the glucocorticoid receptor (GR). We found that CRT mediates nuclear export of GR in permeabilized cell, microinjection, and transfection assays. GR export is insensitive to the Crm1 inhibitor leptomycin B in vivo, and it does not rely on a leucine-rich NES. Rather, GR export is facilitated by its DNA-binding domain, which is shown to function as an NES when transplanted to a green fluorescent protein reporter. CRT defines a new export pathway that may regulate the transcriptional activity of steroid hormone receptors. PMID:11149926

  6. Calreticulin Is a receptor for nuclear export.

    PubMed

    Holaska, J M; Black, B E; Love, D C; Hanover, J A; Leszyk, J; Paschal, B M

    2001-01-01

    In previous work, we used a permeabilized cell assay that reconstitutes nuclear export of protein kinase inhibitor (PKI) to show that cytosol contains an export activity that is distinct from Crm1 (Holaska, J.M., and B.M. Paschal. 1995. Proc. Natl. Acad. Sci. USA. 95: 14739-14744). Here, we describe the purification and characterization of the activity as calreticulin (CRT), a protein previously ascribed to functions in the lumen of the ER. We show that cells contain both ER and cytosolic pools of CRT. The mechanism of CRT-dependent export of PKI requires a functional nuclear export signal (NES) in PKI and involves formation of an export complex that contains RanGTP. Previous studies linking CRT to downregulation of steroid hormone receptor function led us to examine its potential role in nuclear export of the glucocorticoid receptor (GR). We found that CRT mediates nuclear export of GR in permeabilized cell, microinjection, and transfection assays. GR export is insensitive to the Crm1 inhibitor leptomycin B in vivo, and it does not rely on a leucine-rich NES. Rather, GR export is facilitated by its DNA-binding domain, which is shown to function as an NES when transplanted to a green fluorescent protein reporter. CRT defines a new export pathway that may regulate the transcriptional activity of steroid hormone receptors. PMID:11149926

  7. Ravens, New Caledonian crows and jackdaws parallel great apes in motor self-regulation despite smaller brains

    PubMed Central

    Kabadayi, Can; Taylor, Lucy A.; von Bayern, Auguste M. P.; Osvath, Mathias

    2016-01-01

    Overriding motor impulses instigated by salient perceptual stimuli represent a fundamental inhibitory skill. Such motor self-regulation facilitates more rational behaviour, as it brings economy into the bodily interaction with the physical and social world. It also underlies certain complex cognitive processes including decision making. Recently, MacLean et al. (MacLean et al. 2014 Proc. Natl Acad. Sci. USA 111, 2140–2148. (doi:10.1073/pnas.1323533111)) conducted a large-scale study involving 36 species, comparing motor self-regulation across taxa. They concluded that absolute brain size predicts level of performance. The great apes were most successful. Only a few of the species tested were birds. Given birds' small brain size—in absolute terms—yet flexible behaviour, their motor self-regulation calls for closer study. Corvids exhibit some of the largest relative avian brain sizes—although small in absolute measure—as well as the most flexible cognition in the animal kingdom. We therefore tested ravens, New Caledonian crows and jackdaws in the so-called cylinder task. We found performance indistinguishable from that of great apes despite the much smaller brains. We found both absolute and relative brain volume to be a reliable predictor of performance within Aves. The complex cognition of corvids is often likened to that of great apes; our results show further that they share similar fundamental cognitive mechanisms. PMID:27152224

  8. Tuning the electronic and mechanical properties of penta-graphene via hydrogenation and fluorination.

    PubMed

    Li, Xiaoyin; Zhang, Shunhong; Wang, Fancy Qian; Guo, Yaguang; Liu, Jie; Wang, Qian

    2016-06-01

    Penta-graphene has recently been proposed as a new allotrope of carbon composed of pure pentagons, and displays many novel properties going beyond graphene [Zhang et al., Proc. Natl. Acad. Sci. U. S. A., 2015, 112, 2372]. To further explore the property modulations, we have carried out a theoretical investigation of the hydrogenated and fluorinated penta-graphene sheets. Our first-principles calculations reveal that hydrogenation and fluorination can effectively tune the electronic and mechanical properties of penta-graphene: turning the sheet from semiconducting to insulating; changing the Poisson's ratio from negative to positive, and reducing the Young's modulus. Moreover, the band gaps of the hydrogenated and fluorinated penta-graphene sheets are larger than those of fully hydrogenated and fluorinated graphene by 0.37 and 0.04 eV, respectively. The phonon dispersions and ab initio molecular dynamics simulations confirm that the surface modified penta-graphene sheets are dynamically and thermally stable, and show that the hydrogenated penta-graphene has more Raman-active modes with higher frequencies as compared to the fluorinated penta-graphene. PMID:27063837

  9. Phase behavior and local structure of liquid crystalline polymers

    NASA Astrophysics Data System (ADS)

    Fynewever, Herb

    In this work we use a combination of theory and computer simulation to study the phase behavior of liquid crystalline polymers and the local structure of polymer melts. We review experimental and simulation evidence which shows that long and stiff molecules form orientationally ordered phases at packing fractions intermediate between the liquid and the solid. With the aid of a two-molecule simulation, we are able to apply Onsager's theory [Ann. N. Y. Acad. Sci. 51, 627 (1949)] for liquid crystal formation to flexible molecules without any additional approximations. Our results have a quantitative advantage over other theories in comparison with computer simulation data such as for the liquid-liquid crystal phase diagram. We also study the local structure of polymer melts using a two-molecule simulation to apply the density functional theories of Donley, Curro, and McCoy [J. Chem. Phys. 101 , 3205 (1994)1; and Yethiraj and Woodward [J. Chem. Phys 102 , 5499 (1995)]. The accuracy of these methods rivals that of integral equation theories in their predictions of local order. Further, the two-molecule simulation facilitates a more direct calculation of the equation of state via the monitoring of orientational correlations.

  10. Manifestation of compositional heterogeneities and ferropericlase spin crossover on mantle velocities

    NASA Astrophysics Data System (ADS)

    Wu, Z.; Wentzcovitch, R. M.

    2015-12-01

    The origin of lateral velocity heterogeneities is essential for our understanding of Earth's interior. Ferropericlase's (Fp) spin crossover (FSC) fundamentally changes the interpretation of the origin of lateral heterogeneities in the mid lower mantle. In a typical pyrolite compositional model, it induces an unusual increase in bulk sound velocity (Vϕ) with increasing temperature at mid-lower-mantle depths [1]. This reduces the sensitivity of longitudinal velocity (VP) to lateral temperature variations around 1700 km [1]. Here we show that FSC also dramatically impacts the manifestation of two important types of compositional heterogeneities, i.e., changes in iron concentration in Fp or in molar fraction of Fp. It enhances the sensitivity of Vϕ and VP to these compositional variations by several-fold at similar depths. Therefore, heterogeneities in VP tomography models are potentially good indicators of temperature versus compositional contributions to lateral velocity changes. In fact, VP heterogeneities at mid lower mantle depths common to multiple seismic models suggest that both lateral temperature and compositional variations may be significant in this region. [1] Wu, Z.Q., & Wentzcovitch, R.M. (2014). Spin crossover in ferropericlase and velocity heterogeneities in the lower mantle. Proc. Natl. Acad. Sci. U. S. A. 111: 10468-10472.

  11. Temperature and pressure effects on GFP mutants: explaining spectral changes by molecular dynamics simulations and TD-DFT calculations.

    PubMed

    Jacchetti, Emanuela; Gabellieri, Edi; Cioni, Patrizia; Bizzarri, Ranieri; Nifosì, Riccardo

    2016-05-14

    By combining spectroscopic measurements under high pressure with molecular dynamics simulations and quantum mechanics calculations we investigate how sub-angstrom structural perturbations are able to tune protein function. We monitored the variations in fluorescence output of two green fluorescent protein mutants (termed Mut2 and Mut2Y, the latter containing the key T203Y mutation) subjected to pressures up to 600 MPa, at various temperatures in the 280-320 K range. By performing 150 ns molecular dynamics simulations of the protein structures at various pressures, we evidenced subtle changes in conformation and dynamics around the light-absorbing chromophore. Such changes explain the measured spectral tuning in the case of the sizable 120 cm(-1) red-shift observed for pressurized Mut2Y, but absent in Mut2. Previous work [Barstow et al., Proc. Natl. Acad. Sci. U. S. A., 2008, 105, 13362] on pressure effects on GFP also involved a T203Y mutant. On the basis of cryocooling X-ray crystallography, the pressure-induced fluorescence blue shift at low temperature (77 K) was attributed to key changes in relative conformation of the chromophore and Tyr203 phenol ring. At room temperature, however, a red shift was observed at high pressure, analogous to the one we observe in Mut2Y. Our investigation of structural variations in compressed Mut2Y also explains their result, bridging the gap between low-temperature and room-temperature high-pressure effects. PMID:27102429

  12. Reduction of Scattered Light by M"uller Cells in the Human Retina

    NASA Astrophysics Data System (ADS)

    Bendix, Oliver; Fleischmann, Ragnar; Geisel, Theo

    2012-02-01

    It is a long standing question why in the mammalian eye photoreceptors are positioned at the back of the retina, forcing photons to travel through various neuronal layers of the retina before the light-sensitive rods and cones can detect them. Recent studies suggest that certain retinal glial cells--called M"uller cells (MCs)--play an important role in answering that question. It has been experimentally shown that MCs extracted from the retina can act as optical fibers [1]. To understand the light guiding properties of the MC in the natural fluctuating optical environment, we developed a model to analyze the light reflection and transmission of MCs embedded in a random medium neuronal tissue. With these quantities and a simplified geometrical eye model we study how light is scattered in the eye. We found that MCs can lead to a substantial increase of the signal-to-noise ratio (SNR), the ratio of the intensity of direct incident light at a photoreceptor to the intensity of back-scattered light from other areas of the retina. The SNR is most pronounced in the vicinity of the fovea and can be more than an order of magnitude.[4pt] [1] Franze et. al., Proc Natl Acad Sci USA, 2007, 104, 8287-8292.

  13. Transoceanic drift and the domestication of African bottle gourds in the Americas.

    PubMed

    Kistler, Logan; Montenegro, Alvaro; Smith, Bruce D; Gifford, John A; Green, Richard E; Newsom, Lee A; Shapiro, Beth

    2014-02-25

    Bottle gourd (Lagenaria siceraria) was one of the first domesticated plants, and the only one with a global distribution during pre-Columbian times. Although native to Africa, bottle gourd was in use by humans in east Asia, possibly as early as 11,000 y ago (BP) and in the Americas by 10,000 BP. Despite its utilitarian importance to diverse human populations, it remains unresolved how the bottle gourd came to be so widely distributed, and in particular how and when it arrived in the New World. A previous study using ancient DNA concluded that Paleoindians transported already domesticated gourds to the Americas from Asia when colonizing the New World [Erickson et al. (2005) Proc Natl Acad Sci USA 102(51):18315-18320]. However, this scenario requires the propagation of tropical-adapted bottle gourds across the Arctic. Here, we isolate 86,000 base pairs of plastid DNA from a geographically broad sample of archaeological and living bottle gourds. In contrast to the earlier results, we find that all pre-Columbian bottle gourds are most closely related to African gourds, not Asian gourds. Ocean-current drift modeling shows that wild African gourds could have simply floated across the Atlantic during the Late Pleistocene. Once they arrived in the New World, naturalized gourd populations likely became established in the Neotropics via dispersal by megafaunal mammals. These wild populations were domesticated in several distinct New World locales, most likely near established centers of food crop domestication. PMID:24516122

  14. Redefinition of Nosema pyrausta (Perezia pyraustae Paillot 1927) basing upon ultrastructural and molecular phylogenetic studies.

    PubMed

    Tokarev, Yuri S; Malysh, Julia M; Kononchuk, Anastasia G; Seliverstova, Elena V; Frolov, Andrei N; Issi, Irma V

    2015-02-01

    Populations of European corn borer (Ostrinia nubilalis Hübner) from Krasnodar Territory (Southwestern Russia) become regularly infected with Nosema-like microsporidia. To identify the parasite, it was subjected to electron microscopy and small subunit ribosomal RNA (SSU rRNA) gene sequencing. The spore ultrastructure of the parasite was highly similar to Nosema bombycis from China and Nosema pyrausta from the USA. The nucleotide sequence of SSU rRNA gene was identical to a microsporidium isolated from O. nubilalis in southern France (GenBank accession no. HM566196) and closely related to Nosema bombycis (no. AY209011, 99.7 % sequence similarity) from Bombyx mori of Chinese origin and N. pyrausta (no. AY958071) from O. nubilalis of North American origin. As the molecular haplotype of SSU rRNA is fixed for the parasite infecting O. nubilalis across Europe and N. pyrausta was initially described in France as Perezia pyraustae (Paillot CR Acad Sci Paris 185: 673-675, 1927), we conclude that the parasite examined under the present study correspond to the type isolate of N. pyrausta. The microsporidium from O. nubilalis in North America (no. AY958071) corresponds therefore to a closely related, yet distinct haplotype. PMID:25563606

  15. On the parameter β=Re/KC=D2/νT

    NASA Astrophysics Data System (ADS)

    Sarpkaya, T.

    2005-12-01

    This brief communication is a summary of the facts regarding the universalization in 1976 of a parameter β to fully nonlinear unsteady separated flows about bluff bodies nearly 125 years after its first appearance in a linearized analysis of unseparated viscous flow with very slow oscillations about a cylindrical rod and sphere by Sir George Gabriel Stokes [1851. On the effect of the internal friction of fluids on the motion of pendulums. Transactions of the Cambridge Philosophical Society 9(II), 8 106]. The primary purpose of Stokes was to show that “the index of friction” (the kinematic viscosity), in the equations of motion may be deduced from experiments for the vindication of the heuristic reasoning that went into the derivation by . Mémoire sur les lois du movement des fluides. Mémoires de l’Académie de Sciences 6, 389 416.], Poisson [1831. Nouvelle théorie de l’action capillaire Bachelier, Paris.], de Saint-Venant [1843. Note á joindre un memoire sur la dynamique des fluides. Comptes Rendus 17, 1240 1244.] and . On the theories of internal friction of fluids in motion. Transactins of the Cambridge Philosophical Society 8, 287 305.] of what are now called the Navier Stokes equations.

  16. [Aran-Duchenne? Duchenne-Aran? The quarrel around progressive muscular atrophy].

    PubMed

    Bonduelle, M

    1990-01-01

    A description of progressive muscular atrophy, the first item in neuro-muscular nosography, figures in the memoir published by F.A. Aran in 1850. There, all the essential features of the disease can be found: its usual onset at the distal end of the upper limbs, its slowly progressive worsening, with muscular atrophy sparing certain muscles or muscular fascicles, its peculiar "claw hand", its muscular "fasciculations" and cramps, with untouched sensitivity. After praising Aran's "beautiful description", G.B. Duchenne de Boulogne subsequently persisted in claiming paternity, untiringly referring to a memoir on "muscular atrophy with fatty transformation" said to have been submitted to the Académie des Sciences in 1849. There is no trace of this memoir, and while it is true that the "localized electrisation" technique was applied by Duchenne to all the patients in Aran's memoir, and that he was the sole author of two of his observations, it is Aran who must be credited with the clinical description, the synthetic presentation and the appellation of "progressive muscular atrophy". Initially, this term covered a number of disparate facts which were later identified and put in their proper nosological place, even though this dismemberment left standing what Charcot called "Duchenne-Aran disease" before the Aran-Duchenne denomination prevailed. This denomination is now customary, and rightly so. PMID:2181591

  17. Anatomy of a conformational transition of beta-strand 6 in soybean beta-amylase caused by substrate (or inhibitor) binding to the catalytical site.

    PubMed Central

    Pujadas, G.; Palau, J.

    1997-01-01

    A computational study of the five soybean beta-amylase X-ray structure reported so far revealed a peculiar conformational transition after substrate (or inhibitor) binding, which affects a segment of the beta-strand 6 (residues 341-343) in the (beta/alpha)8 molecular scaffold. Backbone distortions that involve considerable changes in the phi and psi angles were observed, as well as two sharp rotamer transitions for the Thr342 and Cys343 side chains. These changes caused the outermost CA-layer (at the C-terminal side of the barrel), which is involved in the catalysis, to shrink. Our observations strongly suggest that the 341FTC343 residue conformations in the free enzyme are not optimal for protein stability. Furthermore, as a result of conformational transitions in the ligand-binding process, there is a negative enthalpy change for these residues (-27 and -34 kcal/mol, after substrate or inhibitor binding, respectively). These findings support the proposed "stability-function" hypothesis for proteins that recognize a ligand (Shoichet BK, Baase WA, Kuroki R, Matthews BW. 1995. A relationship between protein stability and protein function. Proc Natl Acad Sci USA 92:452-456). They are also in good agreement with other experimental results in the literature that describe the role of the 341-343 segment in beta-amylase activity. Site-directed mutagenesis focused on these residues could be useful for undertaking functional studies of beta-amylase. PMID:9385643

  18. Djordje Stanojevic in Works of Jules Janssen

    NASA Astrophysics Data System (ADS)

    Dimitrijevic, M. S.

    2009-09-01

    Jules Janssen (Paris 1824 - Meudon 1907) is well known as the founder of the "Observatoire d'Astronomie Physique de Paris (sisá Meudon)". He was also teacher and coworker of Djordje Stanojević, who was the first Serbian astrophysicist, rector of the Belgrade University and the second person on the head of Belgrade Astronomical Observatory, the first builder of hydro power plants in Serbia, the author of the first color photography in Serbia and the book with colored photographies ("Srbija u slikama" - Serbia in photos), pioneer of electrification and industrialization of our country. His articles in the journal of the French Academy of Sciences (Comptes Rendus de l'Académie des Sciences) are in the Serbian Astronomy the first modern scientific papers. They are presented and commented in Academy by Jules Janssen, who also mentions Stanojevi{ć} in his works in various contexts. In this contribution, the presence of Djordje Stanojevi{ć} in works of Jules Janssen, and his comments on Stanojevi{ć}'s work in Comptes Rendus are analyzed. Also, the work and life of Jules Janssen are presented.

  19. Network reconstruction reveals new links between aging and calorie restriction in yeast

    PubMed Central

    Balázsi, Gábor

    2010-01-01

    Aging affects all known organisms and has been studied extensively. Yet, the underlying mechanisms are insufficiently understood, possibly due to the multiscale complexity involved in this process: the aging of multicellular organisms depends on the aging of their cells, which depends on molecular events occurring in each cell. However, the aging of unicellular populations seeded in new niches and the aging of metazoans are surprisingly similar, indicating that the multiscale aspects of aging may have been conserved since the beginnings of cellular life on Earth. This underlines the importance of aging research in unicellular organisms such as a recent study by Lorenz et al., [(2009) Proc. Natl. Acad. Sci. U.S.A. 106, 1145–1150]. In their paper, the authors combine computational network identification with extensive experimentation and literature mining to discover and validate numerous regulatory interactions among ten genes involved in the cellular response to glucose starvation. Since low levels of glucose (calorie restriction) have been known to extend the longevity of various eukaryotes, the authors test the effect of Snf1 kinase overexpression on chronological aging and discover that this key regulator of glucose repression and two of its newly discovered synergistic repressors significantly affect the chronological lifespan of baker’s yeast. PMID:21119761

  20. Pentahaloethane-based chlorofluorocarbon substitutes and halothane: Correlation of in vivo hepatic protein trifluoroacetylation and urinary trifluoroacetic acid excretion with calculated enthalpies of activation

    SciTech Connect

    Harris, J.W.; Jones, J.P.; Martin, J.L.; LaRosa, A.C.; Olson, M.J.; Pohl, L.R.; Anders, M.W. )

    1992-09-01

    The hydrochlorofluorocarbons (HCFCs) 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123) and 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124) and the hydrofluorocarbon (HFC) pentafluoroethane (HFC-125) are being developed as substitutes for chlorofluorocarbons that deplete stratospheric ozone. The structural similarity of these HCFCs and HFCs to halothane, which is hepatotoxic under certain circumstances, indicates that the metabolism and cellular interactions of HCFCs and HFCs must be explored. In a previous study [Harris et al. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 1407], similar patterns of trifluoroacetylated proteins (TFA-proteins) were detected by immunoblotting with anti-TFA-protein antibodies in livers of rats exposed to halothane or HCFC-123. The present study extends these results and demonstrates that in vivo TFA-protein formation resulting from a 6-h exposure to a 1% atmosphere of these compounds follows the trend: halothane approximately HCFC-123 much greater than HFC-124, greater than HFC-125. The calculated enthalpies of activation of halothane, HCFC-123, HCFC-124, and HFC-125 paralleled the observed rate of trifluoroacetic acid excretion in HCFC- or HFC-exposed rats. Exposure of rats to a range of HCFC-123 concentrations indicated that TFA-protein formation was saturated at an exposure concentration between 0.01% and 0.1% HCFC-123. Deuteration of HCFC-123 decreased TFA-protein formation in vivo. Urinary trifluoroacetic acid excretion by treated rats correlated with the levels of TFA-proteins found after each of these treatments.

  1. Experimental Implementations of Quantum Paradoxes

    NASA Astrophysics Data System (ADS)

    Briggs, G. A. D.

    Remarkable progress is being made in experiments that highlight the distinctive predictions of quantum mechanics. The Leggett-Garg inequality was devised to test for macrorealism (Leggett and Garg in Phys. Rev. Lett. 54:857-860, 1985). Various experiments have been performed, including one with non-invasive measurements in the kind of way that was originally envisaged, using spins in phosphorous impurities in silicon (Knee et al. in Nat. Commun. 3:606, 2012). This has led to fresh understanding of what kind of realism is excluded by the result. The quantum three-box paradox (Aharonov and Vaidman in J. Phys. A, Math. Gen. 24:2315-2328, 1991) provides a further test, which can be re-expressed in terms of the Leggett-Garg inequality. This has been experimentally implemented with projective measurements using an NV- centre in diamond, yielding results 7.8 standard deviations beyond a classical bound (George et al. in Proc. Natl. Acad. Sci. USA 110:3777-3781, 2013). [Editor's note: for a video of the talk given by Prof. Briggs at the Aharonov-80 conference in 2012 at Chapman University, see http://quantum.chapman.edu/talk-18.

  2. Wide-Field Plate Database

    NASA Astrophysics Data System (ADS)

    Tsvetkov, M. K.; Stavrev, K. Y.; Tsvetkova, K. P.; Semkov, E. H.; Mutatov, A. S.

    The Wide-Field Plate Database (WFPDB) and the possibilities for its application as a research tool in observational astronomy are presented. Currently the WFPDB comprises the descriptive data for 400 000 archival wide field photographic plates obtained with 77 instruments, from a total of 1 850 000 photographs stored in 269 astronomical archives all over the world since the end of last century. The WFPDB is already accessible for the astronomical community, now only in batch mode through user requests sent by e-mail. We are working on on-line interactive access to the data via INTERNET from Sofia and parallel from the Centre de Donnees Astronomiques de Strasbourg. (Initial information can be found on World Wide Web homepage URL http://www.wfpa.acad.bg.) The WFPDB may be useful in studies of a variety of astronomical objects and phenomena, andespecially for long-term investigations of variable objects and for multi-wavelength research. We have analysed the data in the WFPDB in order to derive the overall characteristics of the totality of wide-field observations, such as the sky coverage, the distributions by observation time and date, by spectral band, and by object type. We have also examined the totality of wide-field observations from point of view of their quality, availability and digitisation. The usefulness of the WFPDB is demonstrated by the results of identification and investigation of the photometrical behaviour of optical analogues of gamma-ray bursts.

  3. Progress Toward the Development of Noscapine and Derivatives as Anticancer Agents.

    PubMed

    DeBono, Aaron; Capuano, Ben; Scammells, Peter J

    2015-08-13

    Many nitrogen-moiety containing alkaloids derived from plant origins are bioactive and play a significant role in human health and emerging medicine. Noscapine, a phthalideisoquinoline alkaloid derived from Papaver somniferum, has been used as a cough suppressant since the mid 1950s, illustrating a good safety profile. Noscapine has since been discovered to arrest cells at mitosis, albeit with moderately weak activity. Immunofluorescence staining of microtubules after 24 h of noscapine exposure at 20 μM elucidated chromosomal abnormalities and the inability of chromosomes to complete congression to the equatorial plane for proper mitotic separation ( Proc. Natl. Acad. Sci. U. S. A. 1998 , 95 , 1601 - 1606 ). A number of noscapine analogues possessing various modifications have been described within the literature and have shown significantly improved antiprolific profiles for a large variety of cancer cell lines. Several semisynthetic antimitotic alkaloids are emerging as possible candidates as novel anticancer therapies. This perspective discusses the advancing understanding of noscapine and related analogues in the fight against malignant disease. PMID:25811651

  4. Eukaryotic signature proteins of Prosthecobacter dejongeii and Gemmata sp. Wa-1 as revealed by in silico analysis.

    PubMed

    Staley, James T; Bouzek, Heather; Jenkins, Cheryl

    2005-02-01

    The genomes of representatives of three bacterial phyla have been compared with the list of 347 eukaryotic signature proteins (ESPs) derived by Hartman and Fedorov [Proc. Natl. Acad. Sci. USA 99 (2002) 1420]. The species included Prosthecobacter dejongeii of the Verrucomicrobia phylum, Gemmata sp. Wa-1 of the Planctomycetes phylum and Caulobacter crescentus of the Proteobacteria. The protist Trypanosoma brucei was used as a eukaryotic control. P. dejongeii had unique ERGO blast matches to alpha-, beta-, and gamma-tubulin, to Set2, a transcriptional factor associated with eukaryotic DNA, and to LAMMER protein kinase for a total of 10 high-scoring ESP matches altogether. Gemmata sp. Wa-1 shared four of its 17 high-scoring ESP matches with P. dejongeii, and that information coupled with other genomic data provides strong support that these two phyla are related to one another. If the ESP list is an accurate listing of unique eukaryotic proteins, then the low number of high-scoring matches between the proteins of these two bacteria with the list raises doubts about these phyla being direct ancestors of the Eucarya. However, this does not rule out the possibility that ancestral members of either the Verrucomicrobia or Planctomycetes may have played an important role in the evolution of a proto-eukaryotic organism. PMID:15667994

  5. Hydrogen and deuterium in myoglobin as seen by a neutron structure determination at 1.5 A resolution.

    PubMed

    Ostermann, Andreas; Tanaka, Ichiro; Engler, Niklas; Niimura, Nobuo; Parak, Fritz G

    2002-03-28

    From the first days of protein neutron structure determination sperm whale myoglobin was an object under investigation [Nature 224 (1969) 143, J. Mol. Biol. 220 (1991) 381]. Nevertheless myoglobin is still of interest [Proc. Natl. Acad. Sci. USA 97 (2000) 3872]. The feasibility of the monochromatic neutron diffractometer BIX-3 at the JRR-3M reactor at the JAERI [J. Phys. Chem. Solids 60 (1999) 1623], to collect high-resolution diffraction data in a relatively short time stimulated us to repeat the structural determination of myoglobin. The structure of metmyoglobin has been determined up to a resolution of 1.5 A. The hydrogen atoms were replaced in part, by deuterium soaking the crystals for more than 10 years in D(2)O. A refinement of all atoms has been performed including the refinement of individual mean square displacements and occupancies of the exchangeable protons in backbone hydrogen bonds. A method is described to show clear negative scattering densities of the H atoms. Water molecules within the protein and on the molecule surface are shown. The exchangeability of H atoms is correlated with structural distribution and flexibility. PMID:12062378

  6. Robust normalization protocols for multiplexed fluorescence bioimage analysis.

    PubMed

    Ahmed Raza, Shan E; Langenkämper, Daniel; Sirinukunwattana, Korsuk; Epstein, David; Nattkemper, Tim W; Rajpoot, Nasir M

    2016-01-01

    study of mapping and interaction of co-localized proteins at a sub-cellular level is important for understanding complex biological phenomena. One of the recent techniques to map co-localized proteins is to use the standard immuno-fluorescence microscopy in a cyclic manner (Nat Biotechnol 24:1270-8, 2006; Proc Natl Acad Sci 110:11982-7, 2013). Unfortunately, these techniques suffer from variability in intensity and positioning of signals from protein markers within a run and across different runs. Therefore, it is necessary to standardize protocols for preprocessing of the multiplexed bioimaging (MBI) data from multiple runs to a comparable scale before any further analysis can be performed on the data. In this paper, we compare various normalization protocols and propose on the basis of the obtained results, a robust normalization technique that produces consistent results on the MBI data collected from different runs using the Toponome Imaging System (TIS). Normalization results produced by the proposed method on a sample TIS data set for colorectal cancer patients were ranked favorably by two pathologists and two biologists. We show that the proposed method produces higher between class Kullback-Leibler (KL) divergence and lower within class KL divergence on a distribution of cell phenotypes from colorectal cancer and histologically normal samples. PMID:26949415

  7. Introduction of protein or DNA delivered via recombinant Salmonella typhimurium into the major histocompatibility complex class I presentation pathway of macrophages.

    PubMed

    Catic, A; Dietrich, G; Gentschev, I; Goebel, W; Kaufmann, S H; Hess, J

    1999-02-01

    Recombinant (r) Salmonella typhimurium aroA strains which display the hen egg ovalbumin OVA(257-264) peptide SIINFEKL in secreted form were constructed. In addition, attenuated rS. typhimurium pcDNA-OVA constructs harbouring a eukaryotic expression plasmid encoding complete OVA were used to introduce the immunodominant OVA(257-264) epitope into the major histocompatibility complex (MHC) class I presentation pathway. Both modes of antigen delivery (DNA and protein) by Salmonella vaccine carriers stimulated OVA(257-264)-specific CD8 T-cell hybridomas. An in vitro infection system was established that allowed both rSalmonella carrier devices to facilitate MHC class I delivery of OVA(257-264) by coexpression of listeriolysin (Hly) or by coinfection with rS. typhimurium Hlys (Hess J., Gentschev I., Miko D., Welzel M., Ladel C., Goebel W., Kaufmann S.H.E., Proc. Natl. Acad. Sci. USA 93 (1996) 1458-1463). Coexpression of Hly and coinfection with rS. typhimurium Hlys slightly improved MHC class I processing of OVA. Our data provide further evidence for the feasibility of attenuated, Hly-expressing rS. typhimurium carriers secreting heterologous antigens or harbouring heterologous DNA as effective vaccines for stimulating CD8 T cells in addition to CD4 T cells. PMID:10594975

  8. Protection against murine listeriosis by an attenuated recombinant Salmonella typhimurium vaccine strain that secretes the naturally somatic antigen superoxide dismutase.

    PubMed

    Hess, J; Dietrich, G; Gentschev, I; Miko, D; Goebel, W; Kaufmann, S H

    1997-04-01

    A recombinant (r)-Salmonella typhimurium aroA vaccine strain was constructed which secretes the naturally somatic protein of Listeria monocytogenes, superoxide dismutase (SOD), by the HlyB/HlyD/TolC export machinery. Vaccine efficacy of the SOD-bearing carrier strain was compared with that of the p60-secreting construct, S. typhimurium p60s (J. Hess, I. Gentschev, D. Miko, M. Welzel, C. Ladel, W. Goebel, and S. H. E. Kaufmann, Proc. Natl. Acad. Sci. USA 93:1458-1463, 1996). Vaccination of mice with both constructs induced protection against a lethal challenge with the intracellular pathogen, L. monocytogenes. While the somatic listerial antigen, SOD, is immunologically uncharacterized, the naturally secreted protein of L. monocytogenes, p60, is known to be highly immunogenic. Our data emphasize the high vaccine potential of r-Salmonella constructs secreting antigens of somatic or secreted origin. Moreover, they suggest that the HlyB/HlyD/TolC-based antigen delivery system with attenuated Salmonella spp. as the carrier is capable of potentiating the immune response against foreign proteins independent from their immunogenicity in and display by the natural host. PMID:9119463

  9. Psychophysical tuning curves at very high frequencies

    NASA Astrophysics Data System (ADS)

    Yasin, Ifat; Plack, Christopher J.

    2005-10-01

    For most normal-hearing listeners, absolute thresholds increase rapidly above about 16 kHz. One hypothesis is that the high-frequency limit of the hearing-threshold curve is imposed by the transmission characteristics of the middle ear, which attenuates the sound input [Masterton et al., J. Acoust. Soc. Am. 45, 966-985 (1969)]. An alternative hypothesis is that the high-frequency limit of hearing is imposed by the tonotopicity of the cochlea [Ruggero and Temchin, Proc. Nat. Acad. Sci. U.S.A. 99, 13206-13210 (2002)]. The aim of this study was to test these hypotheses. Forward-masked psychophysical tuning curves (PTCs) were derived for signal frequencies of 12-17.5 kHz. For the highest signal frequencies, the high-frequency slopes of some PTCs were steeper than the slope of the hearing-threshold curve. The results also show that the human auditory system displays frequency selectivity for characteristic frequencies (CFs) as high as 17 kHz, above the frequency at which absolute thresholds begin to increase rapidly. The findings suggest that, for CFs up to 17 kHz, the high-frequency limitation in humans is imposed in part by the middle-ear attenuation, and not by the tonotopicity of the cochlea.

  10. On some applications of diophantine approximations

    PubMed Central

    Chudnovsky, G. V.

    1984-01-01

    Siegel's results [Siegel, C. L. (1929) Abh. Preuss. Akad. Wiss. Phys.-Math. Kl. 1] on the transcendence and algebraic independence of values of E-functions are refined to obtain the best possible bound for the measures of irrationality and linear independence of values of arbitrary E-functions at rational points. Our results show that values of E-functions at rational points have measures of diophantine approximations typical to “almost all” numbers. In particular, any such number has the “2 + ε” exponent of irrationality: ǀΘ - p/qǀ > ǀqǀ-2-ε for relatively prime rational integers p,q, with q ≥ q0 (Θ, ε). These results answer some problems posed by Lang. The methods used here are based on the introduction of graded Padé approximations to systems of functions satisfying linear differential equations with rational function coefficients. The constructions and proofs of this paper were used in the functional (nonarithmetic case) in a previous paper [Chudnovsky, D. V. & Chudnovsky, G. V. (1983) Proc. Natl. Acad. Sci. USA 80, 5158-5162]. PMID:16593441

  11. On some applications of diophantine approximations.

    PubMed

    Chudnovsky, G V

    1984-03-01

    Siegel's results [Siegel, C. L. (1929) Abh. Preuss. Akad. Wiss. Phys.-Math. Kl. 1] on the transcendence and algebraic independence of values of E-functions are refined to obtain the best possible bound for the measures of irrationality and linear independence of values of arbitrary E-functions at rational points. Our results show that values of E-functions at rational points have measures of diophantine approximations typical to "almost all" numbers. In particular, any such number has the "2 + epsilon" exponent of irrationality: Theta - p/q > q(-2-epsilon) for relatively prime rational integers p,q, with q >/= q(0) (Theta, epsilon). These results answer some problems posed by Lang. The methods used here are based on the introduction of graded Padé approximations to systems of functions satisfying linear differential equations with rational function coefficients. The constructions and proofs of this paper were used in the functional (nonarithmetic case) in a previous paper [Chudnovsky, D. V. & Chudnovsky, G. V. (1983) Proc. Natl. Acad. Sci. USA 80, 5158-5162]. PMID:16593441

  12. How wet should be the reaction coordinate for ligand unbinding?

    PubMed

    Tiwary, Pratyush; Berne, B J

    2016-08-01

    We use a recently proposed method called Spectral Gap Optimization of Order Parameters (SGOOP) [P. Tiwary and B. J. Berne, Proc. Natl. Acad. Sci. U. S. A. 113, 2839 (2016)], to determine an optimal 1-dimensional reaction coordinate (RC) for the unbinding of a bucky-ball from a pocket in explicit water. This RC is estimated as a linear combination of the multiple available order parameters that collectively can be used to distinguish the various stable states relevant for unbinding. We pay special attention to determining and quantifying the degree to which water molecules should be included in the RC. Using SGOOP with under-sampled biased simulations, we predict that water plays a distinct role in the reaction coordinate for unbinding in the case when the ligand is sterically constrained to move along an axis of symmetry. This prediction is validated through extensive calculations of the unbinding times through metadynamics and by comparison through detailed balance with unbiased molecular dynamics estimate of the binding time. However when the steric constraint is removed, we find that the role of water in the reaction coordinate diminishes. Here instead SGOOP identifies a good one-dimensional RC involving various motional degrees of freedom. PMID:27497545

  13. The induction of cytotoxic T cells and tumor regression by soluble antigen formulation.

    PubMed

    Hariharan, K; Braslawsky, G; Black, A; Raychaudhuri, S; Hanna, N

    1995-08-15

    CTLs specific for tumor antigens play a major role in the immunity against cancer. We have shown that class I-restricted CTLs can be induced by injecting soluble antigens mixed in an antigen formulation (AF) that consists of squalane, Tween 80, and Pluronic L121 (S. Raychaudhuri et al., Proc. Natl. Acad. Sci. USA, 89: 8308-8312, 1992). In this study, using ovalbumin and the ovalbumin-expressing transfectoma (EG7) as a tumor model system, we examined the in vivo antitumor effect of antigen-AF mixture. Vaccination of mice with ovalbumin in AF 2 or 3 days after EG7 tumor challenge showed significant inhibition of tumor growth compared to mice vaccinated with ovalbumin in alum or in saline. Depletion of CD8+ cells at the time of immunization completely abrogated the AF-induced tumor protection, indicating that CD8+ T cells are the major effectors in tumor protection in vivo. Depletion of CD4+ cells led to a marginal loss of tumor protection, which may be the result of inhibition of ovalbumin-specific CTL response due to the lack of T-helper activity. Our results demonstrate that AF can be used in subunit vaccines to stimulate CTLs and tumor regression in vivo. PMID:7627951

  14. Thermodynamic forces in single crystals with dislocations

    NASA Astrophysics Data System (ADS)

    Van Goethem, Nicolas

    2014-06-01

    A simple model for the evolution of macroscopic dislocation regions in a single crystal is presented. This model relies on maximal dissipation principle within Kröner's geometric description of the dislocated crystal. Mathematical methods and tools from shape optimization theory provide equilibrium relations at the dislocation front, similarly to previous work achieved on damage modelling (J Comput Phys 33(16):5010-5044, 2011). The deformation state variable is the incompatible strain as related to the dislocation density tensor by a relation involving the Ricci curvature of the crystal underlying elastic metric. The time evolution of the model variables follows from a novel interpretation of the Einstein-Hilbert flow in terms of dislocation microstructure energy. This flow is interpreted as the dissipation of non-conservative dislocations, due to the climb mechanism, modelled by an average effect of mesoscopic dislocations moving normal to their glide planes by adding or removing points defects. The model equations are a fourth-order tensor parabolic equation involving the operator "incompatibility," here appearing as a tensorial counterpart of the scalar Laplacian. This work encompasses and generalizes results previously announced (C R Acad Sci Paris Ser I 349:923-927, 2011), with in addition a series of physical interpretations to give a meaning to the newly introduced concepts.

  15. Morphological response of injured adult rabbit optic nerve to implants containing media conditioned by growing optic nerves.

    PubMed

    Lavie, V; Harel, A; Doron, A; Solomon, A; Lobel, D; Belkin, M; Ben-Basat, S; Sharma, S; Schwartz, M

    1987-09-01

    Adult rabbit retina can express regeneration-associated characteristics after optic nerve injury, provided it is supplied with appropriate diffusible substances originating from media conditioned by regenerating fish optic nerves or by optic nerves of a newborn rabbit [Hadani et al., Proc. Natl. Acad. Sci. U.S.A., 81 (1984) 7965; Schwartz et al., Science, 228 (1985) 600]. This was shown by applying the active substances to the injured axons in the form of 'wrap-around' implants, consisting of collagen-coated silicone tubes which had been soaked in the conditioned media (CM). The regeneration-associated response was manifested biochemically and by sprouting of nerve fibers in culture. The present work provides morphological evidence that the implantation prolongs survival of ganglion cells and optic nerve fibers and induces new growth. Light microscopic analysis (using horseradish peroxidase (HRP) for labeling the fibers) revealed, 1 week following optic nerve injury, labeled fibers and ganglion cells in both the implanted and control (injured only or injured and implanted with collagen-coated silicone tubes free of CM) nerves. However, from the second week after the injury, distinct differences in the appearance of viable ganglion cells and labeled fibers, were seen between experimental and control preparations. In sections taken through the optic nerve, at the region distal to the site of injury, HRP-labeled fibers were seen in the experimental nerves 1 week, 2 weeks and to a significantly lesser extent 1 month after injury.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3676722

  16. Tumor promoters alter gene expression and protein phosphorylation in avian cells in culture

    SciTech Connect

    Laszlo, A.; Radke, K.; Chin, S.; Bissell, M.J.

    1981-10-01

    We have investigated the effect of 12-O-tetradecanoylphorbol 13-acetate (TPA) on the synthesis and modification of polypeptides in normal avian cells and cells infected by wild-type and temperature-sensitive Rous sarcoma virus (RSV). Using two-dimensional gel electrophoresis, we have detected alterations in both the abundance of cellular polypeptides and in their phosphorylation that seem unique to TPA treatment. However, the state of phosphorylation of the major putative substrate for the action of the src gene-associated protein kinase, the 34- to 36-kilodalton protein, was not altered. Moreover, examination of the phosphorylated amino acid content of total cellular phosphoproteins revealed that the response to TPA was not associated with detectable increases in their phosphotyrosine content. These results make it unlikely that TPA acts by the activation of the phosphorylating activity of the cellular proto-src gene or by the activation of other cellular phosphotyrosine-specific kinases. We have shown previously that temperature-sensitive RSV-infected cells at nonpermissive temperature demonstrate an increased sensitivity to TPA treatment (Bissell, M.J., Hatie, C. and Calfin, M. (1979) Proc. Natl. Acad. Sci. USA 76, 348-352). Our present results indicate that this is not due to reactivation of the phosphorylating activity of the defective src gene product or to its leakiness, and they lend support to the notion of multistep viral carcinogenesis.

  17. Quantifying the distribution of nanodiamonds in pre-Younger Dryas to recent age deposits along Bull Creek, Oklahoma Panhandle, USA

    NASA Astrophysics Data System (ADS)

    Bement, Leland C.; Madden, Andrew S.; Carter, Brian J.; Simms, Alexander R.; Swindle, Andrew L.; Alexander, Hanna M.; Fine, Scott; Benamara, Mourad

    2014-02-01

    High levels of nanodiamonds (nds) have been used to support the transformative hypothesis that an extraterrestrial (ET) event (comet explosion) triggered Younger Dryas changes in temperature, flora and fauna assemblages, and human adaptations [Firestone RB, et al. (2007) Proc Natl Acad Sci USA 104(41):16016-16021]. We evaluate this hypothesis by establishing the distribution of nds within the Bull Creek drainage of the Beaver River basin in the Oklahoma panhandle. The earlier report of an abundance spike of nds in the Bull Creek I Younger Dryas boundary soil is confirmed, although no pure cubic diamonds were identified. The lack of hexagonal nds suggests Bull Creek I is not near any impact site. Potential hexagonal nds at Bull Creek were found to be more consistent with graphene/graphane. An additional nd spike is found in deposits of late Holocene through the modern age, indicating nds are not unique to the Younger Dryas boundary. Nd distributions do not correlate with depositional environment, pedogenesis, climate perturbations, periods of surface stability, or cultural activity.

  18. Potential of ZrO clusters as replacement Pd catalyst

    NASA Astrophysics Data System (ADS)

    Behera, Swayamprabha; King, Nicholas; Samanta, Devleena; Jena, Puru

    2014-07-01

    Atomic clusters with specific size and composition and mimicking the chemistry of elements in the periodic table are commonly known as superatoms. It has been suggested that superatoms could be used to replace elements that are either scarce or expensive. Based on a photoelectron spectroscopy experiment of negatively charged ions, Castleman and co-workers [Proc. Natl. Acad. Sci. U.S.A. 107, 975 (2010)] have recently shown that atoms of Ni, Pd, and Pt which are well known for their catalytic properties, have the same electronic structure as their counterpart isovalent diatomic species, TiO, ZrO, and WC, respectively. Based on this similarity they have suggested that ZrO, for example, could be a replacement catalyst for Pd. Since catalysts are seldom single isolated atoms, one has to demonstrate that clusters of ZrO also have the same electronic structure as same sized Pd clusters. To examine if this is indeed the case, we have calculated the geometries, electronic structure, electron affinity, ionization potential, and hardness of Pdn and (ZrO)n clusters (n = 1-5). We further studied the reaction of these clusters in neutral and charged forms with H2, O2, and CO and found it to be qualitatively different in most cases. These results obtained using density functional theory with hybrid B3LYP functional do not support the view that ZrO clusters can replace Pd as a catalyst.

  19. Potential of ZrO clusters as replacement Pd catalyst.

    PubMed

    Behera, Swayamprabha; King, Nicholas; Samanta, Devleena; Jena, Puru

    2014-07-21

    Atomic clusters with specific size and composition and mimicking the chemistry of elements in the periodic table are commonly known as superatoms. It has been suggested that superatoms could be used to replace elements that are either scarce or expensive. Based on a photoelectron spectroscopy experiment of negatively charged ions, Castleman and co-workers [Proc. Natl. Acad. Sci. U.S.A. 107, 975 (2010)] have recently shown that atoms of Ni, Pd, and Pt which are well known for their catalytic properties, have the same electronic structure as their counterpart isovalent diatomic species, TiO, ZrO, and WC, respectively. Based on this similarity they have suggested that ZrO, for example, could be a replacement catalyst for Pd. Since catalysts are seldom single isolated atoms, one has to demonstrate that clusters of ZrO also have the same electronic structure as same sized Pd clusters. To examine if this is indeed the case, we have calculated the geometries, electronic structure, electron affinity, ionization potential, and hardness of Pdn and (ZrO)n clusters (n = 1-5). We further studied the reaction of these clusters in neutral and charged forms with H2, O2, and CO and found it to be qualitatively different in most cases. These results obtained using density functional theory with hybrid B3LYP functional do not support the view that ZrO clusters can replace Pd as a catalyst. PMID:25053314

  20. Origin of pronounced differences in 77 K fluorescence of the green alga Chlamydomonas reinhardtii in state 1 and 2.

    PubMed

    Ünlü, Caner; Polukhina, Iryna; van Amerongen, Herbert

    2016-04-01

    In response to changes in the reduction state of the plastoquinone pool in its thylakoid membrane, the green alga Chlamydomonas reinhardtti is performing state transitions: remodelling of its thylakoid membrane leads to a redistribution of excitations over photosystems I and II (PSI and PSII). These transitions are accompanied by marked changes in the 77 K fluorescence spectrum, which form the accepted signature of state transitions. The changes are generally thought to reflect a redistribution of light-harvesting complexes (LHCs) over PSII (fluorescing below 700 nm) and PSI (fluorescing above 700 nm). Here we studied the picosecond fluorescence properties of C. reinhardtti over a broad range of wavelengths with very low excitation intensities (0.2 nJ per laser pulse). Cells were directly used for time-resolved fluorescence measurements at 77 K without further treatment, such as medium exchange with glycerol. It is observed that upon going from state 1 (relatively more fluorescence below 700 nm) to state 2 (relatively more fluorescence above 700 nm), a large part of the fluorescence of LHC/PSII becomes substantially quenched in concurrence with LHC detachment from PSII, whereas the absolute amount of PSI fluorescence hardly changes. These results are in agreement with the recent proposal that the amount of LHC moving from PSII to PSI upon going from state 1 to state 2 is rather limited (Unlu et al. Proc Natl Acad Sci USA 111 (9):3460-3465, 2014). PMID:26518693