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Sample records for hiu qu ca

  1. Dampak Ketiadaan Pengaturan Kuota Ekspor Hiu Tikus (Alopias Ssp. di Indonesia

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    Wahyu Hardiningsih

    2017-12-01

    Full Text Available Kuota ekspor merupakan salah satu mekanisme perlindungan ekosistem laut. Banyaknya perburuan Ikan Hiu Tikus (Alopias Ssp. di Indonesia saat ini karena permintaan pasar yang tinggi, khususnya dari luar negeri. Tingginya permintaan menyebabkan ikan jenis ini masuk ke dalam daftar Convention on International Trade in Endanger Species of Wild Fauna and Flora (CITES Appendiks II pada tahun 2016. Jika Ikan Hiu Tikus yang merupakan predator puncak pada rantai makanan di laut ini sampai terancam punah, maka ekosistem laut akan mengalami kerusakan parah. Hasil penelitian menunjukkan bahwa Indonesia belum memiliki perangkat hukum yang memadai terkait dengan penentuan komponen-komponen kuota ekspor Ikan Hiu, khususnya Ikan Hiu Tikus sebagaimana ketentuan yang diatur di dalam CITES. Keadaan ini menimbulkan dampak terhadap kelestarian Ikan Hiu Tikus itu sendiri, kepentingan masyarakat Indonesia, keberlangsungan lingkungan laut dan generasi yang memanfaatkannya, serta berdampak terhadap perdagangan internasional.

  2. JENIS, UKURAN DAN DAERAH PENANGKAPAN HIU THRESHER (FAMILI ALOPIIDAE YANG TERTANGKAP RAWAI TUNA DI SAMUDERA HINDIA

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    Agustinus Anung Widodo

    2016-03-01

    Full Text Available Sebagai anggota Indian Ocean Tuna Commision (IOTC Indonesia wajib mengadopsi isi Resolusi IOTC 10/12 yang mengatur pengelolaan sumberdaya ikan hiu thresher (famili Alopiidae. Secara spesifik Indonesia belum melaksanakan pengelolaan sumberdaya hiu thresher karena spesies tersebut belum mendapatkan perhatian serius. Tulisan ini bermaksud menyampaikan hasil penelitian tentang ikan hiu thresher (Famili Alopiidae yang tertangkap rawai tuna di Samudera Hindia berbasis di Cilacap. Data diperoleh dari kegiatan pengambilan contoh di pelabuhan tahun 2010, kegiatan observasi di atas kapal rawai tuna bulan Januari 2010 dan laporan statistik PPS Cilacap tahun 2006-2010. Hasil kajian menunjukkan bahwa: (a di perairan Indonesia ada dua spesies dari tiga spesies hiu thresher yang ada di dunia, yaitu hiu monyet atau pelagic thresher (Alopias pelagicus Nakamura 1935 dan hiu paitan atau bigeye thresher (A. superciliosus Lowe 1840. Satu spesies lainnya yang belum pernah ditemukan adalah thinfin thresher (A.vulpinus Bonnaterre1788.  Dilihat dari teknologi rawai tuna yang digunakan, daerah sebaran hiu thresher sama dengan tuna di Samudera Hindia, sehingga sulit untuk menghindari tidak tertangkapnya hiu thresher oleh rawai tuna. Jumlah dari jenis hiu monyet yang tertangkap rawai tuna di Samudera Hindia berkisar 0,1-0,6 % dan hiu paitan berkisar 0,1-1,3 % dari total tangkapan. Ukuran hiu thresher yang tertangkap rawai tuna umumnya ikan yang telah dewasa (berkisar 54-74% dan diduga telah mengalami pemijahan. Hampir semua bagian hiu thresher dimanfaatkan sebagai bahan pangan dan farmasi. Selain dipasarkan di dalam negeri, ikan hiu thresher juga diekspor terutama siripnya ke manca negara dan terbanyak ke China.   As a member of IOTC, Indonesia is obliged to implement all IOTC’s resolutions including resolution 10/12 on the conservation of thresher sharks (Family Alopiidae caught in association with fisheries in the IOTC area of competence. Indonsia has not

  3. KOMPOSISI UKURAN, NISBAH KELAMIN DAN DAERAH PENYEBARAN HIU BUAYA (Pseudocarcharias kamoharai YANG TERTANGKAP DI SAMUDERA HINDIA

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    Dian Novianto

    2016-05-01

    Full Text Available Ikan hiu buaya (Pseudocarcharias kamoharai merupakan salah satu jenis hiu yang tertangkap secara tidak sengaja pada perikanan rawai tuna (tuna longline. Ikan hiu buaya dalam penanganannya selalu dibuang di laut karena ukuran tubuhnya yang kecil dan tidak memiliki pasar diantara ikan non target (by-catch lainnya. Penelitian tentang komposisi ukuran, nisbah kelamin dan daerah penyebaran hiu buaya dilakukan pada tahun 2010 – 2011 di perairan WPP 573 – 572 Samudera Hindia dengan mengikuti kapal longline yang berbasis di Benoa dan Bungus. Tujuan penelitian adalah untuk mendapatkan data dan informasi dalam rangka pengelolaan dan konservasi hiu buaya. Hiu buaya memiliki kisaran panjang tubuh 37 – 96 cm FL dengan panjang maksimal 96 cm FL untuk jenis betina dan 94 cm FL untuk jenis jantan dan modus pada kisaran 85 – 89 cm FL untuk jenis betina dan 75 – 79 cm FL untuk jenis jantan. Perbandingan jenis kelamin ikan jantan dan betina adalah 1 : 1,33, menunjukkan bahwa rasio ikan jantan dan betina tidak seimbang. Ikan hiu buaya terdistribusi tidak merata, hanya terdapat di 77 posisi setting pada 1120 – 1220 Bujur Timur dan 090 – 150 Lintang Selatan dari 256 jumlah setting selama periode penelitian ini.   Crocodile shark (Pseudocarcharias kamoharai is one of sharks species caught accidentally in tuna longline fisheries. Crocodile shark handling is always discarded at sea because of it is small size and is not economics value among others non-target fish (by-catch. Research on the biology of crocodile shark was conducted in 2010 – 2011 at Fisheries management Areas (FMA 572 (Indian Ocean – west Sumatera and 573 (South of Java – East Nusa Tenggara following longline vessels based in Benoa and Bungus. The purpose of research was to investigate data and information on the crocodile shark for management and conservation purposes. Crocodile shark has a range of body length of 37-96 cm FL with a maximum length of 96 cm FL for females and 94 cm

  4. PERBEDAAN HASIL TANGKAPAN HIU DARI RAWAI HANYUT DAN DASAR YANG BERBASIS DI TANJUNG LUAR, LOMBOK

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    Agus Arifin Sentosa

    2016-11-01

    Full Text Available Aktivitas penangkapan hiu sebagai target tangkapan utama bagi perikanan rawai di Tanjung Luar, Lombok Timur berlangsung sepanjang tahun dengan upaya penangkapan yang terus meningkat. Tingginya upaya penangkapan dapat meningkatkan jumlah dan jenis hasil tangkapan. Penelitian ini bertujuan untuk mengetahui perbedaan hasil tangkapan hiu dari alat tangkap rawai hanyut dan rawai dasar yang dioperasikan oleh nelayan yang berbasis di PPI Tanjung Luar, Lombok Timur. Data tangkapan diperoleh melalui catatan enumerator di Tanjung Luar, Lombok Timur pada Januari – November 2015. Analisis data dilakukan secara deskriptif dan perhitungan laju tangkap. Hasil penelitian menunjukkan bahwa laju tangkap rawai hiu yang dioperasikan nelayan Tanjung Luar berfluktuasi tiap bulan dengan rerata 73,98±40,58 kg/hari dan rerata laju pancing 4,32±2,23 ekor/100 pancing. Laju tangkap cenderung mulai mengalami peningkatan mulai bulan April dan mencapai puncaknya sekitar November. Laju tangkap rawai hanyut lebih tinggi dibandingkan rawai dasar. Total hasil tangkapan didominasi oleh Carcharhinus falciformis (42,12%, Prionace glauca (10,51% dan C. limbatus (10,32% dimana C. falciformis dan P. glauca cenderung lebih banyak tertangkap oleh rawai hanyut sedangkan C. limbatus banyak tertangkap oleh rawai dasar. Jenis hiu hasil tangkapan rawai dasar lebih beragam (26 jenis dibanding rawai hanyut (18 jenis. Rawai hanyut cenderung lebih banyak menangkap jenis hiu dengan status konservasi rawan dan langka menurut Daftar Merah IUCN serta masuk dalam Appendiks CITES.

  5. 81. Tumor maligno en cav idad ca rdíaca simulando trombosis quística

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    M.aT. Conejero Jurado

    2010-01-01

    Conclusiones: Los sarcomas cardíacos, por su clínica inespecífica y baja incidencia, son difíciles de diagnosticar. La supervivencia a corto plazo es baja. La imagen ecográfica, «simulando» una trombosis quística, es extremadamente rara. La intervención probablemente no se habría indicado en caso de sospecha preoperatorio de sarcoma.

  6. Data of evolutionary structure change: 1CG5B-2QU0C [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 0 C 2QU0C DLHAHKLRVDPence>...0 C 2QU0C FPHFD--LSHGSence...1CG5B-2QU0C 1CG5 2QU0 B C VKLSEDQEHYIKGVWKDVD--HKQITAKALERVFVVYPW... 1CG5 B 1CG5B ence>WKDVD--HKQIT... 384 THR CA 441 2QU0 C 2QU

  7. Data of evolutionary structure change: 1CG8B-2QU0A [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 0 A 2QU0A ence>DLHAHKLRVDP...0 A 2QU0A ence>YFPHF--DLSHG...1CG8B-2QU0A 1CG8 2QU0 B A VKLSEDQEHYIKGVWKDV--DHKQITAKALERVFVVYPW...> 1CG8 B 1CG8B ence>VWKDV--DHKQI...ine> ILE CA 383 2QU0 A 2QU

  8. Data of evolutionary structure change: 1GCWC-2QU0D [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available pdbID> D 2QU0D ence>ARHHGNEFTPVence> D 2QU0D ence>FWGKV--KVDEV...1GCWC-2QU0D 1GCW 2QU0 C D AFTACEKQTIGKIAQVLAKSPEAYGAECLARLFVTHPGS... 1GCW C 1GCWC ence>YKDYS-----AAGAK...2 LYS CA 240 2QU0 D 2QU

  9. Data of evolutionary structure change: 2QU0A-2HHBD [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 0 A 2QU0A ence>WGKVGGNAGAYG...2QU0A-2HHBD 2QU0 2HHB A D -VLSAADKSNVKAAWGKVGGNAGAYGAEALERMFLSFPT... 0 2HHB D 2HHBD ...ence>WGKVN--VDEVGence> GGG --HHHHH ... GLU CA 293 VAL CA 366 GLY CA 390 2QU

  10. Data of evolutionary structure change: 1CBMB-2QU0C [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 0 C 2QU0C ence>WGKVGGNAGAYG...1CBMB-2QU0C 1CBM 2QU0 B C VHLTPEEKSAVTALWGKVN--VDEVGGEALGRLLVVYPW...EVID> 0 1CBM B 1CBMB ...ence>WGKVN--VDEVGence> GGG --HHHHH GLU CA 291 VAL CA 359 GLY CA 385 2QU

  11. Adel en heerlijkheden in Québec: De opkomst en het voortleven van een sociale groep en een feodaal instituut (ca. 1600-- 2000)

    NARCIS (Netherlands)

    Verstegen, S.W.; Grenier, Benoît

    2017-01-01

    The colonization of French Canada started in the late sixteenth century. In Québec a seigneurial system was implemented, dominated by nobles. Not all seigneurs were noble though. A few of the bigger seigneuries belonged to the clergy and others to non- noble bourgeois families or even farmers. In

  12. Data of evolutionary structure change: 2QU0A-2DN1B [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available >A 2QU0A WGKVGGNAGAYGence> HHHH...2QU0A-2DN1B 2QU0 2DN1 A B VLSAADKSNVKAAWGKVGGNAGAYGAEALERMFLSFPTT...index>0 2DN1 B 2DN1B ...ence>WGKVN--VDEVGence> GGG --HHHHH VAL CA 367 GLY CA 400 2QU0

  13. Data of evolutionary structure change: 2QU0A-2DXMB [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available n>A 2QU0A WGKVGGNAGAYGence> HHH...2QU0A-2DXMB 2QU0 2DXM A B -VLSAADKSNVKAAWGKVGGNAGAYGAEALERMFLSFPT...ID> 0 2DXM B 2DXMB ...ence>WGKVN--VDEVGence> GGG --HHHHH VAL CA 716 GLY CA 753 2QU0

  14. Data of evolutionary structure change: 2QU0A-2HCOB [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 2QU0A-2HCOB 2QU0 2HCO A B -VLSAADKSNVKAAWGKVGGNAGAYGAEALERMFLSFPT...ryChain> 2HCO B 2HCOB ence>WGKVN--VDEVG...ne> GLY CA 388 2QU0 A 2QU...0A ence>WGKVGGNAGAYGence> HHHHGGGHHHHH

  15. Data of evolutionary structure change: 1GCWC-2QU0B [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available dbChain>B 2QU0B ence>ARHHGNEFTPVence> B 2QU0B ence>GFWGK--VKVDEence> 0 C B AFTACEKQTIGKIAQVLAKSPEAYGAECLARLFVTHPGS...ex>0 1GCW C 1GCWC ATHLT-EFSPD...ne> PRO CA 171 ASP CA 215 2QU0

  16. Use of thermodynamic chemical potential diagrams (µCaO, µCO2 to understand the weathering of cement by a slightly carbonated water Uso de diagramas de potencial químico termodinâmico (µCaO, µCO2 para o entendimento da resistência do cimento à água levemente carbonatada

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    A. Blandine

    2008-09-01

    Full Text Available Cement is a ubiquitous material that may suffer hazardous weathering. The chemical weathering of cement in natural environment is mostly characterized by the leaching of CaO and the addition of CO2. The different weathering zones that develop at the expense of the cement may be predicted by the help of chemical potential phase diagrams; these diagrams simulate the behaviour of systems open to some chemical elements. Some components have a so-called inert status, that is to say the system is closed for these components, their amount in the system remains constant; some other components have a mobile status, that is to say these components can be exchanged with the outside of the system, their amount can vary from one sample zone to another. The mobile components are represented in the model by their chemical potentials (linked to their concentrations that are variable in the external environment. The main features of the weathering of a cement system open to CaO and CO2 are predicted in a phase diagram with µCaO et µCO2 as diagram axes. From core to rim, one observes the disappearance of portlandite, ettringite and calcium monosulfoaluminate, the precipitation of calcite and amorphous silica, the modification of the composition of the CSH minerals (hydrated calcium silicates that see a decrease of their c/s ratio (CaO/SiO2 from the core to the rim of the sample. For the CSH minerals, we have separated their continuous solid solution into three compositions defined by different CaO/SiO2 ratios and called phases 1, 2 and 3: CaO = 0.8, 1.1, 1.8 respectively for one mole of SiO2 knowing that H2O varies in the three compositions.Cimento é um material de ampla utilização que pode ser sujeito a modificação pelo tempo. A modificação química do cimento em meio natural é principalmente caracterizada por lixiviação de CaO e adição de CO2. As diferentes zonas de resistência que se desenvolvem às custas do cimento podem ser previstas com os

  17. Data of evolutionary structure change: 1CG5A-2QU0C [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available D> C 2QU0C ence>YFPHF-DLSHGence> 0 A C VLSSQNKKAIEELGNLIKANAEAWGADALARLFELHPQT...n> 1CG5 A 1CG5A ence>VNLQA-FTPVT...line> THR CA 269 2QU0 C 2QU...0C ence>CHLPNDFTPAVence> HHHH HHH

  18. Data of evolutionary structure change: 1CG8A-2QU0A [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available /pdbChain> 2QU0A ence>YFPHF-DLSHGence> G - 0 A A VLSSQNKKAIEELGNLIKANAEAWGADALARLFELHPQT...hain> 1CG8 A 1CG8A ence>VNLQA-FTPVT...ine>THR CA 278 2QU0 A 2QU...0A ence>CHLPNDFTPAV HH HHHH HHH

  19. Caracterización físico-química de una vinaza resultante de la producción de alcohol de una industria licorera, a partir del aprovechamiento de la caña de azúcar

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    Carlos Esteban Aristizábal Alzate

    2015-12-01

    Full Text Available El presente artículo tiene como propósito ilustrar los resultados de la caracterización fisico-química de unas vinazas resultantes de la producción de etanol en una industria licorera, a partir del aprovechamiento de la caña de azúcar. Parámetros importantes son presentados para la determinación de la calidad y la evaluación de alternativas de tratamiento para este subproducto, como lo son la temperatura de ebullición, la densidad, entre otros, y parámetros de importancia para el tema de vertimientos líquidos, según la legislación colombiana, como lo son su pH y su curva de titulación.

  20. ¿Por qué perdió el PRI en Yucatán? Las transiciones de este año en bastiones priístas, caída de una imagen distorsionada

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    Lic. Fernando Pacheco Bailón

    2001-01-01

    Full Text Available El pasado domingo 27 de mayo, a eso de las 5:30 de la tarde, los mexicanos nos enteramos a través de los medios de comunicación de televisión abierta y pagada de la ventaja que tenía el candidato a la gubernatura de Yucatán, a través de la coalición PAN, PRD, PVEM, PT, Patricio Patrón Laviada, con respecto al candidato del PRI, Orlando Paredes Lara. Más tarde, de aquella llamada telefónica que hiciera el presidente Vicente Fox para felicitar al candidato que aventajaba al del tricolor, al hacer referencia a las encuestas de salida llevadas a cabo por empresas como Consulta Mitovsky, Garo y otras más. Hay muchas metodologías para poder analizar procesos electorales, así como distintas formas de abordar el problema del por qué perdió el PRI en Yucatán. Para efectos de estudio se planteará las condiciones preelectorales que se dieron, el propio momento electoral del pasado 27 de mayo, así como la visión futura de PRI como organización política en tiempos transitorios.

  1. Data of evolutionary structure change: 1A5CA-2QUTB [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available T B 2QUTB ence>LLTADDRVNPCence> B 2QUTB LKIGE--HTPSA...1A5CA-2QUTB 1A5C 2QUT A B ------LPADVAEELATTAQKLVQAGKGILAADESTQTI...tryIDChain>1A5CA ence>LFGTK-GLGKFence> HH - HHHH PHE CA 426 2QU

  2. Future Potential for Hydro-Québec and the Québec electricity market

    OpenAIRE

    Teig, Atle Nedbu

    2010-01-01

    The purpose of this thesis is to investigate what a restructuring of the Québec electricity market could mean for Hydro-Québec and the Province of Québec. The thesis is divided into four main sections. Section one describes the drivers of electricity markets and we get an introduction to the situation in Québec. The environmental aspect of energy is also explained. Section two describes the electricity market in Norway and the Nordic countries, which works as a benchma...

  3. Química general II

    OpenAIRE

    Olba Torrent, Amparo

    2018-01-01

    El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València Temes de l'assignatura: Química general II del primer curs del Grau de Química Topics of the course: General Chemistry II in the first year of the Degree in Chemistry

  4. La lectura en el aula. Qué se hace, qué se debe hacer y qué se puede hacer

    OpenAIRE

    Pablo Lorente Muñoz

    2011-01-01

    Emilio Sánchez Miguel (Coord.). La lectura en el aula. Qué se hace, qué se debe hacer y qué se puede hacer. Graó, col. Crítica y Fundamentos, 27. Barcelona, 2010. 382 págs. ISBN: 978-84-7827-892-3

  5. Data of evolutionary structure change: 2QU0A-2HHED [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available ID> 0 2QU0 A 2QU0A ...ne> 2QU0 A 2QU0A ...2QU0A-2HHED 2QU0 2HHE A D VLSAADKSNVKAAWGKVGGNAGAYGAEALERMFLSFPTT...ence>HGSAQ-----VKGHGence> HH-----HHHHH D 2HHED ence>TPDAVMGNPKVKAHGence>

  6. Data of evolutionary structure change: 1CG5B-2QU0A [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available Chain>A 2QU0A ence>AWGKVGGNAGAYence> 2QU0 A 2QU0A ence>DLHAHKLRVDP...0 A 2QU0A ence>YFPHF--DLSHG...1CG5B-2QU0A 1CG5 2QU0 B A VKLSEDQEHYIKGVWKDV--DHKQITAKALERVFVVYPW...dex>0 1CG5 B 1CG5B

  7. Química de Heterociclos

    OpenAIRE

    Collado, Daniel

    2014-01-01

    Heterociclos aromáticos con cinco miembros. Pirrol, furano y tiofeno: propiedades. Sustitución electrofílica aromática. Reacciones de los sustituyentes alquílicos. Sustitución nucleofílica. Radicales y carbenos, aperturas de anillo. Síntesis. Capítulo segundo del temario del segundo bloque de la asignatura Ampliación de Química Orgánica Avanzada. Heterociclos aromáticos de cinco miembros.

  8. Aprendiendo química con golosinas

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    José Manuel Rodríguez Rodríguez

    2011-01-01

    Full Text Available Las golosinas (caramelos, chicles, nubes, palotes, papas fritas, etc. nos gustan a casi todos y gozan de una imagen positiva, a pesar de sus efectos secundarios si no se consumen con moderación. Aprovechándonos de esa buena imagen y de la gran variedad de golosinas que existen en el mercado, hemos diseñado una serie de experimentos con los que podemos explicar distintos tipos de reacciones químicas (ácido-base, oxidación reducción, endotérmicas¿, la actuación de un indicador e, incluso, podemos comparar cantidades de vitamina C. En todas las actividades se persigue explicar algún aspecto de la Química que, en general, el público desconoce, captando su atención, por ejemplo, mediante cambios de color espectaculares y con las golosinas como protagonistas. Así mismo, estas experiencias pueden emplearse como recursos didácticos para alumnos de 4º E.S.O. y Bachillerato, apoyando los contenidos teóricos del currículum.

  9. Química de Heterociclos. Quinolina e isoquinolina

    OpenAIRE

    Collado, Daniel

    2014-01-01

    Quinolinas e isoquinolinas: propiedades. Reactividad química: SEAr, SNAr. Reacciones en cadenas laterales. Reacciones de quinolinio e isoquinolinio. Síntesis de quinolinas e isoquinolinas. Otros ciclos. Capítulo sexto de temario de la Asignatura Ampliación de Química Orgánica Avanzada. Quinolina e isoquinolina.

  10. Aumentando la realidad química

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    Mª Luisa Roqueta Buj

    2017-08-01

    Full Text Available El uso de nuevas tecnologías como la Realidad Aumentada en la enseñanza de la Química permite manejar información virtual y asociarla a elementos de la vida real. Se accede a la misma a través de un dispositivo tecnológico con un software específico. Esta herramienta tecnológica recibe el nombre de Realidad Aumentada y permite añadir contenido digital a nuestro mundo real aumentando la percepción que tenemos del mismo. Nos permite incorporar contenido en forma de texto, imagen, audio o vídeo.

  11. de la química

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    Gregorio Jiménez-Valverde

    2006-01-01

    Full Text Available En la presente comunicación se detalla una innovadora experiencia llevada a cabo durante los cursos 2001-02 y 2002-03 consistente en el uso del BSCW, un entorno telemático para el trabajo cooperativo, en el Ciclo Formativo de Grado Superior de Química Ambiental. En el artículo se detallan las principales características del entorno, cómo fue aplicado y los resultados que se obtuvieron, presentados en páginas web creadas por los propios estudiantes sobre diferentes aspectos de metales en aguas. El alumnado, a través de una encuesta, respaldó esta experiencia y mostró una actitud muy positiva en la creación de materiales hipermedia.

  12. Simulated breeding with QU-GENE graphical user interface.

    Science.gov (United States)

    Hathorn, Adrian; Chapman, Scott; Dieters, Mark

    2014-01-01

    Comparing the efficiencies of breeding methods with field experiments is a costly, long-term process. QU-GENE is a highly flexible genetic and breeding simulation platform capable of simulating the performance of a range of different breeding strategies and for a continuum of genetic models ranging from simple to complex. In this chapter we describe some of the basic mechanics behind the QU-GENE user interface and give a simplified example of how it works.

  13. Continuous D-lactic acid production by a novel thermotolerant Lactobacillus delbrueckii subsp. lactis QU 41.

    Science.gov (United States)

    Tashiro, Yukihiro; Kaneko, Wataru; Sun, Yanqi; Shibata, Keisuke; Inokuma, Kentaro; Zendo, Takeshi; Sonomoto, Kenji

    2011-03-01

    We isolated and characterized a D-lactic acid-producing lactic acid bacterium (D-LAB), identified as Lactobacillus delbrueckii subsp. lactis QU 41. When compared to Lactobacillus coryniformis subsp. torquens JCM 1166 (T) and L. delbrueckii subsp. lactis JCM 1248 (T), which are also known as D-LAB, the QU 41 strain exhibited a high thermotolerance and produced D-lactic acid at temperatures of 50 °C and higher. In order to optimize the culture conditions of the QU 41 strain, we examined the effects of pH control, temperature, neutralizing reagent, and initial glucose concentration on D-lactic acid production in batch cultures. It was found that the optimal production of 20.1 g/l D-lactic acid was acquired with high optical purity (>99.9% of D-lactic acid) in a pH 6.0-controlled batch culture, by adding ammonium hydroxide as a neutralizing reagent, at 43 °C in MRS medium containing 20 g/l glucose. As a result of product inhibition and low cell density, continuous cultures were investigated using a microfiltration membrane module to recycle flow-through cells in order to improve D-lactic acid productivity. At a dilution rate of 0.87 h(-1), the high cell density continuous culture exhibited the highest D-lactic acid productivity of 18.0 g/l/h with a high yield (ca. 1.0 g/g consumed glucose) and a low residual glucose (<0.1 g/l) in comparison with systems published to date.

  14. Impact of seawater [Ca

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; Thoms, S.; Nehrke, G.; Reichart, G.J.; de Nooijer, L.J.; Bijma, J.

    2015-01-01

    Mg / Ca ratios in foraminiferal tests are routinely used as paleotemperature proxies, but on long timescales, they also hold the potential to reconstruct past seawater Mg / Ca. The impact of both temperature and seawater Mg / Ca on Mg incorporation in Foraminifera has been quantified by a number of

  15. ¿Qué es el Open Journal System?

    Directory of Open Access Journals (Sweden)

    Natalia I. Osorio Curbelo

    2015-12-01

    Full Text Available ¿Qué es el Open Journal System (OJS? Es un  software de código abierto. ¿Qué significa  “Código Abierto“? El acceso abierto (en inglés, open access es el acceso inmediato, sin requerimientos de registro, suscripción o pago, es decir sin restricciones, a material digital educativo, académico, científico o de cualquier otro tipo, principalmente artículos de investigación científica de revistas especializadas con peer review (revisión por pares. Significa que cualquier usuario individual pueda leer, descargar, copiar, distribuir, imprimir, buscar o enlazar los textos completos de los artículos científicos, y usarlos con cualquier otro propósito legítimo, como hacer minería de datos de su contenido digital, sin otras barreras económicas, legales o técnicas que las que suponga Internet en sí misma. Es decir, es una manera gratuita y abierta de acceder a la literatura científica. Para qué sirve? Permite controlar todo el proceso de publicación:- El envío de los manuscritos, por parte de los autores. - Selección de los revisores, por parte de los editores. - La revisión, por parte de los revisores primero y luego por los autores mismos. - La corrección de estilos y de sintaxis. - La diagramación/maquetación. - La publicación misma del artículo. - Lectura (con herramientas de lectura. - Indexación en bases de datos y buscadores.Características de OJS- Se instala y se controla de manera local en un servidor Web propio. - Los editores pueden configurar los requisitos, secciones, el proceso de revisión, etc. - Todos los contenidos se envían y se gestionan online. - Permite el envío por e-mail de los artículos y la inserción de comentarios por parte de los lectores. - Cuenta con un módulo de suscripción, con la opción de pasar los artículos a libre acceso, pasado un tiempo. - Cuenta con herramientas de lectura, basadas en la configuración proporcionada por el editor. - Como parte del sistema, cuenta con la

  16. La Industria Química: Importancia y Retos

    Directory of Open Access Journals (Sweden)

    Nancy Montes-Valencia

    2015-06-01

    Full Text Available La química siempre ha estado presente en la vida del hombre para satisfacer sus necesidades y mejorar su calidad de vida. Hoy en día la industria química es un importante sector industrial presente en la mayoría de países, que dinamiza el crecimiento económico, genera empleo y ofrece diversidad de productos, no obstante produce contaminación al medio ambiente y utiliza recursos naturales no renovables. Por lo tanto surge el concepto de química verde como respuesta a la problemática ambiental cuya estructura es la sostenibilidad, siendo su principal objetivo prevenir la generación de emisiones y armonizar la química con los recursos naturales. Existe un gran reto para la industria química y es encontrar fuentes alternativas de energía para no seguir dependiendo del petróleo, el gas natural y el carbón, una de estas es el uso de la biomasa para la obtención de combustibles líquidos.

  17. Uma abordagem investigativa do trabalho experimental no ensino da química a alunos não-químicos na universidade

    OpenAIRE

    Figueiredo, Margarida; Maia, Maria Elisa

    2005-01-01

    Pretende-se divulgar os resultados de um estudo sobre a implementação de um tipo de abordagem ao Trabalho Experimental de Química, cujos objectivos são: - Contribuir para motivar os alunos para a aprendizagem da Química; - Contribuir para melhorar o sucesso na formação em Química dos alunos que não sendo de Química necessitam de fazer aprendizagens nesse domínio; - Contribuir para uma revalorização do trabalho experimental enquanto estratégia privilegiada para o ensino da Química....

  18. Introdución ao laboratorio químico

    OpenAIRE

    Rumbo Gómez, Antonio

    2010-01-01

    A materia inclúese no primeiro ano de estudo da titulación de Enxeñería Técnica Industrial especialidade de Química Industrial. Impártese no primeiro cuadrimestre e é o primeiro contacto que ten o alumnado co laboratorio de química, polo que se considera de indubidable interese o estudo de certos conceptos básicos desta area. Os conceptos desta unidade didáctica serán aplicables a todos os laboratorios que o alumnado terá que realizar ao longo da titulación noutras materias práctic...

  19. Petardos, coetes y mucha química

    OpenAIRE

    Prada Pérez de Azpeitia, Fernando Ignacio de

    2014-01-01

    Els espectaculars efectes que produeixen els petards i coets estan relacionats amb la ciència, per la qual cosa poden ser aprofitats com un inusual i atractiu recurs didàctic per a la química. Amb això es pretén aconseguir augmentar l'interès dels estudiants cap a la ciència, alhora que ampliar el coneixement sobre les reaccions químiques relacionades amb la vida quotidiana. Les experiències proposades han estat realitzades per estudiants davant un públic molt variat en fires de ciència di...

  20. Llenguatges de Programació Quàntica

    OpenAIRE

    Marcos Pitarch, Eric

    2009-01-01

    Aprofundir en els coneixements de computació quàntica, tant des del vessant de la física com des del vessant de la teoria de la computació, que em situïn en un punt de "pre-recerca". Tenir un mapa de les diferents aproximacions a llenguatges de programació quàntica que s'han fet en els últims anys. Distingir els pros/contres i limitacions d'aquestes aproximacions. Investigar els avenços recents relacionats amb complexitat de la CQ i els seus límits des del punt de vista de la teoria de ...

  1. crdi.ca

    International Development Research Centre (IDRC) Digital Library (Canada)

    et des enfants d'Afrique. INITIATIVE CONCERTÉE. Innovation pour la santé des mères et des enfants d'Afrique. Centre de recherches pour le développement international. CP Box 8500 Ottawa ON Canada K1G 3H9. Téléphone : +1 613 236 6163 • Télécopieur : +1 613 657 7749 ismea@crdi.ca | www.crdi.ca/ismea crdi.ca.

  2. INTRACELLULAR Ca2+ HOMEOSTASIS

    Directory of Open Access Journals (Sweden)

    Shahdevi Nandar Kurniawan

    2015-01-01

    Full Text Available Ca2+ signaling functions to regulate many cellular processes. Dynamics of Ca2+ signaling or homeostasis is regulated by the interaction between ON and OFF reactions that control Ca2+ flux in both the plasma membrane and internal organelles such as the endoplasmic reticulum (ER and mitochondria. External stimuli activate the ON reactions, which include Ca2+ into the cytoplasm either through channels in the plasma membrane or from internal storage like in ER. Most of the cells utilize both channels/sources, butthere area few cells using an external or internal source to control certain processes. Most of the Ca2+ entering the cytoplasm adsorbed to the buffer, while a smaller part activate effect or to stimulate cellular processes. Reaction OFF is pumping of cytoplasmic Ca2+ using a combination mechanism of mitochondrial and others. Changes in Ca2+ signal has been detected in various tissues isolated from animals induced into diabetes as well as patients with diabetes. Ca2+ signal interference is also found in sensory neurons of experimental animals with diabetes. Ca2+ signaling is one of the main signaling systems in the cell.

  3. A SiQuENC for Solving Physics Problems

    Science.gov (United States)

    Liao, David

    2018-01-01

    Students often struggle in AP Physics 1 because they have not been previously trained to develop qualitative arguments. Extensive literature on multiple representations and qualitative reasoning provides strategies to address this challenge. Table I presents three examples, including SiQuENC, which I adapted from a strategy promoted by Etkina et…

  4. La contaminación Química

    OpenAIRE

    Jimbo G., Marcelo

    2003-01-01

    La contaminación química de la leche se puede verificar mediante cuatro vías: a. Detergentes y desinfectantes usados en las operaciones de lavado. b.Antielmínticos. c. Insecticidas y anticriptogámicos usados en agricultura. d. Elementos radioactivos, sustancias dicersas, metales.

  5. Algunas reflexiones sobre la distancia entre "hablar química" y "comprender química"

    Directory of Open Access Journals (Sweden)

    Lydia Raquel Galagovsky

    2014-12-01

    Full Text Available Una clase de química puede ser considerada como un espacio de comunicación entre el docente experto y los estudiantes novatos, donde los lenguajes utilizados son la interfase explícita y observable del intercambio comunicativo. En el presente trabajo se muestra con dos ejemplos cómo la diversidad de lenguajes químicos en lugar de favorecer la comprensión de los estudiantes, puede actuar como fuente de obstáculos que dificultan la comunicación en el aula. Así mismo, se analizará con otros dos ejemplos cómo el discurso con el que se enseña la disciplina también es potencial generador de errores en los estudiantes, cuando ellos construyen sus modelos mentales idiosincrásicos a partir de un discurso recortado y simplificado, desde las mejores intenciones de realizar buenas transposiciones didácticas. Se plantea que un enfoque de análisis de la situación de aula como un encuentro comunicativo entre experto y novato conduce a una necesaria diferenciación entre "hablar química" y "comprender química".

  6. Fibrosis quística. Aspectos diagnósticos

    OpenAIRE

    Luis Ortigosa

    2007-01-01

    La fibrosis quística (FQ) es una de las enfermedades genéticas mortales más frecuentes en la raza caucásica. Se caracteriza por una disfunción de las glándulas exocrinas, con insuficiencia pancreática y bronconeumopatía crónica. Es una enfermedad de transmisión autonómica recesiva, se sabe que el gen defectuoso está localizado en el cromosoma 7 humano, conocido como gen regulador de la conductancia transmembrana de la fibrosis quística (CFTR),y que de las más de mil mutaciones de este gen, la...

  7. Se aprende poco : ¿Qué podemos hacer?

    OpenAIRE

    Quinquer, Dolors

    2006-01-01

    La situación en las aulas es más compleja, heterogénea y pluricultural que antes; las competencias que se han de desarrollar se han diversificado, ahora son cognitivas, éticas y sociales, mientras que los marcos organizativos siguen tan rígidos como siempre. En este contexto, comparando España con otros países, parece que los alumnos aprenden poco.¿Qué podemos hacer? 

  8. QuEST: Qualifying Environmentally Sustainable Technologies. Volume 6

    Science.gov (United States)

    Lewis, Pattie

    2011-01-01

    QuEST is a publication of the NASA Technology Evaluation for Environmental Risk Mitigation Principal Center (TEERM). This issue contains brief articles on: Risk Identification and Mitigation, Material Management and Substitution Efforts--Hexavalent Chrome-free Coatings and Low volatile organic compounds (VOCs) Coatings, Lead-Free Electronics, Corn-Based Depainting Media; Alternative Energy Efforts Hydrogen Sensors and Solar Air Conditioning. Other TEERM Efforts include: Energy and Water Management and Remediation Technology Collaboration.

  9. iDESWEB: Usabilidad: qué es

    OpenAIRE

    Luján Mora, Sergio

    2012-01-01

    Qué es la usabilidad, definiciones en ISO 9241 (usuario, objetivo, contexto) e ISO/IEC 9126 (funcionalidad, fiabilidad, usabilidad, eficiencia, mantenibilidad, portabilidad), definición de Jakob Nielsen: "La usabilidad es un atributo de calidad que mide lo fácil que son de usar los interfaces de usuario", componentes de la usabilidad: facilidad de aprendizaje, eficiencia, memorabilidad, errores, satisfacción. Sitio web del curso: http://idesweb.es/

  10. Ca isotopes in refractory inclusions

    International Nuclear Information System (INIS)

    Niederer, F.R.; Papanastassiou, D.A.

    1984-01-01

    We report measurements of the absolute isotope abundance of Ca in Ca-Al-rich inclusions from the Allende and Leoville meteorites. Improved high precision measurements are reported also for 46 Ca. We find that nonlinear isotope effects in Ca are extremely rare in these inclusions. The absence of nonlinear effects in Ca, except for the effects in FUN inclusions, is in sharp contrast to the endemic effects in Ti. One fine-grained inclusion shows an excess of 46 Ca of (7 +- 1) per mille, which is consistent with addition of only 46 Ca or of an exotic (*) component with 46 Ca* approx. 48 Ca*. FUN inclusion EK-1-4-1 shows a small 46 Ca excess of (3.3 +- 1.0) per mille; this confirms that the exotic Ca components in EK-1-4-1 were even more deficient in 46 Ca relative to 48 Ca than is the case for normal Ca. The Ca in the Ca-Al-rich inclusions shows mass dependent isotope fractionation effects which have a range from -3.8 to +6.7 per mille per mass unit difference. This range is a factor of 20 wider than the range previously established for bulk meteorites and for terrestrial and lunar samples. Ca and Mg isotope fractionation effects in the Ca-Al-rich inclusions are common and attributed to kinetic isotope effects. (author)

  11. Soil solution and sugar maple response to NH(4)NO (3) additions in a base-poor northern hardwood forest of Québec, Canada.

    Science.gov (United States)

    Moore, Jean-David; Houle, Daniel

    2009-08-01

    Nitrogen additions (NH4NO3) at rates of three- and ten-fold ambient atmospheric deposition (8.5 kg ha(-1) year(-1)) were realised in an acid- and base-poor northern hardwood forest of Québec, Canada. Soil solution chemistry, foliar chemistry, crown dieback and basal area growth of sugar maple (Acer saccharum Marsh.) were measured. Except for a transitory increase of NO3 and NH4 concentrations, there was no persistent increase in their level in soil solution 3 years after N treatments, with the exception of one plot out of three, that received the highest N addition, beginning to show persistent and high NO3 concentrations after 2 years of N additions. Three years of N additions have significantly increased the N DRIS index of sugar maple but not N foliar concentration. Potassium, Ca and Mn foliar concentrations, as well as P and Ca DRIS indices, decreased in treated plots after 3 years. No treatment effect was observed for basal area growth and dieback rate. One unexpected result was the significant decrease in foliar Ca even in the treated plots that received low N rates, despite the absence of significant NO3-induced leaching of Ca. The mechanism responsible for the decrease in foliar Ca is not known. Our results, however, clearly demonstrate that increased N deposition at sites with low base saturation may affect Ca nutrition even when clear signs of N saturation are not observed.

  12. Evolução química em galáxias compactas azuis (BCGs)

    Science.gov (United States)

    Lanfranchi, G. A.; Matteucci, F.

    2003-08-01

    Neste trabalho, a formação estelar e evolução quí mica em galáxias Compactas Azuis (Blue Compact Galaxies - BCGs) foram estudadas através da comparação de previsões de modelos de evolução quí mica a várias razões de abundância quí mica observadas nestas galáxias. Modelos detalhados com recentes dados de nucleossí ntese e que levam em consideração o papel desempenahdo por supernovas de ambos os tipos (II e Ia) na evolução galáctica foram desenvolvidos para as BCGs permitindo seguir a evolução de vários elementos quí micos (H, D, He, C, N, O, Mg, Si, S, Ca, e Fe). O modelo é caracterizado pelas prescrições adotadas para a formação estelar, a qual ocorre em vários surtos de atividade separados por longos perí odos quiescentes. Após ajustar os melhores modelos aos dados observacionais, as previsões destes modelos foram comparadas também a razões de abundância observadas em sistemas Damped Lyman alpha (DLAs) e a origem do N (primária ou secundária) foi discutida. Alguns dos resultados obtidos são: i) as razões de abundância observadas nas BCGs são reproduzidas por modelos com 2 a 7 surtos de formação estelar com eficiência entre n = 0.2-0.9 Gano-1; ii) os baixos valores de N/O observados nestas galáxias são um resultado natural de uma formação estelar em surtos; iii) os modelos para BCGs podem reproduzir os dados dos DLAs, iv) uma quantidade "baixa" de N primário produzido em estrelas de alta massa pode ser uma explicação para os baixos valores de [N/a] observados em DLAs.

  13. Immunization services offered in Québec (Canada) pharmacies

    Science.gov (United States)

    Sauvageau, Chantal; Dubé, Eve; Bradet, Richard; Mondor, Myrto; Lavoie, France; Moisan, Jocelyne

    2013-01-01

    Canadian Pharmacists are easy to reach. Although Québec pharmacists are not allowed to administer vaccines, they can: (1) promote vaccination, (2) counsel patients on vaccination, (3) sell vaccines and (4) provide vaccine administration by a nurse. Our objectives were to describe immunization services given in Québec pharmacies and assess the potential relation between, on one hand, pharmacy characteristics and difficulties perceived by pharmacists and, on the other hand, vaccine administration. In 2008–09, an anonymous questionnaire was mailed to all Québec pharmacy owners (n = 1663). Among the 1102 (66%) respondents, 90% stated that vaccines were sold, 27% that a nurse administered vaccines in their pharmacy and 44% were planning to offer vaccine administration in the next five years. Three out of four stated they were doing vaccine promotion and 65%, vaccine counselling. Half of respondents said they would be willing to administer vaccines themselves if legislative modifications were made. Recommendations for cold chain maintenance were followed in 23% of pharmacies selling vaccines. Presence of another health professional in the pharmacy, higher number of opening hours, not being located in the same building than a medical clinic and having an agreement to collaborate with a public health unit or a medical clinic for immunization were positively associated with vaccine administration in multivariate analysis. Higher perceived difficulties with lack of demand from patients were negatively associated with vaccine administration. Most pharmacists are willing to increase their involvement in immunization. Collaboration between public health professionals and pharmacists should be reinforced. PMID:23782530

  14. QuASAR: quantitative allele-specific analysis of reads.

    Science.gov (United States)

    Harvey, Chris T; Moyerbrailean, Gregory A; Davis, Gordon O; Wen, Xiaoquan; Luca, Francesca; Pique-Regi, Roger

    2015-04-15

    Expression quantitative trait loci (eQTL) studies have discovered thousands of genetic variants that regulate gene expression, enabling a better understanding of the functional role of non-coding sequences. However, eQTL studies are costly, requiring large sample sizes and genome-wide genotyping of each sample. In contrast, analysis of allele-specific expression (ASE) is becoming a popular approach to detect the effect of genetic variation on gene expression, even within a single individual. This is typically achieved by counting the number of RNA-seq reads matching each allele at heterozygous sites and testing the null hypothesis of a 1:1 allelic ratio. In principle, when genotype information is not readily available, it could be inferred from the RNA-seq reads directly. However, there are currently no existing methods that jointly infer genotypes and conduct ASE inference, while considering uncertainty in the genotype calls. We present QuASAR, quantitative allele-specific analysis of reads, a novel statistical learning method for jointly detecting heterozygous genotypes and inferring ASE. The proposed ASE inference step takes into consideration the uncertainty in the genotype calls, while including parameters that model base-call errors in sequencing and allelic over-dispersion. We validated our method with experimental data for which high-quality genotypes are available. Results for an additional dataset with multiple replicates at different sequencing depths demonstrate that QuASAR is a powerful tool for ASE analysis when genotypes are not available. http://github.com/piquelab/QuASAR. fluca@wayne.edu or rpique@wayne.edu Supplementary Material is available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Parto natural ¿Qué nos dice la evidencia?

    Directory of Open Access Journals (Sweden)

    Jorge Andrés Carvajal Cabrera

    2017-05-01

    Full Text Available Introducción: Es deseable que el proceso del parto concluya con una madre y un recién nacido sano, y sea un momento especial e íntimo. El Parto Natural, ha sido propuesto como una opción para mejorar la satisfacción de las mujeres con el proceso del parto. Sin embargo, no existen definiciones serias respecto a qué es el Parto Natural, introduciendo dificultades en la atención de mujeres que solicitan un Parto Natural. Métodos: El objetivo de este artículo es revisar la mejor evidencia disponible para entender cómo debe definirse un Parto Natural y analizar si se asocia a riesgos mayores que los de la atención médica habitual del parto. Resultados: Hemos comprobado que no existen definiciones científicas consensuadas para precisar qué es el Parto Natural, dejando espacio para discusión sobre su verdadero significado. No existen estudios de diseño aleatorizado y controlado que comparen el resultado materno/perinatal del parto natural comparado con la atención habitual del parto. Las intervenciones médicas, usadas en la atención médica del parto, y que podrían ser evitadas en el Parto Natural, producen algunos cambios favorables y otros deletéreos respecto de la salud materna y perinatal. Conclusiones: La decisión de optar por el Parto Natural debe ser discutida con las mujeres que lo solicitan, precisando con ella y su pareja cuál es su concepto de parto natural o qué es lo que desean incluir o evitar, los riesgos y beneficios asociados a cada una de las intervenciones deben ser expuestos por el equipo médico, para adoptar un plan de manejo individualizado.

  16. Historia Experimental de la Química

    Directory of Open Access Journals (Sweden)

    José Antonio Chamizo

    2009-10-01

    Full Text Available A partir de una discusión de la importancia de la experimentación en la enseñanza de las ciencias y el valor que la didáctica le da a la historia y la filosofía, se propone abordar la enseñanza experimental de la historia de la química a partir de la postura historiográfica recurrente empleando diagramas heurísticos. Lo anterior a través de diez experimentos elegidos por su valor didáctico y tecnocientífico.

  17. Por qué todas las cuentas son falsas

    OpenAIRE

    Aerde, Michel van

    1994-01-01

    Los principales criterios para evaluación y decisión, en la sociedad actual, son inspirados por cálculos económicos. Mucho nos preocupamos de cuentas pero muy poco nos preguntamos de lo que es el dinero. Muy poco reflexionamos filosóficamente, ontológicamente, sobre la naturaleza misma del dinero. ¿Qué es esto que pretende ser la base de nuestra sociedad? El dinero es mentiroso por naturaleza. Es una representación de mucha vida, que no puede ser representada. El dinero es peligroso, se convi...

  18. Abundancias químicas de ψ Octantis

    Science.gov (United States)

    Medina, M. C.; Pintado, O. I.

    Se determinan las abundancias químicas de ψ Oct usando espectros obtenidos con EBASIM en CASLEO. Los valores iniciales de temperatura efectiva y gravedad superficial se calculan con la fotometría uvbyβ. Esta estrella fue estudiada por Pintado y Adelman (1996) usando espectros REOSC y Adelman y otros (1993), este último basado en espectros echelle obtenidos con el Telescopio Anglo Australiano. Comparamos nuestros resultados con los de los trabajos anteriormente mencionados, pudiéndose realizar una evaluación de la calidad de los espectros EBASIM.

  19. física y química

    Directory of Open Access Journals (Sweden)

    Cristina Díez-Rodríguez

    2005-01-01

    Full Text Available La experiencia que se plantea a continuación recoge el desarrollo de una estrategia de comunicación entre un grupo de alumnos de Bachillerato y su profesora de Física y Química, basada en el uso de Internet como medio de expresión y comunicación. Se trata de una experiencia piloto, diseñada como paso previo a la integración definitiva de varias herramientas de comunicación en el desarrollo del próximo curso escolar

  20. QuEST: Qualifying Environmentally Sustainable Technologies, Volume 5

    Science.gov (United States)

    Lewis, Pattie

    2010-01-01

    This edition of the QuEST newsletter contains brief articles that discuss the NASA Technology Evaluation for Environmental Risk Mitigation (TEERM) program, and the importance of collaboration, efforts in materials management and substitution for coatings for launch structures, Low volatile organic compound (VOC) Coatings Field Testing, Non-Chrome Coating Systems, Life Cycle Corrosion Testing, Lead-Free Electronics Testing and Corn Based Depainting and efforts in Pollution Control in the area of Hypergolic Propellant Destruction Evaluation, efforts in development of alternative energy in particular Hydrogen Sensors, Energy and Water Management, and efforts in remediation in the removal of Polychlorinated Biphenyl (PCB) contamination

  1. Aditivos alimentarios: ¿qué son, cómo actúan, por qué son tan necesarios?

    OpenAIRE

    Blanco de Alvarado-Ortiz, Teresa

    2014-01-01

    Para John M. deMan, en su obra PrincipIes of Food Chemistry a los aditivos alimentarios con frecuencia se les asocia a algo químico, otorgándose erradamente a lo quimico características de artificial, no siempre bueno para la salud.Dicen bien erradamente, porque hombres, animales, plantas, microorganismos, alimentos, aire, cerros, minas y todo lo que nos rodea en la maravillosa naturaleza, es químico. Los aditivos alimentarios,todos químicos, naturales o artificiales son extraordinarias susta...

  2. ¿Qué es una institución?

    Directory of Open Access Journals (Sweden)

    John R. Searle

    2006-09-01

    Full Text Available Cuando era un estudiante universitario en Oxford, nos enseñaban economía como si fuera una ciencia natural. La materia objeto de la economía podría ser diferente de la física, pero sólo en la medida en la que el contenido de la química o la biología son diferentes de la física. Los resultados propiamente dichos nos fueron presentados como si fuesen teorías científicas. Por ello cuando aprendimos que los ahorros equivalen a la inversión, se nos enseñaba en el mismo tono de voz en el que uno aprende que la fuerza es igual a la masa por la aceleración. Y aprendimos que los empresarios juiciosos venden cuando el coste marginal iguala al beneficio marginal de la misma manera en la que una vez aprendimos que los cuerpos se atraen con una fuerza directamente proporcional al producto de sus masas e inversamente proporcional al cuadrado de la distancia que los separa. En ningún momento se planteó que la realidad descrita por la teoría económica fuera dependiente de las creencias y otras actitudes humanas de una manera que era completamente distinta de la realidad descrita por la física o la química.

  3. Química recreativa con agua oxigenada

    Directory of Open Access Journals (Sweden)

    Mª Luisa Aguilar Muñoz

    2011-01-01

    Full Text Available Con el objeto de despertar el interés por la química así como de tratar diversos conceptos químicos y biológicos, presentamos la reacción de descomposición catalítica del agua oxigenada (H2O2 en tres experiencias diferentes y con distintos catalizadores. Esta reacción es muy exotérmica, produciendo agua y oxígeno. En la primera experiencia, se mezclan en una probeta la disolución de agua oxigenada y un poco de lavavajillas. Al añadir yoduro de potasio, éste actúa como catalizador y aparece gran cantidad de espuma debido al oxígeno desprendido en la reacción. En la segunda, se utiliza como catalizador un óxido de manganeso finamente dividido, que al dejarlo caer en el recipiente que contiene agua oxigenada, produce un espectacular chorro de vapor de agua. En la última, se produce una llamativa reacción luminiscente entre el peróxido de hidrógeno y el luminol utilizando como catalizador el ión hierro contenido en el hexacianoferrato (III de potasio (ferricianuro de potasio.

  4. Cinética Química: el laboratorio

    Science.gov (United States)

    Cabañas Galán, B.

    La interpretación de las transformaciones químicas que se producen en la atmósfera requiere un profundo conocimiento de la cinética, productos y mecanismos de reacción de las posibles interacciones que pueden ocurrir entre las distintas especies presentes en ella. Información cuantitativa de este tipo es un prerrequisito para la construcción de modelos numéricos adecuados que expliquen el comportamiento químico-físico de la atmósfera. Esta información se obtiene a partir de experimentos realizados en laboratorios y por tanto independiente de medidas atmosféricas, por lo que los modelos atmosféricos derivados de ellos, pueden usarse para diagnosticar y predecir adecuadamente el comportamiento atmosférico. En esta exposición se recogen las técnicas experimentales más extendidas para la obtención de datos cinéticos así como los métodos de análisis de datos más utilizados en el estudio de las distintas reacciones de interés atmosférico. Se analizan sus características generales así como su adecuación a los distintos tipos de reacciones.

  5. Características químicas do solo sob algodoeiro em área que recebeu água residuária da suinocultura

    Directory of Open Access Journals (Sweden)

    Salomão de Sousa Medeiros

    2011-06-01

    Full Text Available A crescente geração de efluentes líquidos e o seu lançamento no meio ambiente tem-se constituído numa preocupação mundial devido aos impactos negativos gerados. O objetivo deste trabalho foi avaliar os possíveis impactos da aplicação do efluente proveniente da suinocultura, após seu tratamento, nos atributos químicos do solo, em área cultivada com algodão. O experimento foi realizado no Perímetro Irrigado Formoso, no município de Bom Jesus da Lapa, BA, em área experimental da Companhia de Desenvolvimento dos Vales do São Francisco e do Parnaíba - CODEVASF. Foram testados cinco tratamentos: MC - manejo convencional = água de "boa qualidade" + adubação química; ET100 = 100 % de efluente tratado; ET75:25 = 75 % de efluente tratado + 25 % de água boa; ET50:50 = 50 % de efluente tratado + 50 % de água boa; ET25:75 = 25 % de efluente tratado + 75 % de água boa. O delineamento experimental foi em blocos ao acaso com quatro repetições. Os atributos químicos do solo avaliados foram: pH, condutividade elétrica, teores de N, P, K, Ca, Mg, Na, Zn, Fe, Mn e Cu. Em geral, quanto aos atributos químicos do solo, a adoção do manejo com efluente tratado apresentou resultados semelhantes aos obtidos com o MC, favorecendo a melhoria da fertilidade do solo e constituindo-se em uma fonte alternativa de fertilização de baixo custo. O efluente tratado, independentemente do fator de diluição, também demonstrou ser uma fonte alternativa de água.

  6. Las propiedades químicas del suelo para definir la zona de aplicación del laboreo localizado en los suelos arcillosos pesados

    OpenAIRE

    Yoel Betancourt Rodríguez; Isnel Rodríguez Camacho; Enma Pineda Ruiz

    2009-01-01

    Se montó un experimento en áreas del Bloque Experimental de la Caña "Jesús Menéndez", Villa Clara, Cuba, sobre un suelo arcilloso pesado para definir la aplicación del laboreo localizado en la hilera de caña o en el entresurco, según las propiedades químicas del suelo. Se evaluaron: porcentaje de materia orgánica (M.O.), fósforo asimilable, potasio asimilable y pH del suelo en H2O y KCl; encontrándose que: el porcentaje de M.O. y de fósforo asimilable son significativamente superiores en la h...

  7. Educational Reevaluation, Political Transformation: Québec and Higher Education

    Science.gov (United States)

    Unger, Zoe

    2013-01-01

    This paper considers the history of Québec's higher education system and the reforms that have contributed to the role of education in the province. Québec's education system has repeatedly been a site for social and political transformation; most recently, reevaluation of education's role in the province has revealed a tension between…

  8. Identification and characterization of novel multiple bacteriocins produced by Leuconostoc pseudomesenteroides QU 15.

    Science.gov (United States)

    Sawa, N; Okamura, K; Zendo, T; Himeno, K; Nakayama, J; Sonomoto, K

    2010-07-01

    To characterize novel multiple bacteriocins produced by Leuconostoc pseudomesenteroides QU 15. Leuconostoc pseudomesenteroides QU 15 isolated from Nukadoko (rice bran bed) produced novel bacteriocins. By using three purification steps, four antimicrobial peptides termed leucocin A (ΔC7), leucocin A-QU 15, leucocin Q and leucocin N were purified from the culture supernatant. The amino acid sequences of leucocin A (ΔC7) and leucocin A-QU 15 were identical to that of leucocin A-UAL 187 belonging to class IIa bacteriocins, but leucocin A (ΔC7) was deficient in seven C-terminal residues. Leucocin Q and leucocin N are novel class IId bacteriocins. Moreover, the DNA sequences encoding three bacteriocins, leucocin A-QU 15, leucocin Q and leucocin N were obtained. These bacteriocins including two novel bacteriocins were identified from Leuc. pseudomesenteroides QU 15. They showed similar antimicrobial spectra, but their intensities differed. The C-terminal region of leucocin A-QU 15 was important for its antimicrobial activity. Leucocins Q and N were encoded by adjacent open reading frames (ORFs) in the same operon, but leucocin A-QU 15 was not. These leucocins were produced concomitantly by the same strain. Although the two novel bacteriocins were encoded by adjacent ORFs, a characteristic of class IIb bacteriocins, they did not show synergistic activity. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

  9. Comportamiento del Helio en estrellas químicamente peculiares

    Science.gov (United States)

    Malaroda, S. M.; López García, Z.; Leone, F.; Catalano, F.

    Las estrellas químicamente peculiares (CP) se caracterizan por tener deficiencias y sobreabundancias de algunos elementos químicos de hasta 106 veces la abundancia solar. Además presentan variaciones en las líneas espectrales. Se piensa que ello se debe a que los campos magnéticos presentes en este tipo de estrellas son principalmente dipolares, con un eje de simetría diferente del eje de rotación. La distribución de los elementos sobreabundantes y deficientes no es homogénea sobre la superficie estelar y las variaciones observadas serían una consecuencia directa de la rotación estelar. Entre los elementos con abundancia anómala se encuentra el Helio, cuyas líneas tienen intensidades que no son consistentes con una abundancia normal, que no puede ser determinada del modo usual, o sea, considerando una atmósfera con composición solar. Con el fin de determinar la abundancia de este elemento, se inició un estudio de estrellas anómalas de Helio, Hew y He strong. Además se determinarán las abundancias de otros elementos anómalos como ser el Si, Cr, Mg, Mn y Fe. Las mismas se determinan del modo tradicional, o sea: a) medida de los anchos equivalentes de las líneas de los distintos elementos analizados; b) adopción de la temperatura efectiva, gravedad y abundancia del Helio; c) cálculo del modelo de atmósfera d) comparación con las observaciones y reinicio de un proceso iterativo hasta lograr un acuerdo entre todos los parámetros analizados. Las observaciones se llevaron a cabo en el Complejo Astronómico El Leoncito. Se observaron setenta y ocho estrellas anómalas de Helio. En este momento se está procediendo a calcular las abundancias correspondientes a los distintos elementos químicos. Para ello se hace uso de los modelos de Kurucz, ATLAS9. Los cálculos NLTE de las líneas de Helio se llevan a cabo con el programa MULTI y se compararán con los realizados con el programa WIDTH9 de Kurucz (LTE), con el objeto de resaltar la importancia de

  10. Efecto acaricida de una mezcla química

    Directory of Open Access Journals (Sweden)

    E. Egea

    2000-02-01

    Full Text Available

    Introducción: Se investiga el efecto de una nueva mezcla química (ATLASAC para el control de ácaros del polvo doméstico, microorganismos cosmopolitas que conviven con el hombre, reconocidos como importante fuente de alergenos y la principal causa de exacerbación de las enfermedades alérgicas. En el medio ambiente de los hogares colombianos se conoce por reportes científicos la prevalencia de varias especies comunes en otros países: Dermatophagoides pteronyssinus, D. Farinae, Blomia tropicales, etc, asociados con asma y/o rinitis. Por todo ello, en el medio ambiente residencial del paciente es importante establecer medidas locativas tendientes a evitar la exposición y el control químico para reducir o eliminar la fuente de alergenos, en especial, los ácaros. Un recurso fácil de aplicar son los acaricidas, los cuales varían en el grado de efectividad y tiempo de protección. En nuestro medio no se tienen productos aprobados como acaricidas. Por tal motivo, esta investigación pretende llenar un vacío en el medio colombiano con una mezcla química con efecto acaricida, en especial sobre aquellos implicados con las enfermedades alérgicas.

    Metodología: Se seleccionaron 25 pacientes definidos por historia clínica como alérgicos y 50 voluntarios que por pruebas cutáneas se descartó sensibilización a ácaros. Inmediatamente después del ingreso se hicieron muestreos para determinar la presencia de ácaros del polvo doméstico y fundamentalmente para obtener cultivos puros.

    Resultados preliminares: 100 ácaros de

  11. La violencia humana: ¿Qué hemos aprendido?

    Directory of Open Access Journals (Sweden)

    Enrique Vega Fernández

    Full Text Available El presente trabajo pretende aportar algunas reflexiones que permitan aproximarse al gran interrogante de por qué existen las guerras y siguen existiendo en el mundo de nuestros días. A través del concepto de cratotropismo, basado en la concepción de afán de dominio de Alfred Adler. Y de la traída: competencia ideológica o cultural, presión-resistencia económica, conflicto armado como último recurso, como modos de los enfrentamientos crato-eleuterotrópicos, basada en la concepción de la función moduladora del saber por los poderes sociales de Michel Foucault y en concepto marxista de propiedad.

  12. A SiQuENC for solving physics problems

    Science.gov (United States)

    Liao, David

    2018-04-01

    Students often struggle in AP Physics 1 because they have not been previously trained to develop qualitative arguments. Extensive literature on multiple representations and qualitative reasoning provides strategies to address this challenge. Table I presents three examples, including SiQuENC, which I adapted from a strategy promoted by Etkina et al. To remind students that they can use qualitative reasoning (e.g., arguing from proportionalities), rather than relying only on algebra, I replaced "Solve" with "Analyze." I added a "Communicate" step to guide planning of written responses to AP Physics 1 and 2 questions. To perform this step, draw a circled number around each key point identified in figures, equations, and sentence fragments. Then, convert numbered points into sentences.

  13. 2015. 2. Por qué celebrar primarias

    OpenAIRE

    Sanz Díaz, Benito

    2015-01-01

    ¿Por qué celebrar primarias? ¿Beneficia o perjudica a las organizaciones y partidos que las promueven?, ¿Mejora la participación?, ¿La elección de los dirigentes evita la oligarquización y la Ley de Hierro de los partidos políticos que enunció Robert Michels? Un sistema de selección de candidatos con origen en la política norteamericana, fue adaptado por el PSOE, y a continuación iría extendiéndose su práctica a los todos los partidos políticos. Ignacio Urquizu señalaba sobre l...

  14. QuEChERS extraction of benzodiazepines in biological matrices

    Directory of Open Access Journals (Sweden)

    Jessica L. Westland

    2013-12-01

    Full Text Available Two common analytical chemical problems often encountered when using chromatographic techniques in drug analysis are matrix interferences and ion suppression. Common sample preparation often involves the dilution of the sample prior to injection onto an instrument, especially for liquid chromatography–mass spectrometry (LC–MS analyses. This practice frequently does not minimize or eliminate conditions that may cause ion-suppression and therefore, suffer more from reduced method robustness. In order to achieve higher quality results and minimize possible interferences, various sample preparation techniques may be considered. Through the use of QuEChERS (“catchers”, a novel sample preparation technique used for high aqueous content samples, benzodiazepines can be extracted from biological fluids, such as blood and urine. This approach has shown increased recoveries of target compounds when using quantification by both external and internal standard. This increase in the recoveries has been attributed to a matrix enhancement and was determined through the use of the method of standard addition. While improving the overall analytical method for gas chromatography–mass spectrometry (GC–MS analysis, it is not clear if this approach represents an overall benefit for laboratories that have both GC–MS and high performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS capability. Demonstrating evidence of variable ionization (enhancement, ion source inertness, etc., the method of quantification should be focused on in future studies. Keywords: Forensic science, QuEChERS, Drug analysis, Benzodiazepines, Gas Chromatography–Mass Spectrometry, Biological samples

  15. Efeito do fluoreto de cálcio e do carbonato de cálcio na composição química da solução percolada de um solo ácido

    Directory of Open Access Journals (Sweden)

    F. C. S. Amaral

    1998-09-01

    Full Text Available Durante oito meses, foram estudados, em casa de vegetação, os efeitos da aplicação de CaF2 (p.a. e de CaCO3 (p.a. sobre a concentração de Al e de outros elementos químicos na solução percolada de amostras de um solo ácido, coletado na região de Piracicaba, SP. Os valores de pH aumentaram na solução percolada de amostras de solos que receberam tanto CaCO3 como CaF2. Os tratamentos com CaF2 foram mais eficientes na retirada de Al do solo do que os tratamentos com CaCO3. Na testemunha e nos tratamentos com CaCO3, a maior parte do Al estava, respectivamente, na forma livre Al3+ ou formando complexos Al-OH, ao passo que, nos tratamentos com CaF2 , mais de 99,5% do Al estava complexado com o fluoreto.

  16. Solubility of calcium in CaO-CaCl2

    International Nuclear Information System (INIS)

    Perry, G.S.; Shaw, S.J.

    1991-06-01

    The Direct Oxide Reduction (DOR) process is well established as a process to produce plutonium metal from plutonium dioxide by reaction with calcium. Calcium chloride is added to dissolve the calcium oxide produced, allowing the metal to coalesce into a button. Since calcium metal melts at 840 0 C and DOR can take place successfully below this temperature, it is likely calcium dissolved in calcium chloride reacts with the plutonium dioxide. The solubility of calcium in calcium chloride is reasonably well established but the effect of the CaO formed during the DOR process on the solubility of calcium has not been previously determined. For this reason the solubility of calcium in CaCl 2 -CaO melts at 800 o C has been studied. The solubility decreases from 2.7 mol % in CaCl 2 to 0.4 mol % in 9 mol % CaO-CaCl 2 . (author)

  17. Dinamizando el proceso de enseñanzaaprendizaje de la química. Las demostraciones químicas como una opción para cambiar la forma tradicional de enseñar química

    Directory of Open Access Journals (Sweden)

    Manuel Molina Caballero

    2009-10-01

    Full Text Available Creemos que la “quimifobia” que existe a nivel social está generada en buena medida por la forma cómo se realiza la enseñanza de la química en las aulas. Para generar un cambio en las metodologías habituales proponemos, en este trabajo, el uso de las demostraciones químicas, mostrando un ejemplo a partir de la descomposición del peróxido de hidrógeno, buscando la forma de incorporar las demostraciones en el aula y considerando su carácter atractivo, la participación del estudiante, su vínculo conceptual y las cuestiones de seguridad a tener en cuenta. Dejamos a los profesores la propuesta, esperando que con su ayuda quizá podamos dar un toque especial a la enseñanza de la química.

  18. Prion seeding activities of mouse scrapie strains with divergent PrPSc protease sensitivities and amyloid plaque content using RT-QuIC and eQuIC.

    Directory of Open Access Journals (Sweden)

    Sarah Vascellari

    Full Text Available Different transmissible spongiform encephalopathy (TSE-associated forms of prion protein (e.g. PrP(Sc can vary markedly in ultrastructure and biochemical characteristics, but each is propagated in the host. PrP(Sc propagation involves conversion from its normal isoform, PrP(C, by a seeded or templated polymerization mechanism. Such a mechanism is also the basis of the RT-QuIC and eQuIC prion assays which use recombinant PrP (rPrP(Sen as a substrate. These ultrasensitive detection assays have been developed for TSE prions of several host species and sample tissues, but not for murine models which are central to TSE pathogenesis research. Here we have adapted RT-QuIC and eQuIC to various murine prions and evaluated how seeding activity depends on glycophosphatidylinositol (GPI anchoring and the abundance of amyloid plaques and protease-resistant PrP(Sc (PrP(Res. Scrapie brain dilutions up to 10(-8 and 10(-13 were detected by RT-QuIC and eQuIC, respectively. Comparisons of scrapie-affected wild-type mice and transgenic mice expressing GPI anchorless PrP showed that, although similar concentrations of seeding activity accumulated in brain, the heavily amyloid-laden anchorless mouse tissue seeded more rapid reactions. Next we compared seeding activities in the brains of mice with similar infectivity titers, but widely divergent PrP(Res levels. For this purpose we compared the 263K and 139A scrapie strains in transgenic mice expressing P101L PrP(C. Although the brains of 263K-affected mice had little immunoblot-detectable PrP(Res, RT-QuIC indicated that seeding activity was comparable to that associated with a high-PrP(Res strain, 139A. Thus, in this comparison, RT-QuIC seeding activity correlated more closely with infectivity than with PrP(Res levels. We also found that eQuIC, which incorporates a PrP(Sc immunoprecipitation step, detected seeding activity in plasma from wild-type and anchorless PrP transgenic mice inoculated with 22L, 79A and/or RML

  19. TICs en la enseñanza de la Química: Propuesta de evaluación de Laboratorios Virtuales de Química (LVQs

    Directory of Open Access Journals (Sweden)

    Cataldi, Zulma

    2012-01-01

    Full Text Available Los LVQs son unas nuevas formas de enseñanza de la química a través del uso de TICs. En este contexto se presenta el relevamiento de los laboratorios virtuales de química (LVQs más apropiados para la enseñanza de la química. Se analizan las ventajas de su aplicación en química básica y se delinean las pautas para su evaluación y selección de acuerdo a los indicadores propuestos, articulados con el marco teórico y con las dimensiones de análisis. Se propone una evaluación centrada en tres ejes: a dimensiones tecnológicas y técnicas, b dimensiones pedagógicas y c otras dimensiones como costo y comercialización. Se realizan pruebas de ajuste y aplicación del instrumento según los siguientes objetivos: a Analizar las estrategias didácticas docentes y la percepción en el uso de las TICs y b Delinear acciones formativas en didáctica de la química con uso de TICs.

  20. Method of convex rigid frames and applications in studies of multipartite quNit pure states

    International Nuclear Information System (INIS)

    Zhong Zaizhe

    2005-01-01

    In this letter, we suggest a method of convex rigid frames in the studies of multipartite quNit pure states. We illustrate what the convex rigid frames are, and what is their method. As applications, we use this method to solve some basic problems and give some new results (three theorems): the problem of the partial separability of the multipartite quNit pure states and its geometric explanation; the problem of the classification of multipartite quNit pure states, giving a perfect explanation of the local unitary transformations; thirdly, we discuss the invariants of classes and give a possible physical explanation. (letter to the editor)

  1. Ecología química en el bentos antártico

    OpenAIRE

    Ballesteros, Manuel (Ballesteros Vázquez); Núñez Pons, Laura; Vázquez, J.; Cristobo, F.J.; Taboada Moreno, Sergio; Figuerola Balañá, Blanca; Ávila Escartín, Conxita

    2011-01-01

    El estudio de las interacciones entre los organismos mediadas por sustancias químicas, lo que se denomina ecología química, nos da información sobre la biología de las especies implicadas, el funcionamiento de la comunidad en que viven y nos puede proporcionar además el conocimiento de nuevas sustancias que pueden ser útiles para el ser humano. En el marco de nuestros estudios sobre la ecología química de los invertebrados antárticos, en el proyecto ECOQUIM (2003-2006) se recolectaron numeros...

  2. [Towards Professionalization : the Editorial Discourse of Québec Pharmacy magazine, 1960-2013 ].

    Science.gov (United States)

    Savard, Pierre-André; Meunier-Sirois, Alexandre; Marando, Nancy; Bussières, Jean-François

    2016-12-01

    The second half of the twentieth century and the beginning of the 2000s marked deep changes in the practice of pharmacy in Quebec. The editorials of Québec Pharmacie journal attest these changes on a 50-year period by relating power relationships, conflicts, problems and solutions that concerned pharmacists. This article proposes to analyze the editorial discourse of Québec Pharmacie journal between 1960 and 2013, and to grasp the evolution of the speech. To do so, we analyze the major topics addressed by the editorialists. It appears that Québec Pharmacie’s editorialists aimed the professionalization of pharmacy.

  3. Enseñanza de química a alumnos con discapacidad visual

    OpenAIRE

    Gerson de Souza, M.; Patrícia Neves, R.; Rejane Ferreira, P.

    2009-01-01

    La educación formal en Brasil tiene como primer principio la “igualdad de condiciones de acceso y permanencia en la escuela” (Brasil, 1996). En este contexto, el proyecto “Enseñanza de Química a Alumnos con Discapacidad Visual” busca desarrollar recursos y metodologías para una enseñanza de Química que atienda alumnos con ceguera o baja visión. En este proyecto, con el objetivo de atender alumnos y profesores de la enseñanza secundaria, iniciamos la adaptación del libro “Química e Sociedade” ...

  4. Chemical properties of volcanic soil affected by seven-year rotations Propiedades químicas del suelo volcánico afectado por rotaciones de siete años

    Directory of Open Access Journals (Sweden)

    Juan Hirzel

    2011-06-01

    Full Text Available Long-term crop rotation systems can benefit soil chemical-physical properties and crop productivity. The lack of information on the effect of long-term crop rotations on soil chemical-physical properties for volcanic soils in Chile could restrict reaping real benefits, and make it difficult to take agricultural management decisions, which could lead to possible negative consequences on some soil chemical-physical properties and the environment. The development of information associated with the effect on soil chemical-physical properties with respect to long-term rotation systems and their fertilization management contribute to improving agronomic management decisions for these soils. A study was carried out to assess the effect of six rotation systems replicating fertilization management used by farmers, especially N and P application, and eventually low rates of K, Ca and Mg on soil chemical properties in a volcanic soil after 7 yr in Central South Chile. Affected chemical properties were pH, inorganic N, and available K, along with a general decrease of pH related to fertilization used, which was insufficient in Ca, K, and Mg. Moreover, this soil exhibited high P adsorption capacity (90.2 to 97.5%. Hence, crop rotations that included pasture legumes and crops with high nutrient inputs such as sugar beet (Beta vulgaris L. generated a less negative effect on soil chemical properties. This study indicates that fertilization management in crop rotation systems must consider the input and output nutrient balances to prevent the negative effect on some soil chemical properties.Los sistemas de rotación de cultivos de largo plazo pueden tener varios beneficios sobre las propiedades físico-químicas del suelo y productividad de los cultivos. La falta de información sobre el efecto de rotaciones de largo plazo en las propiedades físico-químicas para suelos volcánicos en Chile podría limitar la obtención de beneficios reales, dificultando

  5. Manifestaciones digestivas en pacientes con fibrosis quística

    Directory of Open Access Journals (Sweden)

    Eloísa Martí Castelló

    1996-08-01

    Full Text Available La mayoría de los pacientes con fibrosis quística presentan una insuficiencia exocrina de la función pancreática que entraña trastornos digestivos complejos. Se estudian 8 pacientes entre 1 y 12 años con el diagnóstico de fibrosis quística. Se les realizó enzimas pancreáticas en suero, electroforesis de proteínas y marcadores virales de la hepatitis B y C. También se les efectuó ultrasonido abdominal, gammagrafía esofágica, hepática y biliar. Las manifestaciones clínicas más frecuentes fueron la esteatorrea, cólicos abdominales y hepatomegalia. Se encontró la lipasa aumentada en suero en 2 pacientes con suficiencia pancreática y las transaminasas normales en todos ellos. Las manifestaciones hepáticas estuvieron presentes en 3 pacientes y el reflujo gastroesofágico y el prolapso rectal en 2, respectivamente. Se observó que el control terapéutico de estas manifestaciones reportan un buen estado nutricional y mejor calidad de vida.Most of the patients suffering from cystic fibrosis present an exocrine insufficiency of the pancreatic function leading to complex digestive disorders. 8 patients between 1 and 12 years old with the diagnosis of cystic fibrosis are studied. Pancreatic enzymes in serum, protein electrophoresis, and viral markers of hepatitis B and C were carried out. Abdominal ultrasound, esophageal, hepatic and biliary gammagraphy were also performed. The most frequent clinical manifestations were steatorrhea, abdominal colics and hepatomegalia. Augmented lipase in serum was found in two patients with pancreatic sufficiency, whereas transaminases were normal in all of them. 3 patients showed clinical manifestations and 2 had gastroesophageal reflux and rectal prolapse, respectively. It was observed that with the therapeutic control of these manifestations a good nutrional status and a better quality of life are reported.

  6. Comportamiento de variables químicas de un suelo sometido a distintos usos, departamento de Nariño, Colombia

    Directory of Open Access Journals (Sweden)

    Julio César Arteaga

    2016-12-01

    Full Text Available El presente estudio se realizó en un Andisol clasificado como Vitric haplustands, ubicado en el Corregimiento de Obonuco, Municipio de Pasto (Colombia. Se evaluaron algunas características químicas, en siete tipos de uso y manejo del suelo: T1: monocultivo de papa (Solanum tubersum L., T2: pradera (Pennisetum clandestinum Hochst. ex Chiov, T3: barrera multiestrato, T4: sistema acacia - aliso, T5: banco de proteína, T6: bosque plantado (Eucaliptus globulus Labill y T7: bosque nativo. El efecto de los tipos de uso y manejo, sobre las propiedades químicas del suelo, se evaluaron a través de pH, %MO, %CO, N total, P, CIC, Ca, Mg, K, Al, Fe, Mn Cu, Zn, B y S. Los resultados fueron sometidos a Análisis de Varianza, Prueba de Comparaciones de Medias (LSD, Diferencia Mínima Significativa (DMS y correlaciones de Persson. Los valores mostraron diferencias significativas (P<0,05 entre los tratamientos para los contenidos de pH, %MO, %CO, N total, P, CIC Ca, Mg, K, Fe y S, mientras que no se presentaron efectos sobre los contenidos de Al, Mn, B, Zn y Cu. Los mayores valores de %MO, %CO, N total, CIC, Ca, Mg y S, fueron obtenidos con los tratamientos T3, T4 y T7. Los resultados sugieren a la materia orgánica, como la variable más sensible al efecto del manejo de los suelos.

  7. Accessing the nuclear symmetry energy in Ca+Ca collisions

    Directory of Open Access Journals (Sweden)

    Chbihi A.

    2012-07-01

    Full Text Available The status of the analysis of the INDRA-VAMOS experiement performed at GANIL, using the reactions 40,48Ca+40,48Ca reactions at 35AMeV, are presented. Isotopic distributions of fragments produced in multifragmentation events provide information on the importance of the surface term contribution in the symmetry energy by comparison to AMD predictions.

  8. Elusidasi struktur isolat skualena dari ikan hiu cucut botol (Centrophurus sp

    Directory of Open Access Journals (Sweden)

    Aniek Setiya Budiatin

    2012-02-01

    Full Text Available The main source of squalene was liver oil of shark. Producing of squalene this oil could be separated from other components inside. The research obtained that the value of squalene was 75.83 ± 1.14%. To discover the purification and safety to consume squalene which had been isolated from oil of the liver €™s shark cucut botol €˜ was used a method which available in AOAC, therefore that could be done elucidation of the structure of isolate with any instruments such as KLT; FTIR; GC; GC-MS; and NMR. Structure elucidation of isolate compare with standard of squalene had result as follows: a. KLT: Rf isolate = 0.457; Rf standard = 0,457; b. FTIR = 2980 €“ 2850 CH of methyl and methylene; 1668.58 & 1446.74 a double chain of carbon (C=C; 1381.16 & 835.25 = branch chain that all for isolate was the same with standard; GC tR = 9.065 minute of isolate and standard was 9.124 minutes; GC-MS the main fraction with mass 69 was one unit of isoprene (C5H9; the value of proton NMR (δ = ppm were 1.601 & 1.674; 2.016; 5.150 & 5.155 for isolate; the standard were 1.599 & 1.670; 2.016; 5.155. The result of elucidation structure could be concluded that the isolate was the same with the squalene standard. Therefore, isolate could be able to consume safety as natural health food for all consumers because it had already pure and free from other compound such as cholesterol.

  9. La enseñanza de la química desde la perspectiva de la Química Verde

    Directory of Open Access Journals (Sweden)

    Pía José González García

    2016-06-01

    Full Text Available La Química Verde, como área de investigación, se comprende como el desarrollo de metodologías para modificar los productos o procesos con la finalidad de reducir o eliminar los riesgos que existen para el medio ambiente y la salud. De este modo, permite proyectar líneas de investigación en la construcción de un conocimiento y enfoques didácticos de las ciencias, y  para ser considerada como parte de los programas Ministeriales. El objetivo del estudio fue conocer y comprender el significado que le otorgan los(as docentes del área a la Química Verde como perspectiva para su enseñanza. A partir de los discursos emanados por los docentes participantes del estudio, se construyeron 4 categorías, las cuales son: la Química Verde como: contexto para la enseñanza de la química, medio de apropiación significativo del aprendizaje de la química, motivadora de la conciencia ambiental y reflejo de la Institución y su relación con los docentes. The teaching of chemistry from the Green Chemistry perspective Green Chemistry (GC, as a research area, understood as the development of methodologies to modify products or processes in order to reduce or eliminate the risks posed to the environment and human health. Thus it is allowing research project lines in building knowledge and didactic approaches of the sciences, and to be considered as part of the ministerial programs. The objective of this study was to know and understand the significance given by teachers in the area to GC as a perspective for education. From the speeches issued by teachers participating in the study, four categories, was built. GC as: context for teaching chemistry, through significant learning chemistry appropriation, motivating environmental awareness and reflection of the institution and its relationship with teachers.  O ensino de química, na perspectiva da Química verde A Química verde, como área de investigação, é compreendida como o desenvolvimento de

  10. ¿Por qué Carl Schmitt?

    Directory of Open Access Journals (Sweden)

    Bernhard Schlink

    2005-12-01

    Full Text Available En la Cultura Jurídica Alemana, Carl Schmitt llegó a tener un prestigio más notable que otros teóricos del derecho alemanes contemporáneos suyos. Aquí se examina a qué se debe eso. ¿A la contribución del pensamiento de Schmitt para interpretar y aplicar la Ley Fundamental? ¿A las contribuciones de su teoría política? La respuesta a las dos preguntas es negativa. Su fama se debe al lugar que le otorga el mito sobre el positivismo y el decisionismo del derecho en el régimen nazi. Se debe a la dificultad de integrar el pensamiento jurídico del Tercer Reich en la historia de la cultura legal alemana. Un intento de conseguirlo fue recurrir a una equívoca interpretación ad hoc de la persona de Schmitt.

  11. ¿Por qué no aprendemos?

    Directory of Open Access Journals (Sweden)

    María Elena Francia Reyes

    2003-04-01

    Full Text Available Se realizó un estudio descriptivo, retrospectivo y transversal con 20 niños entre 1ro. y 4to. grado de la Escuela Primaria "José Joaquín Palma", del Consejo Popular Pueblo Nuevo, en el municipio Centro Habana, cuyas maestras plantearon dificultades en el aprendizaje durante el curso escolar 1999-2000. Nos propusimos como objetivo determinar en qué porcentaje de la muestra se asocia el aprendizaje lento con el cociente intelectual normal, para así dar una mejor orientación a las familias de los que presentan esta dificultad. Se aplicó un pequeño cuestionario validado a criterio de jueces. En los resultados se muestra que el 75 % de los niños tienen un cociente intelectual normal.A retrospective descriptive and cross-sectional study was carried out with 20 children from first to fourth grades, who studied at "Jose Joaquín Palma" elementary school located in the people's council Pueblo Nuevo in Centro Habana municipality. The sample showed learning difficulties during 1991-2000 school year. Our objective was to determine the percentage of the sample in which slow learning is associated with normal intellectual quotient so that we can provide better counseling to the families of children with these learning difficulties. A small questionnaire validated by judges was administered. The results revealed that 75% of children had normal intellectual quotients.

  12. Light Pollution in Québec: Progress Report

    Science.gov (United States)

    Dutil, Yvan

    2005-08-01

    Quebecers are among the worst light polluters in the world, producing 2 to 3 times more light than Americans or Europeans. Nevertheless, there is hope of losing this infamous title in the near future. Recently, there was a large increase in awareness both from the public and policy makers and action is now taken to preserve the dark sky elsewhere in Quebec. A Dark-Sky Preserve is now being put in place around Mont Mégantic Observatory. With a radius of 50 km, it will be will be, once completed, one of the largest in North America. In addition, the city of Sherbrooke is putting in place its own dark-sky policy to complement the protection provide by the preserve. These efforts are expected to stop the growth of light pollution at Mont Mégantic, which has doubled in the last 25 years. Even the cities of Montréal and Québec are taking action against the light pollution. This is a good example of how a few dedicated persons can change perceptions and fight efficiently against light pollution.

  13. ¿Qué se juega al jugar un juego?

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    Kalejman, Cecilia

    2012-06-01

    Full Text Available En el presente artículo se considera el juego en relación a la niñez. Se indaga acerca del papel que juega el juego en la niñez intentando responder a diversas preguntas, entre ellas la más importante: ¿Qué significa jugar? A lo largo de esta etapa del desarrollo en que comienza a constituirse la subjetividad del individuo el juego constituye, sin dudas, un factor central, una herramienta fundamental en el desarrollo. Juego no es sólo el juego dramático, también consideramos para nuestro análisis aquellas modalidades de juego que se transmiten de generación en generación, juegos de construcción, los dibujos, teniendo en cuenta asimismo los objetos utilizados en los juegos, los contenidos de los mismos, los espacios en los que se desarrollan. Se piensa y se interpreta al juego, como un derecho y como un modo de expresión del niño, se finaliza este desarrollo con una conclusión acera del juego y el espacio que ocupa en la vida cotidiana.

  14. Portrait of Antonino Zichichi at Polar QuEEEst Conference

    CERN Multimedia

    Ordan, Julien Marius

    2018-01-01

    Built by school students from Switzerland, Italy, Iceland and Norway at CERN, Polar QuEEEst is a special detector to catch cosmic rays coming from the distant regions of our universe. Three of these special “telescopes” will be built to measure the cosmic ray flux at different latitudes, with one of them on board Nanuq and the two others installed in the schools of the students from Italy and Norway who will build them. The project is part of the Extreme Energy Events - Science Inside Schools (EEE) project coordinated by the Museo storico della Fisica e Centro Studi e Ricerche Enrico Fermi (Centro Fermi), an Italian research institute with its headquarters in the historic building of the old Institute of Physics in via Panisperna in Rome, where Enrico Fermi made his famous studies on the importance of slowing down the neutrons to produce induced radioactivity. The EEE project combines an experiment on cosmic rays studies with an intense program of scientific culture dissemination with the direct participa...

  15. Adaptation of the Quality Indicator for Rehabilitative Care (QuIRC) for use in mental health supported accommodation services (QuIRC-SA).

    Science.gov (United States)

    Killaspy, Helen; White, Sarah; Dowling, Sarah; Krotofil, Joanna; McPherson, Peter; Sandhu, Sima; Arbuthnott, Maurice; Curtis, Sarah; Leavey, Gerard; Priebe, Stefan; Shepherd, Geoff; King, Michael

    2016-04-14

    No standardised tools for assessing the quality of specialist mental health supported accommodation services exist. To address this, we adapted the Quality Indicator for Rehabilitative care-QuIRC-that was originally developed to assess the quality of longer term inpatient and community based mental health facilities. The QuIRC, which is completed by the service manager and gives ratings of seven domains of care, has good psychometric properties. Focus groups with staff of the three main types of supported accommodation in the UK (residential care, supported housing and floating outreach services) were carried out to identify potential amendments to the QuIRC. Additional advice was gained from consultation with three expert panels, two of which comprised service users with lived experience of mental health and supported accommodation services. The amended QuIRC (QuIRC-SA) was piloted with a manager of each of the three service types. Item response variance, inter-rater reliability and internal consistency were assessed in a random sample of 52 services. Factorial structure and discriminant validity were assessed in a larger random sample of 87 services. The QuIRC-SA comprised 143 items of which only 18 items showed a narrow range of response and five items had poor inter-rater reliability. The tool showed good discriminant validity, with supported housing services generally scoring higher than the other two types of supported accommodation on most domains. Exploratory factor analysis showed that the QuIRC-SA items loaded onto the domains to which they had been allocated. The QuIRC-SA is the first standardised tool for quality assessment of specialist mental health supported accommodation services. Its psychometric properties mean that it has potential for use in research as well as audit and quality improvement programmes. A web based application is being developed to make it more accessible which will produce a printable report for the service manager about the

  16. Characteristics and Motivations of Sports Officials in the Province of Québec

    OpenAIRE

    Denis Auger; Julie Fortier; André Thibault; Daniel Magny; François Gravelle

    2010-01-01

    Participation in sport and recreation is important for Quebecers’ health, both mentally and physically. Sports in the province of Québec are organised under the tutelage of Sports-Québec. This is a non-profit organization composed of and representing 63 provincial sports federations, supporting 90 sports and 17 regional leisure and sport units. Federations are responsible for the development of their coaches, instructors and officials. Most federations and associations identify difficulties i...

  17. Eefeito das propriedades físicas e químicas do solo em algumas propriedades da madeira de teca (Tectona grandis

    Directory of Open Access Journals (Sweden)

    Róger Moya

    2010-12-01

    Full Text Available Estudou-se o efeito das propriedades físicas e químicas do solo em algumas propriedades da madeira de Tectona grandis oriundas de plantações entre 7 e 15 anos de idade, localizadas nas regiões Norte e Noroeste da Costa Rica, as quais apresentam dois tipos de clima (tropical seco e tropical úmido e com grande variedade de fertilidade de solo. As análises do solo consistiram no estudo de suas propriedades físicas (porcentagem de argila, limo e areia, densidade aparente, porcentagem de retenção de água e de água útil, retenção 15 Bar e 0,33 Bar e propriedades químicas (pH, acidez e conteúdo de Ca, Mg, K, P, Zn, Cu, Fe e Mn. As contrações tangenciais e radiais foram as propriedades da madeira mais correlacionadas com as características do solo, seguidas da porcentagem de cerne, medula e casca e teor de umidade na condição verde. A propriedade de menor correlação foi a densidade básica, enquanto a contração volumétrica não foi correlacionada com nenhuma propriedade do solo. Os coeficientes de correlação foram altamente significativos (a = 0,05, embora baixos valores (<0,67 foram encontrados, provavelmente influenciados pela ampla variedade das condições de clima e de solo amostrados. As propriedades físicas e químicas do solo não apresentaram influência expressiva nas propriedades da madeira de teca. Assim, apesar da grande variedade de solos existente na Costa Rica, a Teca pode ser cultivada comercialmente em todos eles sem que ocorram grandes variações nas propriedades da madeira.

  18. Caracterização química, mecânica e morfológica do gesso obtido do pólo do Araripe

    Directory of Open Access Journals (Sweden)

    A. A. Barbosa

    2014-12-01

    Full Text Available O gesso é um sulfato de cálcio hemihidratado com fórmula química CaSO4.0,5H2O, este é produzido em grande abundância na região do Araripe estado de Pernambuco e apresenta uma pureza que varia de 80 a 95%, sua aplicação baseia-se principalmente na construção civil e em um segundo plano observa-se sua utilização na odontologia, industria química, ortopedia etc. Frente à elevada qualidade da matéria prima em questão e ao baixo emprego do gesso em materiais e objetos de maior valor agregado, verificou-se a necessidade da caracterização desta matéria prima para um maior conhecimento de suas propriedades, sendo realizadas para tal, análises de FTIR, DRX, FRX, MEV com EDS acoplado, ensaios mecânicos de resistência à compressão e à flexão, cálculo da porosidade geométrica dos corpos sólidos, análise granulométrica das partículas e avaliação do tempo de pega da pasta. Este estudo tem a finalidade de conhecer detalhadamente suas características químicas, morfológicas e mecânicas, para que então posteriormente tais informações possam ser válidas para estudos referentes ao melhoramento de suas propriedades visando sua aplicação em novos produtos.

  19. The site of net absorption of Ca from the intestinal tract of growing pigs and effect of phytic acid, Ca level and Ca source on Ca digestibility.

    Science.gov (United States)

    González-Vega, J Caroline; Walk, Carrie L; Liu, Yanhong; Stein, Hans H

    2014-01-01

    An experiment was conducted to test the hypothesis that the standardised digestibility of Ca in calcium carbonate and Lithothamnium calcareum Ca is not different regardless of the level of dietary Ca, and that phytic acid affects the digestibility of Ca in these two ingredients to the same degree. The objectives were to determine where in the intestinal tract Ca absorption takes place and if there are measurable quantities of basal endogenous Ca fluxes in the stomach, small intestine or large intestine. Diets contained calcium carbonate or L. calcareum Ca as the sole source of Ca, 0% or 1% phytic acid and 0.4% or 0.8% Ca. A Ca-free diet was also formulated and used to measure endogenous fluxes and losses of Ca. Nine growing pigs (initial body weight 23.8 ± 1.3 kg) were cannulated in the duodenum and in the distal ileum, and faecal, ileal and duodenal samples were collected. Duodenal endogenous fluxes of Ca were greater (p calcareum Ca diets, but that was not the case if calcium carbonate was the source of Ca (interaction, p calcareum Ca was greater (p calcareum Ca. In conclusion, under the conditions of this experiment, standardised digestibility of Ca is not affected by the level of phytic acid, but may be affected by dietary Ca level depending on the Ca source. Calcium from calcium carbonate is mostly absorbed before the duodenum, but Ca from L. calcareum Ca is mostly absorbed in the jejunum and ileum.

  20. Rates for some reactions involving 42Ca and 44Ca

    International Nuclear Information System (INIS)

    Cheng, C.W.; King, J.D.

    1980-01-01

    Ground-state reaction rates have been deduced from recent cross section measurements for the 42 CA(α, n) 45 Ti, 42 Ca(p, γ) 43 Sc, and 44 Ca(p, n) 44 Sc reactions. Comparison of these rates with those calculated from a statistical model of nuclear reactions. (Woosley et al) shows good agreement for the first two, but the 44 Ca(p, n) rate is more than a factor of 2 less than the theoretical prediction. Stellar reaction rates have been derived from the ground-state rates by multiplying the ground-state rates by the ratio of stellar to ground-state rates given by the statistical model. Both ground-state and stellar rates have been represented by analytic functions of the temperature. The role of these reactions in the approach to quasi-equilibrium during explosive silicon burning is discussed

  1. Caracterización química de macroelementos en suelos cultivados con plátano (Musa AAB Simmonds en el departamento de Córdoba, Colombia

    Directory of Open Access Journals (Sweden)

    Combatt Caballero Enrique

    2012-11-01

    Full Text Available Las recomendaciones de fertilización para el cultivo de plátano (Musa AAB Simmonds deben estar basadas en las características químicas y el potencial de producción de los suelos. El objetivo de este trabajo fue evaluar las características químicas de macro-elementos presentes en suelos utilizados en la producción de plátano en el departamento de Córdoba, Colombia. Las evaluaciones se hicieron en diez fincas por cada uno de cuatro municipios productores de plãtano en el Alto Sinü (Valencia y Tie- rralta y la región costanera (San Bernardo del Viento y Moñitos. Los parámetros determinados en el suelo fueron: pH, materia orgánica (M.O., P, S, Ca, Mg, Na y K, según metodologías químicas propues- tas por Instituto Geogrãfico Agustin Codazi (IGAC. Los datos obtenidos %ueron sometidos a anãlisis de varianza y pruebas de comparación de medias (Tukey. En los resultados analíticos se encontró que los suelos presentan reacción moderadamente ãcida con pH + / en la zona del Alto Sinü7 a ligeramente alcalina con pH de /.8 en la zona costanera. Los contenidos de 9.;. son + 2.=>7 el P Faria entre =/.G y I8.I mgJQg y el S es deficiente con Falores + =I.8 mgJQg en todas las fincas. Los contenidos de Ca7 Mg y K son altos, pero con tendencia a antagonismos iónicos de Ca con respecto a K por las amplias relaciones catiónicas encontradas.

  2. Caracterización química de macroelementos en suelos cultivados con plátano (Musa AAB Simmonds en el departamento de Córdoba, Colombia

    Directory of Open Access Journals (Sweden)

    Enrique Combatt-Caballero

    2012-04-01

    Full Text Available Las recomendaciones de fertilización para el cultivo de plátano (Musa AAB Simmonds deben estar basadas en las características químicas y el potencial de producción de los suelos. El objetivo de este trabajo fue evaluar las características químicas de macro-elementos presentes en suelos utilizados en la producción de plátano en el departamento de Córdoba, Colombia. Las evaluaciones se hicieron en diez fincas por cada uno de cuatro municipios productores de plátano en el Alto Sinú (Valencia y Tierralta y la región costanera (San Bernardo del Viento y Moñitos. Los parámetros determinados en el suelo fueron: pH, materia orgánica (M.O., P, S, Ca, Mg, Na y K, según metodologías químicas propuestas por Instituto Geográfico Agustín Codazi (IGAC. Los datos obtenidos fueron sometidos a análisis de varianza y pruebas de comparación de medias (Tukey. En los resultados analíticos se encontró que los suelos presentan reacción moderadamente ácida con pH < 6 en la zona del Alto Sinú, a ligeramente alcalina con pH de 6.5 en la zona costanera. Los contenidos de M.O. son < 2.1%, el P varía entre 16.4 y 35.3 mg/kg y el S es deficiente con valores < 13.5 mg/kg en todas las fincas. Los contenidos de Ca, Mg y K son altos, pero con tendencia a antagonismos iónicos de Ca con respecto a K por las amplias relaciones catiónicas encontradas.

  3. Física y química: 1 Bachillerato. Calor y principio de conservación de la energía

    OpenAIRE

    Carrascosa Alís, Jaime; Martínez Sala, Salvador; Martínez-Torregrosa, Joaquín

    1998-01-01

    Cuando la energía mecánica disminuye, los objetos se calientan. ¿Hay alguna relación entre los cambios en propiedades mecánicas y térmicas?. La termología (con su hipótesis del "calórico") y sus límites con la mecánica: ¿cómo explicar que aumente la temperatura de todos los cuerpos cuando hay rozamiento?. Los trabajos de Joule. Generalización de la conservación de la energía. ¿Si la energía siempre se conserva en un sistema aislado, por qué hablamos de "crisis energética"?. Análisis de las ca...

  4. Análisis multivariado de propiedades químicas en Oxisoles con diferentes niveles de intervención agrícola

    Directory of Open Access Journals (Sweden)

    Camacho-Tamayo Jesús H.

    2010-09-01

    Full Text Available La intervención humana en la producción agrícola influye directamente en la calidad del suelo, promoviendo alteraciones en las propiedades físicas y químicas, mediante el uso de fertilizantes, correctivos y prácticas de labranza. El objetivo del presente trabajo fue evaluar los cambios en las propiedades químicas de dos Oxisoles (Typic Hapludox y Typic Haplustox, con diferentes niveles de intervención (cultivos de pasto Brachiaria y rotaciones de maíz y soya, en el municipio de Puerto López (Meta-Colombia. Las muestras fueron tomadas en 42 puntos, distanciados 25 m perpendicularmente, entre 0 y 0.10 m y 0.10 y 0.20 m de profundidad, para un total de 168 muestras en los dos lotes. Los datos fueron analizados mediante análisis de varianza y técnicas de análisis multivariado, a través de componentes principales y agrupamiento jerárquico. Las propiedades estudiadas fueron carbono orgánico, pH, acidez intercambiable, aluminio intercambiable, P, Ca, Mg, P, Na, capacidad de intercambio catiónica efectiva (CICE, suma de bases y saturación de bases. La intervención agrícola se ve reflejada principalmente en la capa superficial del suelo, donde se presentaron los mayores valores de CO, Ca, Mg, K, P, SB y CICE, debido a la presencia de residuos de cosecha, así como a la aplicación de fertilizantes y correctivos.

  5. Análisis multivariado de propiedades químicas en Oxisoles con diferentes niveles de intervención agrícola

    Directory of Open Access Journals (Sweden)

    Jesús H Camacho-Tamayo

    2010-07-01

    Full Text Available La intervención humana en la producción agrícola influye directamente en la calidad del suelo, promoviendo alteraciones en las propiedades físicas y químicas, mediante el uso de fertilizantes, correctivos y prácticas de labranza. El objetivo del presente trabajo fue evaluar los cambios en las propiedades químicas de dos Oxisoles (Typic Hapludox y Typic Haplustox, con diferentes niveles de intervención (cultivos de pasto Brachiaria y rotaciones de maíz y soya, en el municipio de Puerto López (Meta-Colombia. Las muestras fueron tomadas en 42 puntos, distanciados 25 m perpendicularmente, entre 0 y 0.10 m y 0.10 y 0.20 m de profundidad, para un total de 168 muestras en los dos lotes. Los datos fueron analizados mediante análisis de varianza y técnicas de análisis multivariado, a través de componentes principales y agrupamiento jerárquico. Las propiedades estudiadas fueron carbono orgánico, pH, acidez intercambiable, aluminio intercambiable, P, Ca, Mg, P, Na, capacidad de intercambio catiónica efectiva (CICE, suma de bases y saturación de bases. La intervención agrícola se ve reflejada principalmente en la capa superficial del suelo, donde se presentaron los mayores valores de CO, Ca, Mg, K, P, SB y CICE, debido a la presencia de residuos de cosecha, así como a la aplicación de fertilizantes y correctivos.

  6. Complejos de molibdeno con enlace cuádruple y quíntuple metal-metal

    OpenAIRE

    Carrasco Delgado, Mario

    2013-01-01

    La noción de enlace químico es un concepto esencial, de importancia extraordinaria, sobre el que se fundamentan las bases de la Ciencia Química. A pesar de su omnipresencia en lo que se podría considerar el universo químico, y de su conocimiento desde hace alrededor de un siglo, continúa teniendo una importancia capital, y siendo objeto de intensas investigaciones que se han traducido en avances muy notables en las últimas décadas. De los innumerables avances que se produjeron en la químic...

  7. Gestión de desechos químicos en laboratorios de la Universidad Nacional

    Directory of Open Access Journals (Sweden)

    José Carlos Mora Barrantes

    2012-05-01

    Full Text Available Durante el 2009 se realizó un diagnóstico de la ges- tión de desechos químicos en la Universidad Na- cional, tanto en laboratorios de docencia como de investigación. Para recopilar la información: 1 se aplicó un cuestionario, una entrevista y se hizo una visita (inspección a los laboratorios; 2 se realizaron inventarios de desechos químicos; 3 se efectuaron sesiones de trabajo con funcionarios encargados de la gestión universitaria; y 4 se visitó a funcionarios de instituciones públicas y privadas encargados de la gestión de desechos. Con el presente trabajo, se identificaron las condicio- nes actuales de manipulación y disposición final de los desechos químicos en la Universidad Nacional, así como los procedimientos o gestiones administra- tivos que ejecutan las autoridades universitarias para su adecuada manipulación. Se concluye que para una gestión adecuada de de- sechos químicos en la Universidad Nacional es ne- cesario formular e implementar una normativa, a nivel nacional e institucional, enfocada al quehacer universitario, así como la creación de una oficina que se encargue de coordinar todas las actividades y procedimientos relacionados con el manejo de los desechos químicos.

  8. Riesgo químico: estrategias de intervención social

    Directory of Open Access Journals (Sweden)

    A. A. Calera Rubio

    2002-06-01

    Full Text Available La producción, utilización, comercialización y emisión de sustancias químicas pone de manifiesto los fuertes vínculos existentes entre el riesgo químico en el lugar de trabajo, la salud pública y la contaminación ambiental. A pesar de ello, las políticas de gestión del riesgo químico no han sido coherentes y unificadas en las diferentes áreas (seguridad alimentaria, agricultura, salud pública, medio ambiente y salud laboral.La Comisión de las Comunidades Europeas ha elaborado un Libro Blanco sobre la futura política en materia de sustancias químicas en el que reconoce un importante grado de descontrol. Realmente estamos ante una profunda crisis de ineficacia de las estrategias tradicionales que debían servir supuestamente para controlar el riesgo químico.Se hace necesario utilizar estrategias diversificadas: unas destinadas a mejorar los niveles de información; otras dirigidas a la evaluación de las situaciones de riesgo y otras, de mucho mayor calado, que tengan como objetivo la evaluación de alternativas orientadas a la resolución de los problemas.

  9. Fibrose quística em adultos

    Directory of Open Access Journals (Sweden)

    C. Damas

    2007-05-01

    Full Text Available Resumo: Os autores efectuaram uma revisão de doentes adultos com fibrose quística (FQ, seguidos na consulta de Pneumologia no período de 1994-2004 (n=8: cinco mulheres e três homens, com idades compreendidas entre 20 e 34 anos (mediana=27 anos, cuja idade de diagnóstico variou entre os 18 meses e os 31 anos. O diagnóstico foi obtido por prova de suor (positiva em seis doentes e estudo genético (homozigotia para a mutação ΔF508 em quatro doentes. O atingimento respiratório traduziu-se por sinusite e bronquiectasias, acompanhando-se o envolvimento pulmonar por alterações funcionais e também gaso-métricas na maioria dos doentes, ainda que de gravidade variável e não relacionada com a idade de diagnóstico. Verificou-se colonização da árvore brônquica em cinco doentes: Pseudomonas aeruginosa em quatro e Staphilococcus aureus em quatro (verificando-se coloni-zação concomitante por estes agentes em três. As principais causas de exacerbação foram infecções res-piratórias e hemoptises. Quanto ao atingimento não respiratório, quatro doentes apresentavam envolvimento digestivo (com cirrose hepática num caso, um insuficiência renal em hemo-diálise, e em apenas um foi efectuado espermograma para documentação de infertilidade. Quatro doentes tinham osteopenia documentada por densitometria óssea. As medidas terapêuticas mais utilizadas foram a cine-siterapia, os broncodilatadores, a alfa-dornase, muco-líticos, suplementos vitamínicos e enzimáticos, antibio-terapia e oxigenoterapia. Relativamente à evolução, uma doente abandonou a consulta, uma doente faleceu, um doente aguardava transplante pulmonar e os restantes mantiveram as suas características clínicas habituais. Neste grupo, a gravidade da doença pulmonar não se relacionou com o diagnóstico mais tardio, o que se pode dever à diversidade de apresenta

  10. Composição química, evolução e cinemática de estrelas de tipo solar

    Science.gov (United States)

    Silva, R. O.; Porto de Mello, G. F.; Milone, A. C.

    2003-08-01

    A composição química das estrelas de tipo solar é um diagnóstico extremamente valioso da evolução química do disco da Galáxia. Existe alguma evidência de que tal evolução tem sido heterogênea no espaço e ao longo do tempo e que a composição química do Sol pode não ser um padrão representativo de abundâncias. Neste trabalho, foram obtidas as abundâncias dos elementos químicos C, N, Na, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd e Sm em uma amostra de estrelas de tipo solar na vizinhança solar (distâncias £ 25 pc). A técnica empregada foi a análise espectroscópica diferencial em relação ao Sol, baseando-se em dados de alta resolução (R ~ 46.000) e alta razão sinal/ruído (S/R > 300), obtidos com o espectrógrafo échelle de bancada do telescópio de 1,5 m do CTIO. Adicionalmente, abundâncias de C e N foram obtidas através de síntese de bandas moleculares dos Sistemas Eletrônicos Swan do C2 e Vermelho do CN utilizando-se um programa de síntese espectral. Os parâmetros atmosféricos foram estabelecidos usando cores fotométricas, o equilíbrio de excitação e ionização de linhas do Fe e a análise da temperatura e da luminosidade estelares no diagrama HR. Os resultados de abundâncias químicas obtidos proporcionam uma melhor compreensão da relação das abundâncias conhecidas para o Sol com a das estrelas anãs de tipo G da população local, uma vez que as razões de abundâncias de diversos elementos (em relação ao ferro) obtidas para estrelas de metalicidade semelhante à solar diferem daquelas obtidas para o Sol. Tais resultados também contribuem para um melhor entendimento do processo de evolução química da vizinhança solar e do enriquecimento nucleossintético do disco galáctico.

  11. Estudio de las propiedades fisico químicas y calidad nutricional en distintas variedades de frijol consumidas en México

    Directory of Open Access Journals (Sweden)

    América Fernanda Fernández Valenciano

    2017-01-01

    Full Text Available Introducción : El frijol común ( Phaseolus vulgaris L. es la leguminosa más importante para consumo humano en el mundo , es una fuente importante de proteína, calorías, vitamin as del complejo B y minerales . P o r lo que el objetivo del trabajo de investigación fue estudiar las propiedades f isico químicas y la calidad nutricional en las principales variedades de frijol consumidas y producidas en México, con el propósito de conocer sus beneficios nutricionales para el consumidor. Método : En este estudio se seleccionaron seis variedades de frijol más representativas y consumidas en México : Bayo, Negro, Peruano, Flor de Mayo, Alubia y Pinto, así como, una varieda d de frijol ejotero. A estas variedades se les determin aron las propiedades fisicoquímicas, C, H y N por medio del Analizador Orgánico Elemental Flash 2000. La determinación de Cu, Fe, Zn, Ni, Na, K, Ca y Mg se de terminó por espectrofotometría de absorción atómica y el P se terminó por espectrofotometría y metavandato - molibdato de amonio . Resultados : Se encontraron diferencias significativas en las propiedades f isico químicas, así como, en el contenido de macro y micronutrientes en las diferentes variedades de frijol estudiadas. En general, sobresali ó el frijol ejotero en las propiedades f isico químicas, contenido de micronutrientes y macronutrientes en relación a las variedades de frijol en grano. Discusión o Conclusión : La semilla del ejote presentó las máx imas concentraciones en proteína, N, P, K, Mg, Fe y Zn, mientras que las variedades de frijol de grano estudiadas sobresalieron en fibra (Alubia, proteínas (Pinto y Bayo, en Fe (Flor de Mayo. Por ú ltimo , resaltar que la variedad de frijol de grano estud iada que p resent ó un aporte bajo en proteína, contenido de N, Mg y Ca fue la variedad Frijol Peruano. Finalmente, se concluye que el frijol ejotero representa un gran beneficio para el consumidor por el aporte de prote

  12. A pura química : Curso a distancia para alumnos e Ingeniería

    OpenAIRE

    Tocci, Ana María; Fertitta, A. E.; Visintin, Arnaldo

    2015-01-01

    La Facultad de Ingeniería de la ciudad de La Plata (UNLP) requiere para permitir el ingreso a la misma aprobar un examen de matemáticas, el cual se rinde en el mes de diciembre, o aprobar un curso nivelatorio de la misma materia durante el mes de febrero. En ese curso no está contemplada la materia Química. Los docentes de la cátedra de Química General (materia del primer cuatrimestre de primer año) para Ingeniería Química y Materiales, encontramos un vacío en lo que respecta a conocimientos ...

  13. Uma introdução ao cálculo quântico

    OpenAIRE

    Trajano, Brunno de Castro

    2014-01-01

    O Cálculo Quântico consiste em uma outra abordagem da disciplina Cálculo, comumente estudada em cursos como Matemática e Física. Assim, optamos por abordar este tema, tendo como objetivo apresentar a q-derivada e suas aplicações, bem como a integração quântica e suas aplicações. Para isso, baseamo-nos em preceitos tais como q-cálculo e h-cálculo, que consistem em duas áreas do Cálculo Quântico. Quantum Calculus consists of a different approach to the subject Calculus, which ...

  14. Riesgo químico: estrategias de intervención social

    OpenAIRE

    A. A. Calera Rubio; E. Estefanía Blount; J. Riechmann Fernández

    2002-01-01

    La producción, utilización, comercialización y emisión de sustancias químicas pone de manifiesto los fuertes vínculos existentes entre el riesgo químico en el lugar de trabajo, la salud pública y la contaminación ambiental. A pesar de ello, las políticas de gestión del riesgo químico no han sido coherentes y unificadas en las diferentes áreas (seguridad alimentaria, agricultura, salud pública, medio ambiente y salud laboral).La Comisión de las Comunidades Europeas ha elaborado un Libro Blanco...

  15. Hydrogeochemical characterization of groundwater in the Outaouais Region (Québec, Canada) - A regional scale study

    Science.gov (United States)

    Montcoudiol, N.; Molson, J. W.; Lemieux, J.

    2013-12-01

    As part of the Québec regional groundwater characterization program (PACES), a detailed groundwater quality survey was undertaken in the Outaouais Region (Québec, Canada). During the summers of 2011 and 2012, 139 samples were taken from municipal and private wells which were analysed for major ions, nutrients, metals and sulphides. About 70% of the samples were obtained from bedrock wells, mainly in the Canadian Shield and the remainder from wells screened in Quaternary deposit aquifers. Hydrogeochemical facies were determined for 127 samples which had anion-cation charge balance errors within ×10 %. Ca-HCO3 is the dominant water type (65%) which was mainly found in unconfined aquifers, especially Quaternary deposits, and is typical of recently infiltrated rainwater. Other relevant water types are Na-HCO3 and Na-Cl (17 and 6% respectively), characteristic of confined aquifers. This classification by water type is supported by multivariate statistical analysis, namely Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA). PCA allows the identification of three factors controlling groundwater chemistry: salinity, silicate dissolution and F-bearing mineral dissolution. HCA results show that the samples can be grouped into seven clusters. Clusters 1 to 4 are mostly Ca-HCO3 water type and are representative of the enrichment in major ions due to carbonate and silicate dissolution, cluster 1 being closer to rainwater and cluster 4 the most evolved. Cluster 5, made of one sample with a particular chemistry, is not yet fully understood. Samples from cluster 6 present various degrees of Na-Ca exchange, a consequence of remnant Champlain Sea water (some samples from cluster 7 in confined zones) being replaced by infiltrating recharge water. Samples from cluster 7 are evolved waters with high Total Dissolved Solid (TDS) concentrations: they are remnants of the Champlain Sea in confined aquifers (bromide detected) or diluted/mixed by infiltrating

  16. CaWingz user's guide

    International Nuclear Information System (INIS)

    Cha, Ben-chin.

    1994-01-01

    This document assumes that you have read and understood the Wingz user's manuals. CaWingz is an external Wingz program which, when combined with a set of script files, provides easy-to-use EPICS channel access interface functions for Wingz users. The external function run allows Wingz user to invoke any Unix processor within caWingz. Few additional functions for accessing static database field and monitoring of value change event is available for EPICS users after release 3.11. The functions, script files, and usage are briefly described in this document. The script files supplied here serve as examples only. Users are responsible for generating their own spreadsheet and script files. CaWingz communicates with IOC through channel access function calls

  17. El Área de Ciencia y Tecnologías Químicas del CSIC: ¿Un Área de químicas?

    Directory of Open Access Journals (Sweden)

    García-López, María Teresa

    2002-08-01

    Full Text Available Not available

    El artículo titulado "El Area de Ciencia y Tecnologías Químicas del CSIC: ¿un Area de químicas?» pretende mostrar una breve panorámica del lugar que ocupa el género femenino dentro de la citada Area. En la primera parte se aportan las estadísticas que reflejan el número y porcentaje de científicas totales en los distintos Institutos del Area, así como su distribución entre las tres escalas de personal científico del Organismo. Una segunda parte está dedicada a recoger las aportaciones personales de varias científicas del Area acerca del tema, visto desde sus propias experiencias.

  18. Química recreativa i eines 2.0 per a la didàctica i divulgació de la química

    OpenAIRE

    Vieta i Corcoy, Pep Anton; Guillaumes, Laia; Güell, Mireia; Duran, Josep; Simon, Sílvia

    2012-01-01

    Que la societat sovint té una visió negativa de la química i que la recerca científica que té lloc a les universitats es percep com a llunyana per part de la població són fets coneguts. En aquest article, fruit de la presentació feta per l'autor principal a la VII Trobada de Joves Investigadors dels Països Catalans, organitzada el febrer de 2012 per la Societat Catalana de Química (SCQ), es presenten diversos projectes duts a terme des de la Càtedra de Cultura Científica i Comunicació Digi...

  19. La Neurociencia Computacional hoy: I. Qué es y por qué es difícil su estudio

    Directory of Open Access Journals (Sweden)

    Jesús Cortés

    2009-01-01

    Full Text Available La Neurociencia Computacional es una disciplina consolidada, con más de 20 años de desarrollo, y que emplea técnicas muy diversas para entender diferentes computaciones cerebrales. Aquí se introduce brevemente mediante dos artículos. En el primero, “Qué es y por qué es difícil su estudio”, se introducen de forma muy general cuáles son sus objetivos como ciencia y los problemas con los que se encuentra. En el segundo, mediante “Un ejemplo muy representativo en el campo” abordamos su metodología y destacamos la trascendencia que la Neurociencia Computacional está teniendo y tendrá dentro de las Neurociencias.

  20. Didáctica da física e didáctica da química : experimentação no ensino da física e da química

    OpenAIRE

    Pereira, Alda

    1991-01-01

    Formação - Professores A componente experimental no ensino da Física e da Química. Experimentação na sala de aula e alguns exemplos. Disciplina “Didáctica da Física e da Química”, do Curso de Profissionalização em Exercício.

  1. Avances en la química de coordinación de los tetrilenos pesados

    OpenAIRE

    Polo Coca, Diego

    2015-01-01

    Esta tesis doctoral se enmarca en el campo de la Química Inorgánica y, más concretamente, en el de la química que asocia los metales de transición (Ms) con los parientes más pesados de los carbenos, conocidos comúnmente como tetrilenos pesados (TPs) o metalilenos. Su formato es el de ¿Compendio de Publicaciones¿ y contiene los 10 artículos científicos que hasta ahora se han publicado sobre su contenido. En la primera parte de la memoria se describen reacciones de tetrilenos pesados acícli...

  2. Lorsque la croissance ne suffit pas : en quête d'une économie ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    21 juil. 2016 ... Bien que la croissance ait été modérée ces dernières années, on s'attend à ce qu'elle reprenne bientôt. On observe toutefois des ... L'un des principaux enjeux est le fait que l'économie de l'Afrique s'est développée sans qu'aucune transformation structurelle n'ait été apportée. Les experts ont souligné ...

  3. Perfiles toxicológicos de contaminantes químicos peligrosos

    OpenAIRE

    Torres Rodríguez, Marina T; García Melián, Maricel; Hernández, María Teresa; Sardiñas Peña, Olivia; Martínez Varona, Miriam; Brown, Luis Alberto

    2002-01-01

    Con el objetivo de complementar adecuadamente y sustentar el desarrollo de trabajos de investigación y de servicios en el área de Toxicología Ambiental, en la evaluación de riesgos por exposición a sustancias y desechos químicos así como en estudios de impacto ambiental de proyectos de desarrollo que involucren la emisión de contaminantes químicos al ambiente, se elaboró en el Instituto Nacional de Higiene, Epidemiología y Microbiología, la documentación para obtener una información suficient...

  4. Alterações químicas em solos ácidos após a aplicação de resíduos vegetais

    Directory of Open Access Journals (Sweden)

    J. C. Franchini

    1999-09-01

    Full Text Available O conhecimento do comportamento químico de solos ácidos durante a decomposição de resíduos vegetais tem grande importância no manejo destes solos. Em Londrina, foi avaliado, durante os anos de 1995 e 1996, o efeito da incubação (0, 15, 30, 60 e 90 dias de resíduos de nabo, soja e trigo (doses de 2 e 4% finamente moídos com amostras do horizonte Bw de três unidades de solo (Latossolo Vermelho-Amarelo, Latossolo Roxo e Latossolo Vermelho-Escuro sobre o pH, carbono orgânico dissolvido (COD e Al, Ca, Mg e K trocáveis e solúveis. Nos resíduos vegetais, foram determinados o COD e Ca, Mg e K totais e solúveis. Imediatamente após a aplicação dos resíduos vegetais (tempo zero, ocorreram aumentos no pH, no Ca, Mg e K trocáveis e solúveis, no Al solúvel e no COD e redução no Al trocável. A intensidade dessas alterações foi relacionada com o COD e Ca, Mg e K solúveis nos diferentes resíduos, na seguinte ordem: nabo > soja > trigo. Durante a incubação, o COD na solução do solo foi rapidamente diminuído. A redução do COD com o tempo de incubação não alterou o K, mas reduziu drasticamente o Al, Ca e Mg na solução do solo, demonstrando a importância do COD na manutenção de cátions polivalentes em solução por meio do mecanismo de complexação orgânica. A especiação química demonstrou que acima de 90% do Al total em solução estava na forma orgânica. A composição orgânica e inorgânica da fração hidrossolúvel de resíduos vegetais demonstrou ser a principal responsável pelas alterações químicas observadas nas amostras de solos ácidos.

  5. Marketing viral en medios sociales:¿qué contenido es más contagioso y por qué?

    Directory of Open Access Journals (Sweden)

    Paús, Fermín

    2014-12-01

    Full Text Available El marketing viral es una de las herramientas más relevantes del marketing digital que ha tomado gran relevancia luego de la explosión de los medios sociales. El siguiente ensayo brinda un entendimiento integral del fenómeno contagioso a través del estudio de tres elementos claves: su importancia dentro del contexto actual, su definición y su vinculación con el boca a boca tanto offline (Word of Mouth como online (Electronic Word of Mouth y por último, el entendimiento de qué contenido es más viral y por qué. Esta última sección identifica las principales características del contenido contagioso y explica de manera simple por qué los usuarios pasan algunos contenidos y no otros a sus pares. De esta manera, el siguiente ensayo es una buena combinación entre conceptos teóricos y prácticos que resulta en una excelente guía para profundizar el entendimiento del fenómeno y perfeccionar el uso de la herramienta.

  6. Efecto de la Composición Química del Metal de Aporte y del Calor Aportado Sobre la Microestructura y las Propiedades Mecánicas de Juntas Soldadas de Aceros Inoxidables Dúplex

    Directory of Open Access Journals (Sweden)

    Sebastián Zappa

    Full Text Available Resumen Los aceros inoxidables dúplex poseen una microestructura dual (ferrita y austenita con contenidos aproximadamente iguales y se caracterizan por tener buena soldabilidad, buenas propiedades mecánicas y una alta resistencia a la corrosión generalizada y localizada. Gracias a estas características, estos aceros son los principales materiales a emplear en cañerías con altas exigencias, ampliamente utilizados en varias industrias, principalmente la petroquímica. Dichas propiedades están controladas por la composición química, el equilibrio microestructural y la ausencia de compuestos intermetálicos. El objetivo de este trabajo fue estudiar la influencia de la composición química del metal de aporte y el calor aportado sobre la microestructura y las propiedades mecánicas en juntas soldadas de cañerías de acero inoxidable dúplex. El metal base utilizado fue un acero inoxidable dúplex UNS S31803 de 8” de diámetro y 8,18 mm de espesor y los metales de aporte fueron dos alambres tubulares que depositan aceros inoxidables dúplex y lean dúplex (AWS A5.22: E2209T1-1 y E2209T1-G, mediante el proceso de soldadura semi-automático bajo protección gaseosa, soldados con alto y bajo calor aportado. De cada probeta se extrajeron muestras donde se determinó la composición química, se realizó la caracterización microestructural y se determinaron las propiedades mecánicas (dureza, tracción y Charpy-V.

  7. Indiscernibilidade e identidade em química: aspectos filosóficos e formais

    Directory of Open Access Journals (Sweden)

    Jaison Schinaider

    2014-06-01

    Full Text Available Neste artigo tratamos, de um ponto de vista formal e filosófico, com alguns conceitos que fazem parte da química usual. As teorias da química, e seus conceitos, normalmente são apresentadas de um ponto de vista informal (não axiomatizada, e isso pode trazer dificuldades filosóficas (embora a química propriamente - bem como também as outras disciplinas da ciência aplicada - pareçam não sofrer qualquer restrição quanto a isso. Aqui estaremos ocupados em um aspecto parti-cu-lar, que diz respeito à indiscernibilidade de alguns objetos básicos da química, tais como átomos, moléculas, bem como de seus componentes. Começamos com uma visão geral da identidade destes compostos e seus componentes a partir de uma perspectiva filosófica e, em seguida, mostramos em que sentido o conceito de identidade dos compostos químicos é problemático em relação ao conceito correspondente de identidade na lógica e matemática clássicas (que, como em geral é suposto, estão 'alicerçando' as teorias químicas. Argumentamos que, por um lado, a química parece supor que esses objetos básicos precisam ser 'idênticos' (indistinguíveis uns aos outros (como enfatizado há muito tempo por John Dalton, como veremos. Por outro lado, do ponto de vista formal, se a lógica subjacente à teoria atômica for a lógica clássica (que também é pano de fundo da matemática padrão, coisas idênticas devem ser a mesma coisa e logo 'colapsar' em apenas uma (e este não é o caso em química, uma vez que temos uma enorme quantidade de átomos e moléculas semelhantes, mas não apenas um. Esta aparente contradição pode ser tratada de várias perspectivas e, aqui, propomos o uso de uma teoria de conjuntos não-clássica (a saber, a teoria de quase-conjuntos para alicerçar uma formulação axiomática de certas teoria químicas, mostrando como essa diferente base matemática pode nos levar a uma visão que está mais perto da química em si. Como esta

  8. Weak transitions in 44Ca

    International Nuclear Information System (INIS)

    Tauhata, L.; Marques, A.

    1972-01-01

    Energy levels and gamma radiation transitions of Ca 44 are experimentally determined, mainly the weak transition at 564 KeV and 728 KeV. The decay scheme and the method used (coincidence with Ge-Li detector) are also presented [pt

  9. Control of ciliary motility by Ca2+: Integration of Ca2+-dependent functions and targets for Ca2+ action

    International Nuclear Information System (INIS)

    Evans, T.C.

    1988-01-01

    To identify functions that regulate Ca 2+ -induced ciliary reversal in Paramecium, mutants defective in terminating depolarization-induced backward swimming were selected. Six independent recessive mutations (k-shy) comprising two complementation groups, k-shyA and k-shyB, were identified. All mutants exhibited prolonged backward swimming in depolarizing solutions. Voltage clamp studies revealed that mutant Ca 2+ current amplitudes were reduced, but could be restored to wild type levels by EGTA injection. The recovery of the mutant Ca 2+ current from Ca 2+ -dependent inactivation, and the decay of the Ca 2+ -dependent K + and Ca 2+ -dependent Na + currents after depolarization were slow in k-shy compared to wild type. To identify protein targets of Ca 2+ action, ciliary proteins that interact with calmodulin (CaM) were characterized. With a 125 I-CaM blot assay, several CaM-binding proteins were identified including axonemal, soluble, and membrane-bound polypeptides. Competitive displacement studies with unlabeled Paramecium CaM, bovine CaM, and troponinC suggested that both protein types bind CaM with high affinity and specificity. To examine the presence of CaM-binding sites in intact axonemes, a filtration binding assay was developed

  10. Ca isotopic fractionation patterns in forest ecosystems

    Science.gov (United States)

    Kurtz, A. C.; Takagi, K.

    2012-12-01

    Calcium stable isotope ratios are an emerging tracer of the biogeochemical cycle of Ca that are just beginning to see significant application to forest ecosystems. The primary source of isotopic fractionation in these systems is discrimination against light Ca during uptake by plant roots. Cycling of vegetation-fractionated Ca establishes isotopically distinct Ca pools within a forest ecosystem. In some systems, the shallow soil exchangeable Ca pool is isotopically heavy relative to Ca inputs. This has been explained by preferential removal of light Ca from the soil. In other systems, the soil exchange pool is isotopically light relative to inputs, which is explained by recycling of plant-fractionated light Ca back into soil. Thus vegetation uptake of light Ca has been called on to account for both isotopically heavy and light Ca in the shallow soil exchange pools. We interpret patterns in ecosystem δ44Ca with the aid of a simple box model of the forest Ca cycle. We suggest that the δ44Ca of exchangeable Ca in the shallow soil pool primarily reflects the relative magnitude of three key fluxes in a forest Ca cycle, 1) the flux of external Ca into the system via weathering or atmospheric deposition, 2) the uptake flux of Ca from soils into the vegetation pool, and 3) the return flux of Ca to shallow soils via remineralization of leaf litter. Two observations that emerge from our model may aid in the application of Ca isotopes to provide insight into the forest Ca cycle. First, regardless of the magnitude of both vegetation Ca uptake and isotopic fractionation, the δ44Ca of the soil exchange pool will equal the input δ44Ca unless the plant uptake and remineralization fluxes are out of balance. A second observation is that the degree to which the shallow soil exchange pool δ44Ca can differ from the input ratio is controlled by the relative rates of biological uptake and external Ca input. Significant differences between soil exchange and input δ44Ca are seen only

  11. Thinking Interculturally: Decolonizing History and Citizenship Education in Québec

    Science.gov (United States)

    DesRoches, Sarah J.

    2016-01-01

    The main objective of this article is to offer an alternative discursive framework for teaching history and citizenship education in Québec, Canada. Enabling a more inclusive discussion around how citizenship is constructed, thinking interculturally allows us begin thinking about practical ways in which citizenship and history education might…

  12. The Pedagogical Practices of Québec High School Teachers Relative to Sexual Diversity

    Science.gov (United States)

    Richard, Gabrielle

    2015-01-01

    This article explores the ways in which teachers describe their pedagogical and intervention practices relative to sexual diversity in Québec (Canada). Three variables closely associated with teachers who report inclusive practices emerge: experiential training (based on the experience of a lesbian, gay, or bisexual [LGB] teacher), contact…

  13. Parte 4: Estudio comparativo de la composición química

    Directory of Open Access Journals (Sweden)

    L. R. Carballo-Abreu

    2004-01-01

    Full Text Available Se estudió comparativamente, mediante análisis estadístico la composición química de la madera de E. saligna Smith, Corymbia citriodora y E. pellita F. Muell, a tres alturas del fuste comercial (25, 55 y 85 % en muestras procedentes de las Empresas Forestales Integrales (EFI de Macurije y Guanahacabibes en la provincia de Pinar del Río, Cuba. Los resultados obtenidos de la composición química, se trataron mediante un programa estadístico SPSS para Windows, donde no todas las variables analizadas muestran influencias estadísticas en la caracterización química de las especies. Los resultados manifiesta una mejor agrupación con especto a la especie que a la altura del fuste comercial entre las especies. La madera de Corymbia citriodora presenta los mayores contenidos de celulosa, los menores contenidos de lignina y de sustancias extraíbles, siendo la especie más atractiva desde el punto de vista químico para ser utilizada en la Industria de celulosa y papel.

  14. Québécois and Beninese researchers collaborate in the fight ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-10-12

    Oct 12, 2010 ... Québécois and Beninese researchers collaborate in the fight against AIDS ... disabled" — vulnerable groups less able to make the right choices ... Less is more: Improving yields for Sahelian women with tiny dozes of fertilizer.

  15. La matematización de los procesos químicos. Primera parte

    Directory of Open Access Journals (Sweden)

    Rómulo Gallego Badillo

    2012-04-01

    Full Text Available Dada la extensión del presente aporte se ha decidido dividirlo en dos partes. En la primera se adelanta una reconstrucción de la historia del modelo cinético molecular de los gases y de la termodinámica clásica, y se realiza una aproximación al análisis epistemológico. En la segunda se intenta también una reconstrucción histórica de la creación de la fisicoquímica como disciplina científica y la introducción de la mirada desde la termodinámica clásica de los procesos químicos, asumidos como sistemas y como “máquinas térmicas”. Se irá más allá de la inicialmente designada como “dinámica química”. El objetivo consiste en elaborar una explicación admisible que dé cuenta de la introducción en el discurso químico, de una matemática de mayor complejidad que la propia del álgebra, dentro de la cual se construyó, durante la segunda mitad del siglo XIX, la química como ciencia, construcción ésta basada en las leyes ponderales.

  16. Catalizadores Organometálicos en la Industria Química

    Directory of Open Access Journals (Sweden)

    Alfonso Enrique Ramírez Sanabria

    2015-10-01

    Full Text Available Los procesos catalíticos son cada vez más importantes en la industria. Gran número de productos químicos incluyen dentro de su producción reacciones catalizadas. La catálisis se entiende como un proceso por el cual se aumenta la velocidad de una reacción química, debido a la participación de una especie química denominada catalizador. El presente trabajo recopila cinco procesos industriales en los cuales son empleados catalizadores organometálicos en fase homogénea. Busca resaltar la importancia que tienen los complejosorganometálicos como catalizadores, para la industria de química fina y farmacéutica. Se detallan aspectos mecanísticos en los que se puede ver el papel del centro metálico en las propiedades catalíticas del sistema, así como en la estructura del producto final.

  17. Atributos químicos do solo e ocorrência de fungos micorrízicos sob áreas de pastagem e sistema agroflorestal, Brasil

    Directory of Open Access Journals (Sweden)

    Arcângelo Loss

    2009-04-01

    Full Text Available Este trabalho teve como objetivo caracterizar alguns atributos químicos do solo e avaliar a comunidade de fungos micorrízicos arbusculares (FMAs em uma área de pastagem e um sistema agroflorestal (SAF. A área de estudo está localizada na "Fazendinha Agroecológica do Km 47", 22° 45'S, 43° 41'W, no município de Seropédica, Rio de Janeiro, Brasil. Foram coletadas amostras de solo na profundidade de 0-5 cm e quantificados os teores de carbono orgânico total (COT, Ca, Mg, pH, P e K. Os FMAs foram quantificados e posteriormente identificados. Os resultados encontrados foram analisados como delineamento inteiramente casualizado, com aplicação do teste F. Verificaram-se valores estatisticamente maiores de COT, Ca, Mg e K no SAF, assim como o maior número de esporos de fungos micorrízicos. Observou-se uma baixa diversidade de espécies de FMAs, sendo que Glomus macrocarpum e Acaulospora scrobiculata foram as espécies dominantes nas duas áreas. O manejo do solo pode ter influenciado no menor número de esporos de FMAs encontrados sob pastagem. Por meio da análise de componentes principais foi possível separar as duas áreas avaliadas, sendo o comportamento semelhante ao verificado na análise univariada.

  18. A Devil in the Details: Matrix-Dependent 40Ca42Ca++/42Ca+ and Its Effects on Estimates of the Initial 41Ca/40Ca in the Solar System

    Science.gov (United States)

    McKeegan, K. D.; Liu, M.-C.

    2015-07-01

    Ian Hutcheon established that the molecular ion interference 40Ca42Ca++/42Ca+ on 41K+ is strongly dependent on the mineral analyzed. Correction for this "matrix effect" led to a downward revision of the initial 41Ca/40Ca of the solar system.

  19. Caracterização química de compostos de lixo urbano de algumas usinas brasileiras

    Directory of Open Access Journals (Sweden)

    M. S. Cravo

    1998-09-01

    Full Text Available Uma das alternativas para diminuir o volume de lixo urbano a ser descartado é a compostagem, cujo produto - o composto - é utilizado na agricultura. Esses compostos podem apresentar substâncias tóxicas ao ser humano, a exemplo dos metais pesados. O objetivo deste trabalho foi avaliar as características químicas de compostos de lixo urbano de seis capitais brasileiras. Analisaram-se, também, amostras de esterco, calcário, superfosfato simples, KCl e uréia, para comparações com os compostos de lixo. Foram feitas determinações de M.O., C, N, P, K, Ca, Mg, Cu, Mn, Mo, Zn, Fe, Al, Ba, Cd, Co, Cr, Ni, Pb, Sr, Ti e V. As análises foram realizadas, em 1995, nos Laboratórios do Centro de Energia Nuclear na Agricultura - CENA/USP. Houve diferenças nos teores de nutrientes entre os compostos, provavelmente devidas aos diferentes processos de compostagem, estando alguns deles acima dos níveis toleráveis em compostos na Alemanha. Os demais elementos analisados, incluindo os metais pesados, estão dentro da faixa observada em lodo de esgoto na Inglaterra. De acordo com a legislação alemã, o Pb, Cr, Ni e o Cd estão acima dos valores toleráveis para compostos de lixo. Na maioria dos compostos analisados, os teores totais de nutrientes foram menores do que no esterco, mas a concentração dos outros elementos, incluindo metais pesados, foi mais elevada do que no esterco. Embora os teores dos elementos avaliados nos compostos sejam os totais, é necessário cautela para seu uso, até que sejam obtidos resultados seguros sobre a "disponibilidade" desses elementos para as plantas.

  20. Lattice Dynamics of fcc Ca

    DEFF Research Database (Denmark)

    Stassis, C.; Zaretsky, J.; Misemer, D. K.;

    1983-01-01

    A large single crystal of FCC Ca was grown and was used to study the lattice dynamics of this divalent metal by coherent inelastic neutron scattering. The phonon dispersion curves were measured, at room temperature, along the [ξ00], [ξξ0], [ξξξ], and [0ξ1] symmetry directions. The dispersion curves...... to the propagation of elastic waves. The frequencies of the T1[ξξ0] branch for ξ between approximately 0.5 and 0.8 are slightly above the velocity-of-sound line determined from the low-frequency measurements. Since a similar effect has been observed in FCC Yb, it is natural to assume that the anomalous dispersion...... bear a striking resemblance to those of FCC Yb, which is also a divalent metal with an electronic band structure similar to that of Ca. In particular, the shear moduli c44 and (c11-c 12)/2 differ by a factor of 3.4, which implies that FCC Ca (like FCC Yb) is very anisotropic with regard...

  1. Clonación humana: las preguntas «por qué no» y «por qué sí»

    Directory of Open Access Journals (Sweden)

    Velayos Castelo, Carmen

    2002-12-01

    Full Text Available Why not cloning us is a relevant question for contemporary ethics. The question why not, when it refers to a technology (or to some of its applications, is the question for its moral limits. In other words, it is the question for the universal dangers that a technology entails or could entail in some of its applications. The sphere of the moral evaluation of a technology has to do with the public elimination of the possible harms that are inherent or supervenient to its utilisation. If we focus on the relevant normative questions of the justice sphere, it couldn´t be relevant to answer the question why, that is, why a person or a group of them would wish the technology was applied The question why is related to vital options and ways of create ourselves that needn´t be binding on someone nor are characteristic of the moral point of view. However, the suspicion of this article is the following: the specific character of contemporary technological innovation (of which cloning is a paradigmatic case stimulates and makes relevant the debate about the good (given the collective or global implications of the answers.

    Por qué no clonarnos es una pregunta relevante para la ética actual. El por qué no de una técnica -o de determinadas aplicaciones de la misma- es la pregunta por los límites morales. O, de otro modo, es la pregunta por los daños objetivos que ésta supone, o supondría en una determinada aplicación. El marco de evaluación moral de una técnica tiene que ver, pues, con la desestimación pública y universal de posibles daños inherentes o sobrevenibles a su uso. Circunscritas las cuestiones normativas relevantes al ámbito de la justicia, no parecería relevante clarificar cuál sea el por qué -o el por qué sí- un individuo o un conjunto de ellos buscarían la aplicación o puesta en marcha de una técnica. Ésta es la pregunta por opciones vitales y

  2. Propriedades químicas e manejo de solos tiomórficos da várzea do Rio Coruripe, estado de Alagoas

    Directory of Open Access Journals (Sweden)

    V. S. Souza Júnior

    2001-12-01

    Full Text Available Com o objetivo de estudar as propriedades químicas de solos tiomórficos da várzea do rio Coruripe, no estado de Alagoas, foram selecionados seis perfis de Gleissolos e Organossolos, na área pertencente à Usina Coruripe, onde estão estabelecidos um sistema de drenagem e a cultura da cana-de-açúcar. Os solos foram caracterizados morfologicamente, e amostras de cada horizonte foram coletadas para determinações químicas no solo e no extrato da pasta saturada, utilizando amostras na umidade de campo e secas ao ar. Foi realizado um teste de calagem em casa de vegetação com amostras compostas, representativas da área de dois perfis selecionados, nas profundidades de 0-20 e 20-40 cm. Os resultados permitiram concluir que o maior desenvolvimento dos horizontes sulfúricos ocorreu nos solos com mais altos teores de matéria orgânica. O processo de secagem das amostras em laboratório promoveu a oxidação dos sulfetos e a formação de ácido sulfúrico, alterando as condições naturais dos solos no campo. A alta condutividade elétrica observada nos solos tiomórficos estudados não é indicativo de salinidade e está relacionada com a formação de ácido sulfúrico. As características químicas peculiares observadas neste estudo sugerem a realização de pesquisas sobre métodos apropriados de amostragem e análises, específicos a estes solos. Para correção do alumínio trocável dos horizontes superficiais dos solos estudados, foram necessárias doses de 11 a 25 t ha-1 de CaCO3. A manutenção do solo úmido, por meio do controle do lençol freático à profundidade em torno de 30 cm, é a forma mais eficiente e sustentável de controle da acidez dos solos tiomórficos, constituindo condição indispensável à utilização dos solos com cana-de-açúcar.

  3. Abundância química de simbióticas na direção do bojo galáctico

    Science.gov (United States)

    Luna, G. J. M.; Costa, R. D. D.

    2003-08-01

    O estudo da distribuição de metalicidades de gigantes K no Bojo indica um largo intervalo com valores entre 0.1 a 10 vezes o valor solar. As razões elementais Ca/Fe, Si/Fe, Mg/Fe são típicas de estrelas do halo, apontando para um processo rápido de enriquecimento, via estrelas masssivas (SN's tipo II). No entanto, este cenário não combina com os resultados derivados de nebulosas planetárias do bojo tais como os de Ratag et al. (1992, A&A,255,270), Cuisinier et al.(2000, A&A,353, 543), Escudero e Costa (2001, A&A,380, 300),que obtêm abundâncias análogas às do disco. Neste cenário, o estudo de estrelas simbióticas possibilita uma abordagem particularmente apropriada para o problema das abundâncias químicas de estrelas de massa intermediária em estágios avançados da evoluçao estelar. Apresentamos aqui os resultados da determinacão das abundâncias do grupo do CNO numa extensa amostra de simbióticas do bojo. Aliás, com a disponibilidade de espectros no visível determinamos também abundâncias de Ar, Ne, S e He, fundamentais para analisar os processos de enriquecimento químico ocorridos ao longo da evolução estelar, bem como a evolução química do meio interestelar. Com os espectros UV do satelite IUE obtivemos abundâncias de C, necessárias no estudo da evolução dos sistemas. As relaçoes C/N-O/N mostram que o material nebular é produto do vento da componente gigante e não dos eventos de nova que às vezes acontecem nestes sistemas, como foi mostrado por Nussbaumer et al (1988,A&A,198,179). As abundâncias de Ar, S, Ne e O são compativeis com resultados de fontes no disco e bojo, seguindo o gradiente proposto por muitos autores na literatura a partir de diferentes objetos como cefeidas, nebulosas planetárias e anãs G. (CAPES,FAPESP,CNPq)

  4. Acoplamiento de modelos de transporte de solutos y de modelos de reacciones químicas

    Directory of Open Access Journals (Sweden)

    Samper, J.

    1993-08-01

    Full Text Available During subsurface transport, reactive solutes are subject to a variety of hydrodynamic and chemical processes. The major hydrodynamic processes include advection and convection, dispersion and diffusion. The key chemical processes are complexation including hydrolysis and acid-base reactions, dissolution-precipitation, reduction-oxidation, adsorption and ion exchange. The combined effects of all these processes on solute transport must satisfy the principie of conservation of mass. The statement of conservation of mass for N mobile species leads to N partial differential equations. Traditional solute transport models often incorporate the effects of hydrodynamic processes rigorously but oversimplify chemical interactions among aqueous species. Sophisticated chemical equilibrium models, on the other hand, incorporate a variety of chemical processes but generally assume no-flow systems. In the past decade, coupled models accounting for complex hydrological and chemical processes, with varying degrees of sophistication, have been developed. The existing models of reactive transport employ two basic sets of equations. The transport of solutes is described by a set of partial differential equations, and the chemical processes, under the assumption of equilibrium, are described by a set of nonlinear algebraic equations. An important consideration in any approach is the choice of primary dependent variables. Most existing models cannot account for the complete set of chemical processes, cannot be easily extended to include mixed chemical equilibria and kinetics, and cannot handle practical two and three dimensional problems. The difficulties arise mainly from improper selection of the primary variables in the transport equations.La distribución espacial de un soluto reactivo y su movimiento a través del medio subterráneo están controlados por procesos hidrodinámicos de transporte de masa (advección, difusión y dispersión y procesos qu

  5. Preterm birth in the Inuit and First Nations populations of Québec, Canada, 1981–2008

    Science.gov (United States)

    Auger, Nathalie; Sing, Mélanie Fon; Park, Alison L.; Lo, Ernest; Trempe, Normand; Luo, Zhong-Cheng

    2012-01-01

    Objectives To evaluate preterm birth (PTB) for Inuit and First Nations vs. non-Indigenous populations in the province of Québec, Canada. Study design Retrospective cohort study. Methods We evaluated singleton live births for Québec residents, 1981–2008 (n =2,310,466). Municipality of residence (Inuit-inhabited, First Nations-inhabited, rest of Québec) and language (Inuit, First Nations, French/English) were used to identify Inuit and First Nations births. The outcome was PTB (Inuit language speakers in Inuit-inhabited areas and the rest of Québec compared with French/English speakers in the rest of Québec, and disparities persisted over time. Relative to French/English speakers in the rest of Québec, Inuit language speakers in the rest of Québec had the highest risk of PTB (HR 1.98, 95% CI: 1.62–2.41). The risk was also elevated for Inuit language speakers in Inuit-inhabited areas, though to a lesser extent (HR 1.29, 95% CI: 1.18–1.41). In contrast, First Nations language speakers in First Nations-inhabited areas and the rest of Québec had similar or lower risks of PTB relative to French/English speakers in the rest of Québec. Conclusions Inuit populations, especially those outside Inuit-inhabited areas, have persistently elevated risks of PTB, indicating a need for strategies to prevent PTB in this population. PMID:22456035

  6. Preterm birth in the Inuit and First Nations populations of Québec, Canada, 1981-2008.

    Science.gov (United States)

    Auger, Nathalie; Fon Sing, Mélanie; Park, Alison L; Lo, Ernest; Trempe, Normand; Luo, Zhong-Cheng

    2012-03-24

    To evaluate preterm birth (PTB) for Inuit and First Nations vs. non-Indigenous populations in the province of Québec, Canada. Retrospective cohort study. We evaluated singleton live births for Québec residents, 1981-2008 (n = 2,310,466). Municipality of residence (Inuit-inhabited, First Nations-inhabited, rest of Québec) and language (Inuit, First Nations, French/English) were used to identify Inuit and First Nations births. The outcome was PTB (Inuit language speakers in Inuit-inhabited areas and the rest of Québec compared with French/English speakers in the rest of Québec, and disparities persisted over time. Relative to French/English speakers in the rest of Québec, Inuit language speakers in the rest of Québec had the highest risk of PTB (HR 1.98, 95% CI: 1.62-2.41). The risk was also elevated for Inuit language speakers in Inuit-inhabited areas, though to a lesser extent (HR 1.29, 95% CI: 1.18-1.41). In contrast, First Nations language speakers in First Nations-inhabited areas and the rest of Québec had similar or lower risks of PTB relative to French/English speakers in the rest of Québec. Inuit populations, especially those outside Inuit-inhabited areas, have persistently elevated risks of PTB, indicating a need for strategies to prevent PTB in this population.

  7. Preterm birth in the Inuit and First Nations populations of Québec, Canada, 1981–2008

    Directory of Open Access Journals (Sweden)

    Nathalie Auger

    2012-03-01

    Full Text Available Objectives: To evaluate preterm birth (PTB for Inuit and First Nations vs. non-Indigenous populations in the province of Québec, Canada. Study design: Retrospective cohort study. Methods: We evaluated singleton live births for Québec residents, 1981–2008 (n = 2,310,466. Municipality of residence (Inuit-inhabited, First Nations-inhabited, rest of Québec and language (Inuit, First Nations, French/English were used to identify Inuit and First Nations births. The outcome was PTB (<37 completed weeks. Cox proportional hazards regression was employed to estimate hazard ratios (HR and 95% confidence intervals (CI of PTB, adjusting for maternal age, education, marital status, parity and birth year. Results: PTB rates were higher for Inuit language speakers in Inuit-inhabited areas and the rest of Québec compared with French/English speakers in the rest of Québec, and disparities persisted over time. Relative to French/English speakers in the rest of Québec, Inuit language speakers in the rest of Québec had the highest risk of PTB (HR 1.98, 95% CI: 1.62–2.41. The risk was also elevated for Inuit language speakers in Inuit-inhabited areas, though to a lesser extent (HR 1.29, 95% CI: 1.18–1.41. In contrast, First Nations language speakers in First Nations-inhabited areas and the rest of Québec had similar or lower risks of PTB relative to French/English speakers in the rest of Québec. Conclusions: Inuit populations, especially those outside Inuit-inhabited areas, have persistently elevated risks of PTB, indicating a need for strategies to prevent PTB in this population.

  8. Tratamento físico-químico do caldo de cana produz cachaça de qualidade

    Directory of Open Access Journals (Sweden)

    Mara Lucia Dias Ribeiro

    Full Text Available RESUMO A cachaça é a aguardente produzida a partir da destilação do fermentado de caldo de cana. Atualmente destaca-se por ser a segunda bebida alcoólica mais consumida no Brasil e a terceira destilada no mundo. Diversos fatores afetam negativamente a cadeia produtiva, entre eles o tratamento do caldo e a levedura utilizada. Neste sentido, o objetivo do trabalho foi avaliar a influência do tipo de fermento e o tratamento do caldo sobre a qualidade do destilado. O experimento foi realizado na safra 2014/2015, utilizando-se a variedade SP83-2847. O delineamento experimental foi inteiramente casualizado com parcelas subdivididas, com 9 repetições. As parcelas foram constituídas pelo modo de tratamento do caldo (caldo clarificado e não clarificado e as subparcelas os tipos de fermento (Natural e CA-11. Foram determinadas características químicas do mosto, como Sólidos Solúveis Totais (SST, Compostos Fenólicos Totais (CFT, Açúcares Redutores Totais (ART e Acidez Total. No processo fermentativo avaliou-se a viabilidade das células e brotos e o índice de brotamentos. No vinho determinou-se o SST, ARRT, pH, acidez total, teor alcoólico, glicerol e eficiência fermentativa. Determinou-se a composição das cachaças através da quantificação de aldeídos totais, ésteres totais, metanol, acroleína, carbamato de etila, furfural, acidez volátil e coeficiente de congêneres. Analisou-se ainda condutividade elétrica, turbidez e pH, sendo os componentes secundários determinados por cromatografia gasosa. O tratamento prévio do caldo resultou em mosto de condições ideais para a levedura. A levedura CA-11 apresentou maiores teores de viabilidade celular. A associação entre tratamento de caldo e uso de fermento selecionado resulta em cachaça de composição mais equilibrada.

  9. La prevención de caídas recurrentes en el paciente anciano

    Directory of Open Access Journals (Sweden)

    Miriam Bella Beorlegui

    Full Text Available RESUMEN Las caídas son “acontecimientos involuntarios que hacen perder el equilibrio y dar con el cuerpo en la tierra u otra superficie firme que lo detenga”. Las caídas recurrentes (presencia de dos o más caídas en un año constituyen un problema frecuente en centros residenciales, y predisponen a las personas mayores a sufrir incapacidad, dependencia y múltiples enfermedades. La aplicación de medidas de prevención puede disminuir notablemente su incidencia y, por tanto, sus consecuencias. El objetivo de este trabajo es identificar qué intervenciones de enfermería pueden ayudar a prevenir caídas recurrentes en las personas mayores institucionalizadas, y minimizar el impacto emocional que ocasionan estos episodios. Para ello, se desarrolla un caso clínico y, tras el análisis de la evidencia científica, se proponen intervenciones para evitar la recurrencia de un episodio de caída y sus consecuencias. El análisis de este caso se estructura en valoración de riesgo de caídas recurrentes e intervenciones de prevención de las mismas. Y, a su vez, cada apartado se divide en aspectos físicos y emocionales. La literatura especializada refleja que la valoración del riesgo de caídas es clave para implantar un plan de cuidados. Conocer los factores de riesgo intrínsecos y extrínsecos ayudará a los profesionales a diseñar intervenciones de prevención. Asimismo, se ha identificado el impacto emocional que producen las caídas en los pacientes y se proponen algunas intervenciones para aliviarlo. Este trabajo refuerza la importancia de realizar una adecuada valoración de enfermería a las personas mayores en riesgo de sufrir caídas recurrentes, a través de diferentes instrumentos para detectar las áreas específicas de intervención. Se concluye con la necesidad de protocolizar esta valoración, tanto física como emocional, para poder individualizarla posteriormente con cada paciente.

  10. Nueva política europea en productos químicos. REACH

    Directory of Open Access Journals (Sweden)

    Raquel Fernández Sánchez

    2005-12-01

    Full Text Available En febrero de 2001, la Comisión Europea publicó el Libro Blanco relativo a la estrategia para la futura política en materia de sustancias y preparados químicos, que se fundamenta en una revisión del sistema comunitario actual de regulación de las sustancias y preparados químicos. Como consecuencia, el 29 de octubre de 2003, la Comisión adoptó la propuesta de Reglamento sobre registro, evaluación, autorización y restricción de las sustancias químicas (REACH. Mediante esta propuesta, además de crearse la Agencia Europea de Sustancias Químicas, se establece el sistema REACH que consta de los siguientes elementos:Registro, que exige a la industria que facilite información sobre sus sustancias con el objeto de conseguir una utilización segura de las mismas.Evaluación, que garantiza que la industria cumple sus obligaciones y evita que se realicen ensayos innecesarios.Autorización de sustancias con propiedades extremadamente preocupantes (CMR, PBT, disruptores endocrinos, etc. para unos usos particulares.Restricción, como red de seguridad para la reducción de riesgos que no hayan sido abordados en las etapas anteriores.Este sistema de recogida de información en varias fases permitirá conocer y reducir los riesgos derivados del uso de unas 30.000 sustancias químicas que se producen/importan en la Unión Europea en cantidad superior a una tonelada/año. La información, una vez validada, se almacenará en una base de datos y podrá utilizarse para el establecimiento de un vínculo causal entre los factores medioambientales y los efectos negativos sobre la salud derivados de la producción y utilización de los productos químicos.

  11. Multiple C-terminal tail Ca(2+)/CaMs regulate Ca(V)1.2 function but do not mediate channel dimerization.

    Science.gov (United States)

    Kim, Eun Young; Rumpf, Christine H; Van Petegem, Filip; Arant, Ryan J; Findeisen, Felix; Cooley, Elizabeth S; Isacoff, Ehud Y; Minor, Daniel L

    2010-12-01

    Interactions between voltage-gated calcium channels (Ca(V)s) and calmodulin (CaM) modulate Ca(V) function. In this study, we report the structure of a Ca(2+)/CaM Ca(V)1.2 C-terminal tail complex that contains two PreIQ helices bridged by two Ca(2+)/CaMs and two Ca(2+)/CaM-IQ domain complexes. Sedimentation equilibrium experiments establish that the complex has a 2:1 Ca(2+)/CaM:C-terminal tail stoichiometry and does not form higher order assemblies. Moreover, subunit-counting experiments demonstrate that in live cell membranes Ca(V)1.2s are monomers. Thus, contrary to previous proposals, the crystallographic dimer lacks physiological relevance. Isothermal titration calorimetry and biochemical experiments show that the two Ca(2+)/CaMs in the complex have different properties. Ca(2+)/CaM bound to the PreIQ C-region is labile, whereas Ca(2+)/CaM bound to the IQ domain is not. Furthermore, neither of lobes of apo-CaM interacts strongly with the PreIQ domain. Electrophysiological studies indicate that the PreIQ C-region has a role in calcium-dependent facilitation. Together, the data show that two Ca(2+)/CaMs can bind the Ca(V)1.2 tail simultaneously and indicate a functional role for Ca(2+)/CaM at the C-region site.

  12. Multiple Ca2+ sensors in secretion

    DEFF Research Database (Denmark)

    Walter, Alexander M; Groffen, Alexander J; Sørensen, Jakob Balslev

    2011-01-01

    Regulated neurotransmitter secretion depends on Ca(2+) sensors, C2 domain proteins that associate with phospholipids and soluble N-ethylmaleimide-sensitive fusion attachment protein receptor (SNARE) complexes to trigger release upon Ca(2+) binding. Ca(2+) sensors are thought to prevent spontaneous...

  13. An inhibitory effect of extracellular Ca2+ on Ca2+-dependent exocytosis.

    Directory of Open Access Journals (Sweden)

    Wei Xiong

    Full Text Available AIM: Neurotransmitter release is elicited by an elevation of intracellular Ca(2+ concentration ([Ca(2+](i. The action potential triggers Ca(2+ influx through Ca(2+ channels which causes local changes of [Ca(2+](i for vesicle release. However, any direct role of extracellular Ca(2+ (besides Ca(2+ influx on Ca(2+-dependent exocytosis remains elusive. Here we set out to investigate this possibility on rat dorsal root ganglion (DRG neurons and chromaffin cells, widely used models for studying vesicle exocytosis. RESULTS: Using photolysis of caged Ca(2+ and caffeine-induced release of stored Ca(2+, we found that extracellular Ca(2+ inhibited exocytosis following moderate [Ca(2+](i rises (2-3 µM. The IC(50 for extracellular Ca(2+ inhibition of exocytosis (ECIE was 1.38 mM and a physiological reduction (∼30% of extracellular Ca(2+ concentration ([Ca(2+](o significantly increased the evoked exocytosis. At the single vesicle level, quantal size and release frequency were also altered by physiological [Ca(2+](o. The calcimimetics Mg(2+, Cd(2+, G418, and neomycin all inhibited exocytosis. The extracellular Ca(2+-sensing receptor (CaSR was not involved because specific drugs and knockdown of CaSR in DRG neurons did not affect ECIE. CONCLUSION/SIGNIFICANCE: As an extension of the classic Ca(2+ hypothesis of synaptic release, physiological levels of extracellular Ca(2+ play dual roles in evoked exocytosis by providing a source of Ca(2+ influx, and by directly regulating quantal size and release probability in neuronal cells.

  14. Collective flow in central Ca + Ca and Nb + Nb collisions

    International Nuclear Information System (INIS)

    Fai, G.; Csernai, L.P.; Kapusta, J.I.

    1986-01-01

    Questions related to the entropy, equation of state and collective flow of nuclear matter are important to the authors understanding of high energy nuclear collisions. Completion of the analysis of exclusive measurements on central Ca + Ca and Nb + Nb collisions triggered renewed interest in these problems. In order to address the results of exclusive measurements, however, the complex multifragment final states of high energy nuclear collisions need to be incorporated in a theoretical description. The microcanonical event generator model provides statistically generated complete events that can be compared to the exclusive data on an event-by-event basis. To describe the disassembly of hot nuclear matter the model uses an approximate scheme in which the available final states are populated according to their microcanonical weight in phase space. This statistical description is front-ended with simple geometric ideas to divide the collision system into subsystems and with a prescription to share energy and momentum among the subsystems. Any physical quantity of interest is in principle calculable in the model if sufficient statistics is accumulated

  15. La gestión del conocimiento en las Bibliotecas Universitarias: ¿el qué, cómo y para qué?

    Directory of Open Access Journals (Sweden)

    Gerardo Sánchez Ambriz

    2013-04-01

    Full Text Available El presente artículo tiene como propósito proponer la incorporación de la teoría administrativa denominada Gestión del Conocimiento (GC, en Bibliotecas Universitarias (BU. ¿El qué, el cómo y el para qué? Representa un reto de gestión que conlleva a la implementación de diversas estrategias para el cambio y la innovación (ECI. Hipotéticamente, el diseño de estrategias de gestión posibilita que la BU en los escenarios competitivos de la sociedad de conocimiento y el tercer entorno desarrolle nuevas competencias y directrices para el aprovechamiento de sus diversos recursos con eficiencia y logren alcanzar sus objetivos con eficacia. La innovación es otra de las variables que posibilita la transformación de los servicios que son ofertados a los usuarios, también denominados “socios estratégicos”, bajo la visión de creatividad, sustentabilidad y bienestar

  16. La enseñanza de la química vista desde la perspectiva de Jensen: Una red conceptual sobre equilibrio químico

    Directory of Open Access Journals (Sweden)

    Ángela Castrillón Univio

    2009-10-01

    Full Text Available Este trabajo propone una red conceptual basado en el concepto generador equilibrio químico, para la enseñanza de la química desde la propuesta epistemológica de Jensen W. B con el objetivo de integrar la historia y la epistemología en la realización posterior de una propuesta de diseño curricular la cual está definida en el marco de la ley general de educación Ley 115 de 1994, para tal propósito se toma como referencia bibliográfica los postulados de epistemólogos reconocidos como Popper, Lakatos y Khun, luego se describe las concepciones de enseñanzaaprendizaje que posee el profesor como producto de su visión de ciencia, finalmente como éstas se articulan, con la propuesta de Jensen W. B y en el diseño curricular.

  17. La imagen pública de la química y su relación con la generación de actitudes hacia la química y su aprendizaje

    Directory of Open Access Journals (Sweden)

    William Manuel Mora Penagos

    2012-04-01

    Full Text Available El presente ensayo muestra cómo la imagen popular y escolar de la química se caracteriza por ser negativa, lo que viene incidiendo en la generación de actitudes negativas hacia esta ciencia y su aprendizaje. Las inadecuadas formas de comunicación del conocimiento de la química que se muestran en el cine, la TV y las revistas de ciencia popular, la visión irreconciliable entre ciencia y religión, y la poca claridad de las formas de producción del conocimiento químico mostradas en las aulas de clase, aparecen como las principales causas de esta situación. Superar esta imagen implica reconciliar la visión científica con la visión social de la química, por lo que el conocimiento en epistemología e historia de la química y la línea de investigación conocida como Public Understanding of Science desde el enfoque Ciencia/Tecnología/ Sociedad y Ambiente (CTS-A, son fundamentales para una didáctica de la química orientada hacia la alfabetización en química y a la formación docentes en torno al diseño curricular y la enseñanza de contenidos articulados a la generación de actitudes hacia el impacto social y ambiental de la química.

  18. ¿Por qué fracasan las campañas?

    Directory of Open Access Journals (Sweden)

    Andrea Castelnuovo

    2015-01-01

    Full Text Available Analiza tres experiencias en las que puede evidenciarse por qué fracasan las campañas sociales: por la misma razón, fueron concebidas con mensajes destinados a una población que vive y percibe el mundo desde el nivel económico y socio-cultural distinto, el emisor no empata con los perfiles del receptor. Es fundamental empezar por definir qué se debe decir, a quién, y cómo, para luego encontrar los medios más adecuados para su difusión. La espectacularidad y etnocentrismo, las campañas sociales seguirán sirviendo exclusivamente para mejorar las finanzas de los medios de comunicación masivos y secundariamente, para brindar materia prima a humoristas y contestarios.

  19. Fraccionamiento isotópico: efecto de la composición química

    Directory of Open Access Journals (Sweden)

    Caballero, E.

    1989-12-01

    Full Text Available The isotopic fractionation of elements can be afected by several factors such as: Pressure, Crystal structure, Temperature and Chemical Composition. In this review the influence on the isotopic composition of each of these factors, specially that of chemical composition, is studied from a theoretical and experimental point of view.El fraccionamiento isotópico de los elementos puede estar afectado por distintos factores, tales como: Presión, Estructura Cristalina, Temperatura y Composición química. Este trabajo de revisión pretende estudiar la influencia en la composición isotópica de cada uno de estos factores, y en especial, la de la composición química, tanto desde un punto de vista teórico como experimental.

  20. ¿Por qué las caras de otras etnias nos parecen iguales?

    Directory of Open Access Journals (Sweden)

    Beatriz Martín-Luengo

    2013-11-01

    Full Text Available ¿Por qué a veces somos incapaces de distinguir entre personas de otra etnia? Una razón puede ser porque no recordamos de la misma manera las caras dependiendo de la etnia a la que pertenecen. Actualmente existen varias teorías que explican por qué nuestra memoria es mejor para caras de nuestra propia etnia, como son las teorías del procesamiento perceptivo de caras, las teorías basadas en la cognición social del procesamiento de caras y las teorías híbridas entre las perceptivas y las basadas en cognición social. En este artículo repasamos y explicamos a grandes rasgos cada uno de estos acercamientos teóricos.

  1. Propiedades físicas y químicas del cuero para calzado de seguridad

    Directory of Open Access Journals (Sweden)

    Paulina Silva Trejos

    2005-11-01

    Full Text Available Se escogieron 86 muestras de calzado de seguridad disponibles en el mercado nacional y se les determinó algunas propiedades físicas y químicas, con los siguientes resultados promedios y sus respectivas desviaciones estándar para las propiedades físicas, espesor: 2,03 (0,22 mm, resistencia a la tracción 2,51 (0,95kgf/mm2, resistencia al desgarre 12,1 (4,3 y porcentaje de alargamiento a la rotura 66 (13. Las propiedades químicas que se evaluaron fueron el porcentaje de cenizas sulfatadas y el porcentaje de óxido de cromo, obteniéndose los siguientes resultados promedios con sus respectivas desviaciones estándar: 4,9 (1,2 y 3,33 (0,69.

  2. Terapia a la pregunta filosófica: ¿qué es el arte?

    Directory of Open Access Journals (Sweden)

    Adryan Fabrizio Pineda Repizzo

    2011-12-01

    Full Text Available En la tradición del pensamiento occidental, la pregunta “¿Qué es el arte?” ha jugado un papel central, aunque enigmático, para el campo de la filosofía, donde se han avanzado tantas objeciones y respuestas tentativas, que hoy pareciera que han sido tantos esfuerzos sin rumbo ni asidero en el mundo real del arte. Este texto afronta la plausibilidad de asumir la pregunta “¿Qué es el arte?” como problema filosófico. Para responder a este cuestionamiento acudimos a Wittgenstein, con el fin de realizarle una terapia filosófica a la pregunta misma y así mostrar que los principales paradigmas filosóficos sobre este asunto no son sino la manifestación de una confusión del lenguaje en torno al término ‘arte’.  

  3. QuVis interactive simulations: tools to support quantum mechanics instruction

    Science.gov (United States)

    Kohnle, Antje

    2015-04-01

    Quantum mechanics holds a fascination for many students, but its mathematical complexity and counterintuitive results can present major barriers. The QuVis Quantum Mechanics Visualization Project (www.st-andrews.ac.uk/physics/quvis) aims to overcome these issues through the development and evaluation of interactive simulations with accompanying activities for the learning and teaching of quantum mechanics. Over 90 simulations are now available on the QuVis website. One collection of simulations is embedded in the Institute of Physics Quantum Physics website (quantumphysics.iop.org), which consists of freely available resources for an introductory course in quantum mechanics starting from two-level systems. Simulations support model-building by reducing complexity, focusing on fundamental ideas and making the invisible visible. They promote engaged exploration, sense-making and linking of multiple representations, and include high levels of interactivity and direct feedback. Simulations are research-based and evaluation with students informs all stages of the development process. Simulations are iteratively refined using student feedback in individual observation sessions and in-class trials. Evaluation has shown that the simulations can help students learn quantum mechanics concepts at both the introductory and advanced undergraduate level and that students perceive simulations to be beneficial to their learning. Recent activity includes the launch of a new collection of HTML5 simulations that run on both desktop and tablet-based devices and the introduction of a goal and reward structure in simulations through the inclusion of challenges. This presentation will give an overview of the QuVis resources, highlight recent work and outline future plans. QuVis is supported by the UK Institute of Physics, the UK Higher Education Academy and the University of St Andrews.

  4. QuIN: A Web Server for Querying and Visualizing Chromatin Interaction Networks.

    Directory of Open Access Journals (Sweden)

    Asa Thibodeau

    2016-06-01

    Full Text Available Recent studies of the human genome have indicated that regulatory elements (e.g. promoters and enhancers at distal genomic locations can interact with each other via chromatin folding and affect gene expression levels. Genomic technologies for mapping interactions between DNA regions, e.g., ChIA-PET and HiC, can generate genome-wide maps of interactions between regulatory elements. These interaction datasets are important resources to infer distal gene targets of non-coding regulatory elements and to facilitate prioritization of critical loci for important cellular functions. With the increasing diversity and complexity of genomic information and public ontologies, making sense of these datasets demands integrative and easy-to-use software tools. Moreover, network representation of chromatin interaction maps enables effective data visualization, integration, and mining. Currently, there is no software that can take full advantage of network theory approaches for the analysis of chromatin interaction datasets. To fill this gap, we developed a web-based application, QuIN, which enables: 1 building and visualizing chromatin interaction networks, 2 annotating networks with user-provided private and publicly available functional genomics and interaction datasets, 3 querying network components based on gene name or chromosome location, and 4 utilizing network based measures to identify and prioritize critical regulatory targets and their direct and indirect interactions.QuIN's web server is available at http://quin.jax.org QuIN is developed in Java and JavaScript, utilizing an Apache Tomcat web server and MySQL database and the source code is available under the GPLV3 license available on GitHub: https://github.com/UcarLab/QuIN/.

  5. QuIN: A Web Server for Querying and Visualizing Chromatin Interaction Networks.

    Science.gov (United States)

    Thibodeau, Asa; Márquez, Eladio J; Luo, Oscar; Ruan, Yijun; Menghi, Francesca; Shin, Dong-Guk; Stitzel, Michael L; Vera-Licona, Paola; Ucar, Duygu

    2016-06-01

    Recent studies of the human genome have indicated that regulatory elements (e.g. promoters and enhancers) at distal genomic locations can interact with each other via chromatin folding and affect gene expression levels. Genomic technologies for mapping interactions between DNA regions, e.g., ChIA-PET and HiC, can generate genome-wide maps of interactions between regulatory elements. These interaction datasets are important resources to infer distal gene targets of non-coding regulatory elements and to facilitate prioritization of critical loci for important cellular functions. With the increasing diversity and complexity of genomic information and public ontologies, making sense of these datasets demands integrative and easy-to-use software tools. Moreover, network representation of chromatin interaction maps enables effective data visualization, integration, and mining. Currently, there is no software that can take full advantage of network theory approaches for the analysis of chromatin interaction datasets. To fill this gap, we developed a web-based application, QuIN, which enables: 1) building and visualizing chromatin interaction networks, 2) annotating networks with user-provided private and publicly available functional genomics and interaction datasets, 3) querying network components based on gene name or chromosome location, and 4) utilizing network based measures to identify and prioritize critical regulatory targets and their direct and indirect interactions. QuIN's web server is available at http://quin.jax.org QuIN is developed in Java and JavaScript, utilizing an Apache Tomcat web server and MySQL database and the source code is available under the GPLV3 license available on GitHub: https://github.com/UcarLab/QuIN/.

  6. Measurement of gender inequality in neighbourhoods of Québec, Canada

    Directory of Open Access Journals (Sweden)

    Tamambang Lum

    2011-11-01

    Full Text Available Abstract Introduction Few studies have measured gender inequality at levels lower than the country. We sought to develop neighbourhood indicators of gender inequality, and assess their ability to capture variability in gender inequality across Québec, Canada. Methods Aggregate 2001 census data for 11,564 neighbourhoods were obtained for men and women. Twelve indicators of gender inequality representing demographic/household characteristics, education, income, work/leisure, and political participation were selected. Neighbourhood-level gender inequality scores were computed for each indicator, and examined across parts of Québec (metropolitan areas, mid-sized cities, rural areas. Monte Carlo simulations were used to assess the ability of indicators to capture heterogeneity in gender inequality across neighbourhoods. Results Male-dominant neighbourhood-level gender inequality tended to be present for average employment income, labour force participation, employment rate, and employment in managerial positions. Female-dominant gender inequality tended to be present for divorce, single-headed households, and participation in unpaid housework, child and elderly care. Neighbourhood-level gender inequality tended to vary across metropolitan areas, mid-sized cities, and rural areas. Gender inequality scores also varied within these geographic areas. For example, there was greater income-related gender inequality in high than low income neighbourhoods. Monte Carlo simulations suggested that the variation in gender inequality across neighbourhoods was greater than expected with chance alone. Conclusion Neighbourhood-level gender inequality tended to be present in Québec, and varied across parts of the province. Greater awareness of and research on neighbourhood-level gender inequality may be warranted to inform gender policies in Québec and other nations.

  7. Measurement of gender inequality in neighbourhoods of Qu?bec, Canada

    OpenAIRE

    Tamambang, Lum; Auger, Nathalie; Lo, Ernest; Raynault, Marie-France

    2011-01-01

    Abstract Introduction Few studies have measured gender inequality at levels lower than the country. We sought to develop neighbourhood indicators of gender inequality, and assess their ability to capture variability in gender inequality across Québec, Canada. Methods Aggregate 2001 census data for 11,564 neighbourhoods were obtained for men and women. Twelve indicators of gender inequality representing demographic/household characteristics, education, income, work/leisure, and political parti...

  8. Baquero De la Calle, J. (2007. El Derecho... ¿para qué? Quito: CEP

    Directory of Open Access Journals (Sweden)

    Rodrigo Merino Barros

    2008-01-01

    Full Text Available Este trabajo realiza una reseña de la obra El Derecho… ¿para qué?, del autor Jaime Baquero de la Calle. Analiza las fuentes, el tipo de documentos y ejemplos que son empleados en él. Incluye una explicación sobre la estructura del documento, enfatizando la utilidad que proporciona esta publicación para los estudiantes universitarios de Derecho.  

  9. Job Quality and Gender Inequality: Key Changes in Québec over the Last Decade

    OpenAIRE

    Diane-Gabrielle Tremblay; Luc Cloutier; Paul Bernard

    2009-01-01

    Using a new typology based on information available from the Labour Force Survey, the authors analyse how job quality evolved in Québec for both women and men over the last decade (1997-2007). Results show that family situation and educational attainment are two important factors in the determination of gender inequality in the labour market. The analysis emphasizes the very significant decline in gender differences with regard to job quality (from 23% to 35% according to groups), especially ...

  10. Aerofobia ¿A qué le tememos cuando le tememos a volar?

    Directory of Open Access Journals (Sweden)

    Muñoz G. Emilio, Dr.

    2012-09-01

    Full Text Available El siguiente artículo pretende dilucidar qué elementos particulares pueden distinguir la Aerofobia de otras fobias específicas, incluyendo sus orígenes y alternativas terapéuticas. A pesar de que el tratamiento farmacológico está relativamente estandarizado, las aproximaciones psicoterapéuticas, realizadas de una manera ecléctica, pueden conducir a mejores resultados.

  11. Se servir des Objectifs de développement durable en tant qu'outil ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    19 oct. 2017 ... L'astuce, c'est de ne pas s'en tenir aux conclusions immédiates de la recherche et d'identifier des pistes d'actions publiques et privées, qu'il s'agisse des Objectifs de développement durable (ODD) ... Il est incontestable que notre recherche éclaire l'action sur le climat et les efforts de lutte anti-pauvreté.

  12. La Ingeniería Química de la Universidad Nacional de Colombia

    Directory of Open Access Journals (Sweden)

    Daniel Bogoya Maldonado

    1988-01-01

    Full Text Available El presente ensayo es un reflejo de un punto de vista en relación con la Ingeniería Química de la Universidad Nacional, con sus gajes característicos, en un ámbito histórico donde se entreveran opiniones y tesis en torno de la organización, los planes de estudio, el programa de posgrado y siempre en busca de aquellos rasgos que la distinguen.

  13. Using Latent Semantic Analysis to Identify Quality in Use (QU) Indicators from User Reviews

    OpenAIRE

    Syn, Wendy Tan Wei; How, Bong Chih; Atoum, Issa

    2015-01-01

    The paper describes a novel approach to categorize users' reviews according to the three Quality in Use (QU) indicators defined in ISO: effectiveness, efficiency and freedom from risk. With the tremendous amount of reviews published each day, there is a need to automatically summarize user reviews to inform us if any of the software able to meet requirement of a company according to the quality requirements. We implemented the method of Latent Semantic Analysis (LSA) and its subspace to predi...

  14. Modeling Quantum Teleportation with Quantum Tools in Python (QuTiP)

    Science.gov (United States)

    2017-12-01

    Python (QuTiP) (Nation and Johansson 2017), Quantum Entanglement Theory Laboratory (QETLAB) (Johnston 2016), and Forest (Dekant 2017). In this...are given by = and = . The values we see in Fig. 3 are in line with our expectations . While the isotropic state is...conclude from this short investigation into the teleportation of mixed states that, since it would generally be expected that the quality of

  15. Actividad de la Red Iberoamericana de Toxicología y Seguridad Química

    OpenAIRE

    Herrero, Oscar; Pillco, Araceli; Gutiérrez, R.; Escalante, P.; Cavieres, Fernanda; Font, G.; Peña de Torres, Eduardo de la

    2013-01-01

    La Red Iberoamericana de Toxicologia y Seguridad Química (RITSQ) fue una iniciativa de la Asociación Española de Toxicología (AETOX) y la ayuda del Comité Español de Toxicologia - IUTOX - CETOX, utilizando la página web (http://eetox.org) y con el apoyo de la Sociedad Brasileña de Toxicologia y con el dominio de AETOX (http://ritsq.org.)

  16. Québec's Childcare Universal Low Fees Policy 10 Years After: Effects, Costs and Benefits

    OpenAIRE

    Pierre Lefebvre; Philip Merrigan; Francis Roy-Desrosiers

    2011-01-01

    More than ten years ago the province of Québec implemented a universal early childhood education and care policy. This paper examines if the two objectives pursued, to increase mothers’ participation in the labour market (balance the needs of workplace and home) and to enhance child development and equality of opportunity for children, were reasonable meet. A non-experimental evaluation framework based on multiple pre- and post-treatment periods is used to estimate the policy effects. First, ...

  17. La argumentación en la formación de profesores de química: relaciones con la comprensión de la historia de la química

    Directory of Open Access Journals (Sweden)

    Pablo Antonio Archila

    2014-01-01

    Full Text Available En este artículo se trata el tema de la argumentación en ciencias de la naturaleza como habilidad de pensamiento y se promueve su inclusión en la formación inicial de profesores de química, pues se reconocen sus potencialidades para la mejora de las comprensiones que los futuros profesores podrían construir acerca de la historia de la química. Para tal fin, se aborda una breve revisión histórica de uno de los hitos de la química, como lo es el desarrollo de la química estructural, con lo cual se sugiere una de las actividades que forman parte de un módulo propuesto para la preparación en argumentación de profesores de química. Finalmente, se discuten algunas reflexiones y perspectivas que resultarían de la articulación entre argumentación e historia de la química.

  18. Estudio de la composición química de la especie Commelia erecta L., procedente de Ecuador

    OpenAIRE

    Migdalia Miranda; Margarita Hall

    2016-01-01

    En el presente trabajo se realizó el estudio de algunos parámetros físico-químicos y químicos  de las hojas de Cornmelina erecta L. que incluyó el estudio como droga cruda, el control de calidad del extracto y su composición química. Se comprobó las características físico-químicas de la droga cruda (humedad residual 6,64% y cenizas totales de 15,99%) que se encontraban dentro del rango informado por la OMS para drogas y vegetales, aunque este último se considera algo elevado ya que posee una ...

  19. Características morfométricas, rendimento corporal e composição química da piranha

    Directory of Open Access Journals (Sweden)

    Darley do Prado Mafra

    2017-07-01

    Full Text Available O presente estudo teve como objetivo avaliar as características morfométricas, rendimento corporal e composição química da piranha Pygocentrus nattereri. Utilizou-se 50 exemplares, distribuídos em um delineamento inteiramente casualizado, composto por cinco tratamentos (diferentes classes de peso e 10 repetições. Considerou-se como unidade experimental o peixe inteiro e os tratamentos constituídos pelos animais nas classes de peso: 200 a 299g, 300 a 399g, 400 a 499g, 500 a 599g e 600 a 699g. Avaliaram-se as relações morfométricas de comprimento da cabeça/comprimento padrão (CC/CP, comprimento da cabeça/altura da cabeça (CC/AC, comprimento padrão/comprimento total (CP/CT, largura do tronco/comprimento do tronco (LTR/CTR, largura do tronco/altura da cabeça (LTR/AC e altura da cabeça/comprimento do tronco (AC/CTR, na sequência foram avaliados os rendimentos dos cortes: tronco limpo (TL, filé (FL, cabeça (CA, nadadeiras (NA e carcaça (CR. Também foram avaliados os parâmetros de umidade (UM, resíduo mineral (MM e proteína bruta (PB, do filé dos peixes. Os parâmetros CC/CP, CC/AC, CP/CT, LTR/CTR e AC/CTR apresentaram médias de 0,34, 0,96, 0,85, 0,83, 1,56 e 0,54, respectivamente, não apresentando diferenças (p>0,05; os rendimentos dos cortes apresentaram médias de TL=65,32%, FL=47,22%, CA=25,73%, NA=4,64% e CR=17,36% não apresentando diferenças (p>0,05. Os resultados de composição química apresentaram efeito (p0,05 para as demais variáveis estudadas. As piranhas com peso médio variando de 200 a 699g apresentam semelhanças morfométricas e de rendimento corporal. Todavia, o filé apresenta um maior nível de proteína nas classes de peso de 400 a 699g.

  20. Amostragem e variabilidade espacial de características químicas de um latossolo submetido a diferentes sistemas de preparo

    Directory of Open Access Journals (Sweden)

    SILVEIRA PEDRO MARQUES DA

    2000-01-01

    Full Text Available O trabalho foi conduzido na Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, em Santo Antônio de Goiás, GO, em Latossolo Vermelho-Escuro distrófico, textura argilosa, submetido a diferentes sistemas de preparo, durante cinco anos consecutivos (19921996, e cultivado com milho no verão e feijoeiro no inverno, sob irrigação por aspersão. O objetivo foi avaliar as características químicas de um solo Latossolo Vermelho-Escuro após cinco anos de uso de três sistemas de preparo para o plantio. Os sistemas foram: com arado de aiveca, grade aradora e plantio direto. As amostras para análise química foram coletadas, em todos os três tratamentos, em uma malha quadrada de 49 pontos (7x7, a espaços de 4 m x 4 m, e nas profundidades de 0-5 cm e 5-20 cm de solo. As amostras foram analisadas para determinação do pH, Ca, Mg, P, K e cálculo da saturação por bases. Em relação a cada variável calculou-se o valor médio, mínimo, máximo e coeficiente de variação, comparando-se as médias, entre tratamentos, pelo teste t. Os valores de pH, Ca, Mg, P, K e saturação por bases do solo variaram nos diferentes tratamentos. Na profundidade de 0-5 cm, os valores de todas as variáveis foram maiores no sistema plantio direto do que no arado e na grade. Os valores de P e de K apresentaram as maiores variabilidades, e os de pH, as menores.

  1. [FR] Le developpment du Travail Social et le pluralisme au Québec

    Directory of Open Access Journals (Sweden)

    André Jacob

    2011-06-01

    Full Text Available Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 Au Canada et au Québec, traiter des questions liées à la diversité culturelle et au racisme a été un défi pour les gouvernements depuis les années soixante. Auparavant et jusqu'à présent, une grande partie des responsabilités en termes de développement ethnoculturel sensible des services publics (services sociaux, des programmes de formation en travail social, etc. ont été laissés aux mains d’organismes de charité non-lucratifs. Cependant, peu à peu, depuis les années soixante, le gouvernement fédéral et le gouvernement provincial, ont dû développer des politiques et des programmes d'action. Au Québec, le travail social a fait partie du débat face à deux grands courants politiques, l’un canadien basé sur le multiculturalisme, et l’autre québécois basé sur l'interculturalisme. L'article vise à donner une perspective historique

  2. Pengembangan Kecerdasan Spiritual Santri: Studi terhadap Kegiatan Keagamaan di Rumah TahfizQu Deresan Putri Yogyakarta

    Directory of Open Access Journals (Sweden)

    Ulfah Rahmawati

    2016-02-01

    Full Text Available THE DEVELOPMENT SPIRITUAL INTELEGENCE OF SANTRI. The important thing is develop spiritual intelligence, this is the intelligence supreme that guide people find the meaning of life disembogue into God. This research aims to know the religious activities carried out in the TahfidzQu House Putri Deresan. This is field research in the form of qualitative research that is descriptive analytically with pedagogy’s approach. The results of the study showed that the activities carried out in the TahfidzQu House Putri Deresan based on religious activities. The data obtained that the implementation of the activities in the TahfidzQu House Putri Deresan is classified according to the first three sections namely daily activities which include memorize The Qur’an, early time of prayers and invocation, salah rawatib, salah duha, fasting, voluntary charity, remembrance and diniyah. The second, weekly activities, which include; read al-Kahf Surah, read the al-Waqi’ah Surah, study of the Hadith, muhadoroh and tasmi’ , third, monthly activities namely Ta’lim For Kids.

  3. La química y la lengua española en el s. XIX

    Directory of Open Access Journals (Sweden)

    Garriga, Cecilio

    2003-12-01

    Full Text Available The lexis of chemistry registered an important change from the final quarter of the C.18. The translation of the Nueva nomenclatura química («New Chemical Nomenclature» brought in its wake the arrival of new terms to the Spanish language. Bearing in mind the latest data provided from the history of science, this study explains and exemplifies the tension within the lexical system created by the arrival of the new terms.

    El léxico de la química registra un cambio importante a partir del último cuarto del siglo XVIII. La traducción de la Nueva nomenclatura química conlleva la llegada de los nuevos términos al español. En este estudio se explican y ejemplifican las tensiones que la llegada de nuevos términos provoca en el sistema léxico. Todo ello teniendo en cuenta los últimos datos proporcionados desde la historia de la ciencia.

  4. Hydrolysis of molten CaCl2-CaF2 with additions of CaO

    Directory of Open Access Journals (Sweden)

    Espen Olsen

    2017-10-01

    Full Text Available Calcium halide based molten salts have recently attracted interest for a number of applications such as direct reduction of oxides for metal production and as liquefying agent in cyclic sorption processes for CO2 by CaO from dilute flue gases (Ca-looping. A fundamental aspect of these melts is the possible hydrolysis reaction upon exposure to gaseous H2O forming corrosive and poisonous hydrogen halides. In this work experiments have been performed investigating the formation of HCl and HF from a molten salt consisting of a 13.8 wt% CaF2 in CaCl2 eutectic exposed to a flowing gas consisting of 10 vol% H2O in N2. Hydrolysis has been investigated as function of content of CaO and temperature. HCl and HF are shown to be formed at elevated temperatures; HCl forms to a substantially larger extent than HF. Addition of CaO has a marked, limiting effect on the hydrolysis. Thermodynamic modeling of the reaction indicates activity coefficients for CaO above unity in the system. For cyclic CO2-capture based on thermal swing, it is advisable to keep the temperature in the carbonation (absorption reactor well below 850 ℃ while maintaining a high CaO content if molten CaCl2 is employed. Similar conclusions can be drawn with regards to CaF2.

  5. Perception, understanding and initiatives with regard to sustainable development: A profile of Québec tourism organizations

    OpenAIRE

    Auger, Denis; Bélanger, Vincent

    2011-01-01

    The concept of sustainable development is not new. However, its application in the field of tourism in Québec needs to be clarified. This way, this study is aimed at drawing the profile of Québec tourist organizations, at comparing the initiatives developed according to various perspectives (environmental, social and economic) and finally, to verify the coherence between the level of importance these organizations give to the concepts of sustainable development and the application of these wi...

  6. Contaminación química en la infancia: bioacumulación y efectos potenciales

    OpenAIRE

    Sara del Río Paredes

    2005-01-01

    En 2003 Greenpeace demostró la presencia de contaminantes químicos persistentes y bioacumulativos en muestras de polvo recogidas en hogares europeos. Otras investigaciones de Greenpeace revelaron que se pueden encontrar estas mismas sustancias en muchos productos de consumo cotidiano. Este informe cierra el ciclo presentando dos realidades inquietantes. La primera que muchas de las sustancias químicas encontradas en productos de consumo y en el polvo doméstico también est...

  7. Presentación de la Asignatura Laboratorio Integrado de Química Grado en Biotecnología

    OpenAIRE

    Rodríguez-Izquierdo, José María

    2012-01-01

    Seminario de Presentación de la asignatura Laboratorio Integrado de Química del Grado en Biotecnología. Esta presentación se realizó en el marco del proyecto de innovación docente: “Puesta en Marcha y Mejora del Laboratorio Integrado de Química en la Titulación de Biotecnología” (Ref: PI2_12_016)

  8. En quête de justice — les commissariats de police réservés aux ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    24 janv. 2011 ... Beaucoup d'entre eux offrent, entre autres, la coordination avec d'autres services qui fournissent une aide juridique ou psychologique, par exemple ... et leur concentration en zone urbaine rend les femmes vivant en milieu rural plus vulnérables puisqu'elles n'ont qu'un accès limité à la protection qu'ils ...

  9. Photoemission study of Ca-intercalated graphite superconductor CaC6

    International Nuclear Information System (INIS)

    Okazaki, Hiroyuki; Yoshida, Rikiya; Iwai, Keisuke; Noami, Kengo; Muro, Takayuki; Nakamura, Tetsuya; Wakita, Takanori; Muraoka, Yuji; Hirai, Masaaki; Tomioka, Fumiaki; Takano, Yoshihiko; Takenaka, Asami; Toyoda, Masahiro; Oguchi, Tamio; Yokoya, Takayoshi

    2010-01-01

    In this work, we have performed resonant photoemission studies of Ca-intercalated graphite superconductor CaC 6 . Using photon energy of the Ca 2p-3d threshold, the photoemission intensity of the peak at Fermi energy (E F ) is resonantly enhanced. This result provides spectroscopic evidence for the existence of Ca 3d states at E F , and strongly supports that Ca 3d state plays a crucial role for the superconductivity of this material with relatively high T c .

  10. Detectando misticismo quântico em livros publicados no Brasil com Ciência de Dados

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    Mairus Disconzi de Moura

    2017-12-01

    Full Text Available As livrarias têm sido inundadas por títulos incluindo a palavra “quântica”, mas de caráter do chamado “misticismo quântico”, o qual propõe a existência de ligações entre a mecânica quântica e o misticismo oriental, levando a sérios equívocos. Este trabalho tem como objetivo identificar termos que possam ajudar os leitores, especialmente professores do ensino médio, a reconhecer a qual dessas categorias um livro pertence, antes mesmo de lê-lo, ajudando a quebrar o círculo vicioso de estudantes que aprendem pseudociência e a transmitem como verdade. Os catálogos on-line das quatro maiores livrarias do Brasil foram pesquisados por livros que contêm as palavras “quântica” ou “quântico” em seus títulos ou em suas sinopses. O banco de dados resultante foi examinado com a ajuda de técnicas de ciência de dados e recursos de mineração de dados textuais da linguagem de programação R. Foram identificados 22 termos que discriminam com uma acurácia de 94% entre as categorias "misticismo quântico" e popularização científica ou ciência.

  11. Ca2+/cation antiporters (CaCA: Identification, characterization and expression profiling in bread wheat (Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    Mehak Taneja

    2016-11-01

    Full Text Available The Ca2+/cation antiporters (CaCA superfamily proteins play vital function in Ca2+ ion homeostasis, which is an important event during development and defense response. Molecular characterization of these proteins has been performed in certain plants, but they are still not characterized in Triticum aestivum (bread wheat. Herein, we identified thirty four TaCaCA superfamily proteins, which were classified into TaCAX, TaCCX, TaNCL and TaMHX protein families based on their structural organization and evolutionary relation with earlier reported proteins. Since the T. aestivum comprises an allohexaploid genome, TaCaCA genes were derived from each A, B and D subgenome and homeologous chromosome (HC, except chromosome-group 1. Majority of genes were derived from more than one HCs in each family that were considered as homeologous genes (HGs due to their high similarity with each other. These HGs showed comparable gene and protein structures in terms of exon/intron organization and domain architecture. Majority of TaCaCA proteins comprised two Na_Ca_ex domains. However, TaNCLs consisted of an additional EF-hand domain with calcium binding motifs. Each TaCaCA protein family consisted of about ten transmembrane and two α-repeat regions with specifically conserved signature motifs except TaNCL, which had single α-repeat. Variable expression of most of the TaCaCA genes during various developmental stages suggested their specified role in development. However, constitutively high expression of a few genes like TaCAX1-A and TaNCL1-B indicated their role throughout the plant growth and development. The modulated expression of certain genes during biotic (fungal infections and abiotic stresses (heat, drought, salt suggested their role in stress response. Majority of TaCCX and TaNCL family genes were found highly affected during various abiotic stresses. However the role of individual gene needs to be established. The present study unfolded the opportunity

  12. Ca2+/Cation Antiporters (CaCA): Identification, Characterization and Expression Profiling in Bread Wheat (Triticum aestivum L.).

    Science.gov (United States)

    Taneja, Mehak; Tyagi, Shivi; Sharma, Shailesh; Upadhyay, Santosh Kumar

    2016-01-01

    The Ca 2+ /cation antiporters (CaCA) superfamily proteins play vital function in Ca 2+ ion homeostasis, which is an important event during development and defense response. Molecular characterization of these proteins has been performed in certain plants, but they are still not characterized in Triticum aestivum (bread wheat). Herein, we identified 34 TaCaCA superfamily proteins, which were classified into TaCAX, TaCCX, TaNCL, and TaMHX protein families based on their structural organization and evolutionary relation with earlier reported proteins. Since the T. aestivum comprises an allohexaploid genome, TaCaCA genes were derived from each A, B, and D subgenome and homeologous chromosome (HC), except chromosome-group 1. Majority of genes were derived from more than one HCs in each family that were considered as homeologous genes (HGs) due to their high similarity with each other. These HGs showed comparable gene and protein structures in terms of exon/intron organization and domain architecture. Majority of TaCaCA proteins comprised two Na_Ca_ex domains. However, TaNCLs consisted of an additional EF-hand domain with calcium binding motifs. Each TaCaCA protein family consisted of about 10 transmembrane and two α-repeat regions with specifically conserved signature motifs except TaNCL, which had single α-repeat. Variable expression of most of the TaCaCA genes during various developmental stages suggested their specified role in development. However, constitutively high expression of a few genes like TaCAX1-A and TaNCL1-B indicated their role throughout the plant growth and development. The modulated expression of certain genes during biotic (fungal infections) and abiotic stresses (heat, drought, salt) suggested their role in stress response. Majority of TaCCX and TaNCL family genes were found highly affected during various abiotic stresses. However, the role of individual gene needs to be established. The present study unfolded the opportunity for detail

  13. Características químicas de solo submetido ao tratamento com esterco líquido de suínos e cultivado com gramíneas forrageiras

    Directory of Open Access Journals (Sweden)

    Queiroz Flávia Martins de

    2004-01-01

    Full Text Available Avaliou-se, neste trabalho, o efeito da aplicação intensiva de esterco líquido de suínos (ELS, pelo método do escoamento superficial, nas características químicas de um solo Podzólico Vermelho-Amarelo cultivado com quatro espécies forrageiras: quicuio da Amazônia (Brachiaria humidicola (Rendle Schweick, braquiária (Brachiaria decumbens Stapf, coastcross (Cynodon dactylon (L. Pers. e tifton 85 (Cynodon spp.. O ELS foi aplicado em parcelas de 4m² e com 5% de declividade, durante 4 meses, na taxa média equivalente a 800kg ha-1d-1 de demanda bioquímica de oxigênio (DBO5. Para caracterização química, amostras de solo foram coletadas à profundidade de 0-0,20m, antes de iniciar o experimento e após o término dele. A aplicação de ELS proporcionou acúmulo de P, K, Na e Zn no solo, enquanto as concentrações de Mg e Cu diminuíram e a de Ca se manteve inalterada. Houve aumento na acidez, na soma de bases, na CTC e redução na saturação por bases. Devido ao acúmulo de nutrientes, recomenda-se monitoramento das características químicas do solo, ao longo de seu perfil e das águas subterrâneas para que se avaliem riscos de contaminação ambiental.

  14. Measurements of natural 41Ca concentrations

    International Nuclear Information System (INIS)

    Steinhof, A.

    1989-05-01

    Atomic mass spectroscopic examinations on 41 Ca were carried out in the UNILAC accelerator. A sensitivity of about 10 -15 was achieved. This would allow the measurement of present natural 41 Ca concentrations as soon as the problem of the transmission determination is solved. In this respect suggestions were worked out and their feasibility discussed. The detection of 41 Ca-ions is especially free of background when high UNILAC-energies are applied. An estimation showed a background level corresponding with a 41 Ca concentration of less then 10 -17 referred to 40 Ca. Besides an independent concept for the electromagnetic concentration of 41 Ca with variable concentration factors was developed. After being concentrated up to 50 respectively 25 times the initial concentration in the GSI mass separator, the 41 Ca concentration of three recent deer bones found in the Odenwald was measured by atomic mass spectroscopy in the 14UD-Pelletron Tandem in Rehovot (Israel). The measured 41 Ca concentrations ranged between 10 -14 to 10 -13 with consideration of the concentration factor. A theoretical study of the 41 Ca production in the earth's surface based on cosmic radiation illustrates the influence of trace elements on the neutron flux and thus on the 41 Ca production. This influence might be a possible explanation for the observed amplitude of variation of the 41 Ca concentration in recent bones which are of decisive importance for the feasibility of 41 Ca-related dating. In this work a method is suggested that does not depend on the amplitude of variation mentioned above and which would allow the determination of the erosion rate of rocks by its 41 Ca concentrations. (orig./HP) [de

  15. Bax regulates neuronal Ca2+ homeostasis.

    Science.gov (United States)

    D'Orsi, Beatrice; Kilbride, Seán M; Chen, Gang; Perez Alvarez, Sergio; Bonner, Helena P; Pfeiffer, Shona; Plesnila, Nikolaus; Engel, Tobias; Henshall, David C; Düssmann, Heiko; Prehn, Jochen H M

    2015-01-28

    Excessive Ca(2+) entry during glutamate receptor overactivation ("excitotoxicity") induces acute or delayed neuronal death. We report here that deficiency in bax exerted broad neuroprotection against excitotoxic injury and oxygen/glucose deprivation in mouse neocortical neuron cultures and reduced infarct size, necrotic injury, and cerebral edema formation after middle cerebral artery occlusion in mice. Neuronal Ca(2+) and mitochondrial membrane potential (Δψm) analysis during excitotoxic injury revealed that bax-deficient neurons showed significantly reduced Ca(2+) transients during the NMDA excitation period and did not exhibit the deregulation of Δψm that was observed in their wild-type (WT) counterparts. Reintroduction of bax or a bax mutant incapable of proapoptotic oligomerization equally restored neuronal Ca(2+) dynamics during NMDA excitation, suggesting that Bax controlled Ca(2+) signaling independently of its role in apoptosis execution. Quantitative confocal imaging of intracellular ATP or mitochondrial Ca(2+) levels using FRET-based sensors indicated that the effects of bax deficiency on Ca(2+) handling were not due to enhanced cellular bioenergetics or increased Ca(2+) uptake into mitochondria. We also observed that mitochondria isolated from WT or bax-deficient cells similarly underwent Ca(2+)-induced permeability transition. However, when Ca(2+) uptake into the sarco/endoplasmic reticulum was blocked with the Ca(2+)-ATPase inhibitor thapsigargin, bax-deficient neurons showed strongly elevated cytosolic Ca(2+) levels during NMDA excitation, suggesting that the ability of Bax to support dynamic ER Ca(2+) handling is critical for cell death signaling during periods of neuronal overexcitation. Copyright © 2015 the authors 0270-6474/15/351706-17$15.00/0.

  16. Biogeochemical cycling of Mg and its isotopes in a sugar maple forest in Québec

    Science.gov (United States)

    Kimmig, Sara R.; Holmden, Chris; Bélanger, Nicolas

    2018-06-01

    A Mg isotope study of sugar maple (Acer saccharum Marsh.) in a field site in southern Québec, Canada, and seedlings grown in sterile soil substrate in the laboratory, both demonstrate per mil level within-tree Mg isotope fractionation. However, only sugar maple seedlings grown in the laboratory fractionate Mg isotopes during uptake into fine roots, favoring heavy isotope enrichment in the plant compared to the growth medium. Absence of uptake-related Mg isotope fractionation in field stands of sugar maple is tentatively attributed to the activities of the arbuscular mycorrhizal fungi that colonize fine roots of the trees in the field, but were absent from the laboratory grown specimens. The fungi facilitate nutrient uptake for the tree, while the tree provides valuable carbohydrates to the fungi. Without the symbiotic fungi, pot-grown trees in the laboratory are visibly stressed and often die. The mechanisms responsible for Mg isotopic fractionation in stressed trees remain to be elucidated. Rivers are isotopically light compared to bedrock weathering sources of Mg, and this has bearing on the δ26Mg value of the continental weathering flux of Mg to the oceans, which is an important parameter in studies of ocean Mg cycling in the geological past. If uptake-related fractionation is negligible in many other naturally growing tree species, as it is in sugar maple, then forest growth will exert little or no influence on the δ26Mg value of the export flux of Mg to first-order streams and rivers, and in turn the ocean Mg cycle. Above the tree line, preferential retention of heavy Mg isotopes in clay minerals formed during silicate weathering has been linked to the low δ26Mg values in rivers. In the forested catchment of this study there is no clear evidence for these effects. The 1 N HNO3 leach of the Bf-BC and C mineral soils, which are often used to identify minerals that may be releasing Mg and other base cations to plant-available pools, have the same average δ26

  17. Comparative study of anisotropic superconductivity in CaAlSi and CaGaSi

    International Nuclear Information System (INIS)

    Tamegai, T.; Uozato, K.; Kasahara, S.; Nakagawa, T.; Tokunaga, M.

    2005-01-01

    In order to get some insight into the origin of the anomalous angular dependence of H c2 in a layered intermetallic compound CaAlSi, electronic, superconducting, and structural properties are compared between CaAlSi and CaGaSi. The angular dependence of H c2 in CaGaSi is well described by the anisotropic GL model. Parallel to this finding, the pronounced lattice modulation accompanying the superstructure along the c-axis in CaAlSi is absent in CaGaSi. A relatively large specific heat jump at the superconducting transition in CaAlSi compared with CaGaSi indicates the presence of strong electron-phonon coupling in CaAlSi, which may cause the superstructure and the anomalous angular dependence of H c2

  18. Ca2+ cycling in heart cells from ground squirrels: adaptive strategies for intracellular Ca2+ homeostasis.

    Directory of Open Access Journals (Sweden)

    Xiao-Chen Li

    Full Text Available Heart tissues from hibernating mammals, such as ground squirrels, are able to endure hypothermia, hypoxia and other extreme insulting factors that are fatal for human and nonhibernating mammals. This study was designed to understand adaptive mechanisms involved in intracellular Ca(2+ homeostasis in cardiomyocytes from the mammalian hibernator, ground squirrel, compared to rat. Electrophysiological and confocal imaging experiments showed that the voltage-dependence of L-type Ca(2+ current (I(Ca was shifted to higher potentials in ventricular myocytes from ground squirrels vs. rats. The elevated threshold of I(Ca did not compromise the Ca(2+-induced Ca(2+ release, because a higher depolarization rate and a longer duration of action potential compensated the voltage shift of I(Ca. Both the caffeine-sensitive and caffeine-resistant components of cytosolic Ca(2+ removal were more rapid in ground squirrels. Ca(2+ sparks in ground squirrels exhibited larger amplitude/size and much lower frequency than in rats. Due to the high I(Ca threshold, low SR Ca(2+ leak and rapid cytosolic Ca(2+ clearance, heart cells from ground squirrels exhibited better capability in maintaining intracellular Ca(2+ homeostasis than those from rats and other nonhibernating mammals. These findings not only reveal adaptive mechanisms of hibernation, but also provide novel strategies against Ca(2+ overload-related heart diseases.

  19. Contaminación química en la infancia: bioacumulación y efectos potenciales

    Directory of Open Access Journals (Sweden)

    Sara del Río Paredes

    2005-01-01

    Full Text Available En 2003 Greenpeace demostró la presencia de contaminantes químicos persistentes y bioacumulativos en muestras de polvo recogidas en hogares europeos. Otras investigaciones de Greenpeace revelaron que se pueden encontrar estas mismas sustancias en muchos productos de consumo cotidiano. Este informe cierra el ciclo presentando dos realidades inquietantes. La primera que muchas de las sustancias químicas encontradas en productos de consumo y en el polvo doméstico también están en el cuerpo humano, incluyendo a los nonatos y a los recién nacidos. La segunda que es probable que estos productos químicos tengan un efecto perjudicial en la salud humana, particularmente en la infantil. El informe Legado Químico, de la Dra Catherine N Dorey, aúna las pruebas que ilustran cómo y por qué la infancia corre un especial riesgo ante los contaminantes químicos. Las pruebas presentadas por académicos, gobiernos e instituciones internacionales, no son fáciles de desestimar, ya que todas hacen una contribución específica al creciente banco de investigación internacional que refuerza la conclusi ón de este informe: la actual legislación no protege a la infancia del «ataque» químico que comienza desde el mismo momento de la concepci ón. El estudio se centra en siete productos químicos clave: los alquilfenoles, el bisfenol A, los pirorretardantes bromados, los compuestos organoestánnicos, los ftalatos, las parafinas cloradas y los almizcles sintéticos; y demuestra la presencia de estas sustancias en los niños y niñas, el incremento de exposición de este grupo y el consecuente aumento de los posibles impactos en la salud, qué enfermedades están relacionadas con la exposición química y los impactos especí- ficos sobre la salud de los siete productos analizados.

  20. El Proceso de Renovación Docente: qué es, qué persigue y su aplicación en la Universidad CEU San Pablo

    Directory of Open Access Journals (Sweden)

    Escribano Ródenas, Mª del Carmen

    2007-01-01

    Full Text Available La adaptación al Espacio Europeo de Educación Superior (EEES implica cambios sustanciales en la concepción de la metodología docente. Así pues, nos encontramos ante un verdadero Proceso de Renovación Docente.Debe destacarse que no se trata de un mero cambio organizativo sino que, el EEES supone una nueva definición de objetivos en términos de competencias y además, se pretende que el centro del proceso formativo sea el aprendizaje activo del alumno.Es indudable que una Universidad privada como la CEU San Pablo, siempre preocupada en lograr los mayores niveles posibles de calidad y excelencia académica, no puede quedar al margen de este proceso de renovación que, sin lugar a dudas, constituye un verdadero desafío que tenemos que afrontar no sólo los profesores sino también los alumnos, ambos pilares fundamentales para mantener activo el cambio que se avecina y lograr los mejores resultados de su correcta aplicación y puesta en funcionamiento.El presente trabajo pretende explicar cuál es la esencia del cambio docente, qué significa fijar objetivos en términos de competencias, qué implican los nuevos objetivos y los nuevos métodos docentes, cuál es el sistema apropiado de evaluación del aprendizaje, cómo abordar el cambio en las asignaturas, y en nuestro caso concreto en la asignatura Matemáticas, y cuál es el protagonismo que poseen los estudiantes.

  1. Prediction of soil chemical attributes using optical remote sensing=Predição de atributos químicos do solo utilizando sensoriamento remoto ótico.

    Directory of Open Access Journals (Sweden)

    José Alexandre Melo Demattê

    2011-10-01

    Full Text Available Soil fertility variability management is one of the pioneering and important areas in which Precision Agriculture has been commercially applied. Consequently, the objective of this work was to predict soil chemical attributes through spectral responses. The 1,000 ha study area used for this report was located in Uberlândia, Minas Gerais State, Brazil. Thirty sampling points were established, at which the soil was collected at 3 different depths. The samples were chemically and physically analyzed and the radiometric data obtained in the 400 – 2500 nm range. Multiple regression equations were generated for sum of bases, cation exchange capacity, base saturation, aluminum saturation, pH, P, K, Ca, Mg, Al, and H, all using 60 soil samples. H, Al, m%, and pH were found to have R2 values less than 0.50. Equations with an R2 > 0.50 for the other attributes were tested for the 30 unknown soil samples, and the estimated values were obtained. These values were then compared with those determined by conventional analysis. The coefficients of correlation were higher than 50% for all attributes except P and V%. Results indicated that determining chemical attributes with models that are specific for the region is feasible. Uma das primeiras e mais importantes áreas nas quais a Agricultura de Precisão está sendo comercialmente aplicada é o manejo da variabilidade da fertilidade do solo. Desta forma, o objetivo deste trabalho foi predizer o teor dos atributos químicos do solo através da sua resposta espectral. A área de estudo de 1000 ha localiza-se em Uberlândia, Estado de Minas Gerais. Estabeleceu-se 30 pontos de amostragem nos quais o solo foi coletado em 3 profundidades. As amostras foram analisadas química e fisicamente e, os dados radiométricos obtidos com um sensor em laboratório na faixa de 400 – 2500 nm. Equações de regressão múltipla foram geradas para soma de bases, CTC, saturação por bases, saturação por alumínio, pH, P, K

  2. Atributos químicos de solos influenciados pela substituição do carbonato por silicato de cálcio Soil chemical properties influenced by the substitution of calcium carbonate by calcium silicate

    Directory of Open Access Journals (Sweden)

    Renato Ferreira de Souza

    2008-08-01

    Full Text Available A aplicação de silicatos pode promover incrementos na capacidade de troca de cátions, favorecer a disponibilização de ânions, especialmente o H2PO4- (fosfato diácido, elevar o pH, amenizar a toxidez de Al e, de maneira geral, incrementar a disponibilidade de nutrientes para as plantas, apresentando, porém, uma eficiência agronômica inferior em comparação aos carbonatos. Com o objetivo de avaliar o efeito da substituição do carbonato de Ca por silicato de Ca sobre as propriedades químicas dos solos, especialmente em relação à disponibilidade de P, foram realizados quatro experimentos em casa de vegetação, num delineamento inteiramente casualizado, com quatro repetições. Os tratamentos consistiram de cinco níveis de substituição (0, 25, 50, 75 e 100 % do carbonato de Ca por silicato de Ca, mantendo uma relação estequiométrica Ca:Mg de 4:1 e o mesmo conteúdo de CaO, suficientes para elevar V = 60 %. Os tratamentos foram aplicados em amostras de 4 dm³ de Neossolo Quartzarênico órtico, Latossolo Vermelho-Amarelo textura média, Latossolo Vermelho-Amarelo textura argilosa e Latossolo Vermelho textura muito argilosa, sendo cada solo um experimento. Foram determinados os valores dos atributos químicos dos solos: pH em H2O, P, P remanescente (P-rem, K, Ca, Mg, Si, Al, H + Al, matéria orgânica (MO, Cu, Mn, Zn e B, soma de bases (S, a CTC efetiva (t, a CTC em pH 7,0 (T, a saturação por bases (V e a saturação por Al (m, os quais foram submetidos à analise de variância e ao ajuste de modelos de regressão simples, considerando os níveis de substituição de CaCO3 por CaSiO3. Verificou-se que a substituição de carbonato por silicato promoveu aumentos significativos nos valores de Si, Al, H + Al e m e redução nos valores de P-rem, pH, S, t e V; já os valores de P Mehlich-1, K, Mg, MO, T, Mn, Cu e B não foram influenciados significativamente. Houve declínio na disponibilidade de Zn somente no solo RQo. A efic

  3. Variabilidad espacial de propiedades físicas y químicas en suelos de la granja experimental de la Universidad del Magdalena (Santa Marta, Colombia

    Directory of Open Access Journals (Sweden)

    Menjivar Flores Juan Carlos

    2010-12-01

    Full Text Available En suelos destinados a la actividad agrícola de la granja experimental de la Universidad del Magdalena, Santa Marta - Colombia (74º 07' Y 74º 12' longitud oeste y 11º 11' y 11º 15' latitud, se estudió la variabilidad espacial de las propiedades físicas: humedad gravimétrica, textura, densidad aparente (Da, resistencia a la penetración (RP y conductividad hidráulica (KH y químicas: Materia orgánica (MO, pH, CIC, N, P, K, Ca+2, Mg+2, Na+, Cu, Zn, Fe, Mn, B, utilizando una grid o malla de 29m*29m con 184 puntos de muestreo. El análisis de los datos se realizó empleando enfoques univariado, geoestadístico y multivariado. El análisis estadístico de los resultados mostró gran variabilidad de las propiedades; la densidad aparente y el pH presentaron baja variación; los componentes texturales, la RP, Ca+2, Mg+2, Cu y B mostraron variación media, mientras que la humedad gravimétrica, KH, MO, K+, Na+, CIC, Zn, P, Mn y Fe, expresaron alta variación. Con el análisis Geoestadístico se visualizó y graficó la variabilidad de cada propiedad evaluada y se evidenció la existencia de moderada dependencia espacial en las propiedades excepto en los contenidos de arena, Ca+2, CIC, P y Cu que revelan fuerte dependencia espacial. El índice de homogeneidad multivariado para los suelos en estudio fue bajo, siendo textura, Na+, B, Fe, K, pH, Ca y MO las propiedades con mayor contribución a la heterogeneidad. El análisis de clasificación permitió agrupar cuatro zonas con condiciones edáficas similares, las que se podrán utilizar para determinar el sistema de muestreo, número de muestras, tamaño y distribución de unidades experimentales y con ello facilitar la implementación de prácticas de manejo agronómico acordes con las características de cada zona.

  4. Variabilidad espacial de propiedades físicas y químicas en suelos de la granja experimental de la Universidad del Magdalena (Santa Marta, Colombia

    Directory of Open Access Journals (Sweden)

    José Rafael Vásquez Polo

    2010-10-01

    Full Text Available En suelos destinados a la actividad agrícola de la granja experimental de la Universidad del Magdalena, Santa Marta - Colombia (74° 07' Y 74° 12' longitud oeste y 11° 11' y 11° 15' latitud, se estudió la variabilidad espacial de las propiedades físicas: humedad gravimétrica, textura, densidad aparente (Da, resistencia a la penetración (RP y conductividad hidráulica (KH y químicas: Materia orgánica (MO, pH, CIC, N, P, K, Ca+2, Mg+2, Na+, Cu, Zn, Fe, Mn, B, utilizando una grid o malla de 29m*29m con 184 puntos de muestreo. El análisis de los datos se realizó empleando enfoques univariado, geoestadístico y multivariado. El análisis estadístico de los resultados mostró gran variabilidad de las propiedades; la densidad aparente y el pH presentaron baja variación; los componentes texturales, la RP, Ca+2, Mg+2, Cu y B mostraron variación media, mientras que la humedad gravimétrica, KH, MO, K+, Na+, CIC, Zn, P, Mn y Fe, expresaron alta variación. Con el análisis Geoestadístico se visualizó y graficó la variabilidad de cada propiedad evaluada y se evidenció la existencia de moderada dependencia espacial en las propiedades excepto en los contenidos de arena, Ca+2, CIC, P y Cu que revelan fuerte dependencia espacial. El índice de homogeneidad multivariado para los suelos en estudio fue bajo, siendo textura, Na+, B, Fe, K, pH, Ca y MO las propiedades con mayor contribución a la heterogeneidad. El análisis de clasificación permitió agrupar cuatro zonas con condiciones edáficas similares, las que se podrán utilizar para determinar el sistema de muestreo, número de muestras, tamaño y distribución de unidades experimentales y con ello facilitar la implementación de prácticas de manejo agronómico acordes con las características de cada zona.

  5. Ahorro de energía en la clinkerización empleando CaF2 y CaS04 como mineralizadores. Estudio de la fluorellestadita

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    Vázquez, Tomás

    1981-03-01

    Full Text Available Not availableEl clínker portland está compuesto esencialmente por cuatro fases: alita, belita, fase alumínica y fase ferrítica, que se corresponden de forma aproximada con C3S, C2S, C3A y C4AF (*, respectivamente. Estas dos últimas ("fundentes" tienen como misión principal el facilitar la formación de los hidráulicamente activos, C3S y C2S. Es decir, su aportación a las resistencias mecánicas del cemento hidratado es prácticamente despreciable. Aquellas fases (C3A y C4AF se forman en el horno a partir de los crudos empleados (generalmente caliza y arcilla; su coste energético es elevado ya que además del que precisan para su síntesis les es necesaria una alta proporción de CaO. Este óxido proviene a su vez de la descarbonatación del CaC03, que es el proceso químico que mayor energía consume en la clinkerización. Por ello, una forma que a priori sería válida para ahorrar energía en la fabricación de cemento es la de sustituir total o parcialmente la "fase líquida" (C3A + C4AF tradicional por otra que no precisara tanto CaO, ni que se formara con tan elevado gasto de energía.

  6. Atributos físicos e químicos de um latossolo, sob diferentes sistemas de cultivo Physical and chemical attributes of a typical acrustox soil under different systems of cultivation

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    William Diniz Bilibio

    2010-08-01

    Full Text Available Diferentes sistemas de manejo impactam em intensidades diferentes os atributos físicos e químicos do solo. Com o propósito de avaliar alterações em propriedades físicas e químicas de um Latossolo Vermelho distrófico, conduziu-se um experimento na Fazenda Glória/UFU, desde o ano 2000. O latossolo foi disposto num esquema de delineamento em blocos casualizados e conduzido durante sete anos para avaliar algumas alterações em atributos físicos e químicos do solo, nas profundidades de 0-5; 5-15 e 15-30 cm. Os sistemas de manejo avaliados foram o convencional e os considerados conservacionistas. Os parâmetros analisados foram: densidade do solo, porosidade total, macro e microporosidade, estabilidade de agregados, carbono orgânico total (COT, fósforo (P, cálcio (Ca2+, magnésio (Mg2+, potássio (K+, nitrogênio (N e alumínio (Al3+. Foram verificadas diferenças estatísticas entre os sistemas de manejo conservacionistas e o convencional. Os resultados indicam aumento da densidade do solo com a profundidade, associada à redução da porosidade total e da relação macro/microporos, bem como uma menor estabilidade de agregados no sistema convencional, em relação aos sistemas conservacionistas. Para os atributos químicos do solo, diferenças estatísticas entre os tratamentos conservacionistas e convencional foram observadas apenas nos primeiros 5 cm do solo, para os elementos P, Ca e K. A correção do Al é mais eficiente no sistema convencional, devido à incorporação do calcário ao solo, independente da aplicação de gesso agrícola.Different management systems impact soil physical and chemical characteristics differently. Physical and chemical attribute changes of a typical Acrustox soil submitted to different soil preparation systems were evaluated in an experiment at the Glória/UFU farm since the year 2000. The experimental design was randomized blocks, and the experiment was conducted for seven years to evaluate some

  7. Variabilidade espacial das propriedades físicas e químicas do solo em áreas intensamente cultivadas Spatial variability of physical and chemical properties of soil in intensively cultivated areas

    Directory of Open Access Journals (Sweden)

    Gláucia de Mello

    2006-06-01

    Full Text Available Neste trabalho, avaliou-se a variabilidade espacial das propriedades físicas e químicas do solo, visando fornecer subsídios ao manejo localizado de insumos. Foram analisadas as variáveis químicas: P, MO, K, Ca, Mg, pH, CTC e V(% e físicas: areia e argila. Coletaram-se amostras de solo em duas profundidades (0-0,2 e 0,6-0,8 m situadas em malha irregular de amostragem na região de Monte Alto, num Argissolo Vermelho-Amarelo (PVA, sob diferentes manejos, perfazendo 88 pontos em área total de 1465 ha; e na região de Jaboticabal, em Latossolo Vermelho (LV cultivado com cana-de-açúcar, perfazendo 128 pontos, em área total de 2597 ha. As propriedades químicas e físicas dos solos estudados apresentaram dependência espacial, com exceção da CTC na profundidade de 0,6-0,8 m para o solo LV; Ca e argila na profundidade de 0-0,2 m, e P, MO, K, Mg e argila na camada de 0,6-0,8 m, no solo PVA. As variáveis estudadas ajustaram-se aos modelos esférico e exponencial, e algumas apresentaram semivariograma sem estrutura definida. O solo PVA apresentou menor continuidade espacial das propriedades químicas e físicas, principalmente na profundidade 0,6-0,8 m, camada que sofre menor influência antrópica. O solo LV apresentou zonas mais homogêneas de fertilidade e granulometria.The spatial variability of physical and chemical properties of soil were evaluated to provide subsidies for management of the agricultural input. The chemical variables: P, organic matter (OM, K, Ca, Mg, pH, CEC and base saturation (BS; and physical variables: sand and clay were analysed. Soil samples were collected at two depths (0-0.2 and 0.6-0.8 m located at irregular mesh of sampling in the region of Monte Alto, in a Yellow-Red Podzol (Alfissolo (PVA, under different managements, resulting in 88 points in 1465 ha of total area; and at the region of Jaboticabal in a Red Latosol (LV cultivated with sugarcane, resulting in 128 points in 2597 ha of total area. The chemical

  8. Biphasic decay of the Ca transient results from increased sarcoplasmic reticulum Ca leak

    Science.gov (United States)

    Sankaranarayanan, Rajiv; Li, Yatong; Greensmith, David J.; Eisner, David A.

    2016-01-01

    Key points Ca leak from the sarcoplasmic reticulum through the ryanodine receptor (RyR) reduces the amplitude of the Ca transient and slows its rate of decay.In the presence of β‐adrenergic stimulation, RyR‐mediated Ca leak produces a biphasic decay of the Ca transient with a fast early phase and a slow late phase.Two forms of Ca leak have been studied, Ca‐sensitising (induced by caffeine) and non‐sensitising (induced by ryanodine) and both induce biphasic decay of the Ca transient.Only Ca‐sensitising leak can be reversed by traditional RyR inhibitors such as tetracaine.Ca leak can also induce Ca waves. At low levels of leak, waves occur. As leak is increased, first biphasic decay and then slowed monophasic decay is seen. The level of leak has major effects on the shape of the Ca transient. Abstract In heart failure, a reduction in Ca transient amplitude and contractile dysfunction can by caused by Ca leak through the sarcoplasmic reticulum (SR) Ca channel (ryanodine receptor, RyR) and/or decreased activity of the SR Ca ATPase (SERCA). We have characterised the effects of two forms of Ca leak (Ca‐sensitising and non‐sensitising) on calcium cycling and compared with those of SERCA inhibition. We measured [Ca2+]i with fluo‐3 in voltage‐clamped rat ventricular myocytes. Increasing SR leak with either caffeine (to sensitise the RyR to Ca activation) or ryanodine (non‐sensitising) had similar effects to SERCA inhibition: decreased systolic [Ca2+]i, increased diastolic [Ca2+]i and slowed decay. However, in the presence of isoproterenol, leak produced a biphasic decay of the Ca transient in the majority of cells while SERCA inhibition produced monophasic decay. Tetracaine reversed the effects of caffeine but not of ryanodine. When caffeine (1 mmol l−1) was added to a cell which displayed Ca waves, the wave frequency initially increased before waves disappeared and biphasic decay developed. Eventually (at higher caffeine concentrations), the

  9. Atributos químicos do solo e ocorrência de fungos micorrízicos sob áreas de pastagem e sistema agroflorestal, Brasil

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    Saggin Junior Orivaldo José

    2009-06-01

    Full Text Available Este trabalho teve como objetivo caracterizar alguns atributos químicos do solo e avaliar a comunidade de fungos micorrízicos arbusculares (FMAs em uma área de pastagem e um sistema agroflorestal (SAF. A área de estudo está localizada na "Fazendinha Agroecológica do Km 47", 22° 45'S, 43° 41'W, no município de Seropédica, Rio de Janeiro, Brasil. Foram coletadas amostras de solo na profundidade de 0-5 cm e quantificados os teores de carbono orgânico total (COT, Ca, Mg, pH, P e K. Os FMAs foram quantificados e posteriormente identificados. Os resultados encontrados foram analisados como delineamento inteiramente casualizado, com aplicação do teste F. Verificaram-se valores estatisticamente maiores de COT, Ca, Mg e K no SAF, assim como o maior número de esporos de fungos micorrízicos. Observou-se uma baixa diversidade de espécies de FMAs, sendo que Glomus macrocarpum e Acaulospora scrobiculata foram as espécies dominantes nas duas áreas. O manejo do solo pode ter influenciado no menor número de esporos de FMAs encontrados sob pastagem. Por meio da análise de componentes principais foi possível separar as duas áreas avaliadas, sendo o comportamento semelhante ao verificado na análise univariada.

  10. Caracterización química de material particulado PM10 en la atmósfera de La Guajira Colombia

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    Carlos Julio Doria Argumedo

    2016-11-01

    Full Text Available Durante el año 2013, se realizó un estudio en La Guajira, Colombia, con el fin de determinar  la composición química del  material particulado PM10, producto de las actividades mineras de carbón a cielo abierto que ocupan casi 30% del territorio; también se evaluó su asociación a fuentes naturales y antropogénicas. La recolección de filtros se realizó por medio de un sistema de monitoreo conformado por catorce estaciones mediante equipos muestreadores de alto volumen PM10 (Thermo Scientific VFC-PM10 High Volume Air Sampler. Para el análisis, los filtros de cuarzo fueron sometidos a extracción acuosa en caliente y se determinaron los iones por espectrofotometría UV-VIS e ICP-MS. Las concentraciones más altas corresponden a la especies SO42- (0,25 µg/m3, Cl- (0,19 µg/m3, NH4+ (0,032 µg/m3, Na+ (1,98µg/m3, Ca2+ (0,40 µg/m3 y Mg2+ (0,31 µg/m3. Los resultados indican que las principales fuentes responsables del material particulado corresponden al aerosol marino impulsado por las corrientes (Cl- y Na+ de origen natural, y las actividades agrícolas, pecuarias (NH4+ y mineras (SO42-, Ca2+ y Mg2+ de origen antropogénico.

  11. Sedimentología química de los sedimentos miocenos con diatomeas de la Cuenca del Guadalquivir

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    López García, M. J.

    1995-12-01

    Full Text Available The chemical data of major elements is used to study the precise lithological composition and the sedimentology of Miocene diatomaceous sediments from 24 sections of the Guadalquivir Basin. Three main episodes (Lower, Middle and Upper, defined on the basis of diatom zones have been studied. They record a highly productive coastal upwelling regime in the area during the Miocene. The wide range of variation of SiO2 (12.1878.00, CaO (1.60-43.73 and Al2O3 (2.76-10.32 contents reflects the important variations of the main components: Opal A, calcite (mainly biogenic and clay minerals-terrigenous components. Biogenic silica has been estimated by using normative calculations after determination of the mineralogical compositions of the samples by means of X-ray diffraction. Maximum and minimum contents in biogenic silica are related to the dominant diatom taxa, the structure of the rock and the geographicallocation in the basin. The ternary diagrams SiO2 biogenic- Al2O3-CaO reveal that the Upper Episode has the highest amounts of clay minerals-terrigenous components. Plots of SiO2 biogenic/CaO versus Al2O3show a relation between the biogenic calcite and the clay-minerals-terrigenous components. The plots of Fe2O3/TiO2 versus Al2O3/ Al2O3+ Fe2O3 show that most of the samples may be interpreted as deposited in a continental margin enviranment. The data obtained fram the slope of linear regressions Fe (y - Al (x are indicative of areas with varying influence of a terrigenous source. The MnO/ Al2O3 ratio is used to estimate rates of sedimentation of the diatomaceous sediments. The range is between 1.7 and 180 mm/103 years, which is consistent with the sedimentation rate values fram sediments formed in coastal upwelling regimes. The rate of sedimentation varies in relation to the structure of the rack, the dominant diatom taxa and the age of the episodes.La composición química de elementos mayores es utilizada para analizar las caracter

  12. QuEChERS-HPLC-DAD method for sulphonamides in chicken breast

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    Simone Caetani Machado

    2013-03-01

    Full Text Available The development of a QuEChERS-HPLC-DAD method using a Lichrospher 60 RP-Select B column (250 x 4.6 mm x 5 µm at 40ºC, mobile phase constituted by phosphate buffer:acetonitrile (75:25, v/v at a initial flow rate of 0.5 mL min-1, increased by 1.2 mL min-1 and at 265 nm is presented for simultaneous determination of sulphadiazine, sulphametoxipiridazine and sulphamethoxazole in chicken breast samples. QuEchERS is inexpensive, fast and easy, and the extraction of the analytes of the matrix was successfully employed. In addition, the method presented linearity, in the range of 25, 50, 100, 150, 175, and 200 µg kg-1, precision, selectivity and sensitivity. The intraday precision (RSD % for QuEChERS method was between 3.6-10.8 (SDZ, 6.9-14.1 (SPZ and 1.9-10.9 (SMX and interday precision (RSD% was between 1.5-9.7, 1.7-4.1 and 2.1-10.2, respectively. Results of accuracy (bias were in the range of -8.6 to +11.9 %. Therefore, the validated method is clearly useful for the practical residue monitoring of the drugs evaluated in chicken samples, as all the values were within the acceptable criteria used for food safety. Of 6 samples analyzed, none of them showed contamination of the sulphonamides studied at detectable levels.O desenvolvimento de um método QuEChERS-HPLC-DAD usando uma coluna Lichrospher RP-60 Select B (250 x 4,6 mm x 5 µm a 40 ºC, fase móvel constituída por tampão de fosfato: acetonitrila (75:25, v/v a uma vazão inicial de 0,5 mL min-1, aumentando 1,2 mL min-1 e a 265 nm é apresentado para a determinação simultânea de sulfadiazina, sulfametoxipiridazina e sulfametoxazol em amostras de peito de frango. O QuEChERS é barato, rápido e fácil, e a extração dos analitos da matriz foi empregada com sucesso. Além disso, o método apresentou linearidade, na faixa de 25, 50, 100, 150, 175 e 200 µg kg-1, precisão, seletividade e sensibilidade. A precisão intradia (RSD % para o método QuEChERS foi entre 3,6-10,8 (SDZ, 6,9-14,1 (SPZ

  13. Atributos químicos, carbono orgânico e substâncias húmicas em Organossolos háplicos de várias regiões do Brasil

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    Adierson Gilvani Ebeling

    2011-04-01

    Full Text Available A dinâmica e os atributos da matéria orgânica do solo (MOS há muito vêm sendo estudados em solos minerais. Entretanto, em condições tropicais, poucos estudos envolvem os solos orgânicos e a caracterização das substâncias húmicas (SH, ou sua relação com atributos químicos relevantes, para avaliar o potencial agrícola. Os objetivos deste estudo foram: avaliar atributos químicos de Organossolos Háplicos de diferentes regiões do Brasil; quantificar o teor de C orgânico no solo e nas frações da MOS; e avaliar as relações entre esses atributos em cada ambiente de formação. Foram avaliados os atributos químicos e quantificados os teores de C orgânico total e das frações da MOS (ácido fúlvico - C-FAF, ácido húmico - C-FAH e humina - C-HUM, bem como as relações C-FAH/C-FAF, C-EA/C-HUM, em que C-EA (carbono do extrato alcalino é obtido pelo somatório de C-FAF e C-FAH. Os Organossolos apresentaram elevada acidez, saturação por bases abaixo de 50 % e elevada capacidade de troca catiônica potencial (T, embora com valores altos de Ca2+ e Mg2+ e de soma de bases, na maioria dos perfis. Os teores de C nas frações húmicas apresentaram correlação significativa com diferentes atributos dos solos, como entre os valores de C-FAH e de C-HUM e os teores de N, H+ e T. O C-HUM e o C-FAH predominaram sobre o C-FAF. A relação C-FAH/C-FAF foi menor nos horizontes mais superficiais, dos perfis com maior intensidade de uso ou efeito de queimadas, assim como os teores de matéria orgânica, C-HUM e C-FAH. Os atributos químicos e os teores de C nas substâncias húmicas refletiram o grau de transformação da MOS e alterações pelo uso agrícola, indicando a vulnerabilidade dos Organossolos.

  14. Características de fermentação e composição químico-bromatológica de silagens de capim-tifton 85 confeccionadas com cinco teores de matéria seca

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    Castro Flávio Geraldo Ferreira

    2006-01-01

    Full Text Available Objetivou-se avaliar o efeito do emurchecimento e da aplicação de aditivo bacteriano-enzimático (ABE ou ácido propiônico tamponado (APT sobre as características de fermentação e a composição química da silagem de capim-tifton 85 (Cynodon spp. armazenada em forma de fardos retangulares revestidos de filme plástico. Foram confeccionadas cinco silagens (250, 350, 450, 550 e 650 g/kg MS sem aplicação de ABE (SA, três (250, 450 e 650 g/kg MS com aplicação de ABE (CA e uma (650 g/kg MS foi pulverizada com uma solução contendo APT. As amostras foram colhidas nos tempos zero hora antes da ensilagem e 6, 12 horas, 1, 2, 4, 8, 16, 32, 90 e 180 dias após a ensilagem, para se estabelecer a tendência das características de fermentação e composição química. O delineamento experimental utilizado foi inteiramente casualizado, com três repetições, em parcelas subdivididas no tempo, sendo os tratamentos os fatores das parcelas, arranjados em esquema fatorial 5 x 2 incompleto. O emurchecimento a teores médios de MS (450 g/kg MS favoreceu os parâmetros de fermentação (pH, N-NH3 e poder tampão e a composição química das silagens de capim-tifton 85. O uso de APT não melhorou as características qualitativas de fermentação e a composição química das silagens. A utilização de ABE apresentou mínimos benefícios somente nas silagens contendo elevado teor de matéria seca (650 g/kg MS, sendo ineficiente para forragens contendo alto teor de umidade (250 g/kg MS.

  15. Edward C. Little Water Recycling Plant, El Segundo, CA: CA0063401

    Science.gov (United States)

    Joint EPA and Los Angeles Regional Water Quality Control Board NPDES Permit and Waiver from Secondary Treatment for the West Basin Municipal Water District Edward C. Little Water Recycling Plant, El Segundo, CA: CA0063401

  16. Control de los contaminantes químicos en el Perú

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    Betty Chung

    2008-10-01

    Full Text Available La contaminación del agua, aire, suelo y alimentos es la consecuencia de las actividades que el hombre ha desarrollado para vivir y mejorar su calidad de vida. Sin embargo, el hombre se ha olvidado de vivir en armonía con la naturaleza y de cuidarla. Hoy tenemos un sinnúmero de sustancias químicas y biológicas en el ambiente que significan un riesgo para la salud porque se encuentran en altas concentraciones o debido a su naturaleza tóxica. Para tener referencia y conocimiento del nivel de contaminación que existe en cada lugar, es necesario que existan metodologías y técnicas analíticas, así como normas técnicas referidas al control de contaminantes en el ambiente, es decir en el agua, aire, suelo y alimentos. Actualmente en el país, tenemos reglamentación referidas al agua y aire; las normas para agua incluyen parámetros físicos, químicos, elementos y sustancias orgánicas e inorgánicas, las normas para aire están referidas a los contaminantes primarios, mientras que para suelos se consultan las normas internacionales y para alimentos las normas de la FDA (Food and Drug Administration. En el contexto nacional actual, con 9,7% de crecimiento en la productividad y desarrollo de actividades económicas diversas, es necesario la complementación del marco normativo medioambiental y el desarrollo de la capacidad analítica nacional para la evaluación de sustancias químicas y el control de la contaminación del ambiente, la preservación de los recursos naturales del país y la certificación de productos de exportación y consumo.

  17. Tecnologias e professores de Química: um programa brasileiro de desenvolvimento profissional

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    Marcelo Prado Amaral-Rosa

    2017-01-01

    Full Text Available O setor educacional é uma das esferas sociais afetadas diretamente pelas tecnologias digitais. Destinar atenção aos caminhos tomados por tais aparatos é vital para compreender os próprios processos educacionais. Nessa situação, enquadra-se a formação de professores. Assim, o objetivo geral é apresentar as nuances gerais do Programa de Desenvolvimento Profissional para Professores com a finalidade de contextualizar uma estratégia inovadora de formação de professores da rede básica pública de educação a partir das ações formativas desenvolvidas na área de Química. O programa foi ofertado pelo governo brasileiro aos professores da educação básica por meio de um acordo de cooperação internacional entre Brasil e Portugal. As formações ocorreram na Universidade do Porto e na Universidade de Aveiro. Foram ofertadas 175 vagas para professores de todas as regiões do Brasil nas áreas de Língua Portuguesa, Pedagogia, Física, Matemática e Química. A área de Química foi a única que ocorreu em ambas as instituições parceiras, sendo acompanhadas in loco. Percebe-se que o conhecimento por parte da comunidade de professores e pesquisadores sobre a ocorrência dessa formação ofertada pelo governo brasileiro é praticamente inexistente, assim faz-se se suma importância a divulgação dos contextos de ocorrência da mesma, tendo enquanto macro destaque a valorização dos professores da rede pública nacional.

  18. QuASAR-MPRA: accurate allele-specific analysis for massively parallel reporter assays.

    Science.gov (United States)

    Kalita, Cynthia A; Moyerbrailean, Gregory A; Brown, Christopher; Wen, Xiaoquan; Luca, Francesca; Pique-Regi, Roger

    2018-03-01

    The majority of the human genome is composed of non-coding regions containing regulatory elements such as enhancers, which are crucial for controlling gene expression. Many variants associated with complex traits are in these regions, and may disrupt gene regulatory sequences. Consequently, it is important to not only identify true enhancers but also to test if a variant within an enhancer affects gene regulation. Recently, allele-specific analysis in high-throughput reporter assays, such as massively parallel reporter assays (MPRAs), have been used to functionally validate non-coding variants. However, we are still missing high-quality and robust data analysis tools for these datasets. We have further developed our method for allele-specific analysis QuASAR (quantitative allele-specific analysis of reads) to analyze allele-specific signals in barcoded read counts data from MPRA. Using this approach, we can take into account the uncertainty on the original plasmid proportions, over-dispersion, and sequencing errors. The provided allelic skew estimate and its standard error also simplifies meta-analysis of replicate experiments. Additionally, we show that a beta-binomial distribution better models the variability present in the allelic imbalance of these synthetic reporters and results in a test that is statistically well calibrated under the null. Applying this approach to the MPRA data, we found 602 SNPs with significant (false discovery rate 10%) allele-specific regulatory function in LCLs. We also show that we can combine MPRA with QuASAR estimates to validate existing experimental and computational annotations of regulatory variants. Our study shows that with appropriate data analysis tools, we can improve the power to detect allelic effects in high-throughput reporter assays. http://github.com/piquelab/QuASAR/tree/master/mpra. fluca@wayne.edu or rpique@wayne.edu. Supplementary data are available online at Bioinformatics. © The Author (2017). Published by

  19. Validity of congenital malformation diagnostic codes recorded in Québec's administrative databases.

    Science.gov (United States)

    Blais, Lucie; Bérard, Anick; Kettani, Fatima-Zohra; Forget, Amélie

    2013-08-01

    To assess the validity of the diagnostic codes of congenital malformations (CMs) recorded in two of Québec's administrative databases. A cohort of pregnancies and infants born to asthmatic and non-asthmatic women in 1990-2002 was reconstructed using Québec's administrative databases. From this cohort, we selected 269 infants with a CM and 144 without CM born to asthmatic women, together with 284 and 138 infants, respectively, born to non-asthmatic women. The diagnoses of CMs recorded in the databases were compared with the diagnoses written by the physicians in the infants' medical charts. The positive predictive values (PPV) and negative predictive values (NPV) for all, major, and several specific CMs were estimated. The PPVs for all CMs and major CMs were 82.2% (95% confidence interval (CI): 78.5%-85.9%) and 78.1% (74.1%-82.1%), respectively, in the asthmatic group and were 79.2% (75.4%-83.1%) and 69.0% (64.6%-73.4%), respectively, in the non-asthmatic group. PPVs >80% were found for several specific CMs, including cardiac, cleft, and limb CMs in both groups. The NPV for any CM was 88.2% (95% CI: 85.1%-91.3%) in the asthmatic group and 94.2% (92.2%-96.2%) in the non-asthmatic group. Québec's administrative databases are valid tools for epidemiological research of CMs. The results were similar between infants born to women with and without asthma. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Propriedades físicas e químicas de substratos renováveis

    Directory of Open Access Journals (Sweden)

    Dagma Kratz

    2013-12-01

    Full Text Available A necessidade premente de aumento no número de mudas plantadas anualmente, bem como a crescente diminuição na disponibilidade de matérias-primas tradicionais para composição de substratos, tem levado à necessidade do desenvolvimento de estudos que visam à avaliação e disponibilização de novos materiais para sua composição técnica e economicamente eficientes. Em vista disso, este estudo objetivou analisar as propriedades físicas e químicas de substratos formulados com base em materiais renováveis e de grande disponibilidade (fibra de coco, casca de arroz carbonizada em diferentes granulometrias, biossólido e casca de pinus semidecomposta, bem como suas intercorrelações. Para tanto, foram formulados 41 substratos, os quais tiveram suas propriedades físicas e químicas avaliadas. Com base nos resultados, pôde-se concluir que, pelas suas propriedades físicas e químicas, uma série de materiais renováveis e, ou, resíduos agroindustriais e humanos se adéquam para serem utilizados como componentes na formulação de substratos para produção de mudas florestais, embora os conteúdos de alguns nutrientes em determinados substratos devam ser ajustados via adubação de base. Em vista do fato de as propriedades físicas serem mais decisivas na escolha de determinada formulação de substrato, entre os componentes e misturas avaliadas se pode concluir que os substratos formulados à base de fibra de coco e casca de arroz carbonizada se mostraram mais adequados.

  1. ¿De qué hablamos cuando hacemos referencia a la psicosis ordinaria?

    OpenAIRE

    Llaneza, Sebastián

    2017-01-01

    Como es sabido estamos aquí reunidos en torno a una pregunta que podríamos formular del siguiente modo: ¿de qué hablamos cuando hacemos referencia a la psicosis ordinaria? Para empezar diré lo siguiente, expresaré una afirmación: cuando hablamos de psicosis ordinaria hacemos referencia a un sintagma que no alude a una nueva categoría diagnóstica. Es importante destacar que, con dicho término, no nos referimos a una nueva clasificación. Por esta misma razón, en el marco de una confer...

  2. El equilibrio químico : una investigación de aula

    OpenAIRE

    Huerta Ruíz, María Patricia

    2008-01-01

    Se presenta una metodología didáctica para promover el aprendizaje del equilibrio químico. El punto de inicio es la identificación y construcción de las características del concepto, con base en el uso de analogías, resolución de problemas y trabajos prácticos y se sugiere no introducir el Principio de LeChatelier antes de trabajar suficientemente los conceptos de equilibrio dinámico e irreversibilidad de reacciones. La propuesta se probó con alumnos del último año del bachillerato de la UNAM...

  3. Apuntes de historia de la química industrial en México

    OpenAIRE

    Bucay, Benito

    2001-01-01

    La química industrial en México desciende de las actividades mineras de la época de la Colonia. Su despegue ocurre durante la Segunda Guerra Mundial y tiene un fuerte desarrollo en varios frentes entre 1960 y 1990. A partir de entonces, se ha dado un proceso de consolidación y reestructura como consecuencia de la apertura económica, lo cual ha conducido a una reducción en el número de participantes y actividades, quedando sólo aquéllas que tienen una base firme de tecnología y capacidad que l...

  4. Abundancias químicas de estrellas de Mercurio-Manganeso obtenidas con espectros EBASIM

    Science.gov (United States)

    Pintado, O. I.; Adelman, S. J.

    Se determinan las abundancias químicas de estrellas de HgMn usando espectros obtenidos con EBASIM en CASLEO en un rango de longitud de onda comprendido entre los 400 y 890 nm. Los valores iniciales de temperatura efectiva y gravedad superficial se calculan con la fotometría uvbyβ. Las abundancias se calculan usando WIDTH9 y SYNTHE. Los resultados se comparan análisis realizados por los autores usando espectros obtenidos con el espectrógrado REOSC del CASLEO, el espectrógrafo echelle del Telescopio Anglo-Australiano y el espectrógrafo Coudé del Dominion Astrophysical Observatory.

  5. Química de especies del genero espeletia Espeletia killipii - Espeletia tunjana

    Directory of Open Access Journals (Sweden)

    Rubén Darío Torrenegra

    2010-07-01

    Full Text Available De las partes aéreas de 2 especies del género Espeletia se aislaron compuestos del tipo diterpeno Acido (-i-Kaur-9( 11, 16-dien-19-oico, el (-Kaur-16-en-19-ol, los terpenos friedeiina, sitosterol-estigmasterol, y dos sesquiterpenlactonas del tipo melampólido, Acetato de Longipilin y Polimatin B. Los últimos compuestos no reportados hasta el momento en la química del género Espeletia. Del extracto etanólico se identificaron dos flavonoides: Quercetina y 3-metoxiquercetina.

  6. Experimentos de química recreativa con sulfato de cobre pentahidratado

    Directory of Open Access Journals (Sweden)

    Santiago Heredia-Avalos

    2006-01-01

    Full Text Available En este trabajo se proponen varias experiencias sencillas usando sales de sulfato de cobre pentahidratado. Todas ellas pueden realizarse en casa con utensilios de cocina y usando sustancias baratas, la mayoría de las cuales pueden encontrarse en un supermercado. Las experiencias propuestas permiten estudiar el proceso de cristalización del sulfato de cobre pentahidratado, reacciones de oxidación-reducción, de formación de precipitados e, incluso, reacciones de formación de complejos. Estas experiencias pretenden despertar el interés de los alumnos por la química.

  7. Metodología para estudios de estabilidad química en formulaciones de quitina

    OpenAIRE

    Yania Suárez Pérez; Ivone Almirall Díaz; Hilda María González San Miguel; Ofelia Bilbao Revoredo; Olga M Nieto Acosta

    2000-01-01

    Se propuso combinar la gravimetría directa como método cuantitativo con la espectroscopia infrarroja como técnica cualitativa complementaria, con el objetivo de establecer la metodología para el seguimiento de la estabilidad química de la quitina como fármaco en diferentes formas farmacéuticas: suspensión, crema, supositorio. La determinación del contenido de quitina por técnicas gravimétricas se validó en cada caso según los parámetros: linealidad, precisión, exactitud y especificidad. El an...

  8. ¿Qué recursos tenemos en la traducción médica?

    OpenAIRE

    Brugué Botia, Lidia; Giró Anglada, Rubén

    2004-01-01

    La traducción especializada requiere mucha investigación y, si hablamos de la traducción médica en particular, debemos ser conscientes de que cada especialidad tiene su propio vocabulario. Aparte de la terminología común utilizada en la medicina, es necesario que el traductor conozca los términos específicos de cada ámbito médico. Cuando nos encontramos delante de un texto de estas características, como por ejemplo un artículo sobre oftalmología, ¿qué herramientas son las que debemos conocer ...

  9. Compatibilidad química del piracetam determinada por calorimetría diferencial de barrido

    Directory of Open Access Journals (Sweden)

    Luis Octavio Martínez Álvarez

    2013-03-01

    Full Text Available Introducción: en la primera etapa de preformulación de un medicamento se seleccionan los excipientes y es importante la realización de los estudios de compatibilidad química entre el ingrediente activo farmacéutico (IFA y excipientes. Una de las técnicas más rápidas para realizar dichos estudios es la Calorimetría diferencial de barrido (DSC, y como técnica complementaria la Termogravimetría (TG. Objetivo: empleando DSC y TG, se realiza un estudio de compatibilidad química entre IFA y excipientes preseleccionados, para comprobar la existencia o no de interacción química. Métodos: el equipo empleado fue el TA3000Mettler, aco­plado a la celda DSC20 y al horno TG50. El IFA utilizado fue Piracetam, y los excipientes: Kollidon VA 64, Estearato de magnesio, Celulosa microcristalina, Polietilenglicol 20 000 y Aerosil. Dichos excipientes se caracterizaron por DSC al igual que el IFA, al cual se le detectó la transición física de fusión. Para el estudio de compatibilidad se prepararon mezclas físicas binarias en una relación de concentración 1:1 Resultados: la figura 1 muestra la detección del punto de fusión por DSC del IFA. Se obtuvieron dos transiciones endotérmicas, comprobándose por TG cuál era la de fusión. La figura 2 muestra los termogramas de las mezclas formadas entre IFA y excipientes. Conclusiones: no se detectó aparición de nuevos picos, por lo que se infiere que no hay incompatibilidad química entre las sustancias estudiadas y se recomienda el uso de los excipientes para el desarrollo de la formulación farmacéutica.

  10. Estudo quÃmico e farmacolÃgico de Senna reticulata

    OpenAIRE

    RogÃrio Nunes dos Santos

    2007-01-01

    Este trabalho descreve a investigaÃÃo fitoquÃmica de Senna reticulata Willd., (Leguminoseae), popularmente conhecida no Cearà como mangerioba grande, que tem uso na medicina popular no tratamento de doenÃas do fÃgado, reumatismo e cÃlicas menstruais. Os gÃneros Senna, Chamaecrista e Cassia foram investigados a partir de seus compostos antraquinÃnicos relatados na literatura atà os dias atuais, no interesse de se traÃar um perfil, que contribuÃsse com distinÃÃo quÃmica dos mesmos que atà algun...

  11. ¿Por qué no bajan las tasas de criminalidad en Chile?

    OpenAIRE

    Matus Acuña, Jean Pierre

    2006-01-01

    En un contexto de alza de las tasas de delito en Chile, se investiga mediante un análisis empírico si se encuentran presentes y en qué medida los factores que en la discusión norteamericana se consideran causantes del desenso de la criminalidad que allá se aprecia (Levitt, 2004). La investigación permite sostener la hipótesis que la mayor parte de los factores que se asocian a los movimientos de las tasas de criminalidad en Estados Unidos: 1) no son de carácter idiosincrático; 2) pr...

  12. Introducción a la Química Orgánica

    OpenAIRE

    Autino, Juan Carlos; Romanelli, Gustavo Pablo; Ruiz, Diego Manuel

    2013-01-01

    Esta obra ha sido concebida atendiendo a las características del Curso de Química Orgánica que ofrecemos en la Facultad de Ciencias Agrarias y Forestales de la Universidad Nacional de La Plata a nuestros alumnos del primer año de las Carreras de Ingeniería Agronómica e Ingeniería Forestal, así como del segundo año de la Licenciatura en Biología. En la misma incorporamos elementos didácticos que hemos introducido y mejorado gradualmente durante varios años, logrando un cierto grado de original...

  13. Normativismo continental y su contraparte británico: ¿Qué tan diferentes son?

    OpenAIRE

    Paulson, Stanley L.

    2005-01-01

    Al plantear la pregunta ¿qué es el derecho?, la tradición jurídica filosófica ha encontrado múltiples respuestas que, sin embargo, parecen agruparse en torno a dos tradiciones iusfilosóficas predominantes: la del positivismo jurídico y la del derecho natural. Los postulados del primero, en su matiz empírico reductivo, establecen una vinculación específica entre el derecho y los hechos (tesis reductiva), mientras que los del segundo se han caracterizado por la vinculación entre la moral y el d...

  14. A indústria de fertilizantes químicos no Brasil

    OpenAIRE

    Telles, Adalberto Franco Netto

    2014-01-01

    O presente estudo trata do desenvolvimento da Indústria de Fertilizantes Químicos no Brasil, especialmente a partir de 1950. Analisa neste período os condicionantes do crescimento da oferta de fertilizantes e de sua demanda. A ênfase dada, no tocante à oferta nacional de fertilizantes, recai sobre a estrutura industrial originada com a implantação do Programa Nacional de Fertilizantes e Calcário Agrícola, subprograma do II Plano Nacional de Desenvolvimento, e seu ajustamento à crise setorial ...

  15. A modification of QuEChERS method to analyse anticoagulant rodenticides using small blood samples

    OpenAIRE

    P Gómez-Ramírez; E Martínez-López; I Navas; P María-Mojica; AJ García-Fernández

    2012-01-01

    El uso de rodenticidas anticoagulantes es el método más frecuentemente utilizado para el control de plagas de roedores. Debido a sus características físico-químicas y particular mecanismo de acción, la utilización de estos compuestos en zonas rurales puede suponer un riesgo de intoxicación secundaria de sus depredadores. Para evaluar el riesgo a estos compuestos para la fauna silvestre, especialmente en aves rapaces que se alimentan de roedores, se llevan a cabo los programas de biomonitoriza...

  16. Constituintes químicos das folhas e do caule de Coccoloba mollisCasaretto (Polygonaceae)

    OpenAIRE

    Oliveira,Patrícia Emanuella S.; Santos,Wagner S. dos; Conserva,Lucia M.; Lemos,Rosangela P. de Lyra

    2008-01-01

    O estudo químico das frações neutra em hexano das folhas e em diclorometano do caule de Coccoloba mollis resultou no isolamento de um triterpeno pentacíclico (simiarenol), que pela primeira vez ocorre em Polygonaceae, dois fitoesteróides (sitostenona e sitosterol), um diterpeno (trans-fitol) e de um benzenóide (ácido vanílico) que está sendo descrito pela vez neste gênero. A identificação estrutural destes compostos foi feita com base na análise dos dados espectrais (IV, EM e RMN, incluindo D...

  17. Coupled Ca2+/H+ transport by cytoplasmic buffers regulates local Ca2+ and H+ ion signaling.

    Science.gov (United States)

    Swietach, Pawel; Youm, Jae-Boum; Saegusa, Noriko; Leem, Chae-Hun; Spitzer, Kenneth W; Vaughan-Jones, Richard D

    2013-05-28

    Ca(2+) signaling regulates cell function. This is subject to modulation by H(+) ions that are universal end-products of metabolism. Due to slow diffusion and common buffers, changes in cytoplasmic [Ca(2+)] ([Ca(2+)]i) or [H(+)] ([H(+)]i) can become compartmentalized, leading potentially to complex spatial Ca(2+)/H(+) coupling. This was studied by fluorescence imaging of cardiac myocytes. An increase in [H(+)]i, produced by superfusion of acetate (salt of membrane-permeant weak acid), evoked a [Ca(2+)]i rise, independent of sarcolemmal Ca(2+) influx or release from mitochondria, sarcoplasmic reticulum, or acidic stores. Photolytic H(+) uncaging from 2-nitrobenzaldehyde also raised [Ca(2+)]i, and the yield was reduced following inhibition of glycolysis or mitochondrial respiration. H(+) uncaging into buffer mixtures in vitro demonstrated that Ca(2+) unloading from proteins, histidyl dipeptides (HDPs; e.g., carnosine), and ATP can underlie the H(+)-evoked [Ca(2+)]i rise. Raising [H(+)]i tonically at one end of a myocyte evoked a local [Ca(2+)]i rise in the acidic microdomain, which did not dissipate. The result is consistent with uphill Ca(2+) transport into the acidic zone via Ca(2+)/H(+) exchange on diffusible HDPs and ATP molecules, energized by the [H(+)]i gradient. Ca(2+) recruitment to a localized acid microdomain was greatly reduced during intracellular Mg(2+) overload or by ATP depletion, maneuvers that reduce the Ca(2+)-carrying capacity of HDPs. Cytoplasmic HDPs and ATP underlie spatial Ca(2+)/H(+) coupling in the cardiac myocyte by providing ion exchange and transport on common buffer sites. Given the abundance of cellular HDPs and ATP, spatial Ca(2+)/H(+) coupling is likely to be of general importance in cell signaling.

  18. PROHEXADIONA-CA, UNA ALTERNATIVA EN LA PRODUCCIÓN DE TOMATE DE CÁSCARA (Physalis ixocarpa Brot.

    Directory of Open Access Journals (Sweden)

    H. Ramírez

    2010-01-01

    Full Text Available El tomate de cáscara, por su superficie cultivada y su constante aumento en el consumo per capita, se considera una de las principales hortalizas en México. Se cultiva en cualquier región del país, aunque con una producción media nacional por debajo de su potencial. Prohexadiona de Ca (P-Ca, es un retardante del crecimiento señalado recientemente como una alternativa prometedora en la horticultura moderna, principalmente para mejorar la producción y calidad del producto cosechado. Con base en lo anterior, se evaluaron los efectos de P-Ca sobre el crecimiento vegetativo y productivo; así como las propiedades químicas del fruto en tomate de cáscara. Se realizaron dos aplicaciones de P-Ca a diferentes dosis (0, 125, 175 y 200 mg·litro-1. La primera se realizó cuando las plantas presentaron primordios florales y la segunda 20 días después. Con un diseño en bloques completos al azar y una comparación de medias con la prueba DMS a una P¿0.05, se demostró que P-Ca redujo significativamente la altura de la planta, aumentó notablemente el número de frutos, el rendimiento por planta (200 mg·litro-1, el contenido de vitamina C en frutos (175 y 200 mg·litro-1 y la actividad enzimática catalasa (175 mg·litro-1. Las variables de tamaño y peso de fruto, el contenido de proteína, la actividad enzimática peroxidasa y el contenido mineral en fruto no fueron afectados por P-Ca.

  19. Cuento: Sangre de caña

    Directory of Open Access Journals (Sweden)

    Segundo Benjamín Corredor

    1967-09-01

    Full Text Available El viento se convertía en murmullo contra las hojas de los cañaverales y contra los techos semipelados del rancho. También menguaba el calor que maduraba los plantíos de caña y que hacía más efusiva la sangre de los moradores.

  20. Impact of seawater [Ca2+] on the calcification and calcite Mg / Ca of Amphistegina lessonii

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; Thoms, S.; Nehrke, G.; Reichart, G. J.; de Nooijer, L. J.; Bijma, J.

    2015-01-01

    Mg / Ca ratios in foraminiferal tests are routinely used as paleotemperature proxies, but on long timescales, they also hold the potential to reconstruct past seawater Mg / Ca. The impact of both temperature and seawater Mg / Ca on Mg incorporation in Foraminifera has been quantified by a number of

  1. LnqR, a TetR-family transcriptional regulator, positively regulates lacticin Q production in Lactococcus lactis QU 5.

    Science.gov (United States)

    Iwatani, Shun; Ishibashi, Naoki; Flores, Floirendo P; Zendo, Takeshi; Nakayama, Jiro; Sonomoto, Kenji

    2016-09-01

    Lacticin Q is an unmodified leaderless bacteriocin produced by Lactococcus lactis QU 5. It has been revealed that the production and self-immunity of lacticin Q are facilitated by a gene cluster lnqQBCDEF The gene for a putative TetR-family transcriptional regulator, termed lnqR, was found nearby the lnqQBCDEF cluster, but its involvement in lacticin Q biosynthesis remained unknown. In this study, we created an LnqR-overexpressing QU 5 recombinant by using lactococcal constitutive promoter P32 The recombinant QU 5 showed enhanced production of and self-immunity to lacticin Q. RT-PCR analysis has revealed that an overexpression of LnqR increases the amounts of lnqQBCDEF transcripts, and these six genes are transcribed as an operon in a single transcriptional unit. Interestingly, LnqR expression and thus lacticin Q production by L. lactis QU 5 was found temperature dependent, while LnzR, an LnqR-homologue, in L. lactis QU 14 was expressed in a similar but not identical manner to LnqR, resulting in dissimilar bacteriocin productivities by these strains. This report demonstrates LnqR as the first TetR-family transcriptional regulator involved in LAB bacteriocin biosynthesis and that, as an exceptional case of TetR-family regulators, LnqR positively regulates the transcription of these biosynthetic genes. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Ca-Dependent Folding of Human Calumenin

    Science.gov (United States)

    Mazzorana, Marco; Hussain, Rohanah; Sorensen, Thomas

    2016-01-01

    Human calumenin (hCALU) is a six EF-hand protein belonging to the CREC family. As other members of the family, it is localized in the secretory pathway and regulates the activity of SERCA2a and of the ryanodine receptor in the endoplasmic reticulum (ER). We have studied the effects of Ca2+ binding to the protein and found it to attain a more compact structure upon ion binding. Circular Dichroism (CD) measurements suggest a major rearrangement of the protein secondary structure, which reversibly switches from disordered at low Ca2+ concentrations to predominantly alpha-helical when Ca2+ is added. SAXS experiments confirm the transition from an unfolded to a compact structure, which matches the structural prediction of a trilobal fold. Overall our experiments suggest that calumenin is a Ca2+ sensor, which folds into a compact structure, capable of interacting with its molecular partners, when Ca2+ concentration within the ER reaches the millimolar range. PMID:26991433

  3. CaMKII in the Cardiovascular System: Sensing Redox States

    Science.gov (United States)

    Erickson, Jeffrey R.; He, B. Julie; Grumbach, Isabella M.; Anderson, Mark E

    2013-01-01

    The multifunctional Ca2+ and calmodulin-dependent protein kinase II (CaMKII) is now recognized to play a central role in pathological events in the cardiovascular system. CaMKII has diverse downstream targets that promote vascular disease, heart failure and arrhythmias, so improved understanding of CaMKII signaling has the potential to lead to new therapies for cardiovascular disease. CaMKII is a multimeric serine-threonine kinase that is initially activated by binding calcified calmodulin (Ca2+/CaM). Under conditions of sustained exposure to elevated Ca2+/CaM CaMKII transitions into a Ca2+/CaM-autonomous enzyme by two distinct but parallel processes. Autophosphorylation of threonine 287 in the CaMKII regulatory domain ‘traps’ CaMKII into an open configuration even after Ca2+/CaM unbinding. More recently, our group identified a pair of methionines (281/282) in the CaMKII regulatory domain that undergo a partially reversible oxidation which, like autophosphorylation, prevents CaMKII from inactivating after Ca2+/CaM unbinding. Here we review roles of CaMKII in cardiovascular disease with an eye to understanding how CaMKII may act as a transduction signal to connect pro-oxidant conditions into specific downstream pathological effects that are relevant to rare and common forms of cardiovascular disease. PMID:21742790

  4. Jenis dan Status Konservasi Ikan Hiu yang Tertangkap di Tempat Pelelangan Ikan (TPI Labuan Bajo, Manggarai Barat, Flores

    Directory of Open Access Journals (Sweden)

    Ismail Syakurachman Alaydrus

    2016-03-01

    Full Text Available The study aimed to determine the types of sharks are caught, sold and conservation status in the fish auction place (TPI Labuan Bajo, West Manggarai, Flores, East Nusa Tenggara have been conducted in February and March 2014 in Labuan Bajo. The research method was the survey method and used Market Survey sampling techniques and identification by Rapid Assessment method. Descriptively analyzed data, displayed in the form of narration and a table. Based on the results of the study, found 114 individual sharks, 55 individual males, 59 females were classified into three orders, namely Orectolobiformes, Lamniformes, and Carcharhiniformes; 4 families that Carcharhinidae, Odontaspididae, Rhynchobatidae, and Ginglymostomatidae; 5 genera namely Carcharhinus, Triaenodon, Rhyncobatus, Prionace, and Rhizoprionodon and 9 types of sharks that Carcharhinus melanopterus, Triaenodon obesus, Carcharhinus limbatus, Carcharhinus taurus, Carcharhinus amblyrhynchos, Rhynchobatus australiae, Prionace glauca, Rhizoprionodon acutus, and Nebrius ferrugineus. Based on the state of conservation, shark found in Labuan Bajo TPI classified Vulnerable and Near Threatened, the dominant type of shark found is Carcharhinus melanopterus (91 fishes while the least was found is Rhynchobatus australiae, Prionace glauca, Rhizoprionodon acutus, and Nebrius ferrugineus (each 1 individual.

  5. Actitudes y rendimiento académico: su evolución desde química general e inorgánica hasta química orgánica

    Directory of Open Access Journals (Sweden)

    María S. Reyes

    2014-01-01

    Full Text Available Esta investigación tiene un doble propósito, en primer lugar, valorar las actitudes hacia la química de alumnos universitarios de carreras biológicas en dos cursos relacionados con esta disciplina y, por otro lado, relacionar dichas actitudes con el rendimiento académico presentado por los estudiantes. El instrumento elegido para medir las actitudes de los alumnos fue un cuestionario según la escala Likert, encuestándose a la totalidad de estudiantes que cursaban cada uno de los cursos de química analizados: Química General e Inorgánica (QGI y Química Orgánica (QO. Para estimar el rendimiento académico se analizaron actas de parciales y se realizaron cálculos de correlación. Los alumnos que cursaban QGI presentaron actitudes hacia la química valoradas como indiferentes. Sin embargo al finalizar el curso de QO sus actitudes fueron evolucionando favorablemente, ya que la puntuación media obtenida para los ítems positivos y negativos estuvo en el rango de actitudes positivas. Los valores del coeficiente de Pearson obtenidos para los dos cursos estudiados fueron superiores a 0,80, lo que indica una fuerte relación entre las variables implicadas, por lo cual se infiere la importancia de desarrollar actitudes positivas hacia la química para favorecer el rendimiento académico de los alumnos.

  6. Stress cracking e ataque químico do PET em diferentes agentes químicos Stress cracking and chemical attack of pet under different chemicals

    Directory of Open Access Journals (Sweden)

    Edvânia T. Teófilo

    2009-01-01

    Full Text Available A análise de resistência ao stress cracking (ESCR do PET foi feita em corpos de prova de tração moldados por injeção, utilizando vários agentes químicos (metanol, etanol, propanol, butanol e soluções de hidróxido de sódio em diferentes concentrações. Foram realizados ensaios dinâmicos e estáticos de tração. Durante os testes os corpos de prova foram mantidos em contato com os agentes e as propriedades mecânicas monitoradas. Os resultados evidenciam que todas as soluções de hidróxidos de sódio testadas são agentes agressivos de ESC por diminuírem as propriedades mecânicas do polímero, ocasionando falha catastrófica. Já os demais fluidos, apesar de não terem efeito significativo nas propriedades do PET, afetam drasticamente sua aparência superficial. Observou-se também a ocorrência de ataque químico nos ensaios com NaOH, resultando em redução nas massas molares.The investigation of stress cracking resistance (ESCR of PET was done in injection-moulded tensile test bars using different fluids as active agents. These were methanol, ethanol, propanol, butanol and solutions based on sodium hydroxide. Both dynamic and static tensile experiments were conducted. During the tensile experiments, the samples were kept in contact with the fluids and the mechanical properties were monitored. The results showed that all sodium hydroxide solutions were aggressive stress cracking agents for PET, reducing mechanical properties and causing catastrophic failure. On the other hand, the other fluids did not cause much influence on the mechanical behaviour but changed drastically the surface appearance. Also observed was a chemical attack when NaOH solutions were used, causing a reduction in molar mass of PET molecules.

  7. Laboratório químico-prático do Rio de Janeiro: primeira tentativa de difusão da Química no Brasil (1812- 1819)

    OpenAIRE

    Santos Nadja Paraense dos

    2004-01-01

    Until the present date, historians of science have described inaccurately the first laboratory created in Brazil for establishing and divulging Chemistry, namely the "Laboratório Químico-Prático do Rio de Janeiro". During recent research carried out in the Arquivo do Museu Imperial (Petrópolis, RJ), I localized a document entitled "Ensaio histórico analítico das operações do Laboratório Químico-Prático do Rio de Janeiro", which allowed me to gain the relevant information to correct some of th...

  8. Actitudes y rendimiento académico: su evolución desde química general e inorgánica hasta química orgánica

    OpenAIRE

    María S. Reyes; Silvia Porro; María E. Pirovani

    2014-01-01

    Esta investigación tiene un doble propósito, en primer lugar, valorar las actitudes hacia la química de alumnos universitarios de carreras biológicas en dos cursos relacionados con esta disciplina y, por otro lado, relacionar dichas actitudes con el rendimiento académico presentado por los estudiantes. El instrumento elegido para medir las actitudes de los alumnos fue un cuestionario según la escala Likert, encuestándose a la totalidad de estudiantes que cursaban cada uno de los cursos de quí...

  9. ¿Qué competencias digitales manifiestan los alumnos de 4º de ESO frente a una animación sobre una reacción química a nivel molecular?

    OpenAIRE

    Valverde Crespo, Daniel; De Pro Bueno, Antonio; González Sánchez, Joaquín

    2017-01-01

    El trabajo presentado pretende estudiar cómo utilizan unos alumnos de 4º de ESO la información contenida en una animación digital por medio de sus competencias digitales. La animación presenta una reacción química a nivel molecular y forma parte del proyecto Ulloa, un recurso TIC para la enseñanza de la química propuesto por la Administración Educativa. Los resultados indican que los participantes no presentan dificultades para identificar ideas, describir observaciones y realizar prediccione...

  10. Ensino de conceitos químicos em um enfoque CTS a partir de saberes populares

    Directory of Open Access Journals (Sweden)

    Ricardo Luiz Zanotto

    Full Text Available Resumo: O presente artigo objetiva apresentar resultados de um estudo realizado sobre a utilização de saberes populares como ponto de partida para o ensino de conceitos químicos, articulando os diversos saberes sob o enfoque CTS. O trabalho foi realizado com 30 alunos da 3ª série do ensino médio de um colégio da rede estadual de ensino, da região sul do Paraná, Brasil. A abordagem metodológica foi a qualitativa, de natureza interpretativa, com observação participante. A coleta de dados se deu por meio de questionários, apresentação e discussão dos resultados das pesquisas bibliográficas, elaboração e análise de mapas conceituais, produção de infográficos (historinhas. A pesquisa demonstrou que a utilização dos saberes populares se constituiu num fator motivador e de apoio para a aprendizagem, possibilitando a contextualização dos conteúdos, tornando o ensino de Química mais atraente e significativo, facilitando, dessa maneira, a criação de estruturas cognitivas e mudanças de perfil conceitual.

  11. Determination of coumarin in seasonal bakery products using QuEChERS and GC-MS.

    Science.gov (United States)

    Vetter, F; Müller, C; Stöckelhuber, M; Bracher, F

    2017-06-01

    Cinnamon is a traditional herbal drug, but more importantly, it is used as a flavor compound in the production of foodstuff. Due to the content of significant concentrations of coumarin in Cassia cinnamon, effective control of the coumarin content in seasonal bakery products like ginger bread and cinnamon biscuits is urgently needed. Here we present a novel, fast and fully validated protocol for the determination of coumarin in marketed bakery products using the QuEChERS sample preparation technique in combination with GC-MS analysis. Ten grams of homogenized sample was mixed with 20 mL acetonitrile/water (1:1) and 5 g magnesium sulfate/sodium chloride mixture (4:1). The organic phase was cleaned by dSPE with 25 mg magnesium sulfate/PSA (5:1). The LOD was 0.15 μg/mL and the LOQ 0.50 μg/mL. We detected a mean coumarin content of 19.5 μg/kg in 9 out of 14 seasonal food products (ranging from 1.45 to 39.4 mg/kg). No coumarin was detected in five cinnamon containing products. With this investigation we demonstrate that the QuEChERS sample preparation, previously applied mainly to the analysis of pesticides in vegetables, is also suitable for other complex matrices.

  12. Generalidades sobre Rocas y Análisis Químicos de Suelos.

    Directory of Open Access Journals (Sweden)

    Orozco Aycardo

    1940-12-01

    Full Text Available Tomaré como base para estas anotaciones un análisis químico de suelo siguiendo el método de la fusión con carbonato de sodio, acentuando mis apuntes sobre los distintos métodos seguidos para la determinación de los elementos hierro, aluminio, calcio, magnesio, fósforo y potasio, partiendo de una solución clorhídrica. Al tratar Ia muestra con carbonato de sodio con una molécula, de agua o anhidro a la temperatura de la fusión se acusa una modificación de la molécula de silicatos complejos, haciéndolos pasar a la forma de silicatos alcalinos que es la operación que en química se conoce con los nombres de Disgragación o Desgregación. Los demás minerales presentes en la muestra se modifican. obteniéndolos así en forma de aluminatos y fosfatos. De esta manera se tienen silicatos, aluminatos y fosfatos de hierro, calcio, magnesio, manganeso, bario, etc., solubles en solución de ácido clorhídrico.

  13. ¿Qué pueden ofrecer los modelos basados en agentes vivos en el contexto docente?

    Directory of Open Access Journals (Sweden)

    Marta Ginovart Gisbert

    2015-07-01

    Full Text Available Los sistemas biológicos o sistemas formados por entidades vivas (individuos son sistemas complejos, tanto por la “complejidad” que cada individuo o agente vivo tiene, como por las posibles relaciones que se pueden establecer entre ellos, así como por las posibles relaciones con el entorno o medioambiente en el que estos individuos se desarrollan, viven, compiten y mueren, y que por tanto, modifican como resultado de sus acciones. Este trabajo se basa en la experiencia acumulada en los últimos años en el uso de modelos basados en agentes en el ámbito de los biosistemas en la Universidad Politècnica de Catalunya. El objetivo es ofrecer elementos de estudio y discusión para poder responder a las siguientes preguntas: 1 ¿Qué son los modelos basados en agentes vivos?, 2 ¿Cómo se puede trabajar con estos modelos computacionales en el aula?, y 3 ¿Qué pueden ofrecer estos modelos en un entorno educativo? Asimismo, se proporciona información y referencias específicas para facilitar la incorporación de este tipo de modelo en planes de estudios con diferentes niveles de instrucción matemática y biológica, como complemento a otras metodologías de modelización.

  14. Myocardial infarction in Québec rural and urban populations between 1995 and 1997.

    Science.gov (United States)

    Loslier, Julie; Vanasse, Alain; Niyonsenga, Théophile; Courteau, Josiane; Orzanco, Gabriela; Hemiari, Abbas

    2007-01-01

    There is abundant evidence of health inequities between urban and rural populations. The purpose of this paper is to describe the socioeconomic characteristics of Québec urban and rural populations and the relation between rurality and incidence of myocardial infarction (MI), care management and outcomes. Socioeconomic data by census subdivisions were available from the 1996 Canadian census, representing 7,137,245 individuals. Data on patients with MI were taken from the provincial administrative health database (MED-ECHO), which is managed by the Ministry of Health and contains clinical and demographic information collected when patients are released from acute care hospitals in Québec. We included a total of 37,678 cases compiled over the 3 years of follow-up in the analyses. Residents of rural areas with low urban influence have higher MI incidence rates than all of the other populations in the study. In comparison with urban populations, their observed rural counterparts are at a disadvantage with regard to education, employment and income. Although angioplasty and coronary artery bypass graft surgery rates were higher in more urban areas, the survival rate was lower than in rural areas. This study revealed geographic heterogeneity of MI incidence, revascularization rates and survival rates among urban and rural populations.

  15. Climatic changes and caribou abundance in northern Québec over the last century

    Directory of Open Access Journals (Sweden)

    Michel Crête

    1990-09-01

    Full Text Available The temperature increase observed in the Northern hemisphere during the first half of this century was also detectable in Québec; it affected both summer and winter. In northern Québec, warmer summers stimulated growth and favored range expansion of trees and shurbs. Based on black spruce krummholz height and water level in lakes, the warmer period was also characterized by greater snowfall and deeper snow cover. This period of deep snow coincided with apparent caribou scarcity. Three hypotheses were explored to relate increased temperature with caribou decline: 1 destruction of winter habitat due to high frequency of forest fires, 2 increased energy cost to obtain forage in deep snow and 3 delayed melting of snow on calving grounds that shortened the time to raise calves. The combined effect of the 3 mechanism could explain caribou scarcity, particularly for the Rivière George herd whose calving ground becomes snow free in late June. Ways to test the third hypothesis are proposed.

  16. ¿Qué «yo» es valioso para el mundo de hoy?

    Directory of Open Access Journals (Sweden)

    José Ángel LÓPEZ HERRERÍAS

    2010-07-01

    Full Text Available Las propuestas de renovación pedagógica están motivadas por la conciencia de vivir un mundo problemático. Es frecuente el interés social y académico referido a cómo actuar bien en un mundo multicultural, exigido de desarrollo sostenible, y en el que la experiencia de los derechos humanos impida el incremento del analfabetismo, el hambre, la pobreza y la injusticia, además de promover más acciones de dignidad y de libertad. Desde la Pedagogía, las respuestas se afanan en promover renovaciones metodológicas (educación popular, animación sociocultural, desarrollo comunitario, que puedan educarnos para ser capaces de superar esos retos. El problema central reside en clarificar qué sujeto, qué actor narrativo, ponemos en el escenario del teatro de la convivencia que realice las metodologías referidas, y que, sobre todo, alcance la «renovación ética» necesaria. El ser humano metamoderno: un yo más ético que cognitivo.

  17. Extraction of ochratoxin A in bread samples by the QuEChERS methodology.

    Science.gov (United States)

    Paíga, Paula; Morais, Simone; Oliva-Teles, Teresa; Correia, Manuela; Delerue-Matos, Cristina; Duarte, Sofia C; Pena, Angelina; Lino, Celeste Matos

    2012-12-15

    A QuEChERS method for the extraction of ochratoxin A (OTA) from bread samples was evaluated. A factorial design (2(3)) was used to find the optimal QuEChERS parameters (extraction time, extraction solvent volume and sample mass). Extracts were analysed by LC with fluorescence detection. The optimal extraction conditions were: 5 g of sample, 15 mL of acetonitrile and 3 min of agitation. The extraction procedure was validated by systematic recovery experiments at three levels. The recoveries obtained ranged from 94.8% (at 1.0 μg kg(-1)) to 96.6% (at 3.0 μg kg(-1)). The limit of quantification of the method was 0.05 μg kg(-1). The optimised procedure was applied to 20 samples of different bread types ("Carcaça", "Broa de Milho", and "Broa de Avintes") highly consumed in Portugal. None of the samples exceeded the established European legal limit of 3 μg kg(-1). Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. ¿De qué hablamos cuando hablamos de cuerpo desde las ciencias sociales?

    Directory of Open Access Journals (Sweden)

    Mariana del Mármol

    2011-06-01

    Full Text Available La antropología del cuerpo es un área de estudios relativamente reciente. Por este motivo quienes trabajamos dentro de este campo nos encontramos con diversas preguntas y cuestionamientos, provenientes tanto del exterior como del interior del campo. En el desarrollo de este artículo nos proponemos responder a dos de esas preguntas que consideramos centrales: ¿De qué hablamos cuando hablamos de cuerpo? y ¿Qué implicancias políticas tiene el estudio de lo corporal? Para ello reseñaremos los desarrollos teóricos y conceptuales de la antropología del cuerpo y los entrelazaremos con algunos planteos filosóficos que consideramos aportan elementos valiosos para pensar la complejidad de lo corporal en sus múltiples dimensiones. A lo largo de este recorrido, encontraremos diversas propuestas que desde momentos históricos y contextos teóricos diferentes se oponen, denuncian o critican la lógica binaria y jerarquizante que ha estructurado el pensamiento en occidente, poniendo en duda la fe en la razón, la centralidad de la palabra, la confianza en lo constante e inmutable y el menosprecio al cuerpo, para resaltar el valor de la percepción, la fuerza del movimiento, y el carácter ilusorio y ficcional de lo inmutable, dándole, de este modo, un lugar central a la corporalidad.

  19. Áreas metropolitanas:¿qué ha cambiado?: La experiencia de la Caracas Metropolitana

    Directory of Open Access Journals (Sweden)

    Sonia Barrios

    2001-05-01

    Full Text Available La nueva economía de la información y del conocimiento ha tenido tres decisivas implicaciones de orden territorial. Primero, ha acelerado el proceso de aglomeración urbana a escala planetaria. Segundo, ha provocado fuertes alteraciones en las redes urbanas de ámbito mundial, regional y nacional. Y tercero, ha impulsado la reestructuración interna de las áreas metropolitanas que se habían conformado durante la era industrial. Todo parece anticipar, por lo tanto, polarizaciones y fragmentaciones territoriales todavía más acentuadas que las conocidas en un pasado cercano. Tomando como referencia el caso de Caracas, se trata de averiguar en qué medida el desarrollo reciente de esta metrópoli sigue las grandes tendencias territoriales antes anotadas; y qué esfuerzos se están haciendo para ajustar sus instancias locales a las nuevas realidades urbanas. Como un recurso adicional, en distintos momentos se establecen comparaciones con Barcelona (España, considerada un ejemplo emblemático de las metrópolis de la era de la información

  20. Caracterização química do óleo essencial de Hypericum brasiliense Choisy

    Directory of Open Access Journals (Sweden)

    E.S. Carvalho

    Full Text Available Hypericum brasiliense Choisy, planta da família Guttiferae, ocorre principalmente nas regiões Sudeste e Sul do Brasil. Em trabalhos anteriores foram isolados e identificados nesta espécie, dentre outras classes de compostos, xantonas, floroglucinóis e flavonóides. Apesar da presença de óleos essenciais ser uma característica do gênero, ainda não há registros na literatura da composição química do óleo essencial desta espécie. Neste trabalho foi realizado o estudo químico da fração volátil de H. brasiliense visando identificar e quantificar as substâncias químicas presentes através da cromatografia em fase gasosa acoplada a espectrômetro de massas equipado com banco de dados.

  1. Calidad de abonos orgánicos empleados en la depresión de Quíbor-Venezuela bajo ambientes protegidos

    Directory of Open Access Journals (Sweden)

    Duilio Torres Rodríguez

    2017-01-01

    Full Text Available La depresión de Quíbor es una de las zonas agrícolas más importante de Venezuela, donde en los últimos años se han introducido sistemas de producción bajo ambientes protegidos, los cuales están acompañados por el uso de abonos orgánicos, no certi cados. El objetivo de esta investigación fue evaluar la calidad de los abonos orgánicos empleados en sistemas de producción bajo ambientes protegidos en la depresión de Quíbor, Venezuela. Se realizó un diseño experimental completamente al azar y se evaluaron once (11 abonos orgánicos (cuatro sólidos y siete líquidos por triplicados. Los abonos sólidos fueron colectados en la parte superior, inferior y media de las pilas, mientras que los líquidos fueron tomados directamente de los tanques de almacenamiento. Para la caracterización de los abonos se empleó el protocolo TMECC, la materia orgánica se determinó por calcinación a 450°C, el nitrógeno por Kjeldahl y los macronutrientes (potasio y calcio y micronutrientes (cobre, manganeso, hierro y zinc en extracto acuoso 1/20 (v/v del material y cuantificación por absorción atómica. Los resultados obtenidos muestran que el vermicompost y compost de gallinaza presentaron los valores más altos de macronutrientes, mientras, para los abonos líquidos Macro®, fue quien presentó la mayor concentración de nitrógeno, humus1 los valores más altos de Ca y Mg y Micro® y humus2 los mayores contenidos de manganeso, hierro, cobre y zinc fueron encontrados, todos los abonos sólidos presentaron valores bajos de micronutrientes.

  2. Juvenile Hippocampal CA2 Region Expresses Aggrecan

    Directory of Open Access Journals (Sweden)

    Asako Noguchi

    2017-05-01

    Full Text Available Perineuronal nets (PNNs are distributed primarily around inhibitory interneurons in the hippocampus, such as parvalbumin-positive interneurons. PNNs are also present around excitatory neurons in some brain regions and prevent plasticity in these neurons. A recent study demonstrated that PNNs also exist around mouse hippocampal pyramidal cells, which are the principle type of excitatory neurons, in the CA2 subregion and modulate the excitability and plasticity of these neurons. However, the development of PNNs in the CA2 region during postnatal maturation was not fully investigated. This study found that a main component of PNNs, aggrecan, existed in the pyramidal cell layer of the putative CA2 subarea prior to the appearance of the CA2 region, which was defined by the CA2 marker protein regulator of G protein signaling 14 (RGS14. We also found that aggrecan immunoreactivity was more evident in the anterior sections of the CA2 area than the posterior sections, which suggests that the function of CA2 PNNs varies along the anterior-posterior axis.

  3. PGC-1α accelerates cytosolic Ca2+ clearance without disturbing Ca2+ homeostasis in cardiac myocytes

    International Nuclear Information System (INIS)

    Chen, Min; Wang, Yanru; Qu, Aijuan

    2010-01-01

    Energy metabolism and Ca 2+ handling serve critical roles in cardiac physiology and pathophysiology. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) is a multi-functional coactivator that is involved in the regulation of cardiac mitochondrial functional capacity and cellular energy metabolism. However, the regulation of PGC-1α in cardiac Ca 2+ signaling has not been fully elucidated. To address this issue, we combined confocal line-scan imaging with off-line imaging processing to characterize calcium signaling in cultured adult rat ventricular myocytes expressing PGC-1α via adenoviral transduction. Our data shows that overexpressing PGC-1α improved myocyte contractility without increasing the amplitude of Ca 2+ transients, suggesting that myofilament sensitivity to Ca 2+ increased. Interestingly, the decay kinetics of global Ca 2+ transients and Ca 2+ waves accelerated in PGC-1α-expressing cells, but the decay rate of caffeine-elicited Ca 2+ transients showed no significant change. This suggests that sarcoplasmic reticulum (SR) Ca 2+ -ATPase (SERCA2a), but not Na + /Ca 2+ exchange (NCX) contribute to PGC-1α-induced cytosolic Ca 2+ clearance. Furthermore, PGC-1α induced the expression of SERCA2a in cultured cardiac myocytes. Importantly, overexpressing PGC-1α did not disturb cardiac Ca 2+ homeostasis, because SR Ca 2+ load and the propensity for Ca 2+ waves remained unchanged. These data suggest that PGC-1α can ameliorate cardiac Ca 2+ cycling and improve cardiac work output in response to physiological stress. Unraveling the PGC-1α-calcium handing pathway sheds new light on the role of PGC-1α in the therapy of cardiac diseases.

  4. La Química, la Ingeniería Química y su relación con otras disciplinas El papel de la Química en la restauración de monumentos

    Directory of Open Access Journals (Sweden)

    Manuel Sánchez Martínez

    2012-02-01

    Full Text Available Chemical Engineering as such has a little more than a hundred years of existence. During this time, his development has generated research, data and books which made innovations in the curriculum and new paradigms in education. The development of this discipline has influenced the creation or modification of others such as Environmental Engineering, Food Engineering, Electrochemical Engineering, Metallurgical Engineering, etc. The future presents new challenges and opportunities for development in the area of biofuels, nanotechnology and climate control.  La restauración de los monumentos es una disciplina imprescindible para la conservación de los elementos físicos que dan identidad, así como para guardar las evidencias de la historia. En estas tareas de la restauración se requiere la intervención de otras disciplinas. La Química tiene un papel importante dentro de la restauración para conocer con mayor objetividad la conformación de la materia física que constituye los monumentos; gracias a ella es posible conocer la composición mineralógica y elemental de los materiales, así como entender los mecanismos de deterioro que los degradan; asimismo, es un gran auxiliar para conocer el resultado de los tratamientos a los que son sometidos para alargar su vida útil. Para ello se utiliza una metodología científica que incluye el uso de técnicas tales como Difracción de Rayos X, Microscopía Electrónica de Barrido o Espectrografía de Fluorescencia de Rayos X entre otras.

  5. Alianza de marca. ¿Por qué, cómo y cuándo?

    OpenAIRE

    Longinos Marín; Alicia Rubio

    2010-01-01

    En los últimos años, las actividades de alianza de marca han tenido un creciente protagonismo en el lanzamiento de nuevos productos por parte de las empresas. No obstante, apenas hay trabajos que analicen de forma integral la justificación por parte de las empresas de esta estrategia. El presente trabajo analiza las teorías que justifican por qué y en qué escenarios deben utilizarse las alianzas de marca desde la perspectiva del comportamiento del consumidor. El artículo también profund...

  6. Qu'Appelle River Dam, dam break analysis using advanced GIS tools for rapid modelling and inundation mapping

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, D. [Hatch Energy, Winnipeg, MB (Canada); Campbell, C. [Saskatchewan Watershed Authority, Moose Jaw, SK (Canada); Groeneveld, J. [Hatch Energy, Calgary, AB (Canada)

    2008-07-01

    The South Saskatchewan River Project (SSRP) comprises a multi-purpose reservoir that provides water for conservation and irrigation, flood control, power generation, recreation, and municipal and industrial water supply. In addition to the 64 m high Gardiner Dam, the 27 m high Qu'Appelle River Dam and the 22 km long Lake Diefenbaker Reservoir, the SSRP also includes ancillary works. The Qu'Appelle River valley extends for 458 km before connecting to the Assiniboine River. The valley is incised up to 90 m in depth and is a popular cottaging and recreational area with several major communities located in the flood plain. In the event of a breach of the Qu'Appelle Dam, the discharge will increase from a normal maximum discharge of under 60 m{sup 3} per second to over 50,000 m{sup 3} per second. The Saskatchewan Watershed Authority (SWA) is responsible for ensuring safe development of the Province's water resources, without affecting reservoir or lake operations, and preventing damage from flooding, erosion or land slides. It is in the process of developing Hazard Assessments and emergency preparedness plans for each of their dams in accordance with the Canadian Dam Safety Guidelines. Studies using GIS technology and the hydrodynamic routing model HEC-RAS have been completed to evaluate the potential inundation that may result in the event of failure of the Qu'Appelle River Dam. These studies involved the development of a breach parameter model using a breach data set revised to better reflect the Qu'Appelle River Dam; the development of a dam break model for the Qu'Appelle River Dam and downstream river and flood plain; and, the use of this model to simulate two potential dam failure scenarios for the Qu'Appelle River Dam, notably failure during passage of the PMF and failure during fair weather conditions. Inundation maps have been prepared for the downstream Qu'Appelle River valley for each of the above events. 3 refs., 4

  7. Riesgo químico laboral: elementos para un diagnóstico en España

    OpenAIRE

    Alfonso A. Calera Rubio; José María Roel Valdés; Amparo Casal Lareo; Rafael Gadea Merino; Fernando Rodrigo Cencillo

    2005-01-01

    Fundamento: La falta de información junto a la ausencia de un conocimiento preciso de las propiedades intrínsecas de cada agente químico y de la exposición derivada de un uso concreto dificultan en gran medida la prevención de los trabajadores expuestos a los riesgos generados por la presencia de estos productos en los puestos de trabajo. El objetivo del presente estudio es identificar los elementos que permitan efectuar un diagnóstico de la situación del riesgo químico e...

  8. Algunos peligros químicos y nutricionales del consumo de los alimentos de venta en espacios públicos

    OpenAIRE

    Bejarano Roncancio, Jhon Jairo; Suárez Latorre, Lina María

    2015-01-01

    Los alimentos manufacturados y comercializados pueden contener peligros químicos por sustancias adicionadas intencionalmente como los aditivos que utiliza la industria, otros añadidos por el consumidor y contaminantes naturales como metales que se pueden obtener del aire en el espacio público; también se consideran peligrosos los cambios químicos que tienen algunos nutrientes como las grasas y los aceites (lípidos) y el uso excesivo de estas en la dieta. Algunos métodos de cocción empleados y...

  9. Algunas leyes fundamentales de la química y las magnitudes físicas relacionadas con el equivalente

    OpenAIRE

    Antonio M. Navarro López

    2010-01-01

    En este tema se tratan algunas leyes fundamentales de la química, tales como la Ley de la conservación de la materia, la Ley de las proporciones definidas o ley de los equivalentes, así como las magnitudes físicas relacionadas con el equivalente como son: La cantidad de sustancia en equivalente , masa molar del equivalente tanto de un elemento químico , de los ácidos, de las bases, de las sales ,todo expresado en el sistema Internacional de Unidades ....

  10. Características físico-químicas de amostras de mel de Melipona asilvai (Hymenoptera: Apidae)

    OpenAIRE

    Souza,Bruno de Almeida; Carvalho,Carlos Alfredo Lopes de; Sodré,Geni da Silva; Marchini,Luis Carlos

    2004-01-01

    Análises de amostras de mel da abelha Melipona asilvai provenientes dos municípios de Itaberaba e Tucano, região semi-árida do Estado da Bahia, foram realizadas com o objetivo de contribuir para o conhecimento das características físico-químicas desse produto. A maioria dos parâmetros físico-químicos apresentou valores adequados para o consumo humano, o que possibilita a exploração desse produto pelas comunidades rurais da região semi-árida da Bahia. Contudo, o teor de umidade elevado é um as...

  11. Características físico-químicas de amostras de mel de Melipona asilvai (Hymenoptera: Apidae)

    OpenAIRE

    Souza, Bruno de Almeida; Carvalho, Carlos Alfredo Lopes de; Sodré, Geni da Silva; Marchini, Luis Carlos

    2004-01-01

    p. 1623-1624 Análises de amostras de mel da abelha Melipona asilvai provenientes dos municípios de Itaberaba e Tucano, região semi-árida do Estado da Bahia, foram realizadas com o objetivo de contribuir para o conhecimento das características físico-químicas desse produto. A maioria dos parâmetros físico-químicos apresentou valores adequados para o consumo humano, o que possibilita a exploração desse produto pelas comunidades rurais da região semi-árida da Bahia. Contudo, o teor de u...

  12. La disciplina Química para la formación ambiental del ingeniero agrónomo

    OpenAIRE

    Triana-Hernández, Bartolo M

    2014-01-01

    El objetivo del trabajo es crear una propuesta didáctica para propiciar la formación ambiental en los estudiantes de la carrera de Ingeniería Agrónoma, desde la disciplina Química. La metodología utilizada fue la de casos simulados con enfoque ciencia, tecnología, sociedad y ambiente (CTSA). La propuesta se implementó durante tres cursos y sus resultados contribuyeron a que los estudiantes mostraran mayor satisfacción por el estudio de la Química. Se comprobó que utilizando esta propuesta se ...

  13. Evaluation of Serum CEA, CA19-9, CA72-4, CA125 and Ferritin as Diagnostic Markers and Factors of Clinical Parameters for Colorectal Cancer.

    Science.gov (United States)

    Gao, Yanfeng; Wang, Jinping; Zhou, Yue; Sheng, Sen; Qian, Steven Y; Huo, Xiongwei

    2018-02-09

    Blood-based protein biomarkers have recently shown as simpler diagnostic modalities for colorectal cancer, while their association with clinical pathological characteristics is largely unknown. In this study, we not only examined the sensitivity and reliability of single/multiple serum markers for diagnosis, but also assessed their connection with pathological parameters from a total of 279 colorectal cancer patients. Our study shown that glycoprotein carcinoembryonic antigen (CEA) owns the highest sensitivity among single marker in the order of CEA > cancer antigen 72-4 (CA72-4) > cancer antigen 19-9 9 (CA19-9) > ferritin > cancer antigen 125 (CA125), while the most sensitive combined-markers for two to five were: CEA + CA72-4; CEA + CA72-4 + CA125; CEA + CA19-9 + CA72-4 + CA125; and CEA + CA19-9 + CA72-4 + CA125 + ferritin, respectively. We also demonstrated that patients who had positive preoperative serum CEA, CA19-9, or CA72-4 were more likely with lymph node invasion, positive CA125 were prone to have vascular invasion, and positive CEA or CA125 were correlated with perineural invasion. In addition, positive CA19-9, CA72-4, or CA125 was associated with poorly differentiated tumor, while CEA, CA19-9, CA72-4, CA125 levels were positively correlated with pathological tumor-node-metastasis stages. We here conclude that combined serum markers can be used to not only diagnose colorectal cancer, but also appraise the tumor status for guiding treatment, evaluation of curative effect, and prognosis of patients.

  14. Regulated release of Ca2+ from respiring mitochondria by Ca2+/2H+ antiport.

    Science.gov (United States)

    Fiskum, G; Lehninger, A L

    1979-07-25

    Simultaneous measurements of oxygen consumption and transmembrane transport of Ca2+, H+, and phosphate show that the efflux of Ca2+ from respiring tightly coupled rat liver mitochondria takes place by an electroneutral Ca2+/2H+ antiport process that is ruthenium red-insensitive and that is regulated by the oxidation-reduction state of the mitochondrial pyridine nucleotides. When mitochondrial pyridine nucleotides are kept in a reduced steady state, the efflux of Ca2+ is inhibited; when they are in an oxidized state, Ca2+ efflux is activated. These processes were demonstrated by allowing phosphate-depleted mitochondria respiring on succinate in the presence of rotenone to take up Ca2+ from the medium. Upon subsequent addition of ruthenium red to block Ca2+ transport via the electrophoretic influx pathway, and acetoacetate, to bring mitochondrial pyridine nucleotides into the oxidized state, Ca2+ efflux and H+ influx ensued. The observed H+ influx/Ca2+ efflux ratio was close to the value 2.0 predicted for the operation of an electrically neutral Ca2+/2H+ antiport process.

  15. Reduced endogenous Ca2+ buffering speeds active zone Ca2+ signaling.

    Science.gov (United States)

    Delvendahl, Igor; Jablonski, Lukasz; Baade, Carolin; Matveev, Victor; Neher, Erwin; Hallermann, Stefan

    2015-06-09

    Fast synchronous neurotransmitter release at the presynaptic active zone is triggered by local Ca(2+) signals, which are confined in their spatiotemporal extent by endogenous Ca(2+) buffers. However, it remains elusive how rapid and reliable Ca(2+) signaling can be sustained during repetitive release. Here, we established quantitative two-photon Ca(2+) imaging in cerebellar mossy fiber boutons, which fire at exceptionally high rates. We show that endogenous fixed buffers have a surprisingly low Ca(2+)-binding ratio (∼ 15) and low affinity, whereas mobile buffers have high affinity. Experimentally constrained modeling revealed that the low endogenous buffering promotes fast clearance of Ca(2+) from the active zone during repetitive firing. Measuring Ca(2+) signals at different distances from active zones with ultra-high-resolution confirmed our model predictions. Our results lead to the concept that reduced Ca(2+) buffering enables fast active zone Ca(2+) signaling, suggesting that the strength of endogenous Ca(2+) buffering limits the rate of synchronous synaptic transmission.

  16. Extremely Elevated CA 125 and CA 19-9 in Endometrioma; A Case Series

    Directory of Open Access Journals (Sweden)

    Vugar Bayramov

    2010-03-01

    Full Text Available Although endometriosis is a benign condition, increased levels of the tumor markers CA 125 and CA 19-9 may be seen. However, these tumor markers reach to very high levels, rarely. In this report, 4 patients between 20 and 43 year-old with extremely elevated CA 125, CA 19-9 and CA 15-3 levels are discussed. In endometriosis extremely increased tumor markers are determined in the case of ruptured endometrioma cyst. There are two mechanisms to clarify extremely elevated levels of CA 125 in endometriosis. First, the peritoneal irritation of CA 125 molecule after the rupture of endometioma cyst and CA 125 secretion from the periton. And the second is penetration of the CA 125 moecule easily to the circulation through the peritoneal endothelial surface after the cyst rupture. In conclusion, the diagnosis of ruptured endometrioma cyst should be kept in mind especially in young patients with extremely elevated serum CA 125 levels with regard to the history and ultrasonographical signs and invasive procedures should be avoided.

  17. ¿Nuevos recursos o juegos de siempre? Del elemento a la reacción química a través de un modelo

    OpenAIRE

    Civantos, Laura; Costa, Rafel; Llobera, Rosa

    1987-01-01

    Utilización de los juegos de construcción como modelo para conseguir una mejor adquisición de conceptos básicos para el estudio de la química, como elemento, compuesto, substancia pura, mezcla y reacción química.

  18. EnviroAtlas - Fresno, CA - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Fresno, CA EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  19. Laboratório químico-prático do Rio de Janeiro: primeira tentativa de difusão da Química no Brasil (1812- 1819) "Laboratório químico-prático do Rio de Janeiro": the first attempt at establishing the science of Chemistry in Brazil (1812- 1819)

    OpenAIRE

    Nadja Paraense dos Santos

    2004-01-01

    Until the present date, historians of science have described inaccurately the first laboratory created in Brazil for establishing and divulging Chemistry, namely the "Laboratório Químico-Prático do Rio de Janeiro". During recent research carried out in the Arquivo do Museu Imperial (Petrópolis, RJ), I localized a document entitled "Ensaio histórico analítico das operações do Laboratório Químico-Prático do Rio de Janeiro", which allowed me to gain the relevant information to correct some of th...

  20. Ischemic damage in hippocampal CA1 is dependent on glutamate release and intact innervation from CA3

    DEFF Research Database (Denmark)

    Benveniste, H; Jørgensen, M B; Sandberg, M

    1989-01-01

    The removal of glutamatergic afferents to CA1 by destruction of the CA3 region is known to protect CA1 pyramidal cells against 10 min of transient global ischemia. To investigate further the pathogenetic significance of glutamate, we measured the release of glutamate in intact and CA3-lesioned CA...

  1. YouthCaN 2001 / Sirje Janikson

    Index Scriptorium Estoniae

    Janikson, Sirje

    2001-01-01

    Aprillis 2001 toimus keskkonnateemaline õpilaskonverents YouthCaN 2001 Ameerika Loodusajaloo Muuseumis New Yorkìs. 35 seminarist ühe viis läbi Tartu Noorte Loodusmaja geoloogia ja keskkonnaringi esindus, tutvustati loodusmaja keskkonnaprojekte ja räägiti keskkonnaalaste veebilehtede koostamise kogemustest. YouthCaN (Youth Communicating and Networking) on rahvusvaheline noorte organisatsioon, mis vahendab kogemusi ja uusi ideid elukeskkonnast huvitatud noorte hulgas

  2. BiCaSrCuO superconductors

    International Nuclear Information System (INIS)

    Polvi, V.M.; Niemi, K.J.

    1989-01-01

    BiCaSrCuO and BiPbCaSrCuO powders have been synthesized. Different research methods (SEM,EDS,XRF,SRD,DTA) have been used to characterize the bulk specimen and wires. Resistance and current density measured as a function of temperature are reported. The ceramic products contained several phases. Lead containing specimen gave the best results and the synthesis was easily reproducible

  3. Defesas químicas de plantas: fitoalexinas Chemical defense of plants: phytoalexins

    Directory of Open Access Journals (Sweden)

    Márcia Regina Braga

    1987-01-01

    Full Text Available A resistência de plantas ao ataque de microorganismos causadores de doenças relaciona-se à presença de barreiras físicas e (juímicas de defesa. Dentre as barreiras químicas destacam-se as fitoalexinas, substâncias fungitoxicas sintetizadas de novo pelas plantas principalmente após a invasão ou o contato de seus tecidos com microorganismos, Essas substâncias englobam vários grupos compostos naturais tais como terpenos, isoflavonóides e poliacetilenos e seu acúmulo pode ser induzido por organismos vivos, seus produtos (elíciadores ou ainda agentes químicos, como sais de metais pesados, ou físicos (congelamento, luz U.U.. Alguns aspectos abordados nesta revisão são: a ocorrência de fitoalexinas em angiospermas, a relação entre sua natureza química e o grupo taxonômico das plantas que as produzem, a sua ação sobre organismos pró e eucarióticos. São descritas também os fatores que interferem nas respostas das plantas aos agentes indutores e as técnicas usuais para a indução e detecção de fitoalexinas. O papel dos eliciadores na indução da sâitese de fitoalexinas e o mecanismo pelo qual exercem sua função indutora são discutidos. Nesse contexto está incluída a teoria das oligossacarinas, fragmentos de parede celular que parecem controlar não só a resposta de defesa em plantas mas também outros fenômenos fisiológicos em plantas.Chemical defense of plants: phytoalexins - This review describes the concept of phytoalexins as a chemical defense of plants against microorganisms as well as a response of plants to chemical or physical agents. The current information on phytoalexins is presented, regarding the following aspects: occurrence in angiosperms; relation-snips between chemical composition and taxonomy; toxicity; factors affecting plant response; techniques for induction and detection of phytoalexins; role of elicitors and mechanisms of action. The latter includes the oligosaccharins-fragments of cell

  4. Quantitative automated microscopy (QuAM elucidates growth factor specific signalling in pain sensitization

    Directory of Open Access Journals (Sweden)

    Levine Jon D

    2010-12-01

    Full Text Available Abstract Background Dorsal root ganglia (DRG-neurons are commonly characterized immunocytochemically. Cells are mostly grouped by the experimenter's eye as "marker-positive" and "marker-negative" according to their immunofluorescence intensity. Classification criteria remain largely undefined. Overcoming this shortfall, we established a quantitative automated microscopy (QuAM for a defined and multiparametric analysis of adherent heterogeneous primary neurons on a single cell base. The growth factors NGF, GDNF and EGF activate the MAP-kinase Erk1/2 via receptor tyrosine kinase signalling. NGF and GDNF are established factors in regeneration and sensitization of nociceptive neurons. If also the tissue regenerating growth factor, EGF, influences nociceptors is so far unknown. We asked, if EGF can act on nociceptors, and if QuAM can elucidate differences between NGF, GDNF and EGF induced Erk1/2 activation kinetics. Finally, we evaluated, if the investigation of one signalling component allows prediction of the behavioral response to a reagent not tested on nociceptors such as EGF. Results We established a software-based neuron identification, described quantitatively DRG-neuron heterogeneity and correlated measured sample sizes and corresponding assay sensitivity. Analysing more than 70,000 individual neurons we defined neuronal subgroups based on differential Erk1/2 activation status in sensory neurons. Baseline activity levels varied strongly already in untreated neurons. NGF and GDNF subgroup responsiveness correlated with their subgroup specificity on IB4(+- and IB4(--neurons, respectively. We confirmed expression of EGF-receptors in all sensory neurons. EGF treatment induced STAT3 translocation into the nucleus. Nevertheless, we could not detect any EGF induced Erk1/2 phosphorylation. Accordingly, intradermal injection of EGF resulted in a fundamentally different outcome than NGF/GDNF. EGF did not induce mechanical hyperalgesia, but blocked

  5. Study on the isospin equilibration phenomenon in nuclear reactions 40Ca + 40Ca , 40Ca + 46Ti , 40Ca + 48Ca , 48Ca + 48Ca at 25 MeV/nucleon by using the CHIMERA multidetector

    Science.gov (United States)

    Martorana, N. S.; Auditore, L.; Berceanu, I.; Cardella, G.; Chatterjee, M. B.; De Luca, S.; De Filippo, E.; Dell'Aquila, D.; Gnoffo, B.; Lanzalone, G.; Lombardo, I.; Maiolino, C.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Pirrone, S.; Politi, G.; Porto, F.; Quattrocchi, L.; Rizzo, F.; Russotto, P.; Trifirò, A.; Trimarchi, M.; Verde, G.; Vigilante, M.

    2017-11-01

    We report on the results obtained by studying nuclear reactions between isotopes of Ca and Ti at 25 MeV/nucleon. We used the multidetector CHIMERA to detect charged reaction products. In particular, we studied two main effects: the isospin diffusion and the isospin drift. In order to study these processes we performed a moving-source analysis on kinetic energy spectra of the isobar nuclei ^{3H} and ^{3He} . This method allows to isolate the emission from the typical sources produced in reactions at Fermi energy: projectile like fragment (PLF), target like fragment (TLF), and mid-velocity (MV) emission. The obtained results are compared to previous experimental investigations and to simulations obtained with CoMD-II model.

  6. Qué identidad y qué escuela para promover la Carta de los Derechos Fundamentales de la Unión Europea

    Directory of Open Access Journals (Sweden)

    José Ángel LÓPEZ HERRERÍAS

    2009-11-01

    Full Text Available RESUMEN: Nuestra problemática sociocultural ha ido cristalizando la realidad sociopolítica de la Unión Europea, tras décadas de propuestas y hechos, que aparece así como un empeño por alcanzar un horizonte de paz y de próspera relación entre pueblos de fondo histórico común.Una de las últimas aportaciones de la Unión es la Carta de los Derechos Fundamentales, que se integran en la Constitución Europea. Estos derechos son el núcleo de los valores que se proponen como escenario vital capaz del logro de esos fines de prosperidad, paz y democracia. Mas esos valores/derechos no aparecerán psicoculturalmente porque sí. Requieren las correspondientes actitudes, ideas y prácticas, que sean coherentes para ser y actuar según esos derechos. Esos procesos concomitantes entiendo que son dos: i clarificar qué tipo de identidad animará esos valores/derechos y ii qué propuesta educativa será capaz del logro de los derechos.ABSTRACT: Our socio-culture has reached the experience of the European Union, after decades of proposals and facts. The Union thus appears as an effort to achieve a horizon of peace and prosperous relations among peoples with a common history.One of the latest contributions of the European Union is the Bill of Rights, which forms part of the future Constitution. These rights are the core of the values that are proposed as a scenario capable of achieving these aims of prosperity and democracy. But these values will not appear psycho-culturally by chance. They require the appropriate attitudes and practices, consistent with acting according to these rights. These concomitant processes are two: i to clarify what type of the identity will animate those values and ii what education will be competent for the achievement of the rights.SOMMAIRE: Après des décades de diverses propositions et faits, notre problématique socioculturelle concrétise la réalité sociopolitique de l'Union Européenne. Elle apparaît ainsi comme un

  7. Mens sana in corpore sano, pero ¿por qué?

    Directory of Open Access Journals (Sweden)

    Daniel Sanabria

    2015-09-01

    Full Text Available Practicar ejercicio físico de forma regular está de moda. Una de las razones, con la que seguramente estarían de acuerdo muchos lectores, es que practicar ejercicio físico se relaciona con un buen funciomiento cognitivo. Si bien el resultado de la investigación en los últimos años parece apoyar esta idea, todavía no está claro qué factores relacionados con la práctica regular del ejercicio físico son la causa de los beneficios observados a nivel cognitivo. En este artículo hacemos un breve repaso por las hipótesis más relevantes.

  8. Deshidratación de banano y cambio químicos ocurridos durante el proceso

    Directory of Open Access Journals (Sweden)

    C. Reyes de

    2009-07-01

    Full Text Available Como el banano es una fruta muy alterable, es necesario transformarlaa estados más estables para prolongar su conservación.Uno de los procesos más sencillos y fáciles de realizar es la deshidratación; en nuestro país ya se efectúa pero necesita una tecnificación y un estudio químico a fondo sobre los cambios ocurridosa los diferentes constituyentes de la pulpa de banano.En este trabajo se buscaron las condiciones óptimas en lascuales podría realizarse la deshidratación del banano, para que lapérdida de nutrientes fuera mínima, y se evaluaron los cambiosquímicos ocurridos durante dicho proceso.

  9. Mundo plural: ¿por qué los individuos hacen lo que hacen?

    OpenAIRE

    Lahire, Bernard

    2017-01-01

    En un contexto de hiper-especialización, el artículo se pregunta por una visión panorámica de la sociedad y una concepción compleja de los individuos, que no olvide a la vez la ambición teórica y el pulso empírico. Con este objetivo, se pregunta: “¿por qué los individuos hacen lo que hacen?” y propone responder con una fórmula de estudio de las prácticas de carácter universal que combina una dimensión disposicionalista con una contextualista. De un lado, las disposiciones y competencias de lo...

  10. Determination of tocopherols and sitosterols in seeds and nuts by QuEChERS-liquid chromatography.

    Science.gov (United States)

    Delgado-Zamarreño, M Milagros; Fernández-Prieto, Cristina; Bustamante-Rangel, Myriam; Pérez-Martín, Lara

    2016-02-01

    In the present work a simple, reliable and affordable sample treatment method for the simultaneous analysis of tocopherols and free phytosterols in nuts was developed. Analyte extraction was carried out using the QuEChERS methodology and analyte separation and detection were accomplished using HPLC-DAD. The use of this methodology for the extraction of natural occurring substances provides advantages such as speed, simplicity and ease of use. The parameters evaluated for the validation of the method developed included the linearity of the calibration plots, the detection and quantification limits, repeatability, reproducibility and recovery. The proposed method was successfully applied to the analysis of tocopherols and free phytosterols in samples of almonds, cashew nuts, hazelnuts, peanuts, tiger nuts, sun flower seeds and pistachios. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. ¿Por qué el hombre controla el comportamiento sexual de la mujer?

    Directory of Open Access Journals (Sweden)

    Vanegas Blanca Cecilia

    1999-12-01

    Full Text Available

    El derrocamiento del derecho materno fue la gran derrota histórica del sexo femenino en todo el mundo. El hombre empezó a tomar las riendas en la casa, y la mujer pasó a ser sometida, servidora, esclava de la lujuria del hombre y considerada como un instrumento de reproducción. Esto explica por qué, en las postrimerías del siglo XX, María obedece y acepta que Roberto dé órdenes sobre su cuerpo y su sexualidad. Sin embargo, lo que se pretende no es volver al matriarcado, sino buscar la convivencia entre hombres y mujeres con unas relaciones justas, equitativas y democráticas.

  12. Secuencia didáctica en química verde

    OpenAIRE

    Cortés Rodríguez, Adriana Janneth

    2017-01-01

    Esta propuesta presenta los resultados del diseño e implementación de una secuencia didáctica cuya finalidad es adaptar los principios de la Química Verde (QV) en el ámbito escolar, a través de actividades específicas que se enmarcan dentro del diseño del Protocolo Verde o Practica Amigable para el Medio Ambiente. La metodología de investigación – acción desarrollada permitió la reflexión de los estudiantes sobre los principios de la QV en relación con la identificación del cambio de color, e...

  13. The Relevance of the Carnivalesque in the Québec Novel

    Directory of Open Access Journals (Sweden)

    Maroussia Ahmed

    1984-09-01

    Full Text Available The Bakhtinian concept of space is topological rather than topographic, and encompasses the cosmic, the social and the corporeal; its function in the Québec novel consists in debasing the hierarchical verticality of Lent and of the "official feast." As Carnival is an anti-law,"law" in the Québec novel will be defined as the chronotope of the sacred space (the land or "terre" of Québec in the genre known as the "novel of the land" ("le roman de Ia terre". Until the Second World War, this chronotope transforms an Augustinian political view of the civitas dei into literary proselytism, via the ideology of agricultural messianism. Sanctification implies closure of space and of the text; the "outside" is debased, as is textual "difference," that is, carnivalesque writing as it appears, for example, in La Scouine by Albert Laberge or in Marie Calumet by Rodolphe Girard. During the 1940s, the "introspective novel" (Robert Charbonneau, Robert Elie, Robert Choquette also connotes the "upper" euphorically and the "lower" dysphorically, but at this historical point as a function of the sanctification of the individual according to a Thomist hierarchy. The quest of the hero can be seen as the ascent of a vertical ladder of time/space/society/values. The novel of the 1960s takes on a carnivalesque air: former sacred spaces are diminished in number and importance or are debased; new spaces appear where the body communicates with other bodies and the world. The space of knowledge is not God, but the land. Novels of this period (by M.C. Blais, R. Carrier, A. Hébert are constructed around two paradigms according to a Manichean view of the world, and bear a great predictability, thus leading to a new set of "upside down" cliches. The carnivalesque multiple is completely realized in Hubert Aquin's first two novels. Space ceases to bear meaning other than as a metaphor for horizontal kinetic writing. The text becomes the open space of a continuous game between

  14. Job Quality and Gender Inequality: Key Changes in Québec over the Last Decade

    Directory of Open Access Journals (Sweden)

    Luc Cloutier

    2010-01-01

    Full Text Available Using a new typology based on information available from the Labour Force Survey, the authors analyse how job quality evolved in Québec for both women and men over the last decade (1997-2007. Results show that family situation and educational attainment are two important factors in the determination of gender inequality in the labour market. The analysis emphasizes the very significant decline in gender differences with regard to job quality (from 23% to 35% according to groups, especially for persons without children and individuals who achieved higher education. The changes represent a definite progress in the status of women in general, although some indicators also reveal degradation with respect to job quality in some of the sub-groups.  

  15. Job Quality and Gender Inequality: Key Changes in Québec over the Last Decade

    Directory of Open Access Journals (Sweden)

    Diane-Gabrielle Tremblay

    2009-12-01

    Full Text Available Using a new typology based on information available from the Labour Force Survey, the authors analyse how job quality evolved in Québec for both women and men over the last decade (1997-2007. Results show that family situation and educational attainment are two important factors in the determination of gender inequality in the labour market. The analysis emphasizes the very significant decline in gender differences with regard to job quality (from 23% to 35% according to groups, especially for persons without children and individuals who achieved higher education. The changes represent a definite progress in the status of women in general, although some indicators also reveal degradation with respect to job quality in some of the sub-groups.  

  16. Constituintes químicos voláteis de especiarias ricas em eugenol

    Directory of Open Access Journals (Sweden)

    Rosilene Aparecida de Oliveira

    Full Text Available Utilizando a técnica de hidrodestilação, usando um adaptador Clevenger, foram extraídos óleos essenciais das espécies Pimenta dioica (folhas e frutos e Syzygium aromaticum (botões florais, talos e folhas. A composição química dos óleos foi determinada através da analise CG-EM. Os teores de óleos essenciais variaram de 0,97 a 1,41% e 2,30 a 15,40% nas espécies Pimenta dioica e Syzygium aromaticum, respectivamente. O componente majoritário presente nessas espécies foi o eugenol, variando de 72,87 a 90,41%. Syzygium aromaticum forneceu maior teor de óleo essencial rico em eugenol. Em quantidades menores foram também encontrados chavicol e? β-cariofileno.

  17. Aprendiendo química con el tratamiento culinario de frutas, hortalizas y verduras

    Directory of Open Access Journals (Sweden)

    Sánchez Guadix, Mª.A.

    2007-09-01

    Full Text Available La necesidad de acercar la ciencia a la realidad cotidiana del alumnado obliga a buscar nuevos recursos que tradicionalmente no eran tratados en la enseñanza formal: la química presente en la cocina y desarrollada a través de los trucos que han funcionadoen los tratamientos culinarios. En el presente artículo encontramos una reflexión acerca de la urgencia alfabetizar científicamente y de introducir saberes considerados femeninos en las aulas, una estrategia de búsqueda de recursos: la interpretacióncientífica y las aplicaciones didácticas de distintos trucos de cocina relacionados con frutas, hortalizas y verduras, y por último, algunas sugerencias para llevar a cabo distintas actividades en el aula de secundaria.

  18. Propiedades químicas de tés de vermicompost

    OpenAIRE

    González Solano, Karla Daniela; Rodríguez Mendoza, Ma. De Las Nieves; Trejo Téllez, Libia Iris; Sánchez Escudero, Julio; García Cué, José Luis

    2013-01-01

    La investigación tuvo como objetivo relacionar algunas características químicas de los tés con el origen de vermicompost usado en la extracción, la relación agua:vermicompost y el tiempo de incubación. Como parámetros de evaluación se consideró la conductividad eléctrica (CE), el pH y la concentración nutrimental. El tipo u origen del vermicompost tuvo efecto significativo sobre pH, CE y la concentración de nutrientes; los tés extraídos del vermicompost de pasto y estiércoles de borrego y bov...

  19. Síndrome de Sensibilidad Múltiple a sustancias químicas: un problema ambiental emergente

    Directory of Open Access Journals (Sweden)

    E. Ordaz Castillo

    2001-11-01

    Full Text Available El Síndrome de Sensibilidad Múltiple (SSM es un conjunto de múltiples síntomas asociados producidos tras la exposición a agentes químicos a muy bajas concentraciones.Se han propuesto diferentes teorías para explicar sus causas, incluyendo alergia, efectos tóxicos y sensibilización neurobiológica. La evidencia científica es insuficiente para confirmar la relación entre las posibles causas y los síntomas. Los pacientes con SSM presentan depresión, ansiedad y trastornos somatoformes, pero no está clara la relación existente entre este síndrome y los problemas psiquiátricos.El objetivo de esta revisión es presentar de forma resumida el estado actual del conocimiento del tema.

  20. Introducció matemàtica a la computació quàntica

    OpenAIRE

    Rué Perna, Juanjo; Xambó Descamps, Sebastián

    2013-01-01

    El propòsit d'aquest article és exposar les nocions essencials de la computació quàntica en termes purament matemàtics. En particular, definim les nocions de q-computació, q-mesura, q-procediment, q-computador i q-algorisme, i cadascuna s'il.lustra amb diversos exemples. A més d'alguns q-algorismes de baix nivell, discutim en detall una bona mostra dels més rellevants que s'han descobert. Aquests inclouen un q-algorisme per a la transformada de Fourier discreta i els q-algorismes de Deutsc...

  1. Ca(2+-dependent regulation of the Ca(2+ concentration in the myometrium mitochondria. II. Ca(2+ effects on mitochondria membranes polarization and [Ca(2+](m

    Directory of Open Access Journals (Sweden)

    L. G. Babich

    2017-06-01

    Full Text Available It is known that Ca2+ accumulation in the mitochondria undergoes complex regulation by Ca2+ itself. But the mechanisms of such regulation are still discussed. In this paper we have shown that Ca ions directly or indirectly regulate the level of myometrium mitochondria membranes polarization. The additions of 100 µM Ca2+ were accompanied by depolarization of the mitochondria membranes. The following experiments were designed to study the impact of Ca2+ on the myometrium mitochondria [Ca2+]m. Isolated myometrium mitochondria were preincubated without or with 10 μM Са2+ followed by 100 μM Са2+ addition. Experiments were conducted in three mediums: without ATP and Mg2+ (0-medium, in the presence of 3 mM Mg2+ (Mg-medium and 3 mM Mg2+ + 3 mM ATP (Mg,ATP-medium. It was shown that the effects of 10 μM Са2+ addition were different in different mediums, namely in 0- and Mg-medium the [Ca2+]m values increased, whereas in Mg,ATP-medium statistically reliable changes were not registered. Preincubation of mitochondria with 10 μM Са2+ did not affect the [Ca2+]m value after the addition of 100 μM Са2+. The [Ca2+]m values after 100 μM Са2+ addition were the same in 0- and Mg,ATP-mediums and somewhat lower in Mg-medium. Preliminary incubation of mitochondria with 10 μM Са2+ in 0- and Mg-mediums reduced changes of Fluo 4 normalized fluorescence values that were induced by 100 μM Са2+ additions, but in Mg,ATP-medium such differences were not recorded. It is concluded that Са2+ exchange in myometrium mitochondria is regulated by the concentration of Ca ions as in the external medium, so in the matrix of mitochondria. The medium composition had a significant impact on the [Са2+]m values in the absence of exogenous cation. It is suggested that light increase of [Са2+]m before the addition of 100 μM Са2+ may have a positive effect on the functional activity of the mitochondria.

  2. Making "Good" or "Critical" Citizens: From Social Justice to Financial Literacy in the Québec Education Program

    Science.gov (United States)

    Lefrançois, David; Ethier, Marc-André; Cambron-Prémont, Amélie

    2017-01-01

    Purpose: The Québec Ministry of Education has introduced--as of September 2017--a new mandatory course focusing on financial literacy and addressing such issues as credit scores, loans, taxes and budgets. This announcement has created intense educational debate on the "raison d'être" and content of the course. This article will summarise…

  3. Qu'est-ce qui détermine l'accès aux TIC aux Philippines ? | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    8 févr. 2011 ... Le guide dépasse cependant l'anecdote et les conseils pour traiter de la question ... par la population à ces instruments et ses capacités à les utiliser ». .... sont les possibilités qu'elles servent d'outils pour le développement.

  4. Development and application of the RE-AIM QuEST mixed methods framework for program evaluation

    Directory of Open Access Journals (Sweden)

    Jane Forman

    2017-06-01

    The RE-AIM QuEST framework may be a useful tool for improving interventions in real-time, for understanding retrospectively why an intervention did or did not work, and for enhancing its sustainability and translation to other settings.

  5. Influence of ER leak on resting cytoplasmic Ca2+ and receptor-mediated Ca2+ signalling in human macrophage.

    Science.gov (United States)

    Layhadi, Janice A; Fountain, Samuel J

    2017-06-03

    Mechanisms controlling endoplasmic reticulum (ER) Ca 2+ homeostasis are important regulators of resting cytoplasmic Ca 2+ concentration ([Ca 2+ ] cyto ) and receptor-mediated Ca 2+ signalling. Here we investigate channels responsible for ER Ca 2+ leak in THP-1 macrophage and human primary macrophage. In the absence of extracellular Ca 2+ we employ ionomycin action at the plasma membrane to stimulate ER Ca 2+ leak. Under these conditions ionomycin elevates [Ca 2+ ] cyto revealing a Ca 2+ leak response which is abolished by thapsigargin. IP 3 receptors (Xestospongin C, 2-APB), ryanodine receptors (dantrolene), and translocon (anisomycin) inhibition facilitated ER Ca 2+ leak in model macrophage, with translocon inhibition also reducing resting [Ca 2+ ] cyto . In primary macrophage, translocon inhibition blocks Ca 2+ leak but does not influence resting [Ca 2+ ] cyto . We identify a role for translocon-mediated ER Ca 2+ leak in receptor-mediated Ca 2+ signalling in both model and primary human macrophage, whereby the Ca 2+ response to ADP (P2Y receptor agonist) is augmented following anisomycin treatment. In conclusion, we demonstrate a role of ER Ca 2+ leak via the translocon in controlling resting cytoplasmic Ca 2+ in model macrophage and receptor-mediated Ca 2+ signalling in model macrophage and primary macrophage. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Determinantes Socieconómicos en la Lucha contra la Malaria en Honduras: ¿Qué Sabemos? ¿Qué Funciona?

    Directory of Open Access Journals (Sweden)

    María Victoria Avilés

    2006-01-01

    Full Text Available Existe un escaso conocimiento a escala mundial de los determinantes socioeconómicos de la malaria, una tragedia que ha trascendido los límites sanitarios para convertirse en un obstáculo al desarrollo. La evaluación de intervenciones públicas concretas provee importante información pero es insuficiente para lograr un conocimiento extensivo de qué factores socioeconómicos (a nivel del hogar y de la comunidad están más asociados con los diferenciales de incidencia de la malaria; con diferentes prácticas preventivas y curativas; y con el conocimiento de tratamientos e intervenciones públicas eficaces. Este estudio provee ese tipo de conocimiento para Honduras, un país con altos niveles de pobreza y malaria. Para ello, se diseñó y levantó en Agosto del 2004 una encuesta piloto en 29 comunidades localizadas en nueve municipios a lo largo del país. Se encontraron marcadas diferencias socioeconómicas entre los individuos afectados por la malaria, aunque estas diferencias estaban más relacionadas con la localización, género e infraestructura social que con sus niveles de ingreso. La incidencia de la malaria también resultó ser sensible a políticas efectivas, entre otras cosas, porque la población en su conjunto conoce los tratamientos y cuando los comienza, típicamente los completa. Es pues necesario enfatizar la eficiencia más que la cobertura de estas intervenciones. También hay un amplio espacio para mejorar los hábitos higiénicos y la institucionalización de prácticas médicas en áreas de alta incidencia.

  7. Determinantes Socieconómicos en la Lucha contra la Malaria en Honduras: ¿Qué Sabemos? ¿Qué Funciona?

    Directory of Open Access Journals (Sweden)

    Avilés, María Victoria

    2006-07-01

    Full Text Available Existe un escaso conocimiento a escala mundial de los determinantes socioeconómicos de la malaria, una tragedia que ha trascendido los límites sanitarios para convertirse en un obstáculo al desarrollo. La evaluación de intervenciones públicas concretas provee importante información pero es insuficiente para lograr un conocimiento extensivo de qué factores socioeconómicos (a nivel del hogar y de la comunidad están más asociados con los diferenciales de incidencia de la malaria; con diferentes prácticas preventivas y curativas; y con el conocimiento de tratamientos e intervenciones públicas eficaces. Este estudio provee ese tipo de conocimiento para Honduras, un país con altos niveles de pobreza y malaria. Para ello, se diseñó y levantó en Agosto del 2004 una encuesta piloto en 29 comunidades localizadas en nueve municipios a lo largo del país. Se encontraron marcadas diferencias socioeconómicas entre los individuos afectados por la malaria, aunque estas diferencias estaban más relacionadas con la localización, género e infraestructura social que con sus niveles de ingreso. La incidencia de la malaria también resultó ser sensible a políticas efectivas, entre otras cosas, porque la población en su conjunto conoce los tratamientos y cuando los comienza, típicamente los completa. Es pues necesario enfatizar la eficiencia más que la cobertura de estas intervenciones. También hay un amplio espacio para mejorar los hábitos higiénicos y la institucionalización de prácticas médicas en áreas de alta incidencia.

  8. Soporte alimentario y nutricional en niños con fibrosis quística

    Directory of Open Access Journals (Sweden)

    Aida Esplugas Montoya

    2011-03-01

    Full Text Available INTRODUCCIÓN. La fibrosis quística es una enfermedad que se manifiesta en las vías respiratorias, el páncreas y el tracto intestinal. El control nutricional es un aspecto decisivo en el tratamiento de la enfermedad. El objetivo del estudio fue caracterizar un grupo de pacientes que se encontraban en fases de soporte y rehabilitación nutricional. MÉTODOS. Se realizó un estudio prospectivo con 7 pacientes menores de 18 años, que ingresaron para su tratamiento en la unidad especializada en fibrosis quística del Hospital Pediátrico Universitario «William Soler» (La Habana. Se realizaron mediciones antropométricas al ingreso y al egreso, y se clasificó a los niños en desnutrido, de bajo peso y de peso normal. Los valores fueron comparados con las tablas de crecimiento y desarrollo de la población cubana. RESULTADOS. A 3 pacientes se les aplicó una intervención de soporte nutricional y 4 pacientes fueron tratados además con nutrición enteral suplementaria. En la evaluación nutricional se encontró que la distribución porcentual calórica que aportaron los alimentos fue de un 12 % para las proteínas, 37 % para las grasas y 51 % para los carbohidratos. La energía que aportaron los alimentos consumidos ascendió a 4 360 kcal, 134,27 g de proteínas, 177,51 g de grasas y 558,20 g de carbohidratos. CONCLUSIONES. Al aumentar la densidad calórica de los alimentos y aplicar nutrición enteral a los pacientes se obtuvo un incremento de la ganancia ponderal y mejoró el estado nutricional.

  9. ¿Qué es una revista científica?

    Directory of Open Access Journals (Sweden)

    Rafael Capurro

    2015-11-01

    Full Text Available El artículo busca responder la pregunta ¿qué es una revista científica? Para ello, comienza analizando algunos momentos históricos en su desarrollo. Por ejemplo, el surgimiento de las revistas Le Journal des sçavans, primera revista considerada científica, Nouvelles de la république des lettres, la primera revista con periodicidad mensual y Philosophical Transactions of the Royal Society of London, revista orientada hacia las ciencias experimentales. En la segunda parte, se expone la crisis informacional ocurrida al fin de la Modernidad, que tiene como uno de sus resultados la pregunta antes planteada. En la tercera parte, se intentará responder ¿qué es una revista científica en la era digital? Se puede considerar la creación de Internet y, en forma más general, el impacto de la tecnología digital en todos los ámbitos de la vida como índice de una nueva era. Si la imprenta y con ella el libro y la revista son hijos de la Modernidad, Internet y la circulación global de datos digitales son hijos de lo que podemos llamar era digital.  El artículo culmina con un estudio sobre el título de la revista Informatio, identificando su etimología, estableciendo su conexión con el término información y mencionando el ámbito de investigación abierto de la revista del Instituto de Información de la Facultad de Información y Comunicación de la Universidad de la República.

  10. Travel agents and the prevention of health problems among travelers in Québec.

    Science.gov (United States)

    Provost, Sylvie; Gaulin, Colette; Piquet-Gauthier, Blandine; Emmanuelli, Julien; Venne, Sylvie; Dion, Réjean; Grenier, Jean-Luc; Dessau, Jean-Claude; Dubuc, Martine

    2002-01-01

    Among the factors influencing travelers to seek preventive health advice before departure, the travel agent's recommendation plays an important role. The objective of our study was to document the practices and needs of travel agents in Québec (Canada) in relation to the prevention of health problems among travelers. In June 2000, a cross-sectional descriptive survey was carried out among travel agents from all travel agencies in Québec. One agent per agency was asked to answer our questions. Data were collected using a 32-item telephone questionnaire. Altogether, 708 travel agents from the 948 agencies contacted answered our questionnaire (participation rate: 75%). Most respondents (81%) believed that the travel agent has a role to play in the prevention of health problems among travelers, especially to recommend that travelers consult a travel clinic before departure. Although over 80% of the agents interviewed mentioned recommending a visit to a travel clinic before an organized tour to Thailand or a backpacking trip in Mexico, less than half said they make the same recommendation for a stay in a seaside resort in Mexico. The majority of respondents were acquainted with the services offered in travel health clinics, and these clinics were the source of travel health information most often mentioned by travel agents. However, nearly 60% of the agents questioned had never personally consulted a travel clinic. When asked about the best way to receive information about travelers' health, more than 40% of respondents favoured receiving information newsletters from public health departments regularly whereas 28% preferred the Internet. Despite the limits of this study, our results should help the public health network better target its interventions aimed to inform travel agents on prevention of health problems among travelers.

  11. Metodología para estudios de estabilidad química en formulaciones de quitina

    Directory of Open Access Journals (Sweden)

    Yania Suárez Pérez

    2000-04-01

    Full Text Available Se propuso combinar la gravimetría directa como método cuantitativo con la espectroscopia infrarroja como técnica cualitativa complementaria, con el objetivo de establecer la metodología para el seguimiento de la estabilidad química de la quitina como fármaco en diferentes formas farmacéuticas: suspensión, crema, supositorio. La determinación del contenido de quitina por técnicas gravimétricas se validó en cada caso según los parámetros: linealidad, precisión, exactitud y especificidad. El análisis cuantitativo mostró resultados satisfactorios con respecto al contenido de fármaco en el tiempo en todas las formulaciones evaluadas. Estos resultados fueron corroborados por los espectros infrarrojos, manifestándose que la quitina es el único producto retenido en los filtros y que desde el punto de vista químico no ha sufrido alteraciones transcurridos 2 a de estudio.We proposed to combine direct gravimetry as a quantitative method with infrared spectrophotometry as a supplementary qualitative technique so as to establish a methodology for monitoring chemical stability of chitin as a drug in various pharmaceutical forms: suspension, cream and suppository. The determination of chitin by gravimetric techniques was valiadated in every case according to linearity, precision, accuracy and specificity parameters. The qualitative analyses showed satisfactory results in the drug contents in time in all the evaluated formulations. These outcomes were corroborrated by infrared spectra, which showed that chitin is the only product left in filters and that it has not changed from the clinical viewpoint after two year of study.

  12. Efeito de diferentes tratamentos químicos em cama para aves de corte

    Directory of Open Access Journals (Sweden)

    Walter Lucca

    2012-04-01

    Full Text Available O objetivo do experimento foi avaliar diferentes tratamentos químicos em cama aviária para frango de corte. Foram 2 utilizadas 500 aves, em delineamento inteiramente casualizado, com cinco tratamentos: Hidróxido de cálcio (500g/m ; Sulfato de Alumínio (500g/m ; Sulfato de cálcio (1000g/m ; Sulfato de cálcio 48% + Filosilicato Expandido 28% (500g/m e testemunha com quatro repetições. As amostras de cama aviária foram coletadas a cada sete dias para determinação do pH, umidade e contagem bacteriana nos meios de cultura Ágar MacConkey, Plate Count Agar (PCA. O peso das aves não se diferenciaram estatisticamente aos 42 dias, porém se observou significância na mortalidade e a conversão alimentar, entretanto em relação ao pH da cama o ideal seria após o término da segunda semana fazer nova aplicação dos produtos químicos. Todos os tratamentos foram eficazes quanto à umidade. Na contagem bacteriana com o meio PCA para mesófilas totais houve redução do desenvolvimento bacteriano, porém com o meio Ágar MacConkey para Enterobactérias totais somente o tratamento a base de Sulfato de cálcio (48% + Filosilicato expandido (28% se mostrou significativo (P < 0,05. Para a análise estatística utilizou-se sistema SISVAR (Sistema de Analise Estatístico e Planejamento de Sistemas, 2006.

  13. Prognostic significance of preoperative serum CA125, CA19-9 and CEA in gastric carcinoma

    Science.gov (United States)

    Wang, Wei; Chen, Xiao-Long; Zhao, Shen-Yu; Xu, Yu-Hui; Zhang, Wei-Han; Liu, Kai; Chen, Xin-Zu; Yang, Kun; Zhang, Bo; Chen, Zhi-Xin; Chen, Jia-Ping; Zhou, Zong-Guang; Hu, Jian-Kun

    2016-01-01

    The prognostic significance of preoperative serum CA125, CA19-9 and CEA in gastric carcinoma (GC) has been widely reported and is still under debate. Here, we evaluated the prognostic significance of preoperative serum CA125, CA19-9 and CEA in patients with GC. 1692 patients with GC who underwent gastrectomy were divided into the training (from January 2005 to December 2011, n = 1024) and the validation (from January 2012 to December 2013, n = 668) cohorts. Positive groups of CA125 (> 13.72 U/ml), CA19-9 (> 23.36 U/ml) and CEA (> 4.28 ng/ml) were significantly associated with more advanced clinicopathological traits and worse outcomes than that of negative groups (all P tumor size (P tumor markers (NPTM) were more accurate in prognostic prediction than TNM stage alone. Our findings suggested that elevated preoperative serum CA125, CA19-9 and CEA were associated with more advanced clinicopathological traits and less favorable outcomes. In addition, CA125 as an independent prognostic factor should be further investigated. Nomogram based on NPTM could accurately predict the prognosis of GC patients. PMID:27097114

  14. Electronic structures and magnetism of CaFeAsH and CaFeAsF

    International Nuclear Information System (INIS)

    Wang Guangtao; Shi Xianbiao; Liu Haipeng; Liu Qingbo

    2015-01-01

    We studied the electronic structures, magnetism, and Fermi surface (FS) nesting of CaFeAsH and CaFeAsF by first-principles calculations. In the nonmagnetic (NM) states, we found strong FS nesting, which induces magnetic instability and a spin density wave (SDW). Our calculations indicate that the ground state of CaFeAsH and CaFeAsF is the stripe antiferromagnetic state. The calculated bare susceptibility χ 0 (q) peaked at the M-point and was clearly suppressed and became slightly incommensurate with both electron doping and hole doping for both materials. (author)

  15. Study of 40Ca-40Ca elastic scattering at intermediate energy

    International Nuclear Information System (INIS)

    Kumar, Ashok; Srivastava, B.B.

    1980-01-01

    The differential cross sections for 40 Ca- 40 Ca elastic scattering have been calculated at laboratory incident energy of 240 MeV using a sharp cut off of the partial waves below a critical angular momentum, 1sub(c)' to account for absorption. The effective 40 Ca- 40 Ca potential is taken to be the sum of a real nuclear potential and the Coulomb potential. The calculated differential cross sections which are in fair agreement with the experimental data are presented and discussed. (author)

  16. Impact parameter determination for 40Ca + 40Ca reactions using a neural network

    International Nuclear Information System (INIS)

    Haddad, F.; Hagel, K.; Li, J.; Mdeiwayeh, N.; Natowitz, J.B.; Wada, R.; Xiao, B.; David, C.; Freslier, M.; Aichelin, J.

    1995-01-01

    A neural network is used for the impact parameter determination in 40 Ca + 40 Ca reactions at energies between 35 and 70 AMeV. A special attention is devoted to the effect of experimental constraints such as the detection efficiency. An overall improvement of the impact parameter determination of 25% is obtained with the neural network. The neural network technique is then used in the analysis of the Ca+Ca data at 35 AMeV and allows separation of three different class of events among the selected 'complete' events. (authors). 8 refs., 5 figs

  17. Mg/Ca of Continental Ostracode Shells

    Science.gov (United States)

    Ito, E.; Forester, R. M.; Marco-Barba, J.; Mezquita, F.

    2007-12-01

    Marine ionic chemistry is thought to remain constant. This, together with the belief that marine calcifiers partition Mg/Ca in a systematic manner as functions of temperature (and Mg/Ca) of water forms the basis of the Mg/Ca thermometer. In continental settings both of these assumptions are usually not true. Continental waters contain a wide variety of solutes in absolute and relative ion concentrations. Hence, waters with identical Mg/Ca may have very different concentrations of Mg and Ca and very different anions. Here we use two examples to focus on the effects of ion chemistry on Mg/Ca partitioning in continental ostracode shells and we ignore the complexities of solute evolution, which can change Mg/Ca over timescales of minutes to millennia. Palacios-Fest and Dettman (2001) conducted a monthly study of ,Cypridopsis vidua at El Yeso Lake in Sonora, Mexico. They established a relation between temperature and average shell Mg/Ca using regression analyses on averaged data. When their Mg/Ca-temperature relation is applied to monthly ,C. vidua data from Page Pond near Cleveland, Ohio, water temperatures of -8 to -1°C are obtained. The observed Mg/Ca ranges for El Yeso Lake (0.31 to 0.46) and Page Pond (0.33 to 0.46) are similar, as are their specific conductivities (700 to 850μS for El Yeso Lake; 400 to 600μS for Page Pond). However, [Ca] is 140-260 mg/L for El Yeso, but only 70-90 mg/L for Page Pond. Page Pond data, in fact, shows a good temperature shell Mg/Ca relation for .C. vidua, but the relation is different from that at El Yeso. Hence, shell Mg/Ca is a multi-valued, family of curves function of temperature and Mg/Ca of water that depends on the [Mg] and [Ca] values in water and perhaps other factors. Our second example comes from sites near Valencia, Spain and involves shell data for ,Cyprideis torosa, an estuarine ostracode that is tolerant of a wide range of salinity and can live in continental waters as long as the carbonate alkalinity to Ca ratio is

  18. Physical conditions in CaFe interstellar clouds

    OpenAIRE

    Gnacinski, P.; Krogulec, M.

    2007-01-01

    Interstellar clouds that exhibit strong Ca I and Fe I lines were called CaFe clouds. The ionisation equilibrium equations were used to model the column densities of Ca II, Ca I, K I, Na I, Fe I and Ti II in CaFe clouds. The chemical composition of CaFe clouds is that of the Solar System and no depletion of elements onto dust grains is seen. The CaFe clouds have high electron densities n=1 cm^-3 that leads to high column densities of neutral Ca and Fe.

  19. Absolute Ca Isotopic Measurement Using an Improved Double Spike Technique

    Directory of Open Access Journals (Sweden)

    Jason Jiun-San Shen

    2009-01-01

    Full Text Available A new vector analytical method has been developed in order to obtain the true isotopic composition of the 42Ca-48Ca double spike. This is achieved by using two different sample-spike mixtures combined with the double spike and natural Ca data. Be cause the natural sample (two mixtures and the spike should all lie on a single mixing line, we are able to con strain the true isotopic composition of our double spike using this new approach. Once the isotopic composition of the Ca double spike is established, we are able to obtain the true Ca isotopic composition of the NIST Ca standard SRM915a, 40Ca/44Ca = 46.537 ± 2 (2sm, n = 55, 42Ca/44Ca = 0.31031 ± 1, 43Ca/44Ca = 0.06474 ± 1, and 48Ca/44Ca = 0.08956 ± 1. De spite an off set of 1.3% in 40Ca/44Ca between our result and the previously re ported value (Russell et al. 1978, our data indicate an off set of 1.89__in 40Ca/44Ca between SRM915a and seawater, entirely consistent with the published results.

  20. Development and application of the RE-AIM QuEST mixed methods framework for program evaluation.

    Science.gov (United States)

    Forman, Jane; Heisler, Michele; Damschroder, Laura J; Kaselitz, Elizabeth; Kerr, Eve A

    2017-06-01

    To increase the likelihood of successful implementation of interventions and promote dissemination across real-world settings, it is essential to evaluate outcomes related to dimensions other than Effectiveness alone. Glasgow and colleagues' RE-AIM framework specifies four additional types of outcomes that are important to decision-makers: Reach, Adoption, Implementation (including cost), and Maintenance. To further strengthen RE-AIM, we propose integrating qualitative assessments in an expanded framework: RE-AIM Qualitative Evaluation for Systematic Translation (RE-AIM QuEST), a mixed methods framework. RE-AIM QuEST guides formative evaluation to identify real-time implementation barriers and explain how implementation context may influence translation to additional settings. RE-AIM QuEST was used to evaluate a pharmacist-led hypertension management intervention at 3 VA facilities in 2008-2009. We systematically reviewed each of the five RE-AIM dimensions and created open-ended companion questions to quantitative measures and identified qualitative and quantitative data sources, measures, and analyses. To illustrate use of the RE-AIM QuEST framework, we provide examples of real-time, coordinated use of quantitative process measures and qualitative methods to identify site-specific issues, and retrospective use of these data sources and analyses to understand variation across sites and explain outcomes. For example, in the Reach dimension, we conducted real-time measurement of enrollment across sites and used qualitative data to better understand and address barriers at a low-enrollment site. The RE-AIM QuEST framework may be a useful tool for improving interventions in real-time, for understanding retrospectively why an intervention did or did not work, and for enhancing its sustainability and translation to other settings.

  1. Caracterização físico-química do enxerto de osso bovino liofilizado Physicochemical characterization of lyophilized bovine bone grafts

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Galia

    2011-01-01

    Full Text Available OBJETIVO: Avaliar as características físico-químicas do enxerto bovino liofilizado manufaturado em escala semi-industrial (OrthoGen, Baumer S/A* de acordo com protocolo previamente desenvolvido pelos autores. MÉTODOS: A caracterização do enxerto de osso bovino liofilizado foi feita por meio de microscopia eletrônica de varredura (MEV, energy dispersive spectroscopy (EDS, difratometria de raios-X, análise por termogravimetria, análise de calorimetria exploratória diferencial (DSC e espectroscopia por infravermelho Fourier-transform (FT-IR. RESULTADOS: Ca foi o principal componente (60% encontrado nas amostras, seguido por P (28% e O (5%. O tamanho médio (dp dos poros foi 316µm (146,7, variando de 91,2 a 497,8µm, e 333,5µm (304,8, variando de 87,2 a 963,9µm com 50x e 150x magnificação, respectivamente. Picos de hidroxiapatita foram a 26ºC e 32ºC, e perda de massa foi observada entre 250ºC e 640ºC, correspondendo material orgânico e água. Duas transições de temperatura (45,67°C e 91,89°C mostraram desnaturação de colágeno tipo I e desidratação da hidroxiapatita. CONCLUSÃO: A avaliação físico-química do enxerto de osso bovino liofilizado, de acordo com o protocolo desenvolvido em escala semi-industrial, confirma que este produto apresenta excelente biocompatibilidade, com características semelhantes ao osso in natura.OBJECTIVE: To evaluate the physicochemical characteristics of lyophilized bovine grafts manufactured on a semi-industrial scale (Orthogen; Baumer S/A* in accordance with a protocol previously developed by the authors. METHODS: The lyophilized bovine bone grafts were characterized by means of scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS, X-ray diffractometry (XRD, thermogravimetric (TG analysis, differential exploratory scanning calorimetry (DSC and Fourier-transform infrared (FT-IR spectroscopy. RESULTS: Ca was the main component (60% found in the samples, followed by P (28

  2. Caracterización química de la vidriera de Sant Pere i Sant Jaume (segundo cuarto del s. XIV, Monestir de Pedralbes, Barcelona

    Directory of Open Access Journals (Sweden)

    Gimeno, D.

    2002-04-01

    Full Text Available Several architectural medieval stained glass (1330 a.C. from Pedralbes monastery’s church (Barcelona, Spain have been characterised chemically. This note explains the results obtained with EMPA, representative of bulk chemistry of several coloured glasses (white, green, pink, blue, yellow, red coming from the Sant Pere and Sant Jaume stained-glass window. Most of them are Na-rich (13-19 % Na2O homogeneous in colour and composition, and show minor variations in bulk chemistry related with colour (i.e., CuO in the 1.6-6 % range in green glass. Singularly, red glass is K-rich (16.5 % K2O, 14 % CaO, and was elaborated in a way technologically more sophisticated (it is a plaqué glass, with a red Cu-rich layer sandwiched between a white transparent Cu-poor glass similar in composition. While Na-rich glasses are mostly unaltered, K-rich ones show moderate corrosion and partial loss of transparency. Dominance of Na-rich glasses in the stained glass windows (rare at that time, if we consider the present state of the art allowed an excellent conservation. Despite of the presence of mortar covering, patina, etc., bulk chemistry of the glass shows its value as a diagnostic tool in an early evaluation of the state of decay of an stained glass window.

    Se han caracterizado químicamente diferentes tipos de vidrios arquitectónicos originales de la iglesia del Monestir de Pedralbes, Barcelona (realizados hacia 1330. Esta nota expone los resultados obtenidos mediante el empleo de microsonda electrónica en vidrios de varios colores (blanco, verde, rosado, azul, amarillo, rojo de la vidriera de Sant Pere y Sant Jaume. Corresponden esencialmente a vidrios sódicos (dentro del rango 13-19 % de Na2O de coloración y composición homogénea, con elementos que actúan como colorante (p.e., CuO en rango 1.6-6 % en los vidrios verdes. El vidrio rojo, potásico, es una excepción notable (16.5 % K2O, 14 % CaO, tecnológicamente diferente (vidrio

  3. The destiny of Ca(2+) released by mitochondria.

    Science.gov (United States)

    Takeuchi, Ayako; Kim, Bongju; Matsuoka, Satoshi

    2015-01-01

    Mitochondrial Ca(2+) is known to regulate diverse cellular functions, for example energy production and cell death, by modulating mitochondrial dehydrogenases, inducing production of reactive oxygen species, and opening mitochondrial permeability transition pores. In addition to the action of Ca(2+) within mitochondria, Ca(2+) released from mitochondria is also important in a variety of cellular functions. In the last 5 years, the molecules responsible for mitochondrial Ca(2+) dynamics have been identified: a mitochondrial Ca(2+) uniporter (MCU), a mitochondrial Na(+)-Ca(2+) exchanger (NCLX), and a candidate for a mitochondrial H(+)-Ca(2+) exchanger (Letm1). In this review, we focus on the mitochondrial Ca(2+) release system, and discuss its physiological and pathophysiological significance. Accumulating evidence suggests that the mitochondrial Ca(2+) release system is not only crucial in maintaining mitochondrial Ca(2+) homeostasis but also participates in the Ca(2+) crosstalk between mitochondria and the plasma membrane and between mitochondria and the endoplasmic/sarcoplasmic reticulum.

  4. Alterações químicas de um Neossolo Flúvico irrigado com águas salinas Chemical changes of a Fluvic Neossol cultivated with tomato and irrigated with saline water

    Directory of Open Access Journals (Sweden)

    Israel Venismare Cordeiro Gonçalves

    2011-09-01

    Full Text Available Com o objetivo de avaliar as alterações químicas de um Neossolo Flúvico do semiárido de Pernambuco cultivado com três cultivares de tomateiro e irrigado com água de dois valores de relação de adsorção de sódio (RAS e seis de condutividade elétrica (CE foi realizado um experimento em vasos de polietileno em delineamento em blocos ao acaso com arranjo fatorial 3 x 6 x 2 (três cultivares de tomateiro, seis valores de CE e dois de RAS e quatro repetições. Os atributos estudados foram: CE, pH e RAS do extrato de saturação do solo, Ca2+, Mg2+, K+ e Na+ solúveis em função dos cultivares e da CE e RAS da água de irrigação. Os cultivares de tomateiro estudados não alteraram os atributos CE, pH, RAS, Ca2+, Mg2+ e Na+ do extrato de saturação do solo. O aumento da salinidade da água de irrigação incrementou a CE do extrato de saturação e os teores de Ca2+, Na+, Mg2+ e K+. A água com RAS de 20 (mmol L-10,5 promoveu aumento da RAS do extrato de saturação do solo.Aiming to evaluate chemical changes of a Fluvic Neossol from Pernambuco's semiarid there were cultivated tree tomato cultivars, irrigated with saline water with two values of sodium adsorption ratio (SAR and six values of electrical conductivity (EC. The experiment was carried out in polyethylene pots in randomized blocks design with factorial arrangement 3 x 6 x 2 (three tomato cultivars, six values of EC and two SAR and four replications. The variables studied were: EC, pH, SAR, Ca2+, Mg2+, K+ e Na+ of the saturation extract of soil depending on the cultivar and the EC and SAR of irrigation water. The tomato cultivars used in this study did not promote significant changes in the EC, pH, SAR, Ca2+, Mg2+ e Na+ of saturation extracts of soil. Increasing salinity of irrigation water promotes increases in the EC, Ca2+, Na+, Mg2+ and K+ of saturation extract of soil. Water with SAR of 20 (mmol L-10,5 increased the SAR value of the soil saturation extract.

  5. Características químicas do solo sob algodoeiro em área que recebeu água residuária da suinocultura Chemical soil properties under cotton using swine wastewater

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    Salomão de Sousa Medeiros

    2011-06-01

    Full Text Available A crescente geração de efluentes líquidos e o seu lançamento no meio ambiente tem-se constituído numa preocupação mundial devido aos impactos negativos gerados. O objetivo deste trabalho foi avaliar os possíveis impactos da aplicação do efluente proveniente da suinocultura, após seu tratamento, nos atributos químicos do solo, em área cultivada com algodão. O experimento foi realizado no Perímetro Irrigado Formoso, no município de Bom Jesus da Lapa, BA, em área experimental da Companhia de Desenvolvimento dos Vales do São Francisco e do Parnaíba - CODEVASF. Foram testados cinco tratamentos: MC - manejo convencional = água de "boa qualidade" + adubação química; ET100 = 100 % de efluente tratado; ET75:25 = 75 % de efluente tratado + 25 % de água boa; ET50:50 = 50 % de efluente tratado + 50 % de água boa; ET25:75 = 25 % de efluente tratado + 75 % de água boa. O delineamento experimental foi em blocos ao acaso com quatro repetições. Os atributos químicos do solo avaliados foram: pH, condutividade elétrica, teores de N, P, K, Ca, Mg, Na, Zn, Fe, Mn e Cu. Em geral, quanto aos atributos químicos do solo, a adoção do manejo com efluente tratado apresentou resultados semelhantes aos obtidos com o MC, favorecendo a melhoria da fertilidade do solo e constituindo-se em uma fonte alternativa de fertilização de baixo custo. O efluente tratado, independentemente do fator de diluição, também demonstrou ser uma fonte alternativa de água.The negative impacts of the increasing volume of wastewater and of its discharge into the environment have become a worldwide concern. This study assessed the potential impacts of using treated effluent from pig raising for cotton irrigation, to evaluate their effects on soil chemical properties, and compare the results with those under conventional management. The experiment was conducted in an experimental area of the Company for the Development of the San Francisco and Parnaíba valleys

  6. Small relief shape variations influence spatial variability of soil chemical attributes Pequenas variações das formas de relevo influenciam a variabilidade espacial de atributos químicos do solo

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    Zigomar Menezes de Souza

    2006-04-01

    Full Text Available Soils with small variations in relief and under the same management system present differentiated spatial variabilities of their attributes. This variability is a function of soil position in the landscape, even if the relief has little expression. The aim of this work was to investigate the effects of relief shape and depth on spatial variability of soil chemical attributes in a Typic Hapludox cultivated with sugar cane at two landscape compartments. Soil samples were collected in the intercrossing points of a grid, in the traffic line, at 0-0.2 m and 0.6-0.8 m depths, comprising a set of 100 georeferenced points. The spatial variabilities of pH, P, K, Ca, Mg, cation exchange capacity and base saturation were quantified. Small relief shape variations lead to differentiated variability in soil chemical attributes as indicated by the dependence on pedoform found for chemical attributes at both 0-0.2 m and 0.6-0.8 m depths. Because of the higher variability, it is advisable to collect large number of samples in areas with concave and convex shapes. Combining relief shapes and geostatistics allows the determination of areas with different spatial variability for soil chemical attributes.Solos submetidos ao mesmo sistema de manejo em locais com pequena variação de relevo, manifestam variabilidade espacial diferenciada de seus atributos. Esta variabilidade é condicionada pela posição dos solos na paisagem ou no declive, mesmo que o relevo seja de pequena expressão. O estudo teve como objetivo avaliar a influência da forma do relevo na variabilidade espacial de atributos químicos em um latossolo cultivado com cana-de-açúcar em dois compartimentos da paisagem. Os solos foram amostrados nos pontos de cruzamento de uma malha, com intervalos regulares de 10 m, perfazendo um total de 100 pontos, nas profundidades de 0-0,2 m e 0,6-0,8 m. Foi avaliado a variabilidade espacial do pH, fósforo (P, potássio (K, cálcio (Ca, magnésio (Mg, acidez

  7. Changes in the expression of serum markers CA242, CA199, CA125, CEA, TNF-α and TSGF after cryosurgery in pancreatic cancer patients.

    Science.gov (United States)

    Zhou, Gang; Niu, Lizhi; Chiu, David; He, Lihua; Xu, Kecheng

    2012-07-01

    The presence of serum tumor markers, carbohydrate antigen 242 (CA242), carbohydrate antigen 199 (CA199), carbohydrate antigen 125 (CA125), carcinoembryonic antigen (CEA), tumor-supplied group of factors (TSGF) and tumor necrosis factor-α (TNF-α), is closely associated with invasion and metastasis of many malignancies. The expression of these markers were measured in serum taken from 37 pancreatic cancer patients prior to treatment. Levels of CA242, CA199, CA125, CEA and TNF-α expression correlated with tumor size, clinical stage, tumor differentiation, lymph node and liver metastasis (P markers were significantly reduced compared with levels prior to cryosurgery (P 0.05). Thus, cryosurgery is more effective than chemotherapy for decreasing CA242, CA199, CA125, CEA, TSGF and TNF-α serum levels in these patients.

  8. Composición química del agua de lluvia y de niebla recolectada en la reserva biológica Monteverde

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    Tatiana Vásquez Morera

    2016-03-01

    Full Text Available Se determinó la composición química del agua de lluvia y de niebla en tres sitios en la Reserva Biológica Monteverde, Puntarenas; entre octubre 2009 y enero 2010. Debido a su estado de conservación y a su ubicación geográfica sobre la deriva continental, la Reserva Biológica Monteverde ofrece un sitio de estudio ideal, para el estudio de la composición de las aguas atmosféricas (agua de lluvia y de niebla. Las muestras de agua de niebla se recolectaron al utilizar muestreadores de niebla con líneas de teflón, mientras que las de agua de lluvia se recogieron al emplear muestreadores de lluvia simples y uno de cascada. En ambos tipos de agua se analizaron las especies iónicas más relevantes: H3O+, NH4 +, Ca2+, Mg2+, K+, Na+, Cl-, NO3 - y SO4 2-, al utilizar cromatografía de iones y detección por conductividad eléctrica. Las concentraciones promedio de estas especies en el agua de lluvia estuvieron entre 0,54 ± 0,02 μeq L-1 y 101± 3 μeq L-1, mientras que en el agua de niebla variaron entre 1,00 ± 0,02 μeq L-1 y 93 ± 4 μeq L-1. Además, se presentan el balance iónico y los factores de enriquecimiento con respecto al mar y el suelo de ambos tipos de muestras.

  9. Índice de manejo de carbono e atributos químicos de Latossolo Vermelho sob diferentes sistemas de manejo

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    Jolimar Antonio Schiavo

    2011-10-01

    Full Text Available O objetivo deste trabalho foi avaliar mudanças nos atributos químicos, no estoque de carbono e no índice de manejo de C de um Latossolo Vermelho argiloso, sob diferentes sistemas de manejo. Avaliou-se o solo sob sistemas de manejo com diferentes históricos de uso, sob as seguintes coberturas: Zea mays, Urochloa decumbens e Panicum maximum cv. Tanzania. Como testemunha, avaliou-se área sob vegetação de cerrado. Foram coletadas amostras compostas das camadas de solo de 0-5, 5-10 e 10-20 cm. Os teores de fósforo diminuíram com a profundidade, e os maiores valores foram observados na área com P. maximum. Na área com milho, observaram-se maiores valores de K+, Ca++, Mg++, CTC, e de soma e saturação por bases. O teor de C orgânico total do solo (COT foi maior sob cerrado e menor sob cobertura com P. maximum, à profundidade de 5-10 cm. Os maiores estoques de COT, carbono nas frações particuladas (C-MOP e nas frações associadas à fase mineral do solo ocorreram na área com U. decumbens, o que promoveu maiores índices de labilidade e de manejo de C, similares aos da vegetação de cerrado. Em todas as coberturas, a labilidade da matéria orgânica do solo diminuiu com o aumento da profundidade. A fração C-MOP apresenta maior sensibilidade às alterações de manejo e relaciona-se ao COT.

  10. Caracterización química de macroelementos en suelos cultivados con plátano (Musa AAB Simmonds en el departamento de Córdoba, Colombia Chemical characterization of macroelements in soils cultivated with Harton plantain (Musa AAB Simmonds in the department of Córdoba, Colombia

    Directory of Open Access Journals (Sweden)

    Enrique Combatt-Caballero

    2012-04-01

    Full Text Available Las recomendaciones de fertilización para el cultivo de plátano (Musa AAB Simmonds deben estar basadas en las características químicas y el potencial de producción de los suelos. El objetivo de este trabajo fue evaluar las características químicas de macro-elementos presentes en suelos utilizados en la producción de plátano en el departamento de Córdoba, Colombia. Las evaluaciones se hicieron en diez fincas por cada uno de cuatro municipios productores de plátano en el Alto Sinú (Valencia y Tierralta y la región costanera (San Bernardo del Viento y Moñitos. Los parámetros determinados en el suelo fueron: pH, materia orgánica (M.O., P, S, Ca, Mg, Na y K, según metodologías químicas propuestas por Instituto Geográfico Agustín Codazi (IGAC. Los datos obtenidos fueron sometidos a análisis de varianza y pruebas de comparación de medias (Tukey. En los resultados analíticos se encontró que los suelos presentan reacción moderadamente ácida con pH Fertilizer recommendations for hartón plantain cropping should be done by interpreting the chemical characteristics of soils to be reliable from the technical point of view and principally based in technical adjustments in relation to the nutritional potential of soils. The aim of this study was to evaluate the chemical characteristics of macroelements in soil in 40 farms cultivated with hartón plantain in the department of Córdoba, Colombia. The parameters measured were: pH, organic matter (O.M., P, S, Ca, Mg, Na, K, according to the analytical procedures proposed by Geographic Institute Agustín Codaz (IGAC. Analysis of variance and mean comparison tests (Tukey to the data were performed. The analytical results showed that the soils had a moderately acidic reaction, with pH lower than 6 on the High Sinú zone and slightly alkaline with pH 6.5 in the coastal zone. The organic matter content was less than 2.1%, P between 16.4 and 35.3 mg kg-1 and S deficient with values less than

  11. Ventral tegmental area disruption selectively affects CA1/CA2 but not CA3 place fields during a differential reward working memory task.

    Science.gov (United States)

    Martig, Adria K; Mizumori, Sheri J Y

    2011-02-01

    Hippocampus (HPC) receives dopaminergic (DA) projections from the ventral tegmental area (VTA) and substantia nigra. These inputs appear to provide a modulatory signal that influences HPC dependent behaviors and place fields. We examined how efferent projections from VTA to HPC influence spatial working memory and place fields when the reward context changes. CA1 and CA3 process environmental context changes differently and VTA preferentially innervates CA1. Given these anatomical data and electrophysiological evidence that implicate DA in reward processing, we predicted that CA1 place fields would respond more strongly to both VTA disruption and changes in the reward context than CA3 place fields. Rats (N = 9) were implanted with infusion cannula targeting VTA and recording tetrodes aimed at HPC. Then they were tested on a differential reward, win-shift working memory task. One recording session consisted of 5 baseline and 5 manipulation trials during which place cells in CA1/CA2 (N = 167) and CA3 (N = 94) were recorded. Prior to manipulation trials rats were infused with either baclofen or saline and then subjected to control or reward conditions during which the learned locations of large and small reward quantities were reversed. VTA disruption resulted in an increase in errors, and in CA1/CA2 place field reorganization. There were no changes in any measures of CA3 place field stability during VTA disruption. Reward manipulations did not affect performance or place field stability in CA1/CA2 or CA3; however, changes in the reward locations "rescued" performance and place field stability in CA1/CA2 when VTA activity was compromised, perhaps by trigging compensatory mechanisms. These data support the hypothesis that VTA contributes to spatial working memory performance perhaps by maintaining place field stability selectively in CA1/CA2. Copyright © 2009 Wiley-Liss, Inc.

  12. Synaptotagmin-7 is a principal Ca2+ sensor for Ca2+ -induced glucagon exocytosis in pancreas

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Wei, Shun-Hui; Hoang, Dong Nhut

    2009-01-01

    Hormones such as glucagon are secreted by Ca(2+)-induced exocytosis of large dense-core vesicles, but the mechanisms involved have only been partially elucidated. Studies of pancreatic beta-cells secreting insulin revealed that synaptotagmin-7 alone is not sufficient to mediate Ca(2+)-dependent i...

  13. Capture reactions of 40Ca and 48Ca with targets of 197Au and 208Pb

    International Nuclear Information System (INIS)

    Stokstad, R.; Chan, Y.; Chavez, E.

    1988-03-01

    The reactions of 40 Ca and 48 Ca with targets of 197 Au and 208 Pb have been measured in the region from below the interaction barrier to about twice the barrier energy. The fission-like fragments were detected in a pair of position-sensitive, multi-wire proportional counters and were identified from measurements of position and time using two-body kinematics. In the region above the barrier the cross sections for capture are less than those given by the touching condition, indicating that an /open quotes/extra push/close quotes/ is required to induce capture. The observations for 40 Ca and 48 Ca show different fissilities for the onset of the extra push and indicate that charge equilibration may be an important factor governing capture reactions. Below the barrier the cross sections show an enhancement relative to the prediction for a one dimensional barrier. The enhancements are larger for 40 Ca than for 48 Ca (for both targets) and this is in qualitative agreement with predictions based on the coupling of the relative motion to low-lying collective states. Both above and below the barrier, we find that the change in the light partner, from 48 Ca to 40 Ca, has a larger effect on the cross sections than the change from 208 Pb to 197 Au, after correction for the change in the Coulomb barrier. 16 refs., 7 figs

  14. Intercellular Ca2+ Waves: Mechanisms and Function

    Science.gov (United States)

    Sanderson, Michael J.

    2012-01-01

    Intercellular calcium (Ca2+) waves (ICWs) represent the propagation of increases in intracellular Ca2+ through a syncytium of cells and appear to be a fundamental mechanism for coordinating multicellular responses. ICWs occur in a wide diversity of cells and have been extensively studied in vitro. More recent studies focus on ICWs in vivo. ICWs are triggered by a variety of stimuli and involve the release of Ca2+ from internal stores. The propagation of ICWs predominately involves cell communication with internal messengers moving via gap junctions or extracellular messengers mediating paracrine signaling. ICWs appear to be important in both normal physiology as well as pathophysiological processes in a variety of organs and tissues including brain, liver, retina, cochlea, and vascular tissue. We review here the mechanisms of initiation and propagation of ICWs, the key intra- and extracellular messengers (inositol 1,4,5-trisphosphate and ATP) mediating ICWs, and the proposed physiological functions of ICWs. PMID:22811430

  15. Fusion dynamics in 40Ca induced reactions

    International Nuclear Information System (INIS)

    Prasad, E.; Hinde, D.J.; Williams, E.

    2017-01-01

    Synthesis of superheavy elements (SHEs) and investigation of their properties are among the most challenging research topics in modern science. A non-compound nuclear process called quasi fission is partly responsible for the very low production cross sections of SHEs. The formation and survival probabilities of the compound nucleus (CN) strongly depend on the competition between fusion and quasi fission. A clear understanding of these processes and their dynamics is required to make reliable predictions of the best reactions to synthesise new SHEs. All elements beyond Nh are produced using hot fusion reactions and beams of 48 Ca were used in most of these experiments. In this context a series of fission measurements have been carried out at the Australian National University (ANU) using 40;48 Ca beams on various targets ranging from 142 Nd to 249 Cf. Some of the 40 Ca reactions will be discussed in this symposium

  16. Alterações dos atributos físicos e químicos de um Neossolo após aplicação de doses de manipueira

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    Anamaria de S. Duarte

    2013-09-01

    Full Text Available O resíduo gerado no processamento industrial da mandioca (manipueira apresenta alta carga orgânica e elevada concentração de nutrientes. Tal resíduo, se descartado indiscriminadamente no solo, pode trazer sérios riscos ao ambiente. Assim, o objetivo deste estudo foi avaliar as alterações dos atributos físicos e químicos em um Neossolo Regolítico cultivado com alface e submetido às diferentes doses de manipueira. O experimento foi conduzido em casa de vegetação e se utilizou um delineamento inteiramente casualizado, com seis tratamentos compostos das seguintes doses: 0, 5, 15, 25, 45, 65 m³ ha-1 com cinco repetições. Para caracterização dos atributos do solo foram determinados parâmetros físicos (grau de floculação, argila dispersa em água e químicos (condutividade elétrica do extrato de saturação do solo, pH, teor de P e teores de cátions trocáveis K+, Ca2+, Mg2+ e Na+ do solo. A aplicação de manipueira ao solo propiciou um aumento significativo do grau de floculação, do pH, da condutividade elétrica do extrato de saturação, dos teores de cátions trocáveis e do teor de P, além de uma diminuição significativa da argila dispersa em água, constatando-se também tendência à salinização, em virtude do uso da manipueira.

  17. Caracterización química de panojas y vainas con semillas nativas del estado de Guerrero, México, para uso en la alimentación animal

    Directory of Open Access Journals (Sweden)

    Fernando Pérez-Gil Romo

    2014-01-01

    Full Text Available Se seleccionaron e identificaron cinco especies forrajeras nativas del estado de Guerrero, México: Bothriochloa sp, Sorghum halepense (L. Pers, Desmanthus virgatus (L. Willd, Gliricidia sepium (Jacq. Stend, Acacia farnesiana (L. Willd, consideradas forrajes no convencionales por ser productos naturales, no utilizados actualmente para la alimentación animal. El objetivo fue determinar la composición química en muestras representativas de las cinco plantas, vainas con semillas y panojas. Los análisis realizados fueron: análisis químico proximal, fracciones de fibra, perfil de aminoácidos, factores antinutricios, minerales y vitaminas hidrosolubles. Se encontró que el valor de proteína cruda osciló entre 60 y 202, fibra cruda entre 132.5 y 354.8, extracto etéreo 17 a 32.4, reportados en g-1 kg-1 de materia seca (MS. El contenido de lignina en las gramíneas fue 52 a 82 y en las muestras de leguminosas fue de 132 a 202 g; mientras que la celulosa para el primer grupo fue de 189 a 276 y para el segundo de 95 a 269 g kg -1 MS. De los factores antinutricios analizados el inhibidor de tripsina cuantificado fue de 1.0 a 4.97 UIT mg-1, hemaglutininas y saponinas no se detectaron. Se analizaron los siguientes minerales: Ca (301-652, Mg (57-88, K (565-1286, Na (64.3-630, Zn (0.93-5.1 y Fe (8.3-21.0 (reportados en g kg-1. Se cuantificaron 17 aminoácidos y 3 vitaminas (B1, B2 y B3 de cada muestra presentando valores similares entre ellas. Se concluye que las panojas y las vainas con semillas podrían considerarse como un recurso no convencional en la alimentación de rumiantes.

  18. Applicative Value of Serum CA19-9, CEA, CA125 and CA242 in Diagnosis and Prognosis for Patients with Pancreatic Cancer Treated by Concurrent Chemoradiotherapy.

    Science.gov (United States)

    Gu, Yu-Lei; Lan, Chao; Pei, Hui; Yang, Shuang-Ning; Liu, Yan-Fen; Xiao, Li-Li

    2015-01-01

    To evaluate the application value of serum CA19-9, CEA, CA125 and CA242 in diagnosis and prognosis of pancreatic cancer cases treated with concurrent chemotherapy. 52 patients with pancreatic cancer, 40 with benign pancreatic diseases and 40 healthy people were selected. The electrochemiluminescence immunoassay method was used for detecting levels of CA19-9, CEA and CA125, and a CanAg CA242 enzyme linked immunoassay kit for assessing the level of CA242. The Kaplan-Meier method was used for analyzing the prognostic factors of patients with pancreatic cancer. The Cox proportional hazard model was applied for analyzing the hazard ratio (HR) and 95% confidential interval (CI) for survival time of patients with pancreatic cancer. The levels of serum CA19-9, CEA, CA125 and CA242 in patients with pancreatic cancer were significantly higher than those in patients with benign pancreatic diseases and healthy people (PCEA. The specificity of CA242 is the highest, followed by CA125, CEA and CA19-9. The sensitivity and specificity of joint detection of serum CA19-9, CEA, CA125and CA242 were 90.4% and 93.8%, obviously higher than single detection of those markers in diagnosis of pancreatic cancer. The median survival time of 52 patients with pancreatic cancer was 10 months (95% CI7.389~12.611).. Patients with the increasing level of serum CA19-9, CEA, CA125, CA242 had shorter survival times (P=0.047. 0.043, 0.0041, 0.029). COX regression analysis showed that CA19-9 was an independent prognostic factor for patients with pancreatic cancer (P=0.001, 95%CI 2.591~38.243). The detection of serum tumor markers (CA19.9, CEA, CA125 and CA242) is conducive to the early diagnosis of pancreatic cancer and joint detection of tumor markers helps improve the diagnostic efficiency. Moreover, CA19-9 is an independent prognostic factor for patients with pancreatic cancer.

  19. Study on Ca2+ antagonistic effect and mechanism of Chinese herbal drugs using 45Ca

    International Nuclear Information System (INIS)

    Yang Yuanyou; Liu Ning; Mo Shangwu; Qiu Mingfeng; Jin Jiannan; Liao Jiali

    2002-01-01

    The Ca 2+ antagonistic effect and mechanism of Chinese herbal drugs are studied by using 45 Ca. The results indicate that potential-dependent Ca 2+ channel (PDC) and receptor-operated Ca 2+ channel (ROC) in cell membranes of smooth muscle can be blocked by several Chinese herbal drugs, including as Crocus sativus L., Carthamus L., Di-ao-xin-xue-kang (DAXXG) and Ginkgo biloba L. leaves. Among them Crocus sativus L. has the strongest antagonistic effect on Ca 2+ channel, while Ginkgo biloba L. leaves has no obvious effect. The whole prescription and the other functional drugs have significant effect on ROC and PDC. The compositions extracted by hexane have the strongest antagonistic. The wrinkled giant hyssop have five active compositions and Pei-lan have two active compositions

  20. Efeito da escória de siderurgia na química do solo e na absorção de nutrientes e metais pesados pela cana-de-açúcar

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Prezotti

    2012-08-01

    Full Text Available Com a redução das reservas naturais de nutrientes e o alto custo dos fertilizantes, tem aumentado a busca por fontes alternativas, sendo a escória de siderurgia uma opção, uma vez que possui compostos neutralizantes da acidez do solo e elementos químicos importantes para a nutrição das plantas. Este trabalho teve por objetivo avaliar as alterações, nas características químicas do solo e nos teores de nutrientes e de metais pesados, na cana-de-açúcar, em função de doses crescentes de escória de siderurgia. Os tratamentos foram compostos por oito doses de escória de aciaria: 0; 0,5; 1,0; 2,5; 5,0; 10; 20; 40 t ha-1, mais um tratamento adicional composto por uma dose de 2,5 t ha-1 de calcário, totalizando nove tratamentos, distribuídos em blocos ao acaso, com três repetições. Foram determinadas as características químicas de solo e planta, bem como a produtividade da cana-de-açúcar. A aplicação de escória no solo elevou o pH, a saturação por bases e os teores de P, Ca, B, Fe e Mn, não influenciando os teores de K e Mg. Mesmo aplicando-se doses mais elevadas, não houve alteração nos teores dos metais pesados Cd, Pb e Ni do solo. Houve elevação do teor de Cr. O teor de P na folha e no colmo da cana-de-açúcar apresentou tendência de aumento com as doses de escória, não havendo influência para os demais nutrientes, como, também, para os metais pesados. Houve elevação da produtividade tanto da cana-planta como da cana-soca.

  1. Propriedades químicas e fauna do solo influenciadas pela calagem em sistema semeadura direta Effects of liming on chemical properties and soil fauna in no-tillage system

    Directory of Open Access Journals (Sweden)

    Henrique Cesar Almeida

    2007-10-01

    Full Text Available Este trabalho objetivou avaliar o efeito da calagem e sua influência sobre atributos químicos e de fauna do solo em um Cambissolo sob sistema de semeadura direta. O experimento vem sendo conduzido em Lages, SC, desde maio de 2001. Os tratamentos foram: semeadura direta com calcário incorporado na dose de 1 SMP (SD-inc e superficial nas doses de 1/5 SMP (SD-1/5sup e 1/2 SMP (SD-1/2sup. Como padrão, utilizou-se solo sem cultivo e sem aplicação de calcário, e uma área de pastagem perene com calcário incorporado na dose de 1 SMP (PI-inc. O solo foi amostrado nas camadas de 0-5; 5-10; 10-20cm para análise de Ca2+, Mg+2, Al3+, pH em água e em CaCl2; e de 0-10cm para carbono orgânico total e fauna do solo. A aplicação superficial de calcário no sistema de semeadura direta na maior dose (1/2 SMP elevou os teores de Ca2+ até 10cm de profundidade e de Mg+2 até a camada de 10 a 20cm. A abundância e a diversidade da fauna edáfica foram maiores nas áreas sob semeadura direta e pastagem, em relação ao solo sem cultivo, mostrando sensibilidade às alterações advindas do manejo do solo, mas sem correlação direta com as modificações químicas decorrentes da calagem.This research was aimed at evaluating the effect of liming and its influence on chemistry and fauna properties of a Cambisol under no-tillage system. The experiment has been carried out in Lages, SC, southern Brazil, since May 2001. The treatments were: no-tillage with incorporated lime in the rate of 1 SMP (NT-inc; superficial liming in the rate of 1/5 SMP (NT-1/5sup, and 1/2 SMP (NT-1/2sup. As control treatment, bare soil without cultivation without lime application (BS, and plots with perennial pasture with incorporate lime in the rate of 1 SMP (Pp-inc were used. Soil samples were collected in the layers of 0-5; 5-10; 10-20cm depth for analysis of Ca2+, Mg+2, Al3+, water and CaCl2 pH. Total organic carbon and soil fauna were analysed in the layer 0-10cm. The superficial

  2. La ingeniería de procesos químicos: una visión alternativa del programa de Ingeniería Química

    Directory of Open Access Journals (Sweden)

    Alfonso Conde Cotes

    1996-01-01

    Full Text Available El Ingeniero de Procesos ha sido definido como aquel que tiene la responsabilidad de crear sistemas de procesamiento de la materia que, en forma económica, segura y sin alteración perjudicial del ambiente, transformen materias primas, energía y conocimiento en productos de utilidad. Su labor se centra en el análisis y la sintesis de procesos, para lo cual desarrolla labores de descomposición, modelación y simulación (análisis, y de diseño, evaluación, optimización y control (síntesis según se trate de un proceso dado o de su gestación. El proceso es un sistema conformado por elementos (equipos y sus relaciones fisicas controlantes, que interactúa sobre el medio externo recibiendo de él impulsos en forma de materias primas y energía y devuelve productos útiles para el hombre. El proceso es creado y operado por el hombre para su beneficio. Por el objeto de su trabajo, la ingeniería de procesos constituye el enfoque, dentro de la ingeniería quimica, que más cercanamente puede desarrollar la función central definida para la universidad. No se niega la posibilidad del desempeño del profesional en otras funciones que también le son propias, pero la tesis que se formula habla de que una formación como la hasta ahora esbozada, referida a la globalidad de los procesos y que integra los elementos del saber normalmente asociados a la carrera, aventaja los requerimientos del ejercicio profesional medio, es decir, no desatiende el campo de trabajo, y permite formar individuos capaces de transformar. La discusión tiene qué ver con el contenido curricular de la carrera y con la metodología de su desarrollo.

  3. QuEChERS sample preparation for the determination of pesticides and other organic residues in environmental matrices: a critical review.

    Science.gov (United States)

    Bruzzoniti, Maria Concetta; Checchini, Leonardo; De Carlo, Rosa Maria; Orlandini, Serena; Rivoira, Luca; Del Bubba, Massimo

    2014-07-01

    Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) is an extraction and clean-up technique originally developed for recovering pesticide residues from fruits and vegetables. Since its introduction, and until December 2013, about 700 papers have been published using the QuEChERS technique, according to a literature overview carried out using SciFinder, Elsevier SciVerse, and Google search engines. Most of these papers were dedicated to pesticide multiresidue analysis in food matrices, and this topic has been thoroughly reviewed over recent years. The QuEChERS approach is now rapidly developing beyond its original field of application to analytes other than pesticides, and matrices other than food, such as biological fluids and non-edible plants, including Chinese medicinal plants. Recently, the QuEChERS concept has spread to environmental applications by analyzing not only pesticides but also other compounds of environmental concern in soil, sediments, and water. To the best of our knowledge, QuEChERS environmental applications have not been reviewed so far; therefore, in this contribution, after a general discussion on the evolution and changes of the original QuEChERS method, a critical survey of the literature regarding environmental applications of conventional and modified QuEChERS methodology is provided. The overall recoveries obtained with QuEChERS and other extraction approaches (e.g., accelerated solvent extraction, ultrasonic solvent extraction, liquid/solid extraction, and soxhlet extraction) were compared, providing evidence for QuEChERS higher recoveries for various classes of compounds, such as biopesticides, chloroalkanes, phenols, and perfluoroalkyl substances. The role of physicochemical properties of soil (i.e., clay and organic carbon content, as well as cation exchange capacity) and target analytes (i.e., log KOW, water solubility, and vapor pressure) were also evaluated in order to interpret recovery and matrix effect data.

  4. Composição química das sementes de Archontophoenix alexandrae H. Wendl. & Drude (Arecaceae Seed chemical composition of Archontophoenix alexandrae H. Wendl. & Drude (Arecaceae

    Directory of Open Access Journals (Sweden)

    Maria Isabel Vallilo

    2004-10-01

    Full Text Available Sementes de Archontophoenix alexandrae extraídas de frutos coletados no Parque Estadual da Cantareira, São Paulo, foram analisadas quanto à composição química, ao perfil de ácidos graxos do óleo e aos teores de minerais, visando avaliar o seu potencial alimentício. Detectaram-se alto teor de fibras alimentares (38,80% p/p e umidade (47,72% p/p. Na fração oleosa, apesar do baixo conteúdo de óleo encontrado (2,74% p/p, predominaram os ácidos palmítico (19,80% p/p, entre os saturados, e oléico (42% p/p e linoléico (13% p/p, quanto aos insaturados. A presença, no óleo, de alfa-tocoferol (vitamina E equivalente a 4,0 mg 100 g-1 e de delta-tocoferol (1,8 mg 100 g-1 confere ao óleo certa estabilidade oxidativa. Embora contendo minerais como K, P, S, Ca, Fe, Zn, Se e Cu, lipídios e fibras alimentares, a presença do elemento Pb (2,74 mg kg-1 inviabiliza o consumo dessas sementes como alimento da avifauna e sinaliza contaminação antrópica no local de coleta.Seeds of Archontophoenix alexandrae, extracted from fruits collected at the Cantareira State Park, São Paulo, Brazil, were analyzed for chemical composition, oil fatty acids profiles and mineral content aiming to evaluate their nutritional potential. High values of dietary fibers (38.80% w/w and humidity (47.72% w/w were found. Palmitic acid (19.80% w/w was predominant among the saturated oil fraction, and oleic (42% w/w and linoleic (13% w/w among the insaturated oil fraction. The presence of alpha-tocopherol (vitamin E equivalent to 4.0mg 100g-1 and delta-tocopherol (1.8 mg 100g-1 confers some oxidative stability to the oil. Even containing minerals such as K, P, S, Ca, Zn, Se and Cu, lipids and dietary fibers, the presence of Pb (2.74mg kg-1 makes its consume unviable for avifauna, as well as it indicates anthropic contamination at the collect spot.

  5. Large conductance Ca2+-activated K+ (BK channel: Activation by Ca2+ and voltage

    Directory of Open Access Journals (Sweden)

    RAMÓN LATORRE

    2006-01-01

    Full Text Available Large conductance Ca2+-activated K+ (BK channels belong to the S4 superfamily of K+ channels that include voltage-dependent K+ (Kv channels characterized by having six (S1-S6 transmembrane domains and a positively charged S4 domain. As Kv channels, BK channels contain a S4 domain, but they have an extra (S0 transmembrane domain that leads to an external NH2-terminus. The BK channel is activated by internal Ca2+, and using chimeric channels and mutagenesis, three distinct Ca2+-dependent regulatory mechanisms with different divalent cation selectivity have been identified in its large COOH-terminus. Two of these putative Ca2+-binding domains activate the BK channel when cytoplasmic Ca2+ reaches micromolar concentrations, and a low Ca2+ affinity mechanism may be involved in the physiological regulation by Mg2+. The presence in the BK channel of multiple Ca2+-binding sites explains the huge Ca2+ concentration range (0.1 μM-100 μM in which the divalent cation influences channel gating. BK channels are also voltage-dependent, and all the experimental evidence points toward the S4 domain as the domain in charge of sensing the voltage. Calcium can open BK channels when all the voltage sensors are in their resting configuration, and voltage is able to activate channels in the complete absence of Ca2+. Therefore, Ca2+ and voltage act independently to enhance channel opening, and this behavior can be explained using a two-tiered allosteric gating mechanism.

  6. Cardiac microvascular endothelial cells express a functional Ca+ -sensing receptor.

    Science.gov (United States)

    Berra Romani, Roberto; Raqeeb, Abdul; Laforenza, Umberto; Scaffino, Manuela Federica; Moccia, Francesco; Avelino-Cruz, Josè Everardo; Oldani, Amanda; Coltrini, Daniela; Milesi, Veronica; Taglietti, Vanni; Tanzi, Franco

    2009-01-01

    The mechanism whereby extracellular Ca(2+) exerts the endothelium-dependent control of vascular tone is still unclear. In this study, we assessed whether cardiac microvascular endothelial cells (CMEC) express a functional extracellular Ca(2+)-sensing receptor (CaSR) using a variety of techniques. CaSR mRNA was detected using RT-PCR, and CaSR protein was identified by immunocytochemical analysis. In order to assess the functionality of the receptor, CMEC were loaded with the Ca(2+)-sensitive fluorochrome, Fura-2/AM. A number of CaSR agonists, such as spermine, Gd(3+), La(3+) and neomycin, elicited a heterogeneous intracellular Ca(2+) signal, which was abolished by disruption of inositol 1,4,5-trisphosphate (InsP(3)) signaling and by depletion of intracellular stores with cyclopiazonic acid. The inhibition of the Na(+)/Ca(2+) exchanger upon substitution of extracellular Na(+) unmasked the Ca(2+) signal triggered by an increase in extracellular Ca(2+) levels. Finally, aromatic amino acids, which function as allosteric activators of CaSR, potentiated the Ca(2+) response to the CaSR agonist La(3+). These data provide evidence that CMEC express CaSR, which is able to respond to physiological agonists by mobilizing Ca(2+) from intracellular InsP(3)-sensitive stores. Copyright 2008 S. Karger AG, Basel.

  7. The hippocampal CA2 ensemble is sensitive to contextual change.

    Science.gov (United States)

    Wintzer, Marie E; Boehringer, Roman; Polygalov, Denis; McHugh, Thomas J

    2014-02-19

    Contextual learning involves associating cues with an environment and relating them to past experience. Previous data indicate functional specialization within the hippocampal circuit: the dentate gyrus (DG) is crucial for discriminating similar contexts, whereas CA3 is required for associative encoding and recall. Here, we used Arc/H1a catFISH imaging to address the contribution of the largely overlooked CA2 region to contextual learning by comparing ensemble codes across CA3, CA2, and CA1 in mice exposed to familiar, altered, and novel contexts. Further, to manipulate the quality of information arriving in CA2 we used two hippocampal mutant mouse lines, CA3-NR1 KOs and DG-NR1 KOs, that result in hippocampal CA3 neuronal activity that is uncoupled from the animal's sensory environment. Our data reveal largely coherent responses across the CA axis in control mice in purely novel or familiar contexts; however, in the mutant mice subject to these protocols the CA2 response becomes uncoupled from CA1 and CA3. Moreover, we show in wild-type mice that the CA2 ensemble is more sensitive than CA1 and CA3 to small changes in overall context. Our data suggest that CA2 may be tuned to remap in response to any conflict between stored and current experience.

  8. Variabilidade espacial de atributos químicos do solo sob cafeeiro Conilon: relação com textura, matéria orgânica e relevo Spatial variability of soil chemical attributes in Conilon coffee plantation: relationships with soil texture, organic matter and relief

    Directory of Open Access Journals (Sweden)

    Diego Lang Burak

    2012-01-01

    Full Text Available Atributos químicos do solo têm relação com outros atributos, inclusive os geomorfológicos, constituindo fatores que controlam sua variabilidade espacial. Dentro desta premissa, delineou-se o objetivo deste trabalho: avaliar a variabilidade dos atributos químicos do solo e sua inter-relação com as frações granulométricas e componentes da matéria orgânica do solo, contextualizando a influência do relevo, utilizando-se a geoestatística e a análise de componentes principais (ACP. A variabilidade espacial dos atributos químicos em menor profundidade foi mais influenciada pelo relevo. Pela ACP, atributos relacionados com a reação do solo (pH, Ca, Mg, Al, m e V contribuíram com o primeiro componente principal (CP1 nas duas profundidades. Contudo, somente o CP1 na profundidade de 0,0 - 0,1 m foi correlacionado com o relevo: maiores altitudes e menores declividades favoreceram o maior teor da fração argila e menor teor de areia grossa, aumentando a retenção de cátions básicos no solo. Substâncias húmicas da matéria orgânica tiveram fraca influência na variabilidade dos atributos químicos, ressalvando a maior relação entre Ca e Mg com ácidos húmicos em locais de textura mais arenosa. Zonas homogêneas e correlatas com atributos geomorfológicos nas duas profundidades foram melhores obtidas para os teores de K, em comparação aos demais atributos. Dessa forma, o uso da análise espacial para segmentação da paisagem em regiões homogêneas visando otimizar o manejo da adubação depende não somente da topografia, mas também dos atributos químicos e da profundidade de amostragem.Chemical properties are related to other soil attributes, including geomorphology, and constitute one of the factors that control spatial variability. The objective of this work was to evaluate the variability of soil chemistry and how it is interrelated with granulometric size fractions and organic soil components. Geostatistics and

  9. Manejo de plantas daninhas em maracujazeiro amarelo cultivado com adubação química e orgânica

    OpenAIRE

    Ogliari,J.; Freitas,S.P.; Carvalho,A.J.C.; Ferreira,L.R.; Marinho,C.S.; Thiebaut,J.T.L.

    2007-01-01

    Objetivou-se, neste trabalho, avaliar diferentes formas de manejo de plantas daninhas na cultura do maracujazeiro, cultivado com adubação química e orgânica. O delineamento experimental foi em blocos casualizados, com 15 tratamentos, arranjados em esquema de parcelas subdivididas, com quatro repetições e 10 plantas úteis por parcela. Os tratamentos foram constituídos por três tipos de adubações na parcela (orgânica, química e química + orgânica) e cinco manejos de plantas daninhas na subparce...

  10. Eficacia de métodos químicos, físicos y mecánicos en la limpieza de costras y grafitis en granito

    OpenAIRE

    Pozo Antonio, Jose Santiago

    2013-01-01

    [spa] En esta tesis doctoral “Eficacia de métodos químicos, físicos y mecánicos en la limpieza de costras y grafitis en granito” se realiza la evaluación de la eficacia y efectos nocivos de diferentes métodos de limpieza aplicados con el objeto de extraer costras negras biológicas, costras negras sulfatadas y grafitis en granito. Los métodos evaluados son de tipo químico (productos químicos aplicados de manera directa o mezclados con espesantes), mecánicos (abrasivo a baja pres...

  11. Variation spatiotemporelle de la cryptorchidie et de l'hypospadias au Québec : Une étude exploratoire.

    Science.gov (United States)

    Guertin, Sophie; Lemieux, Karine-Sylvie; Makhoulian, Natalie; Michaud, Sébastien; Patry, Rose-Marie; Côté, Anne-Andrée; Gagnon, Fabien; Ayotte, Pierre; Bolduc, Stéphane

    2011-06-01

    RéSUMé: : La majorité des études effectuées au cours des dernières décennies ont mis en évidence une augmentation du nombre de cas de cryptorchidie et d'hypospadias entre 1970 et 1990. De plus, l'importante variabilité géographique de ces anomalies est bien décrite. Cette étude vise à mesurer la prévalence à la naissance de la cryptorchidie et de l'hypospadias au Québec, à vérifier si ces anomalies sont en augmentation et à en évaluer la répartition interrégionale. MéTHODE :: Une étude épidémiologique descriptive a été réalisée à partir du nombre de garçons de cinq ans et moins hospitalisés pour une cryptorchidie ou un hypospadias au Québec de 1989 à 2004 selon les données du fichier administratif d'hospitalisation MED-ÉCHO. Les données sur les naissances provenaient de l'Institut de la statistique du Québec. RéSULTATS :: La prévalence annuelle moyenne pour 1000 naissances vivantes de sexe masculin est de 19,1 (IC à 95 % : 18,8-19,4) pour la cryptorchidie et 11,4 (IC à 95 % 11,1-11,6) pour l'hypospadias au Québec. Au cours de la période étudiée, la prévalence de cryptorchidie a légèrement diminué, alors que celle de l'hypospadias est demeurée stable. Comparativement à la province du Québec, des régions présentent une prévalence significativement différente de cryptorchidie et/ou d'hypospadias. . : Au Québec, la prévalence de cryptorchidie est en légère diminution alors que celle de l'hypospadias est stable. Des variations régionales significatives sont observables. D'autres études sont nécessaires afin d'évaluer l'hypothèse d'un lien avec les contaminants environnementaux en émergence. L'implantation d'un système de surveillance des anomalies congénitales permettrait une représentation plus valide de la situation.

  12. Riesgo químico laboral: elementos para un diagnóstico en España

    Directory of Open Access Journals (Sweden)

    Alfonso A. Calera Rubio

    2005-01-01

    Full Text Available Fundamento: La falta de información junto a la ausencia de un conocimiento preciso de las propiedades intrínsecas de cada agente químico y de la exposición derivada de un uso concreto dificultan en gran medida la prevención de los trabajadores expuestos a los riesgos generados por la presencia de estos productos en los puestos de trabajo. El objetivo del presente estudio es identificar los elementos que permitan efectuar un diagnóstico de la situación del riesgo químico en España y la realización de un inventario de sustancias peligrosas utilizadas en el lugar de trabajo por sectores y/o actividades de producci ón. Métodos: Análisis de las fuentes secundarias, identificación de la percepción del riesgo entre representantes de los trabajadores y análisis del tratamiento que recibe el riesgo químico en las evaluaciones de riesgo. Por último se establecen las bases de una Matriz de Exposición a sustancias químicas por sectores de producción. Resultados: Grandes volúmenes de producción y consumo de agentes químicos, generalización de la multiexposición, pero sin datos sobre su uso concreto, con poca información sobre la peligrosidad intrínseca de las sustancias utilizadas y escasa identificación en las evaluaciones de riesgo. Amplia exposición en los sectores de producci ón con subregistro del daño a la salud y dificultades en la percepci ón del riesgo. Elaboración provisional de una matriz de exposici ón por sectores de producción. Conclusiones: Se obtienen datos y se identifican fuentes de información y procedimientos de análisis que permiten elaborar un diagnóstico de situación ante riesgo químico laboral. Se obtiene una matriz inicial de exposición por sectores de producción (susceptible de revisión y ampliación en función de la evidencia.

  13. Produção de lodo e comportamento químico de sais de ferro empregados no pós-tratamento de esgoto sanitário por precipitação química

    OpenAIRE

    Ferreira Filho,Sidney Seckler; Marguti,André Luiz; Piveli,Roque Passos

    2009-01-01

    A combinação de processos físico-químicos e biológicos no tratamento de esgotos sanitários tem se apresentado como uma alternativa na remoção de fósforo. No entanto, uma das limitações é a sua maior produção de lodo. Desse modo, este trabalho teve por objetivo avaliar a produção de lodo resultante da aplicação de sais de ferro para diferentes tipos de efluentes, bem como estudar o impacto de sua aplicação nas características físico-químicas dos efluentes estudados. Concluiu-se que os valores ...

  14. Satellite Based Probabilistic Snow Cover Extent Mapping (SCE) at Hydro-Québec

    Science.gov (United States)

    Teasdale, Mylène; De Sève, Danielle; Angers, Jean-François; Perreault, Luc

    2016-04-01

    Over 40% of Canada's water resources are in Quebec and Hydro-Quebec has developed potential to become one of the largest producers of hydroelectricity in the world, with a total installed capacity of 36,643 MW. The Hydro-Québec fleet park includes 27 large reservoirs with a combined storage capacity of 176 TWh, and 668 dams and 98 controls. Thus, over 98% of all electricity used to supply the domestic market comes from water resources and the excess output is sold on the wholesale markets. In this perspective the efficient management of water resources is needed and it is based primarily on a good river flow estimation including appropriate hydrological data. Snow on ground is one of the significant variables representing 30% to 40% of its annual energy reserve. More specifically, information on snow cover extent (SCE) and snow water equivalent (SWE) is crucial for hydrological forecasting, particularly in northern regions since the snowmelt provides the water that fills the reservoirs and is subsequently used for hydropower generation. For several years Hydro Quebec's research institute ( IREQ) developed several algorithms to map SCE and SWE. So far all the methods were deterministic. However, given the need to maximize the efficient use of all resources while ensuring reliability, the electrical systems must now be managed taking into account all risks. Since snow cover estimation is based on limited spatial information, it is important to quantify and handle its uncertainty in the hydrological forecasting system. This paper presents the first results of a probabilistic algorithm for mapping SCE by combining Bayesian mixture of probability distributions and multiple logistic regression models applied to passive microwave data. This approach allows assigning for each grid point, probabilities to the set of the mutually exclusive discrete outcomes: "snow" and "no snow". Its performance was evaluated using the Brier score since it is particularly appropriate to

  15. Spring floods prediction with the use of optical satellite data in Québec

    Science.gov (United States)

    Roy, A.; Royer, A.; Turcotte, R.

    2009-04-01

    The Centre d'expertise hydrique du Québec (CEHQ) operates a distributed hydrological model, which integrates a snow model, for the management of dams in the south of Québec. It appears that the estimation of the water quantity of snowmelt in spring remains a variable with a large uncertainty and induces generally to an important error in stream flow simulation. Therefore, the National snow and ice center (NSIDC) produces, from MODIS (Moderate Resolution Imaging Spectroradiometer) data, continuous and homogeneous spatial snow cover (snow/swow-free) data on the whole territory, but with a cloud contamination. This research aims to improve the prediction of spring floods and the estimation of the rate of discharge by integrating snow cover data in the CEHQ's snow model. The study is done on two watersheds: du Nord river watershed (45,8°N) and Aux Écorces river watershed (47,9°N). The snow model used in the study (SPH-AV) is an implementation developed by the CEHQ of the snowmelt model of HYDROLTEL in is hydrological forecast system to simulate the melted water. The melted water estimated is then used as input in the empirical hydrological model MOHYSE to simulate stream flow. MODIS data are considered valid only when the cloud cover on each pixel of the watersheds is less then 30%. A pixel by pixel correction is applied to the snow pack when there is a difference between satellite snow cover and modeled snow cover. In the case of model shows to much snow, a factor is applied on temperatures by iterative process (starting from the last valid MODIS data) to melt the snow. In the opposite case, the snow quantity added to the last valid MODIS data is found by iterative process so that the pixel's snow water equivalent is equal to the nonzero neighbor minimum value. The study shows, through the simulations done on the two watersheds, the interest of the use of snow/snow-free product for the operational update of snow water equivalent with the objective to improve

  16. Fibrose quística: Revisão

    Directory of Open Access Journals (Sweden)

    C. Damas

    2008-01-01

    Full Text Available Resumo: A fibrose quística (FQ é a doença autossómica recessiva mais frequente na raça caucasiana. Caracteriza-se por mutações na CFTR, uma proteína transmembranar responsável pelo transporte de cloretos. Esta proteína tem uma ampla distribuição epitelial, o que dá um carácter sistémico a esta doença e consequentemente múltiplas manifestações clínicas de gravidade variável. A melhoria dos cuidados de saúde, associada ao desenvolvimento do arsenal terapêutico, permitiu um aumento da sobrevida destes doentes, de tal forma que a FQ já não pode ser abordada como doença da idade pediátrica. Também a evolução técnica na transplantação abriu novas perspectivas quanto ao tratamento desta afecção.Assim, cada vez mais esta patologia implica um envolvimento multidisciplinar no qual a pneumologia tem uma parte preponderante. Abstract: Cystic Fibrosis (CF is the recessive autossomic disease more frequent in the caucasian race. The main characteristic is a mutation in CFTR, a trans-membranar protein, responsible for chlorates transportation. This protein has a diffuse epithelial distribution, which gives a multissistemic involvement to this disease, with clinical manifestations with variable degrees of severity. The development of better health care associated with new therapeutic options became responsible for an increase of survival, so CF is no longer a paediatric disease. Lung transplantation also has an important role, bringing new treatment perspectives.So, this pathology has an increased multi-disciplinary involvement in which the pulmonologist have a preponderant role. Palavras-chave: Fibrose quística, revisão, Key-words: Cystic fibrosis, review

  17. Abundâncias químicas de estrelas T Tauri fracas

    Science.gov (United States)

    Rojas, G. A.; Gregorio-Hetem, J.

    2003-08-01

    Apresentamos resultados do estudo de 44 estrelas pré-seqüência principal, para as quais buscamos realizar uma classificação espectroscópica e determinar parâmetros estelares e abundâncias químicas. A amostra foi escolhida da seguinte maneira : 21 objetos selecionados a partir de catálogos de objetos jovens, como o Pico dos Dias Survey e o Herbig Bell Catalogue, e 23 objetos selecionados a partir de contrapartidas ópticas de fontes de raios X detectadas pelo satélite ROSAT. Dentre 24 objetos previamente classificados como estrelas T Tauri Fracas, apenas 7 revelaram ser realmente pertencentes à essa classe, sendo os demais objetos T Tauri Clássicas ou estrelas evoluídas da pré-seqüência principal. Esse resultado demonstra que o critério mais utilizado para distinguir as T Tauri Clássicas das T Tauri Fracas, baseado na largura equivelente da emissão Ha, não é suficiente para determinar o estágio evolutivo desses objetos. Para o cálculo de parâmetros estelares e abundâncias, foram escolhidas as estrelas que apresentam características ideais para esse tipo de estudo, como ausência de velamento, baixa velocidade de rotação e espectros com razão sinal-ruído adequada. Os parâmetros estelares como temperatura efetiva e gravidade foram determinados através do equilíbrio de excitação e ionização das linhas de Ferro, e as abundâncias químicas foram calculadas utilizando o método de síntese espectral. Serão apresentados os parâmetros estelares e as abundâncias de Lítio para toda a amostra, e abundâncias de vários elementos quimicos para 7 estrelas estudadas em maior detalhe

  18. Generalidades sobre Rocas y Análisis Químicos de Suelos.

    Directory of Open Access Journals (Sweden)

    Orozco R. Aycardo

    1940-03-01

    Full Text Available Desde el día en que inicie el presente trabajo, apoyado por la amable circular que me proporcionó el Rector de la Facultad Nacional de Agronomía, el Jorge Gutiérrez, para dirigirme a diversos lugares del país en solitud de material que me sirviera para poner en práctica los diversos métodos que me fuere dado ejecutar, no tuve otro objetivo que el de reunir el mayor número posible de métodos, para hacer un análisis químico del suelo. Tenía el pleno convencimiento de que nada nuevo iba a aportar a las ciencias químicas, pero en cambio, como me lo sugirió el que más tarde designé como Presidente de Tesis, doctor Antonio Durán A., si podría compilar una serie de métodos explicados en un lenguaje tan sencillo, como en texto alguno pudiera presentarse. Entonces nació en mí el deseo de proporcionar a los estudiantes venideros un texto elemental sobre principios de análisis de algunos elementos de importancia agronómica, el cual no lo dudo me ha quedado defectuoso, pero estoy seguro que, el ser corregido por el Profesor respectivo, tendrá el valor a que yo aspiro. Con gran delicadeza he practicado los sistemas de análisis que anoto, procurándome así una experiencia que si es corta en realidad de verdad, si me permite diferenciar los diversos métodos de determinaciones, basado en la bondad de resultados verificados en muchas ocasiones. No creyendo tanto en la influencia del factor personal cuanto es la bondad del método, he resuelto acogerme hasta el conocimiento de nuevos y más eficientes, a los siguientes para las determinaciones de elementos, partiendo de soluciones clorhídricas.

  19. Potential Sensitivity of Québec's Breeding Birds to Climate Change

    Directory of Open Access Journals (Sweden)

    Jean-Luc DesGranges

    2010-12-01

    Full Text Available We examined the relationship between climatic factors and the distribution of breeding birds in southern Québec, Canada to identify the species whose distribution renders them potentially sensitive to climate change in the study area. We determined the degree of association between the distribution of 65 breeding bird species (601 presence-absence squares of the Atlas of the Breeding Birds of Québec and climate variables (212 climatological stations in operation for at least 20 years over the period 1953-1984 by statistically correcting for the effects of several factors that are correlated with bird distribution. Factors considered were the nature and scale of land cover patterns that included vegetation types and landscape characterization, geographical coordinates, and elevation. Canonical Correspondence Analysis (CCA was used to investigate the effect of climatic variables on breeding bird distribution. Independent variables accounted for a total of 29.1% of the variation in the species matrix. A very large portion of the variance explained by climate variables was shared with spatial variables, reflecting the relationships among latitude, longitude, elevation, and climate. After correcting for the effect of land cover variables, climatic variables still explained 11.4% of the variation in the species matrix, with temperature, i.e., warmer summers and milder winters, having a greater influence than precipitation, i.e., wetter summers. Of the 65 species, 14 appeared to be particularly climate-sensitive. Eight are insectivorous neotropical migrants and six species are at the northern limit of their range in the study area. The opposite is largely true for the eight others; they are practically absent from the southern part of the study area, except for the Dark-eyed Junco (Junco hyemalis, which is widespread there. The White-breasted Nuthatch (Sitta carolinensis is the only resident species that seemed responsive to climatic variables, i

  20. Empleabilidad, profesionalización y competencias sociales ¿Qué rol juega la universidad?

    Directory of Open Access Journals (Sweden)

    Miriam Aparicio

    2016-12-01

    Full Text Available Esta investigación se inscribe en un programa más amplio de estudios sobre Calidad de la Universidad en su relación con el mundo del trabajo. Los objetivos fueron: 1 profundizar en los condicionantes de logro en la Universidad y las “razones” subyacentes. 2 Conocer qué influencia ejercen algunos factores psicosociales más “tapados” a la hora de la inserción laboral; hoy un problema serio. Fue efectuada con estudiantes y graduados (UNCuyo y UTN. Cubrió tres etapas temporales durante las cuales las condiciones económicas y de empleo del país cambiaron. A la par, se produjeron reformas educativas. La reunión de distintos factores (de base, personales, psicosociales, estructurales y pedagógico-institucionales, sobre dos décadas de vida de las universidades mostró qué factores resultaban predictivos de logro o fracaso. Se aplicó metodología cuanti-cualitativa en 6 Facultades (1987-2004, N=229 sujetos. Aquí nos centramos en un factor psicosocial entre los abordados: la Alineación. No sin sorpresa, se observó que la falta de alineación constituía un factor predictivo de demora en la Universidad (fracaso relativo y de peor posicionamiento de los graduados en el mundo laboral. Los resultados son importantes para la Gestión Universitaria en un contexto en el que el nivel de fracaso en los estudios es muy marcado y por tratarse, además, del ámbito universitario, el que debiera desarrollar la Profesionalización mirando a la innovación y a la empleabilidad, esto es, formando el juicio crítico, generando las competencias sociales que demanda hoy el mundo del trabajo (iniciativa, apertura, escucha antes que la aceptación tácita y “consentida” de sistemas de ideas. Los hallazgos invitan a la reflexión de parte de quienes gerencian la Universidad y de los formadores de formadores sobre las estrategias y prácticas aún vigentes si se aspira a la mejora.

  1. Áreas metropolitanas:¿qué ha cambiado?: La experiencia de la Caracas Metropolitana

    Directory of Open Access Journals (Sweden)

    Sonia Barrios

    2001-05-01

    Full Text Available La nueva economía de la información y del conocimiento ha tenido tres decisivas implicaciones de orden territorial. Primero, ha acelerado el proceso de aglomeración urbana a escala planetaria. Segundo, ha provocado fuertes alteraciones en las redes urbanas de ámbito mundial, regional y nacional. Y tercero, ha impulsado la reestructuración interna de las áreas metropolitanas que se habían conformado durante la era industrial. Todo parece anticipar, por lo tanto, polarizaciones y fragmentaciones territoriales todavía más acentuadas que las conocidas en un pasado cercano. Tomando como referencia el caso de Caracas, se trata de averiguar en qué medida el desarrollo reciente de esta metrópoli sigue las grandes tendencias territoriales antes anotadas; y qué esfuerzos se están haciendo para ajustar sus instancias locales a las nuevas realidades urbanas. Como un recurso adicional, en distintos momentos se establecen comparaciones con Barcelona (España, considerada un ejemplo emblemático de las metrópolis de la era de la informaciónThe developments of new informational and knowledge-based economies have had three decisive implications at the territorial level. First, it has accelerated the urban agglomeration processes worldwide. Second, it has brought about substantial alterations in the existing global, regional and national urban networks. Finally, it has triggered the internal restructuring of former industrial-based metropolitan areas. All this seems to anticipate that territorial polarization and fragmentation will reach higher levels than those we have observed in the recent past. Taking the case of Caracas as a reference point, the intention is to find out to what extent the recent development of this metropolis follows the main territorial trends mentioned above. Interest is also placed in finding what steps are being taken in order to adjust its local levels of government to the new urban realities. In addition, comparisons are

  2. Value of Combined Detection of Serum CEA, CA72-4, CA19-9, CA15-3 and CA12-5 in the Diagnosis of Gastric Cancer.

    Science.gov (United States)

    Chen, Changguo; Chen, Qiuyuan; Zhao, Qiangyuan; Liu, Min; Guo, Jianwei

    2017-05-01

    To examine whether the combined detection of serum tumor markers (CEA, CA72-4, CA19-9, CA15-3 and CA12-5) improves the sensitivity and accuracy in the diagnosis of gastric cancer (GC). An automatic chemiluminescence immune analyzer with matched kits was used to determine the levels of serum CEA, CA72-4, CA19-9, CA15-3, and CA12-5 in 87 patients with gastric cancer (GC group), 60 patients with gastric benign diseases (GBD group) who were hospitalized during the same period, and 40 healthy subjects undergoing a physical examination. The values of these 5 tumor markers in the diagnosis of gastric cancer were analyzed. The levels of serum CEA, CA72-4, CA19-9, and CA12-5 were higher in the GC group than in the GBD group and healthy subjects, and these differences were significant ( P 0.05). The combined detection of CEA, CA72-4, CA19-9, and CA12-5 had a higher diagnostic value for gastric cancer than did single detection, and the positive detection rate of the combined detection of the four tumor markers was 60.9%. The diagnostic power when using the combined detection of CA72-4, CEA, CA19-9, and CA12-5 was the best. The combined detection of serum CA72-4, CEA, CA19-9 and CA12-5 increases the sensitivity and accuracy in the diagnosis of GC and can thus be considered an important tool for early diagnosis. © 2017 by the Association of Clinical Scientists, Inc.

  3. Production of 34S-labeled gypsum (Ca34SO4.2H2O Produção de gesso (Ca34SO4.2H2O, marcado com 34S

    Directory of Open Access Journals (Sweden)

    Alexssandra Luiza Rodrigues Molina Rossete

    2006-08-01

    Full Text Available Agricultural gypsum (CaSO4.2H2O stands out as an effective source of calcium and sulfur, and to control aluminum saturation in the soil. Labeled as 34S it can elucidate important aspects of the sulfur cycle. Ca34SO4.2H2O was obtained by chemical reaction between Ca(OH2 and H2(34SO4, performed under slow agitation. The acid was produced by ion exchange chromatography using the Dowex 50WX8 cation exchange resin and a Na2(34SO4 eluting solution. After precipitation, the precipitate was separated and dried in a ventilated oven at 60ºC. From 2.2 L H2SO4 0.2 mol L-1 and 33.6 g Ca(OH2, 73.7 ± 0.6 g Ca34SO4.2H2O were produced on average in the tests, representing a mean yield of 94.6 ± 0.8%, with 98% purity. The 34SO2 gas was obtained from Ca34SO4.2H2O in the presence of NaPO3 in a high vacuum line and was used for the isotopic determination of S in an ATLAS-MAT model CH-4 mass spectrometer.O gesso agrícola (CaSO4.2H2O destaca-se como fonte eficiente de cálcio e enxofre e na redução da saturação de alumínio no solo. O 34S como traçador isotópico pode elucidar aspectos importantes no ciclo do enxofre. Para tanto o Ca34SO4.2H2O foi obtido por reação química entre o Ca(OH2 e solução de H2(34SO4, realizada sob agitação lenta. O ácido foi produzido por cromatografia de troca iônica, utilizando resina catiônica Dowex 50WX8 e solução eluente de Na2(34SO4. Após a precipitação foi separado o precipitado e realizada a secagem em estufa ventilada à temperatura de 60ºC. Nos testes, a partir de 2,2 L de H2SO4 0,2 mol L-1 e 33,6 g de Ca(OH2, foram produzidos em média 73,7 ± 0,6 g de Ca34SO4.2H2O representando um rendimento médio de 94,6 ± 0,8%, com pureza de 98%. A partir do Ca34SO4.2H2O na presença de NaPO3, em linha de alto vácuo, obteve-se o gás 34SO2 utilizado para a determinação isotópica do S no espectrômetro de massas ATLAS-MAT modelo CH-4.

  4. Numerical model of Ca(OH)

    NARCIS (Netherlands)

    Koster, T.; Peelen, W.; Larbi, J.; Rooij, M. de; Polder, R.

    2010-01-01

    A mathematical model is being developed to describe a repair method in concrete, called cathodic protection (CP). The model is in principle also useful to describe electrodeposition in concrete, e.g. the process of re-precipitation of Ca(OH)2 invoked by an electrical current. In CP, the

  5. Gene of the month: PIK3CA.

    Science.gov (United States)

    Lai, K; Killingsworth, M C; Lee, C S

    2015-04-01

    PIK3CA encodes the p110α catalytic subunit of phosphatidylinositol 3-kinase (PI3K) which through its role in the PI3K/Akt pathway is important for the regulation of important cellular functions such as proliferation, metabolism and protein synthesis, angiogenesis and apoptosis. Mutations in PIK3CA are known to be involved in a wide range of human cancers and mutant PIK3CA is thought to act as an oncogene. The specific PIK3CA inhibitor, NVP-BYL719, has displayed promising results in cancer therapy and is currently under clinical trials. Furthermore, PI3K regulates autophagy, a cellular process that recycles proteins and organelles through lysosomal degradation and has recently been recognised as an attractive therapeutic target due to its pro- and anti-cancer properties. Several studies have attempted to investigate the effects of combining the inhibition of both PI3K and autophagy in cancer therapy, and an in vivo model has demonstrated that the combined use of a concomitant PI3K and autophagy inhibitor induced apoptosis in glioma cells. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. Exchange stiffness of Ca-doped YIG

    Science.gov (United States)

    Avgin, I.; Huber, D. L.

    1994-05-01

    An effective medium theory for the zero-temperature exchange stiffness of uncompensated Ca-doped YIG is presented. The theory is based on the assumption that the effect of the Ca impurities is to produce strong, random ferromagnetic interactions between spins on the a and d sublattices. In the simplest version of the theory, a fraction, x, of the ad exchange integrals are large and positive, x being related to the Ca concentration. The stiffness is calculated as function of x for arbitrary perturbed ad exchange integral, Jxad. For Jxad≳(1/5)‖8Jaa+3Jdd‖, with Jaa and Jdd denoting the aa and dd exchange integrals, respectively, there is a critical concentration, Xc, such that when x≳Xc, the stiffness is complex. It is suggested that Xc delineates the region where there are significant departures from colinearity in the ground state of the Fe spins. Extension of the theory to a model where the Ca doping is assumed to generate Fe4+ ions on the tetrahedral sites is discussed. Possible experimental tests of the theory are mentioned.

  7. Ca teos report in register N 13377

    International Nuclear Information System (INIS)

    Pena, S; Arrighetti, R.

    2011-01-01

    This work is about a report about ca teos carried out in register N 13377 in the department of Canelones to know the depth of the field. The drilling done allowed to identify granite and clay. This granite outcrops are developed in the east of the middle course of the stream Pando

  8. literacy.ca EXPRESS. April 2010

    Science.gov (United States)

    Movement for Canadian Literacy, 2010

    2010-01-01

    This issue of "literacy.ca EXPRESS" focuses on poverty. The articles included in this issue are: (1) Poverty Overview; (2) Tony's Story; (3) LAN (Learner Advisory Network) Member's Story (Dianne Smith); (4) Linking Adult Literacy to Poverty Reduction; (5) MCL (Movement for Canadian Literacy) Update; (6) Highlights from the LAN; (7) Good…

  9. The study of skeletal calcium metabolism with 41Ca and 45Ca

    Science.gov (United States)

    Freeman, Stewart P. H. T.; Beck, Belinda; Bierman, June M.; Caffee, Marc W.; Heaney, Robert P.; Holloway, Leah; Marcus, Robert; Southon, John R.; Vogel, John S.

    2000-10-01

    The living skeleton can be labeled for life by the administration of radiologically trivial amounts of 41Ca tracer. After initial elimination of tracer from the readily exchangeable calcium pools subsequent skeletal calcium turnover maintains and modulates the urine 41Ca content. Uniquely, bone calcium metabolism may then be studied with tracer in near equilibrium with the body's calcium and resorbing calcium directly measured by accelerator mass spectrometry (AMS) of excreta. Our experiments with 25 41Ca labeled subjects demonstrate excellent diurnal stability and remarkable response to intervention of the urine signal. Thus the tracer method may prove a competitive means of measuring the effects of antiresorptive osteoporosis treatments, for therapy development or even clinical monitoring. Novel studies of long-term skeletal evolution are also possible. We realize that routinely administered short-lived calcium radiotracers contain 41Ca impurities and that thousands of experimental participants have been historically inadvertently 41Ca labeled. The 41Ca urine index might now rapidly further be characterized by contemporary measurements of these one-time subjects, and with their by now thoroughly skeleton-equilibrated tracer they might be ideal participants in other new experiments. We are also investigating 45Ca AMS. It may prove preferable to label the skeleton with this radiotracer already familiar to bioscientists, but new to AMS.

  10. Mg-Ca Alloys Produced by Reduction of CaO: Understanding of ECO-Mg Alloy Production

    Science.gov (United States)

    Jung, In-Ho; Lee, Jin Kyu; Kim, Shae K.

    2017-04-01

    There have been long debates about the environment conscious (ECO) Mg technology which utilizes CaO to produce Ca-containing Mg alloys. Two key process technologies of the ECO-Mg process are the chemical reduction of CaO by liquid Mg and the maintenance of melt cleanliness during the alloying of Ca. Thermodynamic calculations using FactSage software were performed to explain these two key issues. In addition, an experimental study was performed to compare the melt cleanliness of the Ca-containing Mg alloys produced by the conventional route with metallic Ca and the ECO-Mg route with CaO.

  11. DA-6034 Induces [Ca(2+)]i Increase in Epithelial Cells.

    Science.gov (United States)

    Yang, Yu-Mi; Park, Soonhong; Ji, Hyewon; Kim, Tae-Im; Kim, Eung Kweon; Kang, Kyung Koo; Shin, Dong Min

    2014-04-01

    DA-6034, a eupatilin derivative of flavonoid, has shown potent effects on the protection of gastric mucosa and induced the increases in fluid and glycoprotein secretion in human and rat corneal and conjunctival cells, suggesting that it might be considered as a drug for the treatment of dry eye. However, whether DA-6034 induces Ca(2+) signaling and its underlying mechanism in epithelial cells are not known. In the present study, we investigated the mechanism for actions of DA-6034 in Ca(2+) signaling pathways of the epithelial cells (conjunctival and corneal cells) from human donor eyes and mouse salivary gland epithelial cells. DA-6034 activated Ca(2+)-activated Cl(-) channels (CaCCs) and increased intracellular calcium concentrations ([Ca(2+)]i) in primary cultured human conjunctival cells. DA-6034 also increased [Ca(2+)]i in mouse salivary gland cells and human corneal epithelial cells. [Ca(2+)]i increase of DA-6034 was dependent on the Ca(2+) entry from extracellular and Ca(2+) release from internal Ca(2+) stores. Interestingly, these effects of DA-6034 were related to ryanodine receptors (RyRs) but not phospholipase C/inositol 1,4,5-triphosphate (IP3) pathway and lysosomal Ca(2+) stores. These results suggest that DA-6034 induces Ca(2+) signaling via extracellular Ca(2+) entry and RyRs-sensitive Ca(2+) release from internal Ca(2+) stores in epithelial cells.

  12. New limits on 2β processes in 40Ca and 46Ca by using low radioactive CaF2(Eu) crystal scintillators

    International Nuclear Information System (INIS)

    Belli, P.; Bernabei, R.; Dai, C.J.

    2001-01-01

    The development of highly radiopure CaF 2 (Eu) crystal scintillators has been performed aiming at a substantial sensitivity enhancement of the 2β decay investigation and of the search for dark matter particles with spin-dependent (SD) interaction. The results of CaF 2 (Eu) background measurements and simulation are presented. New and highly improved T 1/2 limits on the 2β decay of 46 Ca and the double electron capture of 40 Ca are obtained

  13. Effects of Ca on microstructure, mechanical and corrosion properties and biocompatibility of Mg-Zn-Ca alloys.

    Science.gov (United States)

    Yin, Ping; Li, Nian Feng; Lei, Ting; Liu, Lin; Ouyang, Chun

    2013-06-01

    Zn and Ca were selected as alloying elements to develop an Mg-Zn-Ca alloy system for biomedical application due to their good biocompatibility. The effects of Ca on the microstructure, mechanical and corrosion properties as well as the biocompatibility of the as-cast Mg-Zn-Ca alloys were studied. Results indicate that the microstructure of Mg-Zn-Ca alloys typically consists of primary α-Mg matrix and Ca₂Mg₆Zn₃/Mg₂Ca intermetallic phase mainly distributed along grain boundary. The yield strength of Mg-Zn-Ca alloy increased slightly with the increase of Ca content, whilst its tensile strength increased at first and then decreased. Corrosion tests in the simulated body fluid revealed that the addition of Ca is detrimental to corrosion resistance due to the micro-galvanic corrosion acceleration. In vitro hemolysis and cytotoxicity assessment disclose that Mg-5Zn-1.0Ca alloy has suitable biocompatibility.

  14. Reassigning the CaH+ 11Σ → 21Σ vibronic transition with CaD+

    Science.gov (United States)

    Condoluci, J.; Janardan, S.; Calvin, A. T.; Rugango, R.; Shu, G.; Sherrill, C. D.; Brown, K. R.

    2017-12-01

    We observe vibronic transitions in CaD+ between the 11Σ and 21Σ electronic states by resonance enhanced multiphoton photodissociation spectroscopy in a Coulomb crystal. The vibronic transitions are compared with previous measurements on CaH+. The result is a revised assignment of the CaH+ vibronic levels and a disagreement with multi-state-complete-active-space second-order perturbation theory theoretical calculations by approximately 700 cm-1. Updated high-level coupled-cluster calculations that include core-valence correlations reduce the disagreement between theory and experiment to 300 cm-1.

  15. Mg and Ca isotope fractionation during CaCO3 biomineralisation

    International Nuclear Information System (INIS)

    Chang, Veronica T.-C.; Williams, R.J.P.; Makishima, Akio; Belshawl, Nick S.; O'Nions, R. Keith

    2004-01-01

    The natural variation of Mg and Ca stable isotopes of carbonates has been determined in carbonate skeletons of perforate foraminifera and reef coral together with Mg/Ca ratios to assess the influence of biomineralisation processes. The results for coral aragonite suggest its formation, in terms of stable isotope behaviour, approximates to inorganic precipitation from a seawater reservoir. In contrast, results for foraminifera calcite suggest a marked biological control on Mg isotope ratios presumably related to its low Mg content compared with seawater. The bearing of these observations on the use of Mg and Ca isotopes as proxies in paleoceanography is considered

  16. Thermoluminescence of CaCO3:Dy and CaCO3:Mn

    International Nuclear Information System (INIS)

    Bapat, V.N.; Nambi, K.S.V.

    1976-01-01

    CaCO 3 samples doped with Dy and Mn were prepared in the laboratory by co-precipitation techniques. Thermoluminescence and emission spectra of these phosphors were studied and were compared with those of the naturally occuring calcite and undoped CaCO 3 samples. Dy-doping seems to give a more efficient phosphor and indicates a possibility of getting a better phosphor by a judicious choice of a rare earth doping of CaCO 3 . Interesting result have been obtained on the TL glow curve variations of these phosphors with different temperature treatments prior to irradiation. (author)

  17. Composición Química y Actividad Antibacteriana del Aceite Esencial de Minthostachys mollis

    OpenAIRE

    Torrenegra-Alarcón, Miladys; Granados-Conde, Clemente; Durán-Lengua, Marlene; León-Méndez, Glicerio; Yáñez-Rueda, Xiomara; Martínez, César; Pájaro-Castro, Nerlis

    2016-01-01

    Se evaluó la composición química y la actividad antibacteriana del aceite esencial Minthostachys mollis cultivado en el departamento de Norte de Santander, Colombia.El aceite esencial fue obtenido por hidrodestilación convencional, a partir de las hojas; se determinó densidad relativa a 20°C, índice de refracción; solubilidad de los aceites esenciales en etanol (70% v/v) y rotación óptica. La composición química se evaluó mediante cromatografía de gases/espectrómetro de masa. La actividad se ...

  18. Així escriuen els químics, encara que no tinguin llapis ni bolígraf ...

    OpenAIRE

    Corominas Viñas, Josep

    2013-01-01

    Aquest article explica un treball pràctic de química que consisteix en una electròlisi de substàncies iòniques, presentat en un aspecte lúdic. L’activitat pràctica pot presentar-se com a una activitat POE (Predicció-Observació-Explicació), per a estudiants de química de batxillerat i com un aspecte de la interacció entre matèria (substàncies iòniques) i energia (corrent elèctric) per estudiants d’ESO. Per altra part l’observació dels canvis de colors dels indicadors àcid-base, permet ajuntar ...

  19. Características físico-químicas de amostras de mel de Melipona asilvai (Hymenoptera: Apidae

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    Souza Bruno de Almeida

    2004-01-01

    Full Text Available Análises de amostras de mel da abelha Melipona asilvai provenientes dos municípios de Itaberaba e Tucano, região semi-árida do Estado da Bahia, foram realizadas com o objetivo de contribuir para o conhecimento das características físico-químicas desse produto. A maioria dos parâmetros físico-químicos apresentou valores adequados para o consumo humano, o que possibilita a exploração desse produto pelas comunidades rurais da região semi-árida da Bahia. Contudo, o teor de umidade elevado é um aspecto que merece uma maior atenção por parte do produtor, que deverá ter cuidado com a higiene na manipulação do mel durante a coleta e no processo de armazenamento.

  20. Aula virtual como estrategia para el aprendizaje de la Química Orgánica

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    Alexander Castillo

    2017-01-01

    Full Text Available El propósito fue describir la experiencia de aplicar el aula virtual como estrategia para el aprendizaje de la Química Orgánica. Teóricamente se basa en Scagnoli (2000, fundamentada en la metodología cualitativa, tipo sistematización de experiencias; los actores fueron 43 estudiantes de la asignatura Química Orgánica I de la Facultad de Humanidades y Educación de la Universidad del Zulia. Se utilizó la observación, sesiones en profundidad y la lista de cotejo. Los estudiantes demostraron interés en las TIC para comprender los contenidos de la asignatura. Se concluye que el aula virtual favorece el autoaprendizaje electrónico, incentiva el aprendizaje y la gestión del conocimiento.

  1. Química e colorimetria da madeira de Eucalyptus grandis W. Mill ex Maiden termorretificada

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    Antônio José Vinha Zanuncio

    2014-08-01

    Full Text Available A termorretificação visa melhorar as características para agregar valor à madeira através da aplicação de calor. O objetivo foi avaliar as alterações químicas e colorimétricas da madeira termorretificada de Eucalyptus grandis submetida a 170, 200 e 230 ºC por 3, 5 e 7 h. Os teores de extrativos, lignina, holocelulose, composição elementar e os parâmetros colorimétricos foram determinados. Os teores de extrativos aumentaram nos tratamentos a 170 °C e diminuíram a partir de 200 °C, enquanto o teor de lignina total aumentou e o de holocelulose diminuiu a partir de 200 °C. O teor de carbono aumentou e o de oxigênio diminuiu a 230 °C por 5 e 7 h. A termorretificação reduziu a claridade, matriz vermelho (a* e matriz amarelo (b* da madeira de eucalipto em todos os tratamentos.

  2. ¿Por qué llamarlo fotografía?

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    Natalia Calabrese Castro

    2016-09-01

    Full Text Available En los últimos años, los resultados de una serie de concursos fotográficos generaron debates en torno a las posibilidades y los límites de la fotografía digital. Los trabajos premiados en estos certámenes evidencian y reconocen la gran incidencia del cambio tecnológico (de lo analógico a lo digital y problematizan la idea de la foto como huella, testimonio o prueba, de la existencia física de lo fotografiado y del fotógrafo situado en el lugar de los hechos. ¿Puede un fotógrafo ganar una mención en el más importante concurso de fotoperiodismo gracias a una serie de imágenes tomadas de Google? ¿Se puede obtener un primer premio de fotografía con imágenes que son errores de un escáner? ¿Y con fotos tomadas de Internet? ¿Qué puede ser considerado fotografía en la actualidad? ¿Podemos llamar a esto fotografía o deberíamos inventar otro nombre?

  3. ¿De qué están hechos nuestros emprendedores?

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    Xavier Jolonch

    2016-02-01

    Full Text Available Se realizó una investigación con veinticinco ideas de negocio surgidas del programa “Vive Digital”, de Colciencias en Colombia, en el marco del Convenio Especial de Cooperación 0678-2012 APPSCO-UNAB, sobre aplicaciones móviles. Los objetivos del trabajo fueron: 1 conocer de dónde surgieron las ideas de negocio analizadas; 2 determinar si su ventana de oportunidad está abierta o cerrada, y 3 identificar el perfil de los emprendedores y los mentores que las llevaron a cabo, para saber qué implicación tuvo en el desarrollo de los emprendimientos. La investigación es de tipo descriptivo, cuantitativo y cualitativo. Entre los resultados se destacan: 1 un 86 % de las ideas de negocio nació de una necesidad de mercado y no de una innovación tecnológica; 2 un 44 % de los individuos cree que podrá vivir de su idea, y 3 solo un 50 % de los mentores tiene experiencia en los sectores de su trabajo.

  4. Raleio químico na produção de tangerina 'Ponkan'

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    Maria do Céu Monteiro da Cruz

    2011-03-01

    Full Text Available A prática do raleio em tangerineira 'Ponkan' é utilizada para aumentar o tamanho da fruta e assim obter melhores preços no mercado. O trabalho foi realizado com o objetivo de testar diferentes concentrações de Ethephon sobre o raleio químico de tangerina 'Ponkan', visando a reduzir o número de frutas por planta e melhorar a uniformidade das frutas remanescentes. Foram testadas cinco concentrações de Ethephon: 0; 150; 300; 450 e 600 mg L-1, em dois estádios de desenvolvimento das frutas: 30 mm e 40 mm de diâmetro em tangerineira 'Ponkan'. Foi utilizado o esquema fatorial 5 x 2, com quatro repetições, em blocos casualizados, sendo cinco concentrações de Ethephon e dois estádios de desenvolvimento das frutas. A aplicação de Ethephon promoveu a abscisão de frutas em todas as concentrações testadas. As concentrações a partir de 300 mg L-1 apresentaram maior eficiência no raleio. As frutas remanescentes apresentaram melhor uniformidade no tamanho, e isso favoreceu maior rendimento da produção comercial da tangerina 'Ponkan'.

  5. ¿Qué seguridad? Riesgos y Amenazas de Internet en la Seguridad Humana

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    Rafael Rodríguez Prieto

    2016-01-01

    Full Text Available El auge de Internet ha puesto en cuestión muchas normas y aproximaciones sociopolíticas, incluyendo la forma de pensar la privacidad, la seguridad o los riesgos. Estos temas están muy presentes en nuestra sociedad. Este artículo aborda la ciberseguridad sin perder de vista los grandes temas de Internet. Todo ello implica que haya modos distintos de pensar la guerra, la privacidad, los riesgos, los conflictos o las libertades civiles y cómo podemos ajustarlas para garantizar los derechos civiles y la paz en la arena internacional. Son cuestiones serias e importantes pero es precisamente porque importan a todos, es necesario evaluar el impacto de Internet en los mismos. Lo que se pretende en este trabajo es evaluar el papel de la ciberseguridad en la sociedad internacional. Cuando lo que está en juego es el futuro de la paz o nuestras libertades digitales, no se pueden dejar las soluciones solo en manos de gobiernos o expertos. Precisamos comprender qué sucede y calibrar su importancia. Los ciudadanos debemos ser parte de la solución.

  6. Achocolatados: análise química Chocolate drink powders: chemical analysis

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    Mércia de Freitas Eduardo

    2004-09-01

    Full Text Available Neste trabalho avaliaram-se propriedades químicas de achocolatados do mercado brasileiro, sendo estas os teores de lipídios, proteínas, cinzas, umidade, pH, teobromina e alcalóides totais. Estas propriedades são influenciadas principalmente pelo conteúdo de cacau em pó e pelo conteúdo dos ingredientes lácteos, como o leite em pó e o soro de leite em pó. Foi feito um comparativo entre as marcas de achocolatados, dando ênfase às grandes diferenças, quando existentes, entre os achocolatados dietéticos (para dietas de restrição de sacarose, frutose e glicose (dextrose e "light" (com redução de açúcares e os tradicionais.Some chemical properties of chocolate drink powders from Brazilian market, such as lipid, protein, ashes, moisture, pH, theobromine and total alkaloids content of the samples were evaluated. These properties are mainly influenced by cocoa powder content and by dairy products, such as milk powder and whey. A comparison among the brands, emphasizing their strong differences, when existing, among diet (without sugars and light (low sugar and the standard brands was made.

  7. Breeding Status and Population Trends of Golden Eagles in Northeastern Québec, Canada

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    François Morneau

    2012-12-01

    Full Text Available In North America, it is hypothesized that the Golden Eagle's (Aquila chrysaetos eastern population declined during the period 1946-1973 because of organochlorine pesticides and other anthropogenic causes of mortality. Since 1970, upward trends for the species have been observed at most eastern hawkwatches. To determine whether such positive trends can be observed on breeding grounds, Golden Eagle counts were performed to monitor nesting territory occupancy between 1994 and 2007 in the Moisie and Sainte-Marguerite River valleys, northeastern Québec. Aerial surveys were conducted during seven of the 14 years. During this period, the number of known nesting territories in the study area increased from 10 to 20, while the number of pairs rose from six to 14. The increase is attributed mostly to investigators' improved experience in finding nests and to their greater familiarity with the study area, and possibly to the growth of the regional population. Occupancy of nesting territories by pairs was very stable over the years. Annual mean % of laying pairs (or laying rate was 48.0 (SD = 19.9, and productivity (mean number of fledglings per pair was 0.49 (SD = 0.35.

  8. Política educativa chilena 1965-2009. ¿Qué oculta esa trama?

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    María Angélica Oliva

    2010-01-01

    Full Text Available Se aborda la política educativa chilena del período 1965-2009, inquiriéndose, ¿Qué oculta la trama? La conjetura es, la política educativa, a excepción del gobierno de Allende, muestra la institución del orden neoliberal. Se revisan algunas antinomias, mecanismos de ese orden, que se introduce en1965 con la pedagogía por objetivos y la teoría del capital humano. Esta pedagogía, es profundizada en dictadura, junto a la idea de subsidiariedad, que impulsa el cambio del rol del Estado, regulado en la Constitución de 1980, aún vigente, y presente en la Ley General de Educación. La municipalización, la transformación en el financiamiento y la pérdida del estatus de funcionario público del profesorado, son un legado de la dictadura. Ello, desperfila el afán democrático de la actual política educativa, transformándola en cómplice de un sistema que genera desigualdad y fragmentación social.

  9. Reacciones encadenadas: del reloj de yodo al arco iris químico

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    Carlos Durán Torres

    2011-01-01

    Full Text Available Para motivar a los alumnos en el estudio de la química, presentamos una experiencia que llamará su atención y que puede servir para introducir diversos conceptos en el aula. Consiste en encadenar la reacción de reducción del yodato potásico por hidrogenosulfito de sodio en presencia de almidón con otra reacción en la que aparecen disoluciones de indicadores de pH coloreadas al pasar de medio ácido a básico. En siete copas de vidrio que contienen un líquido incoloro, se añade otra disolución también incolora. El contenido de las copas va cambiando brusca y sucesivamente a azul-negro. Al añadir a las copas una tercera disolución, igualmente incolora, desaparece el color oscuro y aparecen los siete colores del arco iris produciendo un vistoso resultado.

  10. Reacciones encadenadas: del reloj de yodo al arco iris químico

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    Carlos Durán Torres,

    2011-01-01

    Full Text Available Para motivar a los alumnos en el estudio de la química, presentamos una experiencia que llamará su atención y que puede servir para introducir diversos conceptos en el aula. Consiste en encadenar la reacción de reducción del yodato potásico por hidrogenosulfito de sodio en presencia de almidón con otra reacción en la que aparecendisoluciones de indicadores de pH coloreadas al pasar de medio ácido a básico. En siete copas de vidrio que contienen un líquido incoloro, se añade otra disolución también incolora. El contenido de las copas va cambiando brusca y sucesivamente a azul-negro. Al añadir a las copas una tercera disolución, igualmente incolora, desaparece el color oscuro y aparecen los siete colores del arco iris produciendo un vistoso resultado.

  11. La violencia humana: ¿Qué hemos aprendido? Human violence: What have we learned?

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    Enrique Vega Fernández

    2012-09-01

    Full Text Available El presente trabajo pretende aportar algunas reflexiones que permitan aproximarse al gran interrogante de por qué existen las guerras y siguen existiendo en el mundo de nuestros días. A través del concepto de cratotropismo, basado en la concepción de afán de dominio de Alfred Adler. Y de la traída: competencia ideológica o cultural, presión-resistencia económica, conflicto armado como último recurso, como modos de los enfrentamientos crato-eleuterotrópicos, basada en la concepción de la función moduladora del saber por los poderes sociales de Michel Foucault y en concepto marxista de propiedad.The present work aims at inducing reflections upon how to approach the big question as why wars exist, and continue to exist, in the world we live in today. We proceed via the concept of cratotropism, based on Alfred Adler's conception of the thirst for power. And on the triad: ideological or cultural competition, financial pressure/resistance, and armed conflict as a last resource, as a means of confronting problems of a crato-eleuterotropic nature, and based on the conception of the modulating function of human knowledge in respect of Michel Foucault's "social powers" and the Marxist concept of property.

  12. Avaliação química de fertilizantes com micronutrientes tipo fritas

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    F. Vale

    2003-02-01

    Full Text Available O objetivo deste trabalho foi analisar fertilizantes tipo fritas comercializados no Brasil, utilizando o método prescrito para análise de fertilizantes minerais não-fritas, o que normalmente tem sido feito na rotina pelos laboratórios de análises de fertilizantes. Também foram analisados os teores de Cd, Ni e Pb nesses fertilizantes. Observou-se que o método utilizado foi adequado para a análise dos fertilizantes tipo fritas, o que indica que as fritas comercializadas no Brasil não são realmente fritas, isto é, silicatos fundidos com micronutrientes. A presença de micronutrientes metálicos nos produtos sem as respectivas garantias e a alta concentração de metais indesejáveis, principalmente Pb, são fortes indícios de utilização de resíduos industriais na fabricação desses fertilizantes. Sugere-se que sejam estudados e propostos extratores químicos para avaliar a eficiência agrícola desses produtos.

  13. Entre quête et enquête : la distance dans le terrain ethnographique

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    Michèle Baussant

    2009-03-01

    Full Text Available Entre quête et enquête : la distance dans le terrain ethnographique. Cet article revient sur une enquête menée auprès des pieds-noirs, en s’intéressant aux questions de la mémoire, de la représentation et de la légitimité. Comment aborder et analyser un objet à la marge et délégitimé en France, d’un point de vue social et scientifique ? Comment intégrer la manière dont cette question vient déteindre sur la position de l’enquêteur, dès lors confronté à des formes de jugements de valeurs, souvent implicites, qui viennent compliquer l’enquête, l’analyse puis ses utilisations ?Between quest and research: distance in ethnological fieldwork. In this article, I explain how research on repatriates from Algeria, called “pieds-noirs”, leads me to examine the notions of memory, representation and legitimacy. How is it possible to analyse a topic which remains socially and scientifically marginalized in France? I also underline how, in such a context, the researcher can be confronted with value judgments, which are implicit most of the time and which complicate the fieldwork, the analysis and its uses.

  14. Health impacts of the July 2010 heat wave in Québec, Canada.

    Science.gov (United States)

    Bustinza, Ray; Lebel, Germain; Gosselin, Pierre; Bélanger, Diane; Chebana, Fateh

    2013-01-21

    One of the consequences of climate change is the increased frequency and intensity of heat waves which can cause serious health impacts. In Québec, July 2010 was marked by an unprecedented heat wave in recent history. The purpose of this study is to estimate certain health impacts of this heat wave. The crude daily death and emergency department admission rates during the heat wave were analyzed in relation to comparison periods using 95% confidence intervals. During the heat wave, the crude daily rates showed a significant increase of 33% for deaths and 4% for emergency department admissions in relation to comparison periods. No displacement of mortality was observed over a 60-day horizon. The all-cause death indicator seems to be sufficiently sensitive and specific for surveillance of exceedences of critical temperature thresholds, which makes it useful for a heat health-watch system. Many public health actions combined with the increased use of air conditioning in recent decades have contributed to a marked reduction in mortality during heat waves. However, an important residual risk remains, which needs to be more vigorously addressed by public health authorities in light of the expected increase in the frequency and severity of heat waves and the aging of the population.

  15. La Química, la Ingeniería Química y su relación con otras disciplinas La Química, la Ingeniería Química y su relación con otras disciplinas

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    Antonio Valiente Barderas

    2012-02-01

    Full Text Available Chemical Engineering as such has a little more than a hundred years of existence. During this time, his development has generated research, data and books which made innovations in the curriculum and new paradigms in education. The development of this discipline has influenced the creation or modification of others such as Environmental Engineering, Food Engineering, Electrochemical Engineering, Metallurgical Engineering, etc. The future presents new challenges and opportunities for development in the area of biofuels, nanotechnology and climate control.La Ingeniería Química, como tal, tiene apenas un poco más de cien años de existencia. Durante ese tiempo la enseñanza de la misma ha ido cambiando conforme se generaron investigaciones, datos y libros que produjeron innovaciones en el currículo y nuevos pa­radigmas de la enseñanza. El desarrollo de esta disciplina ha incidido en la creación o modificación de otras más, tal como la Ingeniería Ambiental, la Ingeniería de Alimentos, la Bioingeniería, la Ingeniería Electroquímica y la Ingeniería Metalúrgica, etc. En el futuro se presentan nuevos retos y oportunidades de desarrollo en el área de los biocombustibles, la nanotecnología, los nuevos materiales y el control climático.

  16. La quête de l'unité l'aventure de la physique

    CERN Document Server

    Klein, Etienne

    1996-01-01

    L'idée que la diversité du réel puisse être expliquée par une unité sous-jacente est sans doute aussi ancienne que la pensée elle-même : les grandes mythologies le racontent, les premiers philosophes l'affirment, et la science moderne en a repris le programme en unifiant les conceptions du monde, de la matière et du mouvement. De ce pari métaphysique et quasiment religieux, la physique a aussi fait la vérité de sa démarche : identifier les objets les plus élémentaires possibles, violer les lois les plus fondamentales en cherchant à les raccorder jusqu'à pouvoir les unifier, fournir de l'ensemble la description la plus globale qui soit. Ce que l'on pourrait résumer par l'antique formule des néo-platoniciens : hen-ta-panta, c'est-à-dire l'" Un-toutes-les-choses ". Mais comment appréhender le statut exact de cette quête d'unité ? Remontant à ses origines, examinant ses succès comme ses échecs, analysant sa place dans la physique d'aujourd'hui, Etienne Klein et Marc Lachièze-Rey en cern...

  17. Health impacts of the July 2010 heat wave in Québec, Canada

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    Bustinza Ray

    2013-01-01

    Full Text Available Abstract Background One of the consequences of climate change is the increased frequency and intensity of heat waves which can cause serious health impacts. In Québec, July 2010 was marked by an unprecedented heat wave in recent history. The purpose of this study is to estimate certain health impacts of this heat wave. Methods The crude daily death and emergency department admission rates during the heat wave were analyzed in relation to comparison periods using 95% confidence intervals. Results During the heat wave, the crude daily rates showed a significant increase of 33% for deaths and 4% for emergency department admissions in relation to comparison periods. No displacement of mortality was observed over a 60-day horizon. Conclusions The all-cause death indicator seems to be sufficiently sensitive and specific for surveillance of exceedences of critical temperature thresholds, which makes it useful for a heat health-watch system. Many public health actions combined with the increased use of air conditioning in recent decades have contributed to a marked reduction in mortality during heat waves. However, an important residual risk remains, which needs to be more vigorously addressed by public health authorities in light of the expected increase in the frequency and severity of heat waves and the aging of the population.

  18. ¿Con qué saboreamos?: tareas y experiencias para un taller de ciencias

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    Sánchez Ramos, M.A.

    2008-04-01

    Full Text Available En un grupo de primero de primaria hicimos una pregunta aparentemente simple: ¿Con qué saboreamos? La respuesta inmediata entre los niños fue “con la lengua” y, aunque ésta no fue totalmente correcta, sirvió para iniciar un proyecto en el que se ofreció a los niños la oportunidad para observar, proponer hipótesis, establecerobjetivos y buscar métodos que les ayudaran a resolver la pregunta. Planteamos 4 experiencias cuya finalidad fue que los niños extendieran sus conocimientos y su comprensión sobre un proceso aparentemente sencillo como es la percepción al sabor. Primero cuestionamos la idea de que fuera la lengua el lugar primordial para la detección del sabor (experiencia 1; después incluimos al sentido del olfato como parte de la percepción del sabor (experiencia 2; tratamos de convencer a los niños de que el olor es el elemento más importante para detectar el sabor (experiencia 3; por último discutimos la posibilidad de que fuera el cerebro el que realmente saborea (experiencia 4.

  19. ¿Con qué saboreamos?: tareas y experiencias para un taller de ciencias

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    Marco A. Sánchez Ramos

    2008-01-01

    Full Text Available En un grupo de primero de primaria hicimos una pregunta aparentemente simple: ¿Con qué saboreamos? La respuesta inmediata entre los niños fue "con la lengua" y, aunque ésta no fue totalmente correcta, sirvió para iniciar un proyecto en el que se ofreció a los niños la oportunidad para observar, proponer hipótesis, establecer objetivos y buscar métodos que les ayudaran a resolver la pregunta. Planteamos 4 experiencias cuya finalidad fue que los niños extendieran sus conocimientos y su comprensión sobre un proceso aparentemente sencillo como es la percepción al sabor. Primero cuestionamos la idea de que fuera la lengua el lugar primordial para la detección del sabor (experiencia 1; después incluimos al sentido del olfato como parte de la percepción del sabor (experiencia 2; tratamos de convencer a los niños de que el olor es el elemento más importante para detectar el sabor (experiencia 3; por último discutimos la posibilidad de que fuera el cerebro el que realmente saborea (experiencia 4.

  20. Educomunicación en Física y Química de Bachillerato

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    Felipe Quintanal Pérez

    2013-07-01

    Full Text Available Este trabajo pretende mostrar cómo se puede desarrollar la educomunicación en un nivel académico formal, no obligatorio y preuniversitario, colaborando con la implementación de la competencia mediática y favoreciendo el desarrollo de actitudes críticas, reflexivas y plurales ante los medios de comunicación. Para ello se ha trabajado con alumnos de 1º de Bachillerato que cursaban la asignatura de Física y Química desde las modalidades tecnológica y sanitaria durante el curso 2011-2012. Los productos solicitados en este proyecto a los estudiantes han sido podcast científicos, en castellano y en inglés, líneas del tiempo sobre científicos, vídeopodcast sobre recetas de cocina y murales multimedia de presentación. Las herramientas tecnológicas empleadas han sido Audacity, Dipity, Vídeo Maker u otro editor de vídeos y Glogster. Para la comunicación, asignación de tareas, evaluación e información de ésta se utilizó la plataforma Edmodo.

  1. Discursos curriculares na disciplina escolar Química Curriculum discourses in school Chemistry

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    Alice Casimiro Lopes

    2005-08-01

    Full Text Available Neste artigo, é defendido que a disciplina escolar é um híbrido de discursos curriculares. Para argumentar em favor dessa idéia, é analisado como textos na área de ensino de Química influenciam nas políticas de currículo, hibridizando discursos oficiais e outros discursos curriculares. São articuladas as discussões teóricas de Ball, sobre políticas de currículo, de Goodson, sobre disciplinas escolares, de Bernstein, sobre recontextualização, e de Canclini, sobre hibridismo.This paper defends the hybridism of curricular discourses in school subjects. To argue in favor of this idea, chemistry education's texts are analyzed to show the influence of curriculum policy in hybridizing the official discourses and other curricular discourses. The text draws on the analysis of Ball about curriculum policy, on Goodson's school subjects, on Bernsteins's recontextualization and Canclini's hybridism.

  2. Representaciones sociales de la crisis ambiental en futuros profesores de química

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    Yair Alexander Porras Contreras

    2016-06-01

    Full Text Available Resumen La crisis ambiental, como crisis civilizatoria, emerge de las interacciones poco efectivas entre los subsistemas biofísicos, sociales y culturales, constituyéndose en un riesgo global que trasciende el dominio material, para posicionarse en una categoría que involucra el significado y el sentido de la realidad. De esta manera, las ideas, creencias y concepciones que elaboran los profesores en formación inicial sobre la crisis ambiental, se convierten en derroteros desde los cuales se construye su saber pedagógico y su praxis educativa en relación con el ambiente. El propósito del presente artículo consiste en reconocer las representaciones sociales de la crisis ambiental, que circulan en un grupo de profesores en formación inicial de la Licenciatura en Química de la Universidad Pedagógica Nacional de Colombia (UPN, tomando como referente el enfoque estructural de la representación social.

  3. CDCC del profesorado de Química sobre los conceptos cantidad de sustancia y mol

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    Aldemar García

    2009-10-01

    Full Text Available Esta comunicación presenta los resultados finales de una investigación desarrollado durante los años 2007 y 2008 en la Universidad Pedagógica Nacional en Bogotá, para determinar las concepciones del profesorado de educación media de química, del Colegio el Jazmín, y las características del conocimiento didáctico del contenido curricular (CDCC que tienen al diseñar currículos para enseñar los conceptos de cantidad de sustancia y mol. Se describe si sus concepciones están enmarcadas por el modelo teórico atomista o equivalentista, y se explica el origen de dichas concepciones. Se desarrolló una Trama Histórica / Epistemológica (THE en relación con estos modelos teóricos y se diseñó una Unidad Didáctica (UD para enseñar dichos conceptos. Este trabajo forma parte del proyecto del Centro de Investigación CIUP, de la UPN: DQU02507.

  4. Pesticide residues in fruit samples: comparison of different QuEChERS methods using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Christia, C; Bizani, E; Christophoridis, C; Fytianos, K

    2015-09-01

    Acetate- and citrate-buffered quick, easy, cheap, effective, rugged, safe (QuEChERS) pretreatment methods were evaluated for the determination of various pesticides in peaches, grapes, apples, bananas, pears, and strawberries from various regions of Greece, using LC-MS/MS. The purposes of this study were (i) to evaluate which type of QuEChERS method was the most appropriate and effective for each matrix; (ii) to apply the selected QuEChERS method for each matrix, in order to detect and quantify pesticide residues in various fruit samples using UPLC-MS/MS; (iii) to examine the concentration distribution of pesticide classes among fruit originating from various areas; and (iv) to assess pesticide concentration distribution between peel and flesh of fruit in order to evaluate the penetration of pesticide residues in the fruit flesh. Acetate-buffered QuEChERS was found to be the most suitable technique for most of the fruit matrices. According to the recovery values at two different concentration levels, peaches should preferably be treated by the citrate-buffered type, whereas grapes, bananas, apples, pears, and strawberries are best treated by the acetate-buffered version, although the differences in efficiency were small. The addition of graphitized carbon black significantly decreases the recovery of specific pesticides in all matrices except for strawberries. The majority of values do not exceed the official maximum residue levels set by the European Commission. Organophosphates proved to be the most commonly detected category along with triazines-triazoles-conazoles group and by carbamates. Apples and pears seem to be the most contaminated fruit matrices among those tested. Distribution of pesticide classes shows variations between different regions, suggesting different pesticide application practices. In the case of peaches and pears, there is an equal distribution of detected pesticides between peel and flesh, indicating penetration of contaminants into the

  5. Pertinencia de la formación: opiniones de las personas egresadas de la Escuela de Química

    Directory of Open Access Journals (Sweden)

    Quesada Espinoza, Javier

    2016-05-01

    Full Text Available El presente artículo muestra la valoración de la pertinencia de la formación profesional de personas egresadas de Química. Se valoró la percepción de graduados entre el 2010 y 2014 de la carrera de Bachillerato y Licenciatura en Química de la Universidad de Costa Rica, mediante la aplicación de una encuesta donde se evaluó la pertinencia de bloques temáticos durante la formación, conveniencia de temas presentes y ausentes en la malla curricular actual y el papel de los cursos de Química Industrial, en especial la práctica profesional. Como resultados, se obtuvo información que muestra una desvinculación entre la formación brindada en la universidad y las necesidades del futuro profesional. Se identifican bloques temáticos que no aportan lo esperado. Se manifiestan debilidades en temas asociados a habilidades blandas y tópicos específicos del desarrollo profesional de la Química en el país; dichos temas están vinculados a la gestión, el manejo de personal y el trabajo colaborativo. Se concluye que es necesaria la revisión profunda de la malla curricular con el apoyo de empleadores y personas egresadas para alinearla con las necesidades de la sociedad y promover estrategias didácticas que permitan desarrollar mejor habilidades blandas a lo largo de toda la carrera.

  6. ELIPSE E SUBSTITUIÇÃO EM RÉPLICAS DE SIM/NÃO E QU-

    Directory of Open Access Journals (Sweden)

    Maria Fabíola Vasconcelos Lopes

    2016-01-01

    Full Text Available Este trabalho pretende mostrar como os mecanismos de coesão da elipse e substituição se processam em meio à réplicas envolvendo sim/não e tipo Qu-. Para tal finalidade, nos basearemos em Halliday e Hasan e na aná- lise de alguns casos. Palavras-chave: elipse, substituição, réplicas

  7. Nuevas inyecciones químicas estructurales de base silicato en la ingeniería geotécnica

    Directory of Open Access Journals (Sweden)

    López Ruiz, Álvaro

    1982-06-01

    Full Text Available Not available.Se presentan las propiedades de los suelos granulares estabilizados in situ mediante dos «inyecciones químicas» estructurales, de base silicato sódico, utilizadas por primera vez en la Ingeniería Geotécnica por el autor, y se describen las primeras obras importantes ejecutadas con ellas, en Milán, Barcelona y Madrid, Una de estas soluciones químicas, que produce un gel duro, y que utiliza básicamente como reactivo una mezcla de formamida-acetato de etilo, soluble en el sistema líquido, ha sido tratada ampliamente en el reciente congreso sobre inyecciones, organizado por la ASCE, de Nueva Orleans (Febrero 1982 y se consideran sus resultados en este trabajo. Se describe la utilización para la estabilización de suelos, de otro tipo de solución, también de base silicato, que expansiona durante el proceso de gelificación, y que es compatible con la primeramente indicada, es decir, que se pueden obtener productos con propiedades intermedias. Se pone especial énfasis en la necesidad de un mejor conocimiento de los procesos físico-químicos y reológicos en estos sistemas y de la influencia del factor tiempo sobre su estabilidad y comportamiento intrínsecos y su relación con el medio, que se debieran interpretar a partir de su estructura químico-molecular, de la que dependen también sus propiedades mecánicas.

  8. El uso de armas químicas en Siria, un desafío para el derecho internacional

    Directory of Open Access Journals (Sweden)

    Rubén Cardoza Zúñiga

    2015-03-01

    Full Text Available Este artículo analiza las acciones tomadas por la comunidad internacional, a través de la Organización para la Prohibición de las Armas Químicas (opaq y del Consejo de Seguridad sobre la amenaza que representa el hecho de poseer y, sobre todo, de usar armas químicas en contra de la población, como una reacción enérgica por parte del gobierno de Siria, violando las normas y principios más elementales del derecho internacional y del derecho internacional humanitario. Hay que reconocer que en esta ocasión se pudo lograr un consenso unánime entre los miembros del Consejo de Seguridad para imponer un proceso de destrucción de las armas químicas, materiales y aditamentos que posee el gobierno de la República de Siria, mediante la Resolución del Consejo de Seguridad 2118, sin tener que recurrir a las sanciones mencionadas en el capítulo VII de la Carta de las Naciones Unidas, por lo que imperó el derecho internacional. Como podrá observar el lector, las acciones en conjunto tomadas tanto en el seno del Consejo de Seguridad, por la opaq, como en el consenso llevado a cabo entre Rusia y los Estados Unidos obligaron al gobierno de Siria a comprometerse a aceptar lo estipulado en la Convención sobre Armas Químicas, y se evitó de esta manera que se realizara una invasión militar a Siria, situación que empezaba a ser considerada por el gobierno de los Estados Unidos.

  9. Identification and characterization of filamentous fungi isolated from fermentation starters for Hong Qu glutinous rice wine brewing.

    Science.gov (United States)

    Lv, Xu-Cong; Huang, Zhi-Qing; Zhang, Wen; Rao, Ping-Fan; Ni, Li

    2012-01-01

    Hong Qu glutinous rice wine is one of the most popular traditional rice wines in China. Traditionally, this wine is brewed from glutinous rice with the addition of wine fermentation starters (Hong Qu (also called red yeast rice) and White Qu). The objective of this study was to investigate the variability of filamentous fungi associated with traditional fermentation starters through a traditional culture-dependent method and a molecular identification approach. In this study, forty-three filamentous fungi were separated by traditional culture-dependent means (macro- and microscopic characteristics) from 10 fermentation starters and classified into 16 different species based on morphological examination and the internal transcribed spacer (ITS) sequences analysis. It was observed that the genus Aspergillus had the highest number (14 isolates) of isolates followed by Rhizopus (11 isolates), Monascus (5 isolates) and Penicillium (4 isolates). The species R. oryzae, A. niger, A. flavus and M. purpureus were frequently found in wine starter samples, among which R. oryzae was the most frequent species. The enzyme-producing properties (glucoamylase, α-amylase and protease) of all fungal isolates from different starters were also evaluated. A. flavus, R. oryzae and M. purpureus were found to be better glucoamylase producers. A. flavus, R. oryzae and A.oryzae exhibited higher activity of α-amylase. A. flavus and A. oryzae had higher protease activity. However, some fungal isolates of the same species exhibited a significant variability in the production levels for all determined enzyme activity. This study is the first to identify filamentous fungi associated with the starter of Hong Qu glutinous rice wine using both traditional and molecular methods. The results enrich our knowledge of liquor-related micro-organisms, and can be used to promote the development of the traditional fermentation technology.

  10. Estudos ecológicos preliminares e caracterização química dos Cnidaria da costa noroeste portuguesa

    OpenAIRE

    Gadelha, Juliana Rodrigues

    2007-01-01

    O levantamento de recursos em espécies marinhas em Portugal ainda é incipiente, considerando que este domínio de investigação tem sido amplamente desenvolvido noutros pontos do globo, pescas, química, bioquímica e farmacologia de organismos marinhos, de modo a obter informações sobre a química de produtos naturais e ecologia química de organismos marinhos derivadas destes organismos. São de realçar a importância das defesas químicas para as relações ecológicas de predação, comp...

  11. Qu'est-ce que le boson de Higgs mange en hiver et autres détails essentiels

    CERN Document Server

    Gagnon, Pauline

    2015-01-01

    Juillet 2012 : le CERN, le Laboratoire européen de la physique des particules, annonçait en grande pompe la découverte du boson de Higgs. La nouvelle a fait le tour du monde. Mais combien de gens comprennent vraiment ce que c'est et pourquoi cette découverte fut suivie du prix Nobel de physique en 2013 pour les théoriciens François Englert et Peter Higgs qui en avaient prédit l'existence 48 ans auparavant ? Le boson de Higgs était le chaînon manquant du modèle théorique actuel qui décrit ce qui compose toute la matière qu'on voit autour de nous. Ce livre explique comment tout cela fonctionne et le rôle du boson de Higgs. Et le livre va beaucoup plus loin car cette théorie ne s'applique qu'à la matière visible, celle qu'on trouve sur Terre, dans les étoiles et les galaxies, mais qui ne compte que pour 5 % du contenu de l'Univers. Le reste, soit 95 % de l'Univers, consiste en « matière sombre » et en « énergie sombre », deux entités complètement inconnues. Quelle est donc cette mystér...

  12. Ten years of integrated care: backwards and forwards. The case of the province of Québec, Canada

    Directory of Open Access Journals (Sweden)

    Isabelle Vedel

    2011-02-01

    Full Text Available Introduction: Québec's rapidly growing elderly and chronically ill population represents a major challenge to its healthcare delivery system, attributable in part to the system's focus on acute care and fragmented delivery. Description of policy practice: Over the past few years, reforms have been implemented at the provincial policy level to integrate hospital-based, nursing home, homecare and social services in 95 catchment areas. Recent organizational changes in primary care have also resulted in the implementation of family medicine groups and network clinics. Several localized initiatives were also developed to improve integration of care for older persons or persons with chronic diseases. Conclusion and discussion: Québec has a history of integration of health and social services at the structural level. Recent evaluations of the current reform show that the care provided by various institutions in the healthcare system is becoming better integrated. The Québec health care system nevertheless continues to face three important challenges in its management of chronic diseases: implementing the reorganization of primary care, successfully integrating primary and secondary care at the clinical level, and developing effective governance and change management. Efforts should focus on strengthening primary care by implementing nurse practitioners, developing a shared information system, and achieving better collaboration between primary and secondary care.

  13. Ten years of integrated care: backwards and forwards. The case of the province of Québec, Canada

    Directory of Open Access Journals (Sweden)

    Isabelle Vedel

    2011-02-01

    Full Text Available Introduction: Québec's rapidly growing elderly and chronically ill population represents a major challenge to its healthcare delivery system, attributable in part to the system's focus on acute care and fragmented delivery. Description of policy practice: Over the past few years, reforms have been implemented at the provincial policy level to integrate hospital-based, nursing home, homecare and social services in 95 catchment areas. Recent organizational changes in primary care have also resulted in the implementation of family medicine groups and network clinics. Several localized initiatives were also developed to improve integration of care for older persons or persons with chronic diseases.Conclusion and discussion: Québec has a history of integration of health and social services at the structural level. Recent evaluations of the current reform show that the care provided by various institutions in the healthcare system is becoming better integrated. The Québec health care system nevertheless continues to face three important challenges in its management of chronic diseases: implementing the reorganization of primary care, successfully integrating primary and secondary care at the clinical level, and developing effective governance and change management.Efforts should focus on strengthening primary care by implementing nurse practitioners, developing a shared information system, and achieving better collaboration between primary and secondary care.

  14. Dependência química e prevenção à “recaída”

    Directory of Open Access Journals (Sweden)

    Fátima Büchele

    2004-01-01

    Full Text Available El presente estudio se trata de una investigación descriptiva-exploratoria con un abordaje cuali-cuantitativo, el cual posibilitó hacer un levantamiento de los factores considerados de riesgo para las reacaidas según la visión de los entrevistados en la Unidad de Dependencia Química del Instituto de Psiquiatría de Santa Catarina. Para la colecta de los datos se aplicó un cuestionario en la forma de entrevista a una muestra de 25 usuarios internados en la misma unidad, durante el período de abril a mayo del 2003. El objetivo fue levantar las situaciones de riesgo que los dependientes químicos reconocen como signos y síntomas siendo que estos los llevan a una recaida. Entre tanto, presentamos los resultados obtenidos donde se demuestran algunos factores de riesgo para la recaida que contribuyen con el área de dependencia química en este sentido.

  15. QuSpin: a Python package for dynamics and exact diagonalisation of quantum many body systems part I: spin chains

    Directory of Open Access Journals (Sweden)

    Phillip Weinberg, Marin Bukov

    2017-02-01

    Full Text Available We present a new open-source Python package for exact diagonalization and quantum dynamics of spin(-photon chains, called QuSpin, supporting the use of various symmetries in 1-dimension and (imaginary time evolution for chains up to 32 sites in length. The package is well-suited to study, among others, quantum quenches at finite and infinite times, the Eigenstate Thermalisation hypothesis, many-body localisation and other dynamical phase transitions, periodically-driven (Floquet systems, adiabatic and counter-diabatic ramps, and spin-photon interactions. Moreover, QuSpin's user-friendly interface can easily be used in combination with other Python packages which makes it amenable to a high-level customisation. We explain how to use QuSpin using four detailed examples: (i Standard exact diagonalisation of XXZ chain (ii adiabatic ramping of parameters in the many-body localised XXZ model, (iii heating in the periodically-driven transverse-field Ising model in a parallel field, and (iv quantised light-atom interactions: recovering the periodically-driven atom in the semi-classical limit of a static Hamiltonian.

  16. Constituição de identidades em um curso de licenciatura em química

    Directory of Open Access Journals (Sweden)

    Carmen Silvia da Silva

    2017-01-01

    Full Text Available El propósito de este artículo es presentar los resultados obtenidos en la investigación de un curso de formación de maestros en ciencias químicas en una universidad pública. Fueron utilizadas referencias teóricas acerca de la profesionalización docente, identidad y currículo, particularmente los estudios culturales y el abordaje sociológico. La metodología de carácter cualitativo se basa en el análisis de cuestionarios aplicados a 71 licenciandos y entrevistas con seis licenciandos y seis graduados a través del análisis textual del discurso de los datos obtenidos. Los resultados indicaron que el currículo actual del curso conduce a la profesionalización para la investigación específica en ciencias química. Se concluye que los profesores tendrán que cambiar sus prácticas con el fin de romper el modelo de formación que devalúa la profesionalización para la enseñanza de química para los jóvenes, una actividad considerada de poca importancia para muchos de ellos.

  17. Combination of QuEChERS and DLLME for GC-MS determination of pesticide residues in orange samples.

    Science.gov (United States)

    Andraščíková, Mária; Hrouzková, Svetlana; Cunha, Sara C

    2013-01-01

    A new method combining QuEChERS (quick, easy, cheap, effective, rugged and safe) and DLLME (dispersive liquid-liquid microextraction) followed by gas chromatography-mass spectrometry with selected ion monitoring (SIM) was developed for the simultaneous determination of 19 pesticides from nine chemical groups exhibiting or suspected to exhibit endocrine-disrupting properties in orange samples. Acetonitrile extract obtained from QuEChERS extraction was used for DLLME as dispersive solvent and carbon tetrachloride as extractive solvent to increase the enrichment factor of the extraction procedure. The effect of several extraction parameters, such as volume extract achieved by the QuEChERS method and subsequently used for DLLME, selection of extractive solvent and its volume, was tested. Under optimum conditions, good linearity, satisfactory recoveries and repeatability were obtained. Limits of quantification (LOQs) achieved (ranging from 0.02 to 47 ng/g) were below the maximum residue limits established by the European Union. The proposed method was applied to the monitoring of pesticide residue levels in oranges commercialised in Portugal.

  18. Simultaneous Analysis of Ursolic Acid and Oleanolic Acid in Guava Leaves Using QuEChERS-Based Extraction Followed by High-Performance Liquid Chromatography

    OpenAIRE

    Xu, Chang; Liao, Yiyi; Fang, Chunyan; Tsunoda, Makoto; Zhang, Yingxia; Song, Yanting; Deng, Shiming

    2017-01-01

    In this paper, a novel method of QuEChERS-based extraction coupled with high-performance liquid chromatography has been developed for the simultaneous determination of ursolic acid (UA) and oleanolic acid (OA) in guava leaves. The QuEChERS-based extraction parameters, including the amount of added salt, vortex-assisted extraction time, and absorbent amount, and the chromatographic conditions were investigated for the analysis of UA and OA in guava leaves. Under the optimized conditions, the m...

  19. Cómo resolver un balance de energía CON reacción química - parte 1

    OpenAIRE

    Fernandez-Torres, Maria J.

    2013-01-01

    Ejemplo de cómo encontrar el valor de "incremento de entalpía" para resolver un balance de energía dentro de la disciplina de la Ingeniería Química. Para el cálculo que se presenta se utilizan los valores de entalpías de formación de las sustancias que intervienen en la reacción química.

  20. Diagnostic significance of tumor markers CEA, CA50 and CA19-9 for colorectal cancer

    International Nuclear Information System (INIS)

    Chen Yumei; Huang Gang

    2005-01-01

    Objective: To investigate the expression and diagnostic significance of three serum tumor markers (CEA, CA50, CA19-9) in patients with colorectal cancer, with special emphasis on their combined assay. Methods: Serum CEA, CA19-9 levels (with chemiluminescence immunoassay) and CA50 levels (with immunoradiometric assay) were determined in 94 patients with colorectal cancer, 20 patients with benign colorectal disorders and 37 controls. Results: The expressions of the serum tumor markers were significantly higher in patients with colorectal cancer than those in patients with benign colorectal disorders and controls (P<0.05). There was no significant difference between the levels in the latter two groups. CEA assay had the highest sensitivity (57.4%) and specificity (85.9%). Combined assay of the three could enhance both the sensitivity (62.7%) and specificity (96.5%). The serum levels of the markers were significantly higher in patients with colonic cancer than those in patients with rectal cancer (P<0.05). The levels were positively correlated with the size of the growth and stage of the disease. Serum tumor marker levels were also significantly higher in patients with metastasis (regional/distant) than those in patients without metastasis (P<0.05). Conclusion: Determination of serum CEA, CA50 and CA19-9 levels had definite value for the diagnosis and assessment of the pathology as well as biologic behavior colorectal cancer. Combined assay of the three could enhance the diagnostic sensitivity and specificity. (authors)

  1. Exploring physical and chemical factors influencing the properties of recombinant prion protein and the real-time quaking-induced conversion (RT-QuIC) assay.

    Science.gov (United States)

    Cheng, Keding; Sloan, Angela; Avery, Kristen M; Coulthart, Michael; Carpenter, Michael; Knox, J David

    2014-01-01

    Real-time quaking-induced conversion (RT-QuIC), a highly specific and sensitive assay able to detect low levels of the disease-inducing isoform of the prion protein (PrP(d)) in brain tissue biopsies and cerebral spinal fluid, has great potential to become a method for diagnosing prion disease ante mortem. In order to standardize the assay method for routine analysis, an understanding of how physical and chemical factors affect the stability of the recombinant prion protein (rPrP) substrate and the RT-QuIC assay's sensitivity, specificity, and reproducibility is required. In this study, using sporadic Creutzfeldt-Jakob Disease brain homogenate to seed the reactions and an in vitro-expressed recombinant prion protein, hamster rPrP, as the substrate, the following factors affecting the RT-QuIC assay were examined: salt and substrate concentrations, substrate storage, and pH. Results demonstrated that both the generation of the quality and quantities of rPrP substrate critical to the reaction, as well as the RT-QuIC reaction itself required strict adherence to specific physical and chemical conditions. Once optimized, the RT-QuIC assay was confirmed to be a very specific and sensitive assay method for sCJD detection. Findings in this study indicate that further optimization and standardization of RT-QuIC assay is required before it can be adopted as a routine diagnostic test.

  2. Evaluation of Metarhizium anisopliae var. anisopliae Qu-M845 Isolate to Control Varroa destructor (Acari: Varroidae in Laboratory and Field Trials Evaluación del Aislamiento Qu-M845 de Metarhizium anisopliae var. anisopliae para el Control de Varroa destructor (Acari: Varroidae en Ensayos de Laboratorio y Terreno

    Directory of Open Access Journals (Sweden)

    Marta Rodríguez

    2009-12-01

    Full Text Available The effectiveness of the Metarhizium anisopliae (Metschinkoff Qu-M845 isolate was evaluated in laboratory and field trials. It was previously selected for thermal resistance (at 30 and 35 ºC and pathogenicity on Varroa destructor (Anderson and Trueman. In the laboratory, the first evaluations were carried out by spraying and increasing the concentration from zero to 10(8 conidia mL-1 on varroa adults. Lethal concentrations required for 50 and 90% mite mortality (LC50 and LC90 were 3.8 x 10(5 and 8 x 10(7 conidia mL-1, respectively (χ2 = 2.03. In the autumn field trials, three application methods (doses of 5 x 10(10 conidia per hive were evaluated. The treatments were: a conidia stamped on filter paper, located on every second frame inside the hive; b dry conidia sprinkled on and between frames; and c dry conidia in a dispenser path at the entrance of the hive. Furthermore, untreated hives were included as controls. After 21 days of treatment, the dry conidia sprinkled on and between frames showed 67% less bees infested by the mite than the control (p La efectividad del aislamiento Qu-M845 de Metarhizium anisopliae (Metschinkoff, seleccionado previamente por su resistencia a temperaturas de 30 y 35 ºC, y patogenicidad sobre Varroa destructor Anderson y Trueman fue evaluada en laboratorio y en ensayos de terreno. Las primeras pruebas consistieron en pulverizar concentraciones crecientes de 0 a 10(8 conidias mL-1 sobre varroas adultas. La concentración letal para matar el 50 y 90% de la población (CL50 y CL90 fueron de 3,8 x 10(5 y 8 x 10(7 conidias mL-1, respectivamente (χ² = 2,03. En otoño se evaluaron en terreno tres métodos de aplicación de una dosis de 5 x 10(10 conidias por colmena. Los tratamientos fueron: a conidias estampadas en papel filtro ubicado cada dos panales móviles al interior de la colmena; b conidias espolvoreadas sobre y entre los panales; y c dispensador de conidias ubicado en la piquera de las colmenas. Además se

  3. Radiolysis of Ca14CO3

    International Nuclear Information System (INIS)

    Sanchez, M.G.A.

    1986-01-01

    The partition-ion exclusion chromatography is evaluated to analyse non-ionic organic compounds obtained from radiolysis of high specific activity Ca 14 CO 3 . The Ca 14 CO 3 was irradiated by β - decay of carbon-14 or by γ rays from a cobalt-60 source. The crystals were dissolved for qualitative and quantitative analysis of the radiolytic products. Formic and oxalic acids were produced in high yields. Glyoxylic, acetic and glycolic acids, formaldehyde and methanol were produced in low yields. Quantitative determination was carried out by liquid scintillation spectroscopy and the chemical yields (G-values) were calculated for the products. Mechanisms of product formation are proposed based on thermal annealing experiments. (Author) [pt

  4. Clustering and triaxial deformations of 40Ca

    International Nuclear Information System (INIS)

    Taniguchi, Yasutaka; Kimura, Masaaki; Kanada-En'yo, Yoshiko; Horiuchi, Hisashi

    2007-01-01

    We have studied the positive-parity states of 40 Ca using antisymmetrized molecular dynamics (AMD) and the generator coordinate method (GCM). Imposing two different kinds of constraints on the variational calculation, we have found various kinds of 40 Ca structures such as a deformed-shell structure, as well as α- 36 Ar and 12 C- 28 Si cluster structures. After the GCM calculation, we obtained a normal-deformed band and a superdeformed band together with their side bands associated with triaxial deformation. The calculated B(E2) values agreed well with empirical data. It was also found that the normal-deformed and superdeformed bands have non-negligible α- 36 Ar cluster and 12 C- 28 Si cluster components, respectively. This leads to the presence of an α- 36 Ar higher nodal band occurring above the normal-deformed band

  5. Riesgo químico: estrategias de intervención social Chemical risk: strategies for social intervention

    Directory of Open Access Journals (Sweden)

    J. Riechmann Fernández

    2002-06-01

    Full Text Available La producción, utilización, comercialización y emisión de sustancias químicas pone de manifiesto los fuertes vínculos existentes entre el riesgo químico en el lugar de trabajo, la salud pública y la contaminación ambiental. A pesar de ello, las políticas de gestión del riesgo químico no han sido coherentes y unificadas en las diferentes áreas (seguridad alimentaria, agricultura, salud pública, medio ambiente y salud laboral.La Comisión de las Comunidades Europeas ha elaborado un Libro Blanco sobre la futura política en materia de sustancias químicas en el que reconoce un importante grado de descontrol. Realmente estamos ante una profunda crisis de ineficacia de las estrategias tradicionales que debían servir supuestamente para controlar el riesgo químico.Se hace necesario utilizar estrategias diversificadas: unas destinadas a mejorar los niveles de información; otras dirigidas a la evaluación de las situaciones de riesgo y otras, de mucho mayor calado, que tengan como objetivo la evaluación de alternativas orientadas a la resolución de los problemas.Production, use, marketing and emission of chemical substances display the strong links between chemical risks at the workplace, healthcare and environmental pollution. In spite of this fact, the policies for the management of chemical risk are far from being coherent and unified in the different sectors. (Nutritional safety, agriculture, healthcare, environment and occupational health.The Commission of European Communities (EC has elaborated a White Document on the future policy on chemicals that recognizes the existing lack of control in this domain. We are facing a deep crisis of traditional strategies that are supposed to control chemical risks.It becomes essential to diversify the strategies. Some of them must aim at the improvement of information, others at the assessment of risk situations and some strategies must be directed to evaluate the possible alternatives for the

  6. Astrocyte Ca2+ signalling: an unexpected complexity

    OpenAIRE

    Volterra, Andrea; Liaudet, Nicolas; Savtchouk, Iaroslav

    2014-01-01

    Astrocyte Ca(2+) signalling has been proposed to link neuronal information in different spatial-temporal dimensions to achieve a higher level of brain integration. However, some discrepancies in the results of recent studies challenge this view and highlight key insufficiencies in our current understanding. In parallel, new experimental approaches that enable the study of astrocyte physiology at higher spatial-temporal resolution in intact brain preparations are beginning to reveal an unexpec...

  7. 43Ca NMR in solid state

    Science.gov (United States)

    Bellot, P.-V.; Trokiner, A.; Zhdanov, Yu.; Yakubovskii, A.

    1998-02-01

    In this paper we show that 43Ca is a suitable NMR probe to study the properties of high-Tc superconducting oxides. In the normal state, we report the temperature and doping dependencies of the spin susceptibility measured by 43Ca NMR. In the superconducting state and more exactly in the mixed state, by analysing 43Ca NMR linewidth, we have studied the magnetic induction distribution due to the presence of vortices and deduced λ, the penetration depth. Dans cet article, on montre que l'isotope 43 du calcium est une bonne sonde RMN pour l'étude des propriétés des oxydes supraconducteurs à haute température. Dans l'état normal, par la détermination du déplacement de la raie, en fonction de la température, on accède à la variation thermique de la susceptibilité de spin. Dans l'état supraconducteur et plus particulièrement dans l'état mixte, la largeur de raie RMN permet d'étudier la distribution d'induction magnétique due à la présence des vortex et de déterminer λ, la longueur de pénétration.

  8. Mg,Ca-ATPase activity under irradiation

    International Nuclear Information System (INIS)

    Ladutin, V.V.; Orlova, V.V.; Lob, P.A.; Gerasiminko, I.V.; Mack, E.I.

    2003-01-01

    Full text: The influence of different doses irradiation at the Mg,Ca-ATPase activity at the rat brain has been investigated. The analyses were made at the apparatus of LKB and Carl-Ceis-Jena firm with help of reagents of Sigma and Boehringer firm. Rats decapitated after 1, 3, 6, 24 and 48 h after action of irradiation. Dose 0.206 C/kg. Erythrocytes. 1 and 3h after irradiation influence- decrease of Mg,Ca-ATPase activity to 86-87% relatively control level, 24 and 48 h - increase of activity to the control level. Dose 0.312 C/kg. Large hemispheres. 1h - decrease of ATPase activity to 90% relatively control, 3h - increase to control level, 24h - fall to 86%, after 48h small increase to 93% relatively control. Dose 9.287 C/kg. Large hemispheres. 1h - sharp fall of Mg, Ca-ATPase activity to 67 % relatively control, increase of activity to 96% after 3h and sharp fall of activity to 64% 6h after action of irradiation. Dose 9.287 C/kg. Cerebellum. 1h - sharp decrease of ATPase activity to 80%. After 3h -sharp increase to 160% relatively control level and sharp fall of ATPase activity to 47% relatively control after 6h. The mechanism of radiation pathology of active ion transport has been discussed

  9. Ca-48 targets - Home and abroad!

    Science.gov (United States)

    Greene, John P.; Carpenter, Michael; Janssens, Robert V. F.

    2018-05-01

    Using the method of reduction/distillation, high-purity films of robust and ductile calcium metal were prepared for use as targets in nuclear physics experiments. These targets, however, are extremely air-sensitive and procedures must be developed for their handling and use without exposure to the air. In most instances, the thin 48Ca target is used on a carrier foil (backing) and a thin covering film of similar material is employed to further reduce re-oxidation. Un-backed metallic targets are rarely produced due to these concerns. In addition, the low natural abundance of the isotope 48Ca provided an increased incentive for the best efficiencies available in their preparation. Here, we describe the preparation of 48Ca targets employing a gold backing and thin gold cover for use at home, Argonne National Laboratory (ANL), as well as abroad, at Osaka University. For the overseas shipments, much care and preparation were necessary to ensure good targets and safe arrival to the experimental facilities.

  10. Visiones de la revolución química (1794-1943: entre la historia y la memoria

    Directory of Open Access Journals (Sweden)

    José Ramón BERTOMEU SÁNCHEZ

    2009-11-01

    Full Text Available RESUMEN: Iniciada por los propios protagonistas, desarrollada por los «químicos historiadores» del siglo XIX y engrosada, revisada y completamente reformulada desde la historia, la sociología y la filosofía de la ciencia del siglo XX, la narración de la llamada «revolución química» han dado lugar a uno de los capítulos más ricos y extensos de la historiografía de la ciencia. Como si de la narración de los orígenes de una nación se tratara, los químicos historiadores del siglo XIX hicieron de la revolución química el momento fundacional de su disciplina. La narración mítica del nacimiento de la química fue alimentada con la figura de un héroe fundador víctima de la sinrazón (Lavoisier, acontecimientos cruciales (el descubrimiento del oxígeno, el análisis y la síntesis del agua y objetos de culto (la balanza. En este artículo, analizaremos cómo surgieron algunas de estas ideas y las prácticas conmemorativas a través de las cuales fueron configuradas y difundidas. El desarrollo de la historia de la ciencia como disciplina académica introdujo nuevos planteamientos, de modo que la tradición histórica de los libros de química y las reconstrucciones realizadas por los historiadores se fueron alejando progresivamente, sin dejar por ello de interaccionar e influirse mutuamente, a menudo desde la falta de comunicación y entendimiento. A través del ejemplo de la revolución química, pretendemos reflexionar sobre las causas y las consecuencias de esta situación, que debe conducir a reflexionar acerca del papel de la historia en la formación de los científicos.ABSTRACT: Started by those who played a leading role in the events, developed by the chemist-historians of the 19th century and enriched, revised and completely reformulated by the historians, sociologists and philosophers of science of the 20th century, the narration of the so-called “chemical revolution” has given rise to one of the richest and most

  11. Caracterização química e mineralogia de solos antrópicos (terras pretas de índio na amazônia central

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    Francisco Weliton Rocha Silva

    2011-06-01

    Full Text Available Na Amazônia brasileira é comum a ocorrência de sítios arqueológicos. Frequentemente, observa-se que as ações humanas nesses sítios promoveram modificações significativas em muitas das características físicas, morfológicas e químicas dos solos desses ambientes, tornando-os muito diferentes dos solos adjacentes, especialmente nas áreas de terra firme da região. Embora muitos estudos tenham sido conduzidos visando compreender a magnitude dessas modificações e seus reflexos na gênese dos solos influenciados, muitas questões precisam ser mais bem compreendidas, sobretudo as relacionadas com a mineralogia desses solos. Este estudo teve como objetivo avaliar as características químicas, a composição mineralógica das frações argila e areia e o grau de pedogênese de cinco perfis de solos com horizonte A antrópico (Au, em ambientes de terra firme e várzea, localizados na Bacia Sedimentar do Amazonas, entre Coari e Manaus-AM. Amostras de solos foram coletadas, preparadas e submetidas às análises químicas de rotina e caracterizadas quanto aos teores de carbono oxidável e aos teores de Si, Fe, Al e P; adicionalmente, efetuou-se a identificação dos minerais presentes nas frações argila e areia, por meio de difratometria de raios X. Os resultados mostraram que as modificações promovidas pela atividade humana levaram à melhoria da fertilidade do solo, resultando em solos com acidez moderada, elevados teores de Ca2+ e de P disponíveis e baixos teores de Al3+ trocável. Esses resultados também revelaram teores muito elevados de P-total nos horizontes antrópicos, variando entre 1.630 e 8.840 mg kg-1 de P2O5. A mineralogia da fração argila dos solos antrópicos de terra firme revelou dominância de caulinita, além da ocorrência de gibbsita, de goethita e de óxidos de titânio (anatásio. O perfil de várzea, além de caulinita e goethita, apresentou também minerais do tipo 2:1 na fração argila. A mineralogia da

  12. Glucagon releases Ca2+ from a FCCP-sensitive pool

    International Nuclear Information System (INIS)

    Kraus-Friedmann, N.

    1986-01-01

    The effects of physiological levels of glucagon on Ca 2+ efflux were examined in the perfused rat liver. Two methods were used to estimate Ca 2+ efflux: (1) prior labeling of the Ca 2+ pools with 45 Ca 2+ , and (2) measurement of perfusate Ca 2+ with atomic absorption. According to both methods, glucagon administration at the physiological level evoked Ca 2+ release. In order to identify the hormone-sensitive Ca 2+ pool, a method employed by several laboratories was used. In this method, mitochondrial Ca 2+ is released by FCCP, (carbonyl-cyanide 4 (trifluoro/methoxy) phenylhydrazone), a mitochondrial uncoupler. The effect of hormones on Ca 2+ release after such uncoupler administration is measured. A decreased release is taken as an indication that the pool is entirely or partially mitochondrial. FCCP released 90 +/- 29 nmoles Ca 2+ /gr wet liver. Glucagon (5 x 10 -9 M) released 107 +/- 45 nmoles Ca 2+ /gr wet liver before and 26 +/- 9 nmoles Ca 2+ /gr wet liver after FCCP. These data indicate that glucagon releases Ca 2+ mostly from the mitochondria

  13. CaMKII in sinoatrial node physiology and dysfunction

    Directory of Open Access Journals (Sweden)

    Yuejin eWu

    2014-03-01

    Full Text Available The calcium and calmodulin dependent protein kinase II (CaMKII is present in sinoatrial node (SAN pacemaker cells and is required for physiological fight or flight SAN beating rate responses. Inhibition of CaMKII in SAN does not affect baseline heart rate, but reduces heart rate increases in response to physiological stress. CaMKII senses intracellular calcium (Ca2+ changes, oxidation status and hyperglycemia to phosphorylate substrates that regulate Ca2+-sensitive proteins, such as L-type Ca2+ channels, phospholamban (PLN, and cardiac ryanodine receptors (RyR2. All of these substrates are involved in the SAN pacemaking mechanism. Excessive CaMKII activity, as occurs under pathological conditions such as heart failure, ischemia and diabetes, can promote intracellular Ca2+ overload and reactive oxygen species (ROS production. Oxidation of CaMKII (ox-CaMKII locks CaMKII into a constitutively active configuration that contributes to SAN cell apoptosis and fibrosis. This ox-CaMKII-mediated loss of functional SAN cells contributes to sinoatrial node dysfunction (SND and sudden death. Thus, CaMKII has emerged as a central regulator of physiological SAN responses and a key determinant of SND.

  14. IP3 stimulates CA++ efflux from fusogenic carrot protoplasts

    International Nuclear Information System (INIS)

    Rincon, M.; Boss, W.F.

    1986-01-01

    Polyphosphoinositide breakdown plays an important role in signal transduction in animal cells (Berridge and Irvine, 1984, Nature, 312:315). Upon stimulation, phospholipase C hydrolyzes phosphatidylinositol 4,5-bisphosphate to inositol 1,4,5-trisphosphate (IP 3 ) and diacylglycerol both of which act as cellular second messengers. IP 3 mobilizes Ca ++ from internal stores, hence the cytosolic free Ca ++ concentration increases and those physiological activities regulated by Ca ++ are stimulated. To test if plant cells also responded to IP 3 , Ca ++ efflux studies were done with fusogenic carrot protoplasts released in EGTA. The protoplasts were preloaded with 45 Ca ++ placed in a Ca ++ -free medium, and efflux determined as 45 Ca ++ loss from the protoplasts. IP 3 (10-20μM) caused enhanced 45 Ca ++ efflux and the response was sustained for at least 15 min. In plants, as in animals, the observed IP 3 -enhanced 45 Ca ++ efflux suggested that IP 3 released Ca ++ from internal stores, and the increased free cytosolic Ca ++ activated Ca ++ pumping mechanisms which restored the Ca ++ concentration in the cytosol to the normal level

  15. ¿Qué dices tú, hoy, de la democracia en la escuela?

    Directory of Open Access Journals (Sweden)

    Ángels Martínez

    2003-01-01

    Full Text Available Este artículo presenta el Projecto Vivir la democracia en la escuela, lanzado desde un grupo de profesores y profesoras de Primaria, Secundaria y Universidad, vinculados al Movimiento de Renovación Pedagógica Escola d’Estiu del País Valencià. Parte de la hipótesis de que la democracia en los centros escolares, puede ser definida como el conjunto vacío: nadie políticamente correcto la cuestiona, pero casi nadie la usa para resolver los problemas cotidianos que configuran nuestra experiencia en las aulas, en los pasillos, en las reuniones, en la escuela... Por eso la carpeta de materiales «Vivir la democracia en la escuela. Herramientas para intervenir en el aula y en el centro», no quiere parecerse a un libro sobre cómo hacer la democracia en la escuela, sino, más bien, a una maleta de herramientas para provocar una reflexión sobre lo que hacemos, lo que verdaderamente hacemos o hacen en nuestra vida cotidiana de aula o de centro. Con recortes de prensa, historietas, dibujos o cuestionarios, abre análisis sobre ámbitos muy diferentes de la experiencia docente: la programación, la selección de actividades, la organización del aula, los conflictos, la tutoría, la dirección del centro, la coordinación, los debates en claustro, el Consejo Escolar, la evaluación.. Luego propone una lectura de nuestra realidad de partida con claves de análisis: el saber, la ciudadanía, el poder, la identidad. Para que, finalmente, el grupo decida qué quiere y qué puede seguir haciendo con la experiencia de su aula o su centro. Para que cada uno haga su «Agenda Crítica», su plan particular para la democratización del aula o del centro, o… Este artículo quiere evidenciar el vacío significado práctico del concepto de democracia en la enseñanza actual, y a la vez, ser un ejemplo del procedimiento de formación y de renovación pedagógica que proponemos en la carpeta materiales: Aprender dialogando en el grupo de debate. Una manera de

  16. The CaV2.3 R-type voltage-gated Ca2+ channel in mouse sleep architecture.

    Science.gov (United States)

    Siwek, Magdalena Elisabeth; Müller, Ralf; Henseler, Christina; Broich, Karl; Papazoglou, Anna; Weiergräber, Marco

    2014-05-01

    Voltage-gated Ca(2+) channels (VGCCs) are key elements in mediating thalamocortical rhythmicity. Low-voltage activated (LVA) CaV 3 T-type Ca(2+) channels have been related to thalamic rebound burst firing and to generation of non-rapid eye movement (NREM) sleep. High-voltage activated (HVA) CaV 1 L-type Ca(2+) channels, on the opposite, favor the tonic mode of action associated with higher levels of vigilance. However, the role of the HVA Non-L-type CaV2.3 Ca(2+) channels, which are predominantly expressed in the reticular thalamic nucleus (RTN), still remains unclear. Recently, CaV2.3(-/-) mice were reported to exhibit altered spike-wave discharge (SWD)/absence seizure susceptibility supported by the observation that CaV2.3 mediated Ca(2+) influx into RTN neurons can trigger small-conductance Ca(2+)-activated K(+)-channel type 2 (SK2) currents capable of maintaining thalamic burst activity. Based on these studies we investigated the role of CaV2.3 R-type Ca(2+) channels in rodent sleep. The role of CaV2.3 Ca(2+) channels was analyzed in CaV2.3(-/-) mice and controls in both spontaneous and artificial urethane-induced sleep, using implantable video-EEG radiotelemetry. Data were analyzed for alterations in sleep architecture using sleep staging software and time-frequency analysis. CaV2.3 deficient mice exhibited reduced wake duration and increased slow-wave sleep (SWS). Whereas mean sleep stage durations remained unchanged, the total number of SWS epochs was increased in CaV2.3(-/-) mice. Additional changes were observed for sleep stage transitions and EEG amplitudes. Furthermore, urethane-induced SWS mimicked spontaneous sleep results obtained from CaV2.3 deficient mice. Quantitative Real-time PCR did not reveal changes in thalamic CaV3 T-type Ca(2+) channel expression. The detailed mechanisms of SWS increase in CaV2.3(-/-) mice remain to be determined. Low-voltage activated CaV2.3 R-type Ca(2+) channels in the thalamocortical loop and extra

  17. Química de Coordinación de las 3-Benzoiltio (Seleno Ureas

    Directory of Open Access Journals (Sweden)

    Lothar Beyer

    2011-04-01

    Full Text Available Las 3-benzoiitlo (seleno ureas-1,1-dlsustltuldas forman quelatos metálicos. Aquí se describen la síntesis y las propiedades de los ligandos y de algunos derivados, considerando especialmente la estructura en solución. La estructura molecular de los quelatos metálicos fue investigada por rayos X. La energía libre de activación para la rotación Impedida del grupo Et2N alrededor del enlace N-C(X (X = S, Se fue determinada por espectroscopia RMN^H. La barrera rotacional en los quelatos es mayor que la de los ligandos libres. Algunos aspectos del enlace químico y de la distribución electrónica en los quelatos fueron Investigados por espectroscopia fotoelectrónlca de rayos X. Se propone un nuevo método para la determinación de la estabilidad termodinámica de los quelatos azufrados de níquel (11, utilizando los valores M'''^% de la espectroscopia de masas. Mediciones calorimétricas de la formación de los aductos de blspirldlna de los complejos de níquel (11 con los ligandos mencionados y sus CH-análogos muestran diferencias significativas entre los dos tipos. Los resultados ESCA de los aductos NO metálicos confirman ia carga negativa sobre el NO. Las 3-benzolltloúreas-1-monosustltuldas pueden coordinarse con los átomos S/0 ; N/OoSsólo.

  18. Para qué publicar en enfermería Why to publish in nursing

    Directory of Open Access Journals (Sweden)

    Ana Luisa Velandia Mora

    2008-09-01

    Full Text Available En primer lugar se muestra la relación entre ciencia y tecnología y, por ende, entre profesión y disciplina; seguidamente se analizan los aspectos que caracterizan el desarrollo de una disciplina y los indicadores de profesionalización. Posteriormente se habla del papel de las publicaciones en el avance del conocimiento, de cómo la universidad es el espacio sustantivo en donde se desenvuelve la investigación y de su papel en el progreso del conocimiento; luego se analizan los indicadores de ciencia y tecnología a nivel nacional, de los grupos de investigación y de los investigadores, y consecuentemente, se habla de para qué publicar en enfermería. Se toca, además, el tema de cómo publicar en revistas científicas y, como cierre, unas reflexiones sobre el tema central, surgidas de la experiencia de la autora.First, the relation between science and technology is shown, and then between profession and discipline. Second, aspects that characterize the practice of a discipline and professionalization indicators are analyzed. Afterwards, the role of publishing in the evolution of knowledge is discussed since the university is a very important arena where research is developed and how it plays a role in the evolution of knowledge. National science and technology indicators are used to analyze researchers and research groups. The "why one should publish in nursing?" question is also addressed and the topic of how to publish in scientific magazines is mentioned as well. Finally there are some reflections on the central topic based in the author´s experience.

  19. [The materialistic strategy of Henry Howard, a Québec alienist (1815-1887).].

    Science.gov (United States)

    Fugère, A

    1978-01-01

    At the end of the 19th century, Henry Howard appeared as the first Quebec "aliéniste" to attempt to develop an inclusive theoretical treatise on the question of madness. Why this sudden upheaval ? There existed numerous european theories ; that might have sufficed. The author attempts to show the multiple connections of this theoretical pro-lect to the socio-political problems of québécois society. Howard tries, from the perspective of the theory which he elaborates, to intervene in the major discussions affecting Quebec: ultra montanism, the problem of universal compusory education, public morality. At a more professional level he attempts to intervene in the legal dispute opposing judicial and medical competence in the cases of insanity pleas, as well as in the question of the scientific and social status of the "aliéniste". The involvement in these struggles manifests itself in Howard's treatise as much at the level of the concepts themselves, and their architecture, as at the thematic level and in the applications which he naturally draws. It is not onty external and contingent but works on the text from the inside as well. The article attempts to suggest that at the very moment that the treatise on the alienated-which would become the "science" that we know today- seeks to structure itself into a theory, it cannot break its attachment to its determining social context and that, ignoring its ideological role it, in truth, succeeds only in creating illusion and the impression of a progressive process, all the while being circumstantial and having a verted interest.

  20. Consumption of energy drinks among Québec college students.

    Science.gov (United States)

    Picard-Masson, Marianne; Loslier, Julie; Paquin, Pierre; Bertrand, Karine

    2017-03-01

    Consumption of energy drinks (ED) raises concerns because of adverse health effects possibly linked with high levels of caffeine and sugar intake. The study looks at the scope of ED consumption as well as some of the associated characteristics. Thirty-six public colleges in the Canadian province of Québec agreed to participate in a descriptive cross-sectional study (n = 36). In February 2013, participating colleges invited their students to answer an online questionnaire on consumption of ED, alcoholic ED (AED), and ED in combination with other psychotropic drugs. A descriptive and correlational analysis was carried out. Logistic regressions explored associations between ED consumption and associated characteristics. Of the students who successfully completed the questionnaire and participated in the study (n = 10,283), a low proportion consumed ED (9.1%; n = 935) and/or AED (1.1%; n = 109) at least once a week in the previous month. Although low in proportion, a number of participants reported having used ED with other stimulant psychoactive substances (n = 247) and ≥3 ED/day (n = 193) or ≥3 AED/occasion (n = 167), which can pose a risk for serious adverse effects. Weekly ED consumption was associated with consumption of ≥20 cups of coffee/week, smoking, excessive use of alcohol and past use of cannabis, glues or solvents and amphetamines. A majority of respondents are not heavy users of ED, AED, or ED with drugs. Yet, the profiles of ED consumption potentially harmful to health that characterize some participants indicate that the potential health consequences of such behaviour are of concern.

  1. Improving Accessibility to Services and Increasing Efficiency Through Merger and Centralization in Québec

    Directory of Open Access Journals (Sweden)

    Amélie Quesnel-Vallée

    2018-03-01

    Full Text Available On 25 September 2014, Bill 10 was tabled to reorganize Québec’s health and social services network through the abolition of an administrative layer at the regional health authority level and institutional mergers of health and social services facilities under a new governance structure. Thus, the province’s 182 health and social services facilities were merged into 34 Centre intégré de santé et des services sociaux (CISSS / Centre intégré universitaire de santé et des services sociaux (CIUSSS. CISSS/CIUSSS are responsible for delivering a range of health and social services in a designated territory through the administrative integration of facilities including: local community health centres, generalized and specialized hospitals, psychiatric hospitals, child and youth protection centres, residential and long-term care centres, and rehabilitation centres. These mergers were operationalized notably by a new governance structure whereby the minister-appointed board of directors in each CISSS/CIUSSS reports directly to the Minister of Health and Social Services. As such, a centralization of powers was also achieved. While formal evaluations of reform performance have yet to be completed, analyses projecting potential difficulties of the reform were presented during special consultation hearings. Among the key concerns identified was whether there was evidence to support claims that administrative mergers increased efficiency by achieving economies of scale. Additionally, implicit to Bill 10 is the assumption that continuity of care will follow from administrative mergers. Strategic mergers through professional networks can promote more streamlined approaches to information sharing.

  2. Ru486: del aborto químico a la contracepción de emergencia

    Directory of Open Access Journals (Sweden)

    Lucio Romano

    2009-06-01

    Full Text Available El uso del mifepriston (RU486, en combinación con análogos de las prostaglandinas, en la inducción del aborto químico requiere una específica reflexión en relación a los principales aspectos farmacológicos y toxicológicos. La actual dialéctica bioética y biopolítica, a menudo ideologizada, impone aún más un tratamiento riguroso basado en evidencias científicas, para aclarar sobre todo los mecanismos de acción y de los eventos adversos. Estos últimos a veces también subvalorados o minimizados. Considerada la iniquidad del aborto voluntario, el artículo se propone también el objetivo de aclarar cómo, a la luz de una reciente bibliografía, el recurso al RU486 representa un significativo riesgo para la salud de las mujeres. Una particular atención está reservada a la aclaración etiopatogenética de las hemorragias y de las sepsis, en las cuales se han evidenciado también distintos decesos. En el artículo están presentes, además, los más actuales desarrollos de la investigación con RU486 sea para el tratamiento experimental de patologías –ginecológicas y no– como para el uso de la molécula de la contracepción hormonal y la “contracepción de emergencias”.

  3. THE Q/U IMAGING EXPERIMENT: POLARIZATION MEASUREMENTS OF RADIO SOURCES AT 43 AND 95 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Huffenberger, K. M. [Department of Physics, Florida State University, P.O. Box 3064350, Tallahassee, FL 32306-4350 (United States); Araujo, D.; Zwart, J. T. L. [Department of Physics and Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Bischoff, C.; Buder, I. [Kavli Institute for Cosmological Physics, Department of Physics, Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637 (United States); Chinone, Y.; Hasegawa, M. [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Cleary, K. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 E. California Blvd M/C 249-17, Pasadena, CA 91125 (United States); Kusaka, A. [Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Monsalve, R. [School of Earth and Space Exploration, Arizona State University, 781 E. Terrace Road, Tempe, AZ 85287 (United States); Næss, S. K. [Department of Astrophysics, University of Oxford, Keble Road, Oxford, OX1 3RH (United Kingdom); Newburgh, L. B. [Dunlap Institute, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Reeves, R. [CePIA, Departamento de Astronomía, Universidad de Concepción (Chile); Ruud, T. M.; Eriksen, H. K. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Wehus, I. K.; Gaier, T. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Dickinson, C. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Gundersen, J. O., E-mail: huffenbe@physics.fsu.edu [Department of Physics, University of Miami, 1320 Campo Sano Drive, Coral Gables, FL 33146 (United States); Collaboration: QUIET Collaboration; and others

    2015-06-10

    We present polarization measurements of extragalactic radio sources observed during the cosmic microwave background polarization survey of the Q/U Imaging Experiment (QUIET), operating at 43 GHz (Q-band) and 95 GHz (W-band). We examine sources selected at 20 GHz from the public, >40 mJy catalog of the Australia Telescope (AT20G) survey. There are ∼480 such sources within QUIET’s four low-foreground survey patches, including the nearby radio galaxies Centaurus A and Pictor A. The median error on our polarized flux density measurements is 30–40 mJy per Stokes parameter. At signal-to-noise ratio > 3 significance, we detect linear polarization for seven sources in Q-band and six in W-band; only 1.3 ± 1.1 detections per frequency band are expected by chance. For sources without a detection of polarized emission, we find that half of the sources have polarization amplitudes below 90 mJy (Q-band) and 106 mJy (W-band), at 95% confidence. Finally, we compare our polarization measurements to intensity and polarization measurements of the same sources from the literature. For the four sources with WMAP and Planck intensity measurements >1 Jy, the polarization fractions are above 1% in both QUIET bands. At high significance, we compute polarization fractions as much as 10%–20% for some sources, but the effects of source variability may cut that level in half for contemporaneous comparisons. Our results indicate that simple models—ones that scale a fixed polarization fraction with frequency—are inadequate to model the behavior of these sources and their contributions to polarization maps.

  4. Caracterização química de cultivares de aveia (Avena sativa l

    Directory of Open Access Journals (Sweden)

    I. Pedó

    1997-08-01

    Full Text Available O presente trabalho teve por objetivo caracterizar quimicamente quatro cultivares de aveia (Avena sativa, L.: UPF-15, UPF-16, CTC-03 e UFRGS-14, recentemente selecionados pelo programa de melhoramento genético de aveia no sul do Brasil. A caracterização química foi realizada através das seguintes determinações: composição centesimal, composição mineral, composição em aminoácidos e em ácidos graxos. Os quatro cultivares estudados apresentaram altos teores de proteína (13,95 a 16,52% e lipídios (6,33 a 7,50%. Os teores médios de fibra alimentar solúvel e insolúvel também foram relativamente altos nestes cultivares, 4,76 e 6,36% e, conseqüentemente, o teor de amido foi relativamente baixo (53,26% em média. A composição em aminoácidos foi adequada e semelhante ao padrão teórico da FAO, sendo a lisina o primeiro aminoácido limitante, seguido da treonina. Os cultivares apresentaram altas concentrações de ácidos graxos insaturados, sendo que o linoléico, oléico e palmítico representaram 96% do total. Embora não tenham sido observadas grandes diferenças entre os cultivares estudados, observa-se que o UFRGS-14 se destaca principalmente pelo teor mais elevado de proteína.

  5. Research of the lime rich portions of the CaO-SiO2-P2O5 system

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    1995-03-01

    Full Text Available A detailed study has been carried out to explain the influence of Pp^ in silicate phases and in industrial raw meals upon their mineralogical compositions. Some compositions in the lime rich portion of the CaO-SiO2-P2O5 system are studied using laboratory reactants. The results showed that the compositions lying in the range of CaO = 69,5-70,1; P2O5= 16,2-19,5; SiO2 = 11,1-13,6 (wt% give, at 1000 °C, the mineralogical composition (HAp, β-C2S, C5PS which can develop a high strength in chemically bonded ceramics. At high temperature (1400 ºC these compositions give a large amount of silicocarnotite (C5PS and 2C2.C3P phase. A selected composition of the industrial raw meal with added phosphate: CaO = 62,66; SiO2 -= 17,33; Al2O3 = 4,88; Fe2O3 = 4,29; P2O5 = 8,73; MgO = 2,09 (wt% forms at 1350 ºC a clinker containing high amount of α-C2S to replace C3S. Such a clinker may have good applications in the synthesis of active belite cement.Se estudia con detalle la influencia del P2O5 sobre las composiciones mineralógicas en fases silicato y en un crudo industrial. Asimismo se estudian algunas composiciones de la zona rica en cal del sistema CaO-SiO2-P2O5 utilizando reactivos químicos. Los resultados demuestran que, a presión atmosférica y recinto abierto, las composiciones dentro de los límites CaO = 69,5-70,1; P2O5= 16,2-19,5; SiO2 = 11,1-13,6 (% en peso dan a 1000ºC la composición mineralógica siguiente: HAp, β-C2S, C5PS; pueden desarrollar una alta resistencia química en "chemically bonded ceramics". A altas temperaturas (1400°C producen una elevada proporción de silicocarnotita (C5PS S y la fase 2C2.C3P. Con la adición de fosfato a una determinada dosificación de crudo industrial (CaO = 62,66; SiO2 = 17,33; Al2O3 = 4,88; Fe2O3 = 4,29; P2O5 = 8,73; MgO = 2,09 -% en peso- se forma, a 1350°C, un clinker que contiene una alta proporción de α-C2S que reemplaza al C3S. Este clinker puede tener buenas aplicaciones en la obtención de

  6. Evolution of loss tangent with structural ordering of the perovskite-type Ba_3CaNb_2O_9 ceramics

    International Nuclear Information System (INIS)

    Rodrigues, J.E.F.S.; Correr, W.R.; Hernandes, A.C.; Castro, P.J.; Pizani, P.S.

    2016-01-01

    In this paper, we investigate the microwave dielectric properties considering the de-gree of disorder, which plays a fundamental role in the values of dielectric loss, for the perovskite-type Ba_3CaNb_2O_9 ceramics. Dense ceramics were prepared by con-ventional method in solid state reactions and their dielectric properties were then ob-tained as a function of sintering time. The coexistence of domains in the 1:1 (cubic) and the 1:2 (trigonal) ordering types in all samples was realized. Specifically, the in-crease of sintering time tends to reduce the domains 1:1, raising the unloaded quality factor (Q_u). The domain (1:1) acts as a lattice vibration damping, thus increasing the dielectric loss at resonance. The best performance was recorded in sintered ceramic at 1500° C for 32 h: ε_r = 43 (relative permittivity), Q_u × f_R = 15,752 GHz (resonant frequency f_R = 7.76 GHz) and τ_f = 278 ppm/deg C (coefficient of resonant frequency variation with temperature). (author)

  7. Is tissue CA125 expression in epithelial ovarian adenocarcinoma heterogenic?

    DEFF Research Database (Denmark)

    Sparholt, Morten H; Høgdall, Claus K; Nedergaard, Lotte

    2013-01-01

    To evaluate if heterogeneity of tissue cancer antigen 125 (CA125) expression is present in epithelial serous adenocarcinomas. Furthermore, to investigate whether there is a correlation between levels of CA125 tissue expression, serum level of CA125, stage, and grade. A total of 10 patients...... diagnosed with serous ovarian adenocarcinomas were included. Preoperative blood samples were collected to determine serum CA125 levels. Tumor tissue from primary surgery was collected and processed for immunohistochemical analyses. CA125 was expressed in varying degrees in tumor tissues from all patients....... Mean tissue CA125 expression for each patient ranged from 36% to 98%. Intrapatient variations in tissue expression ranged from 10% to 90% point. No significant correlations between levels of CA125 tissue expression, serum level of CA125, stage, and grade were found. We found that the tissue expression...

  8. Characterization of Bacillus subtilis YfkE (ChaA): a calcium-specific Ca2+/H+ antiporter of the CaCA family.

    Science.gov (United States)

    Fujisawa, Makoto; Wada, Yuko; Tsuchiya, Takahiro; Ito, Masahiro

    2009-08-01

    YfkE, a protein from Bacillus subtilis, exhibits homology to the Ca(2+):Cation Antiporter (CaCA) Family. In a fluorescence-based assay of everted membrane vesicles prepared from Na(+)(Ca(2+))/H(+) antiporter-defective mutant Escherichia coli KNabc, YfkE exhibited robust Ca(2+)/H(+) antiport activity, with a K (m) for Ca(2+) estimated at 12.5 muM at pH 8.5 and 113 muM at pH 7.5. Neither Na(+) nor K(+) served as a substrate. Mg(2+) also did not serve as a substrate, but inhibited the Ca(2+)/H(+) antiporter activity. The Ca(2+) transport capability of YfkE was also observed directly by transport assays in everted membrane vesicles using radiolabeled (45)Ca(2+). Transcriptional analysis from the putative yfkED operon using beta-garactosidase activity as a reporter revealed that both of the yfkE and yfkD genes are regulated by forespore-specific sigma factor, SigG, and the general stress response regulator, SigB. These results suggest that YfkE may be needed for Ca(2+) signaling in the sporulation or germination process in B. subtilis. ChaA is proposed as the designation for YfkE of B. subtilis.

  9. MicroRNA-145 suppresses ROS-induced Ca2+ overload of cardiomyocytes by targeting CaMKIIδ

    International Nuclear Information System (INIS)

    Cha, Min-Ji; Jang, Jin-Kyung; Ham, Onju; Song, Byeong-Wook; Lee, Se-Yeon; Lee, Chang Yeon; Park, Jun-Hee; Lee, Jiyun; Seo, Hyang-Hee; Choi, Eunhyun; Jeon, Woo-min; Hwang, Hye Jin; Shin, Hyun-Taek

    2013-01-01

    Highlights: •CaMKIIδ mediates H 2 O 2 -induced Ca 2+ overload in cardiomyocytes. •miR-145 can inhibit Ca 2+ overload. •A luciferase assay confirms that miR-145 functions as a CaMKIIδ-targeting miRNA. •Overexpression of miR-145 regulates CaMKIIδ-related genes and ameliorates apoptosis. -- Abstract: A change in intracellular free calcium (Ca 2+ ) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca 2+ signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca 2+ -mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H 2 O 2 -mediated Ca 2+ overload, we selected and tested 6 putative miRNAs that targeted CaMKIIδ, and showed that miR-145 represses CaMKIIδ protein expression and Ca 2+ overload. We confirmed CaMKIIδ as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca 2+ -related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca 2+ overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses

  10. MicroRNA-145 suppresses ROS-induced Ca{sup 2+} overload of cardiomyocytes by targeting CaMKIIδ

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Min-Ji [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Jang, Jin-Kyung [College of Pharmacy, Sookmyung Women’s University, 52 HyoChangWon-Gil, Yongsan-ku, Seoul 140-742 (Korea, Republic of); Ham, Onju; Song, Byeong-Wook; Lee, Se-Yeon [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Lee, Chang Yeon; Park, Jun-Hee [Department of Integrated Omics for Biomedical Sciences, Graduate School, Yonsei University, 50 Yonsei-ro, Seodamun-gu, Seoul 120-759 (Korea, Republic of); Lee, Jiyun; Seo, Hyang-Hee [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Choi, Eunhyun [Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University Health System, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Jeon, Woo-min [Department of Animal Resource, Sahmyook University, Seoul 139-742 (Korea, Republic of); Hwang, Hye Jin [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Shin, Hyun-Taek [College of Pharmacy, Sookmyung Women’s University, 52 HyoChangWon-Gil, Yongsan-ku, Seoul 140-742 (Korea, Republic of); and others

    2013-06-14

    Highlights: •CaMKIIδ mediates H{sub 2}O{sub 2}-induced Ca{sup 2+} overload in cardiomyocytes. •miR-145 can inhibit Ca{sup 2+} overload. •A luciferase assay confirms that miR-145 functions as a CaMKIIδ-targeting miRNA. •Overexpression of miR-145 regulates CaMKIIδ-related genes and ameliorates apoptosis. -- Abstract: A change in intracellular free calcium (Ca{sup 2+}) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca{sup 2+} signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca{sup 2+}-mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H{sub 2}O{sub 2}-mediated Ca{sup 2+} overload, we selected and tested 6 putative miRNAs that targeted CaMKIIδ, and showed that miR-145 represses CaMKIIδ protein expression and Ca{sup 2+} overload. We confirmed CaMKIIδ as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca{sup 2+}-related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca{sup 2+} overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses.

  11. Polyamines mediate abnormal Ca2+ transport and Ca2+-induced cardiac cell injury in the calcium paradox

    International Nuclear Information System (INIS)

    Trout, J.J.; Koenig, H.; Goldstone, A.D.; Lu, C.Y.; Fan, C.C.

    1986-01-01

    Ca 2+ -free perfusion renders heart cells Ca 2+ -sensitive so that readmission of Ca 2+ causes a sudden massive cellular injury attributed to abnormal entry of Ca 2+ into cells (Ca paradox). Hormonal stimulation of Ca 2+ fluxes was earlier shown to be mediated by polyamines (PA). 5 min perfusion of rat heart with Ca 2+ -free medium induce a prompt 40-50% decline in levels of the PA putrescine (PUT), spermidine and spermine and their rate-regulatory synthetic enzyme ornithine decarboxylase (ODC), and readmission of Ca 2+ -containing medium abruptly ( 2+ reperfusion-induced increases in ODC and PA and also prevented increased 45 Ca 2+ uptake and heart injury, manifested by loss of contractility, release of enzymes (CPK, LDH), myoglobin and protein, and E.M. lesions (contracture bands, mitochondrial changes). 1 mM PUT negated DFMO inhibition, repleted heart PA and restored Ca 2+ reperfusion-induced 45 Ca 2+ influx and cell injury. These data indicate that the Ca 2+ -directed depletion-repletion cycle of ODC and PA triggers excessive transsarcolemmal Ca 2+ transport leading to the calcium paradox

  12. Spatial variability of soil chemical properties after coffee tree removal Variabilidade espacial dos atributos químicos do solo após remoção de cafezal

    Directory of Open Access Journals (Sweden)

    Sidney Rosa Vieira

    2009-10-01

    Full Text Available Assessing the spatial variability of soil chemical properties has become an important aspect of soil management strategies with a view to higher crop yields with minimal environmental degradation. This study was carried out at the Centro Experimental of the Instituto Agronomico, in Campinas, São Paulo, Brazil. The aim was to characterize the spatial variability of chemical properties of a Rhodic Hapludox on a recently bulldozer-cleaned area after over 30 years of coffee cultivation. Soil samples were collected in a 20 x 20 m grid with 36 sampling points across a 1 ha area in the layers 0.0-0.2 and 0.2-0.4 m to measure the following chemical properties: pH, organic matter, K+, P, Ca2+, Mg2+, potential acidity, NH4-N, and NO3-N. Descriptive statistics were applied to assess the central tendency and dispersion moments. Geostatistical methods were applied to evaluate and to model the spatial variability of variables by calculating semivariograms and kriging interpolation. Spatial dependence patterns defined by spherical model adjusted semivariograms were made for all cited soil properties. Moderate to strong degrees of spatial dependence were found between 31 and 60 m. It was still possible to map soil spatial variability properties in the layers 0-20 cm and 20-40 cm after plant removal with bulldozers.A avaliação da variabilidade espacial dos atributos químicos do solo tem se tornado importante ferramenta na determinação de estratégias de manejo que visam aumentar a produtividade agrícola com menor degradação ambiental. O presente trabalho foi realizado no Centro Experimental Central do Instituto Agronômico, localizado em Campinas/SP, com o objetivo de caracterizar a variabilidade espacial dos atributos químicos de um Latossolo Vermelho após a remoção de um cafezal, cultivado por mais de 30 anos, com trator de esteira. As amostras de solo foram coletadas em grade georreferenciada de 20 x 20 m, totalizando 36 pontos nas camadas de 0

  13. Cannabinoids disrupt memory encoding by functionally isolating hippocampal CA1 from CA3.

    Directory of Open Access Journals (Sweden)

    Roman A Sandler

    2017-07-01

    Full Text Available Much of the research on cannabinoids (CBs has focused on their effects at the molecular and synaptic level. However, the effects of CBs on the dynamics of neural circuits remains poorly understood. This study aims to disentangle the effects of CBs on the functional dynamics of the hippocampal Schaffer collateral synapse by using data-driven nonparametric modeling. Multi-unit activity was recorded from rats doing an working memory task in control sessions and under the influence of exogenously administered tetrahydrocannabinol (THC, the primary CB found in marijuana. It was found that THC left firing rate unaltered and only slightly reduced theta oscillations. Multivariate autoregressive models, estimated from spontaneous spiking activity, were then used to describe the dynamical transformation from CA3 to CA1. They revealed that THC served to functionally isolate CA1 from CA3 by reducing feedforward excitation and theta information flow. The functional isolation was compensated by increased feedback excitation within CA1, thus leading to unaltered firing rates. Finally, both of these effects were shown to be correlated with memory impairments in the working memory task. By elucidating the circuit mechanisms of CBs, these results help close the gap in knowledge between the cellular and behavioral effects of CBs.

  14. Estimativa da composição química corporal de tourinhos Santa Gertrudes a partir da composição química e física das 9-10-11ª costelas

    Directory of Open Access Journals (Sweden)

    Henrique Wignez

    2003-01-01

    Full Text Available Foram obtidas equações de regressão linear simples para estimar a composição química corporal de bovinos Santa Gertrudes, a partir da composição química e física do corte das 9-10-11ª costelas. Quinze tourinhos, entre nove a 15 meses de idade e de 220 a 505 kg de peso, foram mantidos confinados. Os animais foram abatidos após jejum completo de 18 horas, sendo que seis deles foram abatidos após adaptação. A composição química em água, proteína, extrato etéreo e minerais foi determinada no corte das costelas e em amostras obtidas após moagem completa e homogeneização de todos os tecidos corporais, divididos em: sangue, couro, cabeça + patas, vísceras e carcaça. A composição física do corte das costelas foi obtida por separação manual do músculo, gordura e ossos. O peso do corpo vazio foi altamente correlacionado ao peso da carcaça quente (rsuperscript two = 0,99. As porcentagens de água e extrato etéreo das 9-10-11ª costelas mostraram-se altamente correlacionadas com a composição química do corpo vazio, o que não ocorreu para as porcentagens de proteína e minerais. Esses teores foram calculados pela composição do corpo vazio desengordurado. A composição física do corte das costelas foi eficiente para estimar as porcentagens de água, extrato etéreo e minerais do corpo vazio, utilizando-se a porcentagem de gordura separável das costelas, mas não para estimar o teor de proteína. A composição física do corte das costelas demonstrou ser uma técnica eficiente, mas a composição química apresentou maiores coeficientes de determinação e menores erros da estimativa. Como a porcentagem de água no corpo vazio e no corte das costelas (rsuperscript two = 0,95, e as porcentagens de água e de extrato etéreo no corpo vazio foram altamente correlacionadas (rsuperscript two = 0,94, a porcentagem de água no corte das 9-10-11ª costelas poderia ser a única variável para estimativa da composição qu

  15. Análisis multivariado de propiedades químicas en Oxisoles con diferentes niveles de intervención agrícola Multivariate analysis of chemical properties in Oxisols with different levels of intervention agricultural

    Directory of Open Access Journals (Sweden)

    Jesús H Camacho-Tamayo

    2010-07-01

    Full Text Available La intervención humana en la producción agrícola influye directamente en la calidad del suelo, promoviendo alteraciones en las propiedades físicas y químicas, mediante el uso de fertilizantes, correctivos y prácticas de labranza. El objetivo del presente trabajo fue evaluar los cambios en las propiedades químicas de dos Oxisoles (Typic Hapludox y Typic Haplustox, con diferentes niveles de intervención (cultivos de pasto Brachiaria y rotaciones de maíz y soya, en el municipio de Puerto López (Meta-Colombia. Las muestras fueron tomadas en 42 puntos, distanciados 25 m perpendicularmente, entre 0 y 0.10 m y 0.10 y 0.20 m de profundidad, para un total de 168 muestras en los dos lotes. Los datos fueron analizados mediante análisis de varianza y técnicas de análisis multivariado, a través de componentes principales y agrupamiento jerárquico. Las propiedades estudiadas fueron carbono orgánico, pH, acidez intercambiable, aluminio intercambiable, P, Ca, Mg, P, Na, capacidad de intercambio catiónica efectiva (CICE, suma de bases y saturación de bases. La intervención agrícola se ve reflejada principalmente en la capa superficial del suelo, donde se presentaron los mayores valores de CO, Ca, Mg, K, P, SB y CICE, debido a la presencia de residuos de cosecha, así como a la aplicación de fertilizantes y correctivos.Human intervention in agricultural production affects directly soil quality by promoting changes in physical and chemical properties through the use of fertilizers, correctives and tillage practices (Brachiria and corn- soybean. The aim of this study was to evaluate changes in the chemical properties of two Oxisols (Typic Hapludox y Typic Haplustox with different intervention levels, in the municipality of Puerto Lopez (Meta-Colombia. Samples were taken at 42 points, spaced 25 m perpendicularly between 0-0, 10 my 0.10 and 0.20 m of deep, for a total of 168 samples in both fields. The data were analyzed by analysis of variance

  16. Compostos orgânicos hidrossolúveis de resíduos vegetais e seus efeitos nos atributos químicos do solo Water-soluble organic compounds in plant residue and the effects on soil chemical properties

    Directory of Open Access Journals (Sweden)

    Raquel Cátia Diehl

    2008-12-01

    Full Text Available Compostos orgânicos hidrossolúveis de resíduos vegetais depositados na superfície do solo podem melhorar a fertilidade do subsolo, pela neutralização da acidez e transporte de Ca e Mg. Com o objetivo de avaliar o efeito dos compostos orgânicos hidrossolúveis de materiais vegetais nos atributos químicos de um Latossolo Vermelho distroférrico, foi desenvolvido um experimento no Instituto Agronômico do Paraná (IAPAR, Londrina, com amostras de solo acondicionadas em colunas nas quais se aplicaram os tratamentos: água destilada, calcário incorporado na camada 0-5 cm de profundidade, calcário e percolação com extratos de nabo forrageiro, aveia preta, palha de trigo, milho e soja. No extrato percolado, foram determinados os teores de ligantes orgânicos hidrossolúveis (LOH por potenciometria com eletrodo seletivo de Cu2+; ácidos orgânicos tituláveis (AOT por titulação ácido-base e ânions orgânicos (AO pela soma de bases. As concentrações de AO e AOT variaram de 7,0 a 32,0 mmol L-1 e de LOH de 0,60 a 2,23 mmol L-1. Todos os extratos vegetais aumentaram o pH, os teores de Ca, Mg e K trocável e diminuíram a acidez potencial e o Al trocável até 15 cm de profundidade, enquanto o efeito da calagem sem extrato foi observado somente até 10 cm de profundidade. A concentração de compostos orgânicos solúveis oriundos dos materiais vegetais correlacionou-se com o pH, Al trocável, H+Al e V % do solo na camada de 0-20 cm, confirmando a participação destes na melhoria dos atributos químicos do solo e ação da calagem superficial quando o material vegetal está presente.The water-soluble organic compounds of plant residues released on the soil surface can improve the subsoil fertility, due to the neutralization of acidity and Ca and Mg transport. An experiment was conducted at the Instituto Agronomico do Parana (IAPAR, Londrina, to evaluate the effect of water-soluble organic compounds of plant extracts on the chemical

  17. 77 FR 44139 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2012-07-27

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... Sacramento, CA. The deviation is necessary to allow the community to participate in the Fleet Feet Event, Run... Tower Drawbridge, mile 59.0, Sacramento River, at Sacramento, CA. The Tower Drawbridge navigation span...

  18. 76 FR 11960 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2011-03-04

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary..., mile 59.0, at Sacramento, CA. The deviation is necessary to allow the community to participate in the... Tower Drawbridge, mile 59.0, Sacramento River, at Sacramento, CA. The Tower Drawbridge navigation span...

  19. 77 FR 22216 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2012-04-13

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... schedule that governs the Tower Drawbridge across the Sacramento River, mile 59.0, at Sacramento, CA. The... River, at Sacramento, CA. The Tower Drawbridge navigation span provides a vertical clearance of 30 feet...

  20. 78 FR 42452 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2013-07-16

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of deviation... Sacramento, CA. The deviation is necessary to allow the bridge owner to make bridge repairs. This deviation... Sacramento, CA. The drawbridge navigation span provides 109 feet vertical clearance above Mean High Water in...

  1. 77 FR 52599 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2012-08-30

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... regulation that governs the Tower Drawbridge across Sacramento River, mile 59.0, at Sacramento, CA. The... change to the operation of the Tower Drawbridge, mile 59.0, over Sacramento River, at Sacramento, CA. The...

  2. 76 FR 26181 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2011-05-06

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... 59.0, at Sacramento, CA. The deviation is necessary to allow the community to participate in the Hope... Drawbridge, mile 59.0, over Sacramento River, at Sacramento, CA. The drawbridge navigation span provides a...

  3. 76 FR 11679 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2011-03-03

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary..., mile 59.0, at Sacramento, CA. The deviation is necessary to allow the community to participate in the... the Tower Drawbridge, mile 59.0, Sacramento River, at Sacramento, CA. The Tower Drawbridge navigation...

  4. 76 FR 23188 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2011-04-26

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary..., mile 59.0, at Sacramento, CA. The deviation is necessary to allow the community to participate in the... Tower Drawbridge, mile 59.0, Sacramento River, at Sacramento, CA. The Tower Drawbridge navigation span...

  5. 76 FR 79067 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2011-12-21

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary..., mile 59.0, at Sacramento, CA. The deviation is necessary to allow community celebration of New Year's... Tower Drawbridge, mile 59.0, Sacramento River, at Sacramento, CA. The Tower Drawbridge navigation span...

  6. 76 FR 20843 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2011-04-14

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary..., mile 59.0, at Sacramento, CA. The deviation is necessary to allow the community to participate in the... the Tower Drawbridge, mile 59.0, Sacramento River, at Sacramento, CA. The Tower Drawbridge navigation...

  7. 77 FR 10372 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2012-02-22

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary..., mile 59.0, at Sacramento, CA. The deviation is necessary to allow the community to participate in the... Tower Drawbridge, mile 59.0, Sacramento River, at Sacramento, CA. The Tower Drawbridge navigation span...

  8. 77 FR 10371 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2012-02-22

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary..., mile 59.0, at Sacramento, CA. The deviation is necessary to allow the bridge owner to conduct... change to the operation of the Tower Drawbridge, mile 59.0, Sacramento River, at Sacramento, CA. The...

  9. 75 FR 16006 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2010-03-31

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary..., mile 59.4, at Sacramento, CA. The deviation is necessary to allow the bridge owner to make bridge... Sacramento River, at Sacramento, CA. The I Street Drawbridge navigation span provides 109 feet vertical...

  10. 78 FR 23489 - Drawbridge Operation Regulation; Sacramento River, Sacramento, CA

    Science.gov (United States)

    2013-04-19

    ... Operation Regulation; Sacramento River, Sacramento, CA AGENCY: Coast Guard, DHS. ACTION: Notice of deviation... operating regulation that governs the Tower Drawbridge across Sacramento River, mile 59.0, at Sacramento, CA... Tower Drawbridge, mile 59.0, over Sacramento River, at Sacramento, CA. The Tower Drawbridge navigation...

  11. Ca and Mg binding induce conformational stability of Calfumirin-1 ...

    Indian Academy of Sciences (India)

    The thermal unfolding curves of wtCAF-1 monitored at neutral pH by CD spectroscopy are reversible and show ... These domains have either structurally dependent or independent Ca2+- ... that behave as a Ca2+ sensor protein, CaBP1 and.

  12. Electronic structure of Ca, Sr, and Ba under pressure.

    Science.gov (United States)

    Animalu, A. O. E.; Heine, V.; Vasvari, B.

    1967-01-01

    Electronic band structure calculations phase of Ca, Sr and Ba over wide range of atomic volumes under pressure electronic band structure calculations for fcc phase of Ca, Sr and Ba over wide range of atomic volumes under pressure electronic band structure calculations for fcc phase of Ca, Sr and Ba over wide range of atomic volumes under pressure

  13. TRPV5, the gateway to Ca2+ homeostasis.

    NARCIS (Netherlands)

    Mensenkamp, A.R.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2007-01-01

    Ca2+ homeostasis in the body is tightly controlled, and is a balance between absorption in the intestine, excretion via the urine, and exchange from bone. Recently, the epithelial Ca2+ channel (TRPV5) has been identified as the gene responsible for the Ca2+ influx in epithelial cells of the renal

  14. Significance of the tumor markers CA 125 and CA 15-3 in postoperative diagnosis of ovarian and breast cancer

    International Nuclear Information System (INIS)

    Johannsen, B.; Bartel, U.; Elling, D.

    1989-01-01

    In 271 patients with ovarian carcinoma, benign ovarian tumors, breast cancer, and two control groups, serum levels of CA 125, CA 15-3, CEA and, partly, CA 19-9 were determined immunoradiometrically. According to the results of the determination of CA 125 in the follow-up of ovarian carcinoma, CA 125 represents a useful marker for early detection of recurrences, especially in cases of diffuse carcinoma dissemination. In incomplete tumor debulking, postoperative CA 125 serum levels did not prove to be helpful except that a positive level renders invasive diagnostic investigation no longer necessary. Postoperative follow-up in breast cancer early reveals distant metastases, with very high levels in patients with bone metastases. By simultaneous measurement of CA 15-3 and CEA the sensitivity could be increased from 86% (CA 15-3 only) to 93%. (author)

  15. Elaboración de Bebida Refrescante con Base en Miel de Caña

    Directory of Open Access Journals (Sweden)

    Sepúlveda Valencia José Uriel

    1998-12-01

    Full Text Available Con el fin de determinar las características de la bebida refrescante elaborada con miel de caña, naranja agria, limón mandarino y ácido cítrico más ácido ascórbico, se elaboraron en la Planta de Leches de la Universidad Nacional de Colombia. Sede Medellín, bebidas a las cuales se les efectuaron análisis físico químicos, microbiológicos y organolépticos en los días uno y quince después de preparados. Los análisis se determinaron así: los físico químicos: los sólidos solubles se expresaron en °Brix determinados por el método de refractometría, la densidad por el método del picnómetro, la acidez por el método de titulación con hidróxido de sodio (NaOH 0,1 N. el pH mediante potenciometría y la viscosidad por el método de Ostwald. Los microbiológicos: coliformes totales y fecales por el método de tubos con caldo lactosado verde bilis brillante, los mohos y levaduras por recuento en placa con agar potato y el recuento total de mesoaerobios por el método de placas con agar nutritivo. Se realizaron tres tratamientos (naranja agria, limón mandarino y ácido cítrico más ácido ascórbico y cada tratamiento se replicó cuatro (4 veces. En los análisis físico químicos entre los tratamientos se encontraron diferencias significativas en las variables pH, viscosidad y densidad con respecto al sabor en el tiempo. No se encontraron diferencias significativas para °Brix y acidez titulable. En el análisis microbiológico para la variable mohos hubo diferencia significativa en el tiempo de almacenamiento, más no en el sabor, las otras variables recuento total de mesoaerobios y número más probable de coliformes totales y fecales no presentaron diferencias significativas. En el análisis organoléptico se encontraron diferencias significativas entre los sabores y el tiempo. Los puntajes obtenidos indicaron, en general una buena aceptación de la bebida refrescante por parte de los 18 jueces, siendo superior el

  16. Chemical purification of CaCO{sub 3} and CaWO{sub 4} powders used for CaWO{sub 4} crystal production for the CRESST experiment

    Energy Technology Data Exchange (ETDEWEB)

    Trinh Thi, H.H.; Defay, X.; Erb, A.; Hampf, R.; Lanfranchi, J.C.; Langenkaemper, A.; Morgalyuk, V.; Muenster, A.; Mondragon, E.; Oppenheimer, C.; Potzel, W.; Schoenert, S.; Steiger, H.; Ulrich, A.; Wawoczny, S.; Willers, M.; Zoeller, A. [Physik-Department and Excellence Cluster Universe, Technische Universitaet Muenchen, Garching (Germany)

    2016-07-01

    CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) uses CaWO{sub 4} single crystals as targets for the direct search for dark matter particles. Since several years these CaWO{sub 4} crystals are grown at the Technische Universitaet Muenchen. Thereby, commercially available CaCO{sub 3} and WO{sub 3} powders are used for the synthesis of CaWO{sub 4} powder. For the experiment low intrinsic contaminations of the crystals play a crucial role. In order to improve the radiopurity of the crystals it is necessary to reduce potential sources for radioactive backgrounds such as U and Th. In this poster we will present our studies of the chemical purification of the CaCO{sub 3} and CaWO{sub 4} powders.

  17. The Ne3LS Network, Québec's initiative to evaluate the impact and promote a responsible and sustainable development of nanotechnology

    Science.gov (United States)

    Endo, Charles-Anica; Emond, Claude; Battista, Renaldo; Parizeau, Marie-Hélène; Beaudry, Catherine

    2011-07-01

    The spectacular progress made by nanosciences and nanotechnologies elicits as much hope and fear. Consequently, a great number of research and training initiatives on the ethical, environmental, economic, legal and social issues regarding nanotechnology development (Ne3LS) are emerging worldwide. In Québec, Canada, a Task Force was mandated by NanoQuébec to conceive a Ne3LS research and training strategy to assess those issues. This Task Force brought together experts from universities, governments or industry working in nanosciences and nanotechnologies or in Ne3LS. Their resulting action plan, made public in November 2006, contained several recommendations, including the creation of a knowledge network (Ne3LS Network). In the following years, after consulting with numerous key players concerned with the possible impacts of nanosciences and nanotechnologies in Québec, the Ne3LS Network was launched in January 2010 in partnership with the Fonds québécois de la recherche sur la nature et les technologies, the Fonds québécois de la recherche sur la société et la culture and the Fonds de la recherche en santé du Québec, NanoQuébec, the Institut de recherche Robert-Sauvé en santé et en sécurité du travail as well as the University of Montreal. Its objectives are to 1) Foster the development of Ne3LS research activities (grants and fellowships); 2) Spearhead the Canadian and international Ne3LS network; 3) Take part in the training of researchers and experts; 4) Encourage the creation of interactive tools for the general public; 5) Facilitate collaboration between decision-makers and experts; 6) Involve the scientific community through a host of activities (symposium, conferences, thematic events); 7) Build multidisciplinary research teams to evaluate the impact of nanotechnology.

  18. Determinación del tiempo de combustión para las briquetas cilíndricas macizas de paja de caña

    OpenAIRE

    David Verdecia Torres; Raúl Pacheco Gamboa; Luis Zamora González; Jorge Ramos Zamora

    2006-01-01

    En el presente trabajo se realiza un estudio de la combustión de briquetas cilíndricas macizas de biomasa cañera, en particular lo referente a la cinética del proceso de combustión, lográndose determinar los tiempos de combustión de cada una de las fases que pudieran ser las controladoras del proceso; la difusión de O2 a través de la película gaseosa, la difusión de los volátiles a través de la capa de ceniza y la reacción química; a partir del modelo del núcleo sin reaccionar...

  19. Produção de fitomassa e atributos químicos do solo sob cultivo em aléias e sob vegetação nativa de cerrado

    Directory of Open Access Journals (Sweden)

    A. L. Mafra

    1998-03-01

    Full Text Available Os sistemas agroflorestais podem aliar produção de alimentos com conservação dos recursos naturais, buscando economia de fertilizantes a partir da reciclagem de nutrientes. A produção de fitomassa e o aporte de nutrientes foram quantificados num cultivo em aléias e em área de vegetação nativa de cerrado em Botucatu (SP, com vistas em verificar as influências do sistema agroflorestal nos atributos químicos do solo. A leucena foi plantada em linhas em 1987, com espaçamento de 6 m, após calagem e aplicação de P. As linhas da leguminosa foram podadas anualmente, permitindo o cultivo intercalar de centeio + aveia e milho + feijão, durante a estação seca e chuvosa, respectivamente. A produção anual de fitomassa no sistema agroflorestal foi de 11.036 kg ha-1 de massa seca, com um aporte mineral pelas plantas de (kg ha-1 149,0 de N, 9,4 de P, 70,0 de K, 75,2 de Ca e 31,1 de Mg. O pH do solo e os teores de Ca e Mg nesse sistema foram superiores aos do cerrado, o que se atribuiu ao efeito do calcário. A adubação verde, principalmente a fitomassa da leucena, colaborou na alteração dos teores de matéria orgânica, N e P no solo sob cultivo em aléias.

  20. Características químicas e avaliação microbiológica de diferentes fases de maturação do biofertilizante Bokashi

    Directory of Open Access Journals (Sweden)

    Flaviane Eva Magrini

    2011-08-01

    Full Text Available O uso de biofertilizantes é uma das alternativas que vêm sendo testada e adotada na agricultura, a fim de reduzir o uso de produtos químicos como forma de reaproveitamento de resíduos da propriedade. O objetivo deste trabalho foi analisar a concentração de N, P, K, Fe, Zn, Mg e Ca e a microbiota fúngica de diferentes fases de maturação do biofertilizante Bokashi. As amostras foram avaliadas aos 15, 30, 60 e 85 dias de maturação. A partir da análise das amostras observou-se que a maioria dos nutrientes avaliados tiveram seu valor mais expressivo aos 60 dias de maturação da compostagem. Os fungos identificados pertencem a diferentes gêneros, destacando-se a presença de Aspergillus sp., Dactylium sp. e Rhizopus sp. na fase final de maturação do composto. Os resultados demonstram que ocorreram variações na concentração dos nutrientes e nas populações de microrganismos do biofertilizante avaliado, demonstrando uma intensa atividade biológica no composto com a liberação de diversos nutrientes para o meio.

  1. Ultrastructural and immunohistochemical localization of plasma membrane Ca2+-ATPase 4 in Ca2+-transporting epithelia

    DEFF Research Database (Denmark)

    Alexander, R Todd; Beggs, Megan R; Zamani, Reza

    2015-01-01

    role in transcellular Ca(2+) flux and investigated the localization and regulation of Pmca4 in Ca(2+)-transporting epithelia. Using antibodies directed specifically against Pmca4, we found it expressed only in the smooth muscle layer of mouse and human intestine, while pan-specific Pmca antibodies...... the cortical thick ascending limbs, macula densa, and early distal tubules as well as smooth muscle layers surrounding renal vessels. In human kidney, a similar pattern of distribution was observed, with highest PMCA4 expression in NCC positive tubules. Electron microscopy demonstrated Pmca4 localization...... in distal nephron cells at both the basolateral membrane and intracellular perinuclear compartments, but not submembranous vesicles, suggesting rapid trafficking to the plasma membrane is unlikely to occur in vivo. Pmca4 expression was not altered by perturbations in Ca(2+) balance, pointing...

  2. Tumor markers CA19-9, CA242 and CEA in the diagnosis of pancreatic cancer: a meta-analysis.

    Science.gov (United States)

    Zhang, Yimin; Yang, Jun; Li, Hongjuan; Wu, Yihua; Zhang, Honghe; Chen, Wenhu

    2015-01-01

    Pancreatic cancer has the worst prognosis and early detection is crucial for improving patient prognosis. Therefore, we performed a meta-analysis to evaluate and compare the sensitivity and specificity of single test of CA19-9, CA242, and CEA, as well as combination test in pancreatic cancer detection. We searched PubMed, Embase, Medline, and Wanfang databases for studies that evaluated the diagnostic validity of CA19-9, CA242, and CEA between January 1990 and September 2014. Data were analyzed by Meta-Disc and STATA software. A total of 21 studies including 3497 participants, which fulfilled the inclusion criteria were considered for analysis. The pooled sensitivities for CA19-9, CA242, and CEA were 75.4 (95% CI: 73.4-77.4), 67.8 (95% CI: 65.5-70), and 39.5 (95% CI: 37.3-41.7), respectively. The pooled specificities of CA19-9, CA242, and CEA were 77.6 (95% CI: 75.4-79.7), 83 (95% CI: 81-85), and 81.3 (95% CI: 79.3-83.2), respectively. Parallel combination of CA19-9+CA242 has a higher sensitivity (89, 95% CI: 80-95) without impairing the specificity (75, 95% CI: 67-82). Our meta-analysis showed that CA242 and CA19-9 have better performance in the diagnosis of pancreatic cancer than CEA. Furthermore, parallel combination test of CA19-9+CA242 could be of better diagnostic value than individual CA242 or CA19-9 test.

  3. Mechanics of Old Faithful Geyser, Calistoga, CA

    Science.gov (United States)

    Rudolph, M.L.; Manga, M.; Hurwitz, Shaul; Johnston, Malcolm J.; Karlstrom, L.; Wang, Chun-Yong

    2012-01-01

    In order to probe the subsurface dynamics associated with geyser eruptions, we measured ground deformation at Old Faithful Geyser of Calistoga, CA. We present a physical model in which recharge during the period preceding an eruption is driven by pressure differences relative to the aquifer supplying the geyser. The model predicts that pressure and ground deformation are characterized by an exponential function of time, consistent with our observations. The geyser's conduit is connected to a reservoir at a depth of at least 42 m, and pressure changes in the reservoir can produce the observed ground deformations through either a poroelastic or elastic mechanical model.

  4. Quasielastic electron scattering from 40Ca

    International Nuclear Information System (INIS)

    Williamson, C.F.; Yates, T.C.; Schmitt, W.M.; Osborn, M.; Deady, M.; Zimmerman, P.D.; Blatchley, C.C.; Seth, K.K.; Sarmiento, M.; Parker, B.; Jin, Y.; Wright, L.E.; Onley, D.S.

    1997-01-01

    Differential cross sections for quasielastic electron scattering on 40 Ca have been measured at laboratory scattering angles of 45.5 degree, 90 degree, and 140 degree with bombarding energies ranging from 130 to 840 MeV. Transverse and longitudinal response functions have been extracted for momentum transfers from 300 to 500 MeV/c. Contrary to some previously reported results, the total observed longitudinal strength agrees with the relativistic Fermi gas prediction to within ±18%. copyright 1997 The American Physical Society

  5. β-decay of 37Ca

    International Nuclear Information System (INIS)

    Trinder, W.; Adelberger, E.G.; Keller, H.; Krumbholz, K.; Rykaczewski, K.

    1994-11-01

    The β-decay of 37 Ca has been studied. The half-life was remeasured with improved precision to be 181(1) ms, and β-delayed γ-rays were observed for the first time. The surprisingly high Γ γ /Γ p values for proton-unbound states in 37 K drastically reduce former discrepancies between the Gamow-Teller strength values B(GT) measured in the 37 Ga β-decay and those deduced from the 37 Cl(p, n) 37 Ar mirror reaction. (orig.)

  6. QUANTICOL - CaSL at work

    OpenAIRE

    Galpin, Vashti; Georgoulas, Anastasis; Gilmore, Stephen; Hillston, Jane; Latella, Diego; Loreti, Michele; Massink, Mieke; Zon, Natalia

    2017-01-01

    This deliverable reports on the work completed in the final reporting period on the modelling language at the centre of the QUANTICOL framework, C ARMA . A major focus of the period has been on making modelling with C ARMA accessible to a wide audience of potential users interested in CAS, not just those already familiar with formal modelling with process algebras. To this end we have further developed the C ARMA Specification Language ( CaSL ) and the software tools that support it; we have ...

  7. Cold fusion reactions with 48Ca

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.; Jost, D.T.; Tuerler, A.

    1989-04-01

    Cold fusion reactions with 48 Ca on the targets 208 Pb, 209 Bi, 197 Au, 184 W, 180 Hf are reported. The experiments were performed at the velocity filter SHIP of GSI. The maximum cross sections show a steep descent by about four orders of magnitude when going from 224 Th to 228 U as compound nuclei. Between uranium and einsteinium the cross sections stay rather low and increase by about two orders of magnitude for nobelium. For lawrencium the cross section decrease again. 7 figs., 1 tab., 38 refs

  8. Ca2+-calmodulin-dependent protein kinase expression and signalling in skeletal muscle during exercise

    DEFF Research Database (Denmark)

    Rose, Adam John; Kiens, Bente; Richter, Erik

    2006-01-01

    Ca2+ signalling is proposed to play an important role in skeletal muscle function during exercise. Here, we examined the expression of multifunctional Ca2+-calmodulin-dependent protein kinases (CaMK) in human skeletal muscle and show that CaMKII and CaMKK, but not CaMKI or CaMKIV, are expressed...

  9. The other side of cardiac Ca2+ signaling: transcriptional control

    Directory of Open Access Journals (Sweden)

    Alejandro eDomínguez-Rodríquez

    2012-11-01

    Full Text Available Ca2+ is probably the most versatile signal transduction element used by all cell types. In the heart, it is essential to activate cellular contraction in each heartbeat. Nevertheless Ca2+ is not only a key element in excitation-contraction coupling (EC coupling, but it is also a pivotal second messenger in cardiac signal transduction, being able to control processes such as excitability, metabolism, and transcriptional regulation. Regarding the latter, Ca2+ activates Ca2+-dependent transcription factors by a process called excitation-transcription coupling (ET coupling. ET coupling is an integrated process by which the common signaling pathways that regulate EC coupling activate transcription factors. Although ET coupling has been extensively studied in neurons and other cell types, less is known in cardiac muscle. Some hints have been found in studies on the development of cardiac hypertrophy, where two Ca2+-dependent enzymes are key actors: Ca2+/Calmodulin kinase II (CaMKII and phosphatase calcineurin, both of which are activated by the complex Ca2+/ /Calmodulin. The question now is how ET coupling occurs in cardiomyocytes, where intracellular Ca2+ is continuously oscillating. In this focused review, we will draw attention to location of Ca2+ signaling: intranuclear ([Ca2+]n or cytoplasmic ([Ca2+]c, and the specific ionic channels involved in the activation of cardiac ET coupling. Specifically, we will highlight the role of the 1,4,5 inositol triphosphate receptors (IP3Rs in the elevation of [Ca2+]n levels, which are important to locally activate CaMKII, and the role of transient receptor potential channels canonical (TRPCs in [Ca2+]c, needed to activate calcineurin.

  10. Variation spatiotemporelle de la cryptorchidie et de l’hypospadias au Québec : Une étude exploratoire

    Science.gov (United States)

    Guertin, Sophie; Lemieux, Karine-Sylvie; Makhoulian, Natalie; Michaud, Sébastien; Patry, Rose-Marie; Côté, Anne-Andrée; Gagnon, Fabien; Ayotte, Pierre; Bolduc, Stéphane

    2011-01-01

    Résumé Objectifs : La majorité des études effectuées au cours des dernières décennies ont mis en évidence une augmentation du nombre de cas de cryptorchidie et d’hypospadias entre 1970 et 1990. De plus, l’importante variabilité géographique de ces anomalies est bien décrite. Cette étude vise à mesurer la prévalence à la naissance de la cryptorchidie et de l’hypospadias au Québec, à vérifier si ces anomalies sont en augmentation et à en évaluer la répartition interrégionale. Méthode : Une étude épidémiologique descriptive a été réalisée à partir du nombre de garçons de cinq ans et moins hospitalisés pour une cryptorchidie ou un hypospadias au Québec de 1989 à 2004 selon les données du fichier administratif d’hospitalisation MED-ÉCHO. Les données sur les naissances provenaient de l’Institut de la statistique du Québec. Résultats : La prévalence annuelle moyenne pour 1000 naissances vivantes de sexe masculin est de 19,1 (IC à 95 % : 18,8–19,4) pour la cryptorchidie et 11,4 (IC à 95 % 11,1–11,6) pour l’hypospadias au Québec. Au cours de la période étudiée, la prévalence de cryptorchidie a légèrement diminué, alors que celle de l’hypospadias est demeurée stable. Comparativement à la province du Québec, des régions présentent une prévalence significativement différente de cryptorchidie et/ou d’hypospadias. . Conclusion : Au Québec, la prévalence de cryptorchidie est en légère diminution alors que celle de l’hypospadias est stable. Des variations régionales significatives sont observables. D’autres études sont nécessaires afin d’évaluer l’hypothèse d’un lien avec les contaminants environnementaux en émergence. L’implantation d’un système de surveillance des anomalies congénitales permettrait une représentation plus valide de la situation. PMID:21672476

  11. Nueva política europea en productos químicos. REACH New European policy on chemical products. REACH

    Directory of Open Access Journals (Sweden)

    Francisco Vargas Marcos

    2005-12-01

    Full Text Available En febrero de 2001, la Comisión Europea publicó el Libro Blanco relativo a la estrategia para la futura política en materia de sustancias y preparados químicos, que se fundamenta en una revisión del sistema comunitario actual de regulación de las sustancias y preparados químicos. Como consecuencia, el 29 de octubre de 2003, la Comisión adoptó la propuesta de Reglamento sobre registro, evaluación, autorización y restricción de las sustancias químicas (REACH. Mediante esta propuesta, además de crearse la Agencia Europea de Sustancias Químicas, se establece el sistema REACH que consta de los siguientes elementos:Registro, que exige a la industria que facilite información sobre sus sustancias con el objeto de conseguir una utilización segura de las mismas.Evaluación, que garantiza que la industria cumple sus obligaciones y evita que se realicen ensayos innecesarios.Autorización de sustancias con propiedades extremadamente preocupantes (CMR, PBT, disruptores endocrinos, etc. para unos usos particulares.Restricción, como red de seguridad para la reducción de riesgos que no hayan sido abordados en las etapas anteriores.Este sistema de recogida de información en varias fases permitirá conocer y reducir los riesgos derivados del uso de unas 30.000 sustancias químicas que se producen/importan en la Unión Europea en cantidad superior a una tonelada/año. La información, una vez validada, se almacenará en una base de datos y podrá utilizarse para el establecimiento de un vínculo causal entre los factores medioambientales y los efectos negativos sobre la salud derivados de la producción y utilización de los productos químicos.In February 2001 the European Commission issued a White Paper on a “Strategy for a future Chemicals Policy” based on a review of the current European Union system for regulating the dangerous substances and preparations. As a result, on 29 October 2003, the Commission endorsed a Proposal for a

  12. Comparison of phosgene, chlorine, and hydrogen chloride as reagents for converting molten CaO.CaCl2 to CaCl2

    International Nuclear Information System (INIS)

    Fife, K.W.

    1985-01-01

    One method at Los Alamos for preparing impure plutonium metal from the impure oxide is by batch reduction with calcium metal at 850 0 C in a CaCl 2 solvent. The solvent salt from this reduction is currently discarded as low-level radioactivity waste only because it is saturated with the CaO byproduct. We have demonstrated a pyrochemical technique for converting the CaO to CaCl 2 thereby incorporating solvent recycling into the batch reduction process. We will discuss the effectiveness of HCl, Cl 2 , and COCl 2 as chlorinating agents and recycling actual spent process solvent salts. 6 refs., 8 figs

  13. Intracellular alkalinization induces cytosolic Ca2+ increases by inhibiting sarco/endoplasmic reticulum Ca2+-ATPase (SERCA.

    Directory of Open Access Journals (Sweden)

    Sen Li

    Full Text Available Intracellular pH (pHi and Ca(2+ regulate essentially all aspects of cellular activities. Their inter-relationship has not been mechanistically explored. In this study, we used bases and acetic acid to manipulate the pHi. We found that transient pHi rise induced by both organic and inorganic bases, but not acidification induced by acid, produced elevation of cytosolic Ca(2+. The sources of the Ca(2+ increase are from the endoplasmic reticulum (ER Ca(2+ pools as well as from Ca(2+ influx. The store-mobilization component of the Ca(2+ increase induced by the pHi rise was not sensitive to antagonists for either IP(3-receptors or ryanodine receptors, but was due to inhibition of the sarco/endoplasmic reticulum Ca(2+-ATPase (SERCA, leading to depletion of the ER Ca(2+ store. We further showed that the physiological consequence of depletion of the ER Ca(2+ store by pHi rise is the activation of store-operated channels (SOCs of Orai1 and Stim1, leading to increased Ca(2+ influx. Taken together, our results indicate that intracellular alkalinization inhibits SERCA activity, similar to thapsigargin, thereby resulting in Ca(2+ leak from ER pools followed by Ca(2+ influx via SOCs.

  14. F-actin-based Ca signaling-a critical comparison with the current concept of Ca signaling.

    Science.gov (United States)

    Lange, Klaus; Gartzke, Joachim

    2006-11-01

    A short comparative survey on the current idea of Ca signaling and the alternative concept of F-actin-based Ca signaling is given. The two hypotheses differ in one central aspect, the mechanism of Ca storage. The current theory rests on the assumption of Ca-accumulating endoplasmic/sarcoplasmic reticulum-derived vesicles equipped with an ATP-dependent Ca pump and IP3- or ryanodine-sensitive channel-receptors for Ca-release. The alternative hypothesis proceeds from the idea of Ca storage at the high-affinity binding sites of actin filaments. Cellular sites of F-actin-based Ca storage are microvilli and the submembrane cytoskeleton. Several specific features of Ca signaling such as store-channel coupling, quantal Ca release, spiking and oscillations, biphasic and "phasic" uptake kinetics, and Ca-induced Ca release (CICR), which are not adequately described by the current concept, are inherent properties of the F-actin system and its dynamic state of treadmilling. Copyright 2006 Wiley-Liss, Inc.

  15. Elementary properties of CaV1.3 Ca(2+) channels expressed in mouse cochlear inner hair cells.

    Science.gov (United States)

    Zampini, Valeria; Johnson, Stuart L; Franz, Christoph; Lawrence, Neil D; Münkner, Stefan; Engel, Jutta; Knipper, Marlies; Magistretti, Jacopo; Masetto, Sergio; Marcotti, Walter

    2010-01-01

    Mammalian cochlear inner hair cells (IHCs) are specialized to process developmental signals during immature stages and sound stimuli in adult animals. These signals are conveyed onto auditory afferent nerve fibres. Neurotransmitter release at IHC ribbon synapses is controlled by L-type Ca(V)1.3 Ca(2+) channels, the biophysics of which are still unknown in native mammalian cells. We have investigated the localization and elementary properties of Ca(2+) channels in immature mouse IHCs under near-physiological recording conditions. Ca(V)1.3 Ca(2+) channels at the cell pre-synaptic site co-localize with about half of the total number of ribbons present in immature IHCs. These channels activated at about 70 mV, showed a relatively short first latency and weak inactivation, which would allow IHCs to generate and accurately encode spontaneous Ca(2+) action potential activity characteristic of these immature cells. The Ca(V)1.3 Ca(2+) channels showed a very low open probability (about 0.15 at 20 mV: near the peak of an action potential). Comparison of elementary and macroscopic Ca(2+) currents indicated that very few Ca(2+) channels are associated with each docked vesicle at IHC ribbon synapses. Finally, we found that the open probability of Ca(2+) channels, but not their opening time, was voltage dependent. This finding provides a possible correlation between presynaptic Ca(2+) channel properties and the characteristic frequency/amplitude of EPSCs in auditory afferent fibres.

  16. Drogas: uma proposta de metodologia da problematização no Ensino de Química

    Directory of Open Access Journals (Sweden)

    Rafaela Alves de Andrade

    2018-03-01

    Full Text Available A metodologia da problematização é algo transformador que desperta a curiosidade do aluno e o desafia a observar a realidade, entender e modificá-la. Assim, o aluno consegue encontrar um estímulo para aprender, no qual o professor é o mediador do conhecimento nessa educação problematizadora. O estudo teve como objetivo analisar a utilização da metodologia da problematização nas aulas de química, em uma turma do 3° ano do ensino médio, analisando o desenvolvimento da aprendizagem dos conceitos de química presentes no tema: as drogas. A investigação ocorreu de forma qualitativa com fins descritivos e explicativos na abordagem do problema, com aplicação de questionários como instrumento de coleta de dados, para analisar o conhecimento dos estudantes no início e final do estudo. O processo de intervenção foi realizado nas aulas de química aplicando as etapas do Arco de Maguerez, no qual ocorreu em cinco momentos: observação da realidade, pontos-chave, teorização, hipóteses de solução e aplicação à realidade. Ao ser executada essa metodologia, verificou- se que os alunos adquirem estímulos para aprenderem com aulas problematizadoras através de um tema social.

  17. Contextual herd factors associated with cow culling risk in Québec dairy herds: A multilevel analysis.

    Science.gov (United States)

    Haine, Denis; Delgado, Hector; Cue, Roger; Sewalem, Asheber; Wade, Kevin; Lacroix, René; Lefebvre, Daniel; Arsenault, Julie; Bouchard, Émile; Dubuc, Jocelyn

    2017-09-01

    Several health disorders, such as milk fever, displaced abomasum, and mastitis, as well as impaired reproductive performance, are known risk factors for the removal of affected cows from a dairy herd. While cow-level risk factors are well documented in the literature, herd-level associations have been less frequently investigated. The objective of this study was to investigate the effect of cow- and herd-level determinants on variations in culling risk in Québec dairy herds: whether herd influences a cow's culling risk. For this, we assessed the influence of herd membership on cow culling risk according to displaced abomasum, milk fever, and retained placenta. A retrospective longitudinal study was conducted on data from dairy herds in the Province of Québec, Canada, by extracting health information events from the dairy herd health management software used by most Québec dairy producers and their veterinarians. Data were extracted for all lactations starting between January 1st and December 31st, 2010. Using multilevel logistic regression, we analysed a total of 10,529 cows from 201 herds that met the inclusion criteria. Milk fever and displaced abomasum were demonstrated to increase the cow culling risk. A minor general herd effect was found for the culling risk (i.e. an intra-class correlation of 1.0% and median odds ratio [MOR] of 1.20). The proportion of first lactation cows was responsible for this significant, but weak herd effect on individual cow culling risk, after taking into account the cow-level factors. On the other hand, the herd's average milk production was a protective factor. The planning and management of forthcoming replacement animals has to be taken into consideration when assessing cow culling risks and herd culling rates. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Oficinas pedagógicas: motivando e engajando estudantes de engenharia no estudo da química

    Directory of Open Access Journals (Sweden)

    Valquíria Villas-Boas Gomes Missell

    2017-06-01

    Full Text Available Este trabalho apresenta resultados da realização de oficinas didáticas extracurriculares cujo objetivo foi avaliar o impacto dessa estratégia na mobilização do interesse de estudantes de Engenharia pelas disciplinas de Química de seu currículo. Os fundamentos teóricos que subsidiaram parte dessa investigação estão embasados em Vygotsky (2005. As oficinas foram realizadas no Núcleo de Apoio ao Ensino da Química (NAEQ, no Centro de Ciências Exatas e da Tecnologia da Universidade de Caxias do Sul. As oficinas foram aplicadas durante os anos de 2013 a 2015. Todos os participantes eram estudantes de 1º e 2º semestres, em um total de 160 estudantes. Os dados oriundos da aplicação de um questionário avaliativo foram avaliados por meio do método da análise textual discursiva. A análise das respostas dos estudantes evidencia o impacto positivo das oficinas na motivação dos estudantes, na construção de conceitos dessa área de conhecimento e na compreensão de processos industriais presentes nas empresas da região da Serra Gaúcha. O estudo demonstrou que a aplicação das oficinas produziu impactos relevantes para motivar os estudantes de Engenharia a estudar as disciplinas de Química dos currículos de seus cursos.

  19. Abundâncias químicas de uma amostra de nebulosas planetárias em M51

    Science.gov (United States)

    Uchida, M. M. M.; Costa, R. D. D.; Maciel, W. J.

    2003-08-01

    A derivação de abundâncias químicas de nebulosas planetárias permite a investigação dos processos de enriquecimento químico ocorridos durante a evolução das estrelas progenitoras, que têm massas entre 0.8 e 8 massas solares. Adicionalmente as abundâncias de elementos como oxigênio, argônio ou neônio, que não são produzidos por nucleossíntese na progenitora, refletem a evolução do meio interestelar: estrelas menos massivas, de evolução mais lenta, tipicamente originam-se de um meio interestelar mais pobre. Reportamos aqui a derivação de parâmetros físicos e abundâncias químicas de uma amostra de nebulosas planetárias da galáxia M51, uma galáxia de tipo Seyfert 2 pertencente ao Grupo de Sculptor. As observações foram feitas com o telescópio Gemini Norte, usando o espectrógrafo GMOS no modo multi-objeto. Os resultados indicam uma distribuição de abundâncias análoga àquela das planetárias da Galáxia. A amostra observada não permite estabelecer-se com clareza a existência de um gradiente radial como é esperado pelos modelos evolutivos de galáxias expirais; espera-se que uma extensão desta amostra deva indicá-lo posteriormente. (FAPESP/CNPq)

  20. QuBiLS-MIDAS: a parallel free-software for molecular descriptors computation based on multilinear algebraic maps.

    Science.gov (United States)

    García-Jacas, César R; Marrero-Ponce, Yovani; Acevedo-Martínez, Liesner; Barigye, Stephen J; Valdés-Martiní, José R; Contreras-Torres, Ernesto

    2014-07-05

    The present report introduces the QuBiLS-MIDAS software belonging to the ToMoCoMD-CARDD suite for the calculation of three-dimensional molecular descriptors (MDs) based on the two-linear (bilinear), three-linear, and four-linear (multilinear or N-linear) algebraic forms. Thus, it is unique software that computes these tensor-based indices. These descriptors, establish relations for two, three, and four atoms by using several (dis-)similarity metrics or multimetrics, matrix transformations, cutoffs, local calculations and aggregation operators. The theoretical background of these N-linear indices is also presented. The QuBiLS-MIDAS software was developed in the Java programming language and employs the Chemical Development Kit library for the manipulation of the chemical structures and the calculation of the atomic properties. This software is composed by a desktop user-friendly interface and an Abstract Programming Interface library. The former was created to simplify the configuration of the different options of the MDs, whereas the library was designed to allow its easy integration to other software for chemoinformatics applications. This program provides functionalities for data cleaning tasks and for batch processing of the molecular indices. In addition, it offers parallel calculation of the MDs through the use of all available processors in current computers. The studies of complexity of the main algorithms demonstrate that these were efficiently implemented with respect to their trivial implementation. Lastly, the performance tests reveal that this software has a suitable behavior when the amount of processors is increased. Therefore, the QuBiLS-MIDAS software constitutes a useful application for the computation of the molecular indices based on N-linear algebraic maps and it can be used freely to perform chemoinformatics studies. Copyright © 2014 Wiley Periodicals, Inc.