Optical Absorptivity versus Molecular Composition of Model Organic Aerosol Matter

Aerosol particles affect the Earth’s energy balance by absorbing and scattering radiation according to their chemical composition, size, and shape. It is generally believed that their optical properties could be deduced from the molecular composition of the complex organic matter contained in these particles, a goal pursued by many groups via high-resolution mass spectrometry, although: (1) absorptivity is associated with structural chromophores rather than with molecular formulas, (2) compositional space is a small projection of structural space, and (3) mixtures of polar polyfunctional species usually exhibit supramolecular interactions. Here we report a suite of experiments showing that the photolysis of aqueous pyruvic acid (a proxy for aerosol α-dicarbonyls absorbing at λ > 300 nm) generates mixtures of identifiable aliphatic polyfunctional oligomers that develop absorptions in the visible upon standing in the dark. These absorptions and their induced fluorescence emissions can be repeatedly bleached and retrieved without carbon loss or ostensible changes in the electrospray mass spectra of the corresponding mixtures and display unambiguous signatures of supramolecular effects. The nonlinear additivity of the properties of the components of these mixtures supports the notion that full structural speciation is insufficient and possibly unnecessary for understanding the optical properties of aerosol particles and their responses to changing ambient conditions

Thermochromism of Model Organic Aerosol Matter

Laboratory experiments show that the optical absorptivity of model organic matter is not an intrinsic property, but a strong function of relative humidity, temperature, and insolation. Suites of representative polyfunctional C_(x)H_(y)O_(z) oligomers in water develop intense visible absorptions upon addition of inert electrolytes. The resulting mixtures reach mass absorption cross sections σ(532 nm) ~ 0.1 m^(2)/gC in a few hours, absorb up to 9 times more solar radiation than the starting material, can be half-bleached by noon sunlight in ~ 1 h, and can be repeatedly recycled without carbon loss. Visible absorptions red-shift and evolve increasingly faster in subsequent thermal aging cycles. Thermochromism and its strong direct dependences on ionic strength and temperature are ascribed to the dehydration of >CH−C(OH)C═C< unsaturations by a polar E1 mechanism, and bleaching to photoinduced retrohydration. These transformations are deemed to underlie the daily cycles of aerosol absorption observed in the field, and may introduce a key feedback in the earth’s radiative balance

El Triásico del sector de Mansilla (Demanda Suroriental-LaRioja)

[ES] Sobre un zócalo paleozoico fuertemente plegado y erosionado se depositan discordantes series atribuibles al Triásico, en general de poco espesor y que en detalle tienen importantes variaciones de facies y potencia. Se reconocen los tres litotipos clásicos, Buntsandstein, Muschelkalk y Keuper. El Buntsandstein suele comenzar por un conglomerado de poco espesor, a veces brechoide, cuya textura, composición litológica y espesor está regulada por el paleorrelieve infrayacente, constituido por una «penillanura» con valles encajados que se rellenan por aportes con gran influencia local. Sobre estos rellenos se encuentra una serie de materiales detríticos que constituyen una grosera alternancia de areniscas y lutitas, con marcado carácter continental, donde predominan los depósitos fluviales, tanto de canal como de llanura de inundación, siendo asimismo patentes los procesos edáficos. Los últimos metros de este litotipo marcan un tránsito gradual al Muschelkalk, apreciándose en ellos una progresiva influencia marina. El Muschelkalk, de poco espesor (máximo 20 mil presenta muchas variaciones de potencia y distribución, llegando incluso a faltar. Las facies más frecuentes corresponden a depósitos carbonáticos con predominio de dolomías con abundantes estructuras algares, deformaciones y brechas atribuibles a la existencia de evaporitas, así como señales de emersión. En conjunto estos depósitos corresponden a un medio mareal carbonatado. Finalmente el Keuper, también de poco espesor (30-40 m. máximo), está formado por lutitas versicolores con sales dispersas que sólo localmente son abundantes. A techo se encuentran dolomías brechoides (carniolas) en contacto impreciso y a veces mecanizado. Por el momento no existen datos bioestratigráficos detallados de esta zona y las referencias bibliográficas, en base a faunas encontradas en el Muschelkalk, no aportan mayor precisión. Los minerales pesados, mayoritariamente turmalina, zircón y óxidos de titanio, revelan en los tramos basales del Buntsandstein una neta influencia del propio Paleozoico de la Sierra de la Demanda como área fuente, pasándose en la vertical a mezcla con aportes de otras áreas fuente más alejadas, caracterizado por la abundancia de micas y variaciones en la morfología de las turmalinas. El alto contenido en turmalina permite comparar estas series con las del Buntsandstein de áreas próximas, excluyendo provisionalmen. te la presencia en la base de facies saxonienses, con diferentes espectros mineralógicos.[EN] Triassic materials outcropping southeast of Sierra de la Demanda are basically represented by germanic type facies: Buntsandstein, Muschelkalk and Keuper. Buntsandstein facies are clastics, towards the bottom predominate conglomerates, occasionally brecciated. This facies lie unconformably over lower paleozoic sediments strongly folded. Unconformity shows areas where scour surfaces predominate here interpreted as ancient valleys. Facies distribution over the unconformity plane are mainly controlled by the pre-existing relief, also controlling its thickness and here interpreted as fluvial deposits. Muschelkalk facies is characterized by the occurrence of algal limestones and tidal associated deposits. Evaporites appear to-wards the top of the stratigraphical sections studied and are primarity composed of fine interbedded clastic with gypsum and associated salts. Heavy minerals occurring in the Buntsandstein facies are basically tourmaline, zircon and titanium oxides. Lacking of palaeontological data, hig tourmaline content suggests that this deposits are comparable to Buntsandstein matehais outcropping in nearly areas. Mineralogical content of the facies here studied suggests the possibility of considering this deposits as Buntsandstein, non existing the typical mineralogical facies characterizing the Saxonian, Permian in age.Este trabajo ha sido financiado por la CAICYT y C.S.I.C., proyecto número 452. 691Peer reviewe

Transcriptional Response to Acute Thermal Exposure in Juvenile Chinook Salmon Determined by RNAseq.

Thermal exposure is a serious and growing challenge facing fish species worldwide. Chinook salmon (Oncorhynchus tshawytscha) living in the southern portion of their native range are particularly likely to encounter warmer water due to a confluence of factors. River alterations have increased the likelihood that juveniles will be exposed to warm water temperatures during their freshwater life stage, which can negatively impact survival, growth, and development and pose a threat to dwindling salmon populations. To better understand how acute thermal exposure affects the biology of salmon, we performed a transcriptional analysis of gill tissue from Chinook salmon juveniles reared at 12° and exposed acutely to water temperatures ranging from ideal to potentially lethal (12° to 25°). Reverse-transcribed RNA libraries were sequenced on the Illumina HiSeq2000 platform and a de novo reference transcriptome was created. Differentially expressed transcripts were annotated using Blast2GO and relevant gene clusters were identified. In addition to a high degree of downregulation of a wide range of genes, we found upregulation of genes involved in protein folding/rescue, protein degradation, cell death, oxidative stress, metabolism, inflammation/immunity, transcription/translation, ion transport, cell cycle/growth, cell signaling, cellular trafficking, and structure/cytoskeleton. These results demonstrate the complex multi-modal cellular response to thermal stress in juvenile salmon

Texture changes during chilled storage of wild and farmed blacspot seabream (Pagellus bogaraveo) fed different diets

The impact of changes in dietary lipids and protein sources on texture was evaluated on farmed blackspot seabream (Pagellus bogaraveo) throughout 14 days of ice storage and compared with wild fish. A commercial diet formulated with a high proportion of lipids, and two diets formulated with an important reduction of lipid levels by 60% and adding either plant protein sources (LL diet) or fishmeal (LL + diet) were supplied during growth until commercial size was attained. In the wild fish, the raw fillet hardness was significantly higher than in farmed fish during the entire ice-storage period. In the farmed fish, an increase of muscle lipid accumulation and change of fiber density were responsible for the variations in texture in the raw fillet. The highest reduction was found in fish fed with diets LL+ and LL. The texture parameters studied on the cooked fillets showed no significant differences, neither attributable to the diets nor to the ice-storage period.JUNTA ASESORA DE CULTIVOS MARINOS (JACUMAR)Postprin

Estudio de la heterosis y acción génica para once características en cinco cruzamientos de algodonero Upland. (Gossypium hirsutum L.).

Se realiza un experimento para determinar la heterosis y el mecanismo genético que operó en la herencia de once características en cinco cruzamientos de algodón upland. Se presentó heterosis significativa en las medidas del número de días a primera flor, rendimiento de algodón, semilla en kg/ha, peso en gramos de la mota, porcentaje de fibra, índice de semilla, índice de fibra y finura. El número de lóculos por cápsula y la resistencia de la fibra presentaron heterosis negativa a niveles significativos. No presentaron heterosis las medidas del número de días a la apertura de las primeras cápsulas y longitud de fibra. La heterosis para número de días a primera flor, número de lóculos por cápsula, peso en gramos de la mota, porcentaje de fibra, índice de semilla y de fibra, fué causada por efectos de dominancia. La dominancia y la epistasis influyeron en la heterosis del rendimiento de algodón semilla en kg/ha y finura de la fibra. No se presentó pérdida del vigor de la F1 en las siguientes características: días de siembra a primera flor, días de siembra a la apertura de la primera cápsula, número de lóculos por cápsula, índice de semilla, índice de fibra, longitud y finura de la fibra. Se sugiere que para mejorar aquellas características en las que la actividad fué importante, se utilice un sismtema de selección masalAlgodón-Gossypium herbaceumMaestría en CienciasMaestrí