819 research outputs found
El género Porphyra (Bangiaceae, Rhodophyta) en la costa Pacífico de México. I. Porphyra suborbiculata Kjellman
Porphyra suborbiculata Kjellman (Bangiaceae, Rhodophyta) is described with detail for the Pacific coast of Mexico, where was recently recorded, based on samples collected from western coast of Baja California between 1985 and 2001. We describe details of vegetative and reproductive morpho-anatomic characters of the thallus, as well as habitat and distribution on the Baja California coast.Se presenta una descripción extensa de Porphyra suborbiculata Kjellman (Bangiaceae, Rhodophyta), specierecientemente registrada para la costa del Pacífico de México, con base en material recolectado en la costaoccidental de Baja California, durante 1985-2001. Se describen en forma detallada los caracteres morfo-anatómicos y estructuras reproductoras de los talos; así como su hábitat y distribución en la costa de Baja California
MACROALGAS MARINAS DE LA BAHÍA DE SAN QUINTÍN, BAJA CALIFORNIA, MÉXICO
In order to know the composition anddistribution of macroalgae species in thelagoon complex of San Quintin Bay, BajaCalifornia, nine sampled were realized inthree sites during 1988, 1989, 1990, 1995 and1996; also a bibliographyc revision on themarine benthic algae cited from the studyarea. A total of 37 genera with 46 species ofmarine macroalgae were determined, ofwhich 22 are Rhodophyta, (47.82 %), 12Phaeophyta (26.08 %) and 12 Chlorophyta(26.08 %). The floristic list includes data onthe presence and distribution of speciesfound, reproductive stage, substrate and epiphytism. The families with bestrepresentation with regard to richnessand occurrence are: Corallinaceae,Ceramiaceae, Rhodomelaceae (Rhodophyta); Ectocarpaceae, Scytosiphonaceae(Phaeophyta) and Ulvaceae (Chlorophyta).18 (39.13 %) represent new records from thestudy area. Ulva expansa Linnaeus isreported for the first time for the occidentalcoast of Baja California. The floristc list andthe bibliographyc information wereactualized; the dates show that the numberod species of marine algae from San QuintinBay is composed for 59 species.Con la finalidad de determinar la distribucióny composición de las especies demacroalgas presentes en el complejolagunar de la bahía de San Quintín, BajaCalifornia, se realizaron nueve muestreos entres sitios, durante 1988, 1989, 1990, 1995 y1996; así como una revisión bibliográficade algas marinas citadas para el área deestudio. Los resultados obtenidos delmaterial recolectado indican la presencia de37 géneros con 46 especies, de las cuales22 son Rhodophyta (47.82 %), 12Phaeophyta (26.08 %) y 12 Chlorophyta(26.08 %). En la lista florística se incluyendatos sobre la presencia y distribuciónde las especies en el área de estudio,su estado reproductivo, sustrato yepifitismo. En términos de diversidadde especies, las familias mejorrepresentadas corresponden a Corallinaceae, Ceramiaceae, Rhodomelaceae(Rhodophyta), Ectocarpaceae, Scytosiphonaceae (Phaeophyta) y Ulvaceae(Chlorophyta). Del total de algasidentificadas, 18 (39.13 %) representannuevos registros para el área de estudio. Se cita por primera vez a Ulva expandaLinnaeus para la costa occidental de BajaCalifornia. Al depurar y actualizar lainformación bibliográfica desde el punto devista florístico y nomenclatural, se encontróque la flora marina conocida hasta hoy parala bahía de San Quintín es de 59 especies
LA PRESENCIA DEL ALGA EUROPEA CLADOSTEPHUS SPONGIOSUS (HUDSON) C. AGARDH (SPHACELARTIALES, OCHROPHYTA) EN LA PENÍNSULA DE BAJA CALIFORNIA, MÉXICO: ESPECIE INTRODUCIDA
The brown algae Cladostephus spongiosus(Hudson) C. Agardh which is native fromEngland, has recently been reported inMexico. This introduced species deservesspecial attention. In order to understandits distribution along the Mexican Pacificcoast, sampling campaigns were carriedout in 2006 and 2010 SebastiánVizcaínoBay and surrounding areas. A literaturereview and herbaria specimens were carriedout to obtain information and records. Wefound that the C. spongiosus distribution isrestricted mainly to SebastiánVizcaíno Bay.Its distribution range is extended westwardin the Mexican Pacific coast with 360 kmof fishing area Queen, Baja California Surto Guadalupe Island, Baja California. Weobserved juvenile and reproductive thalliin C. spongiosus populations attached torocks and also specimens deposited on thebeach, indicating that the colonization ofthis species is not limited to spread beyondits current distribution range.La especie de alga parda Cladostephusspongiosus (Hudson) C. Agardh originariade Inglaterra ha sido reportada recientemente en México, la cual por su carácter de“especie introducida” merece especial atención en su conocimiento. Con el propósitode conocer su distribución en la costa delPacífico mexicano, se realizaron muestreosen Bahía de Sebastián Vizcaíno y áreasaledañas durante 2006 y 2010. Además,para obtener registros e información de laespecie, se realizó una revisión bibliográficay ejemplares depositados en los herbarios.Se determinó que la distribución de C.spongiosus, está restringida principalmente a la Bahía de Sebastián Vizcaíno, BajaCalifornia. Se amplía su rango de distribución hacia el oeste en la costa del Pacíficomexicano con 360 km de campo pesqueroQueen, Baja California Sur a Isla Guadalupe, Baja California. En las poblacionesencontradas, se observaron talos jóvenes yadultos reproductivos adheridos a sustratorocoso, además de especímenes depositadosen la playa, indicando que la colonizaciónde esta especie no está limitada para dispersarse más allá de su rango de distribuciónactual
Does native Trypanosoma cruzi calreticulin mediate growth inhibition of a mammary tumor during infection?
Indexación: Web of Science.Background: For several decades now an antagonism between Trypanosoma cruzi infection and tumor development has been detected. The molecular basis of this phenomenon remained basically unknown until our proposal that T. cruzi Calreticulin (TcCRT), an endoplasmic reticulum-resident chaperone, translocated-externalized by the parasite, may mediate at least an important part of this effect. Thus, recombinant TcCRT (rTcCRT) has important in vivo antiangiogenic and antitumor activities. However, the relevant question whether the in vivo antitumor effect of T. cruzi infection is indeed mediated by the native chaperone (nTcCRT), remains open. Herein, by using specific modified anti-rTcCRT antibodies (Abs), we have neutralized the antitumor activity of T. cruzi infection and extracts thereof, thus identifying nTcCRT as a valid mediator of this effect.
Methods: Polyclonal anti-rTcCRT F(ab')(2) Ab fragments were used to reverse the capacity of rTcCRT to inhibit EAhy926 endothelial cell (EC) proliferation, as detected by BrdU uptake. Using these F(ab')(2) fragments, we also challenged the capacity of nTcCRT, during T. cruzi infection, to inhibit the growth of an aggressive mammary adenocarcinoma cell line (TA3-MTXR) in mice. Moreover, we determined the capacity of anti-rTcCRT Abs to reverse the antitumor effect of an epimastigote extract (EE). Finally, the effects of these treatments on tumor histology were evaluated.
Results: The rTcCRT capacity to inhibit ECs proliferation was reversed by anti-rTcCRT F(ab')(2) Ab fragments, thus defining them as valid probes to interfere in vivo with this important TcCRT function. Consequently, during infection, these Ab fragments also reversed the in vivo experimental mammary tumor growth. Moreover, anti-rTcCRT Abs also neutralized the antitumor effect of an EE, again identifying the chaperone protein as an important mediator of this anti mammary tumor effect. Finally, as determined by conventional histological parameters, in infected animals and in those treated with EE, less invasive tumors were observed while, as expected, treatment with F(ab')(2) Ab fragments increased malignancy.
Conclusion: We have identified translocated/externalized nTcCRT as responsible for at least an important part of the anti mammary tumor effect of the chaperone observed during experimental infections with T. cruzi.http://bmccancer.biomedcentral.com/articles/10.1186/s12885-016-2764-
Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV
The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8 TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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