中国北方中新世风尘物质来源及古气候的地球化学指示

The most prominent tectonic and environmental events during the Cenozoic in Asia are the uplift of the Himalaya-Tibetan plateau, aridification in the Asian interior, and onset of the Asian monsoons. These caused more humid conditions in southeastern China and the formation of inland deserts in northwestern China. The 22 Ma eolian deposits in northern China provide an excellent terrestrial record relative to the above environmental events. Up to date, many studies have focused on the geochemical characters of the late Mio-Pleistocene eolian deposits, however, the geochemical characteristics of the Miocene loess and soils is still much less known. In this study, the elemental and Sr-Nd isotopic compositions of the eolian deposits from the Qinan (from 22.0 to 6.2 Ma) and the Xifeng (from 3.5 Ma until now) loess-soil sections were analyzed to examine the grain size effects on the element concentrations and the implications about the dust origin and climate. The main results are as follows: 1. The contents of Si, Na, Zr and Sr are higher in the coarser fractions while Ti and Nb have the highest contents in the 2-8 μm fractions. Al, Fe, Mg, K, Mn, Rb, Cu, Ga, Zn, V, Cr, Ni, LOI have clear relationships with grain-size, more abundant in the fine fraction while non significant relationship is observed for Y. Based on these features, we suggest that K2O/Al2O3 ratio can be used to address the dust provenance, and that VR (Vogt ratio = (Al2O3+K2O)/(MgO+CaO+Na2O)) can be used as a chemical weathering proxy for the Miocene eolian deposits because of their relative independence on the grain size. Meanwhile, SiO2/Al2O3 molar ratio is a best geochemical indicator of original eolian grain size, as suggested in earlier studies. 2. Analyses on the Sr and Nd isotope composition of the last glacial loess samples (L1) and comparison with the data from the deserts in northern China suggest that that Taklimakan desert is unlikely to be the main source region of the eolian dust. In contrast, these data suggest greater contributions of the Tengger, Badain Jaran and Qaidam deserts to the eolian dust during the last glacial cycle. Since the geochemical compositions (major, trace, REE and Sr, Nd isotope) of loess samples for the past 22 Ma are broadly similar with the samples from L1, these data trend to suggest relatively stable and insignificant changes of dust sources over the past 22 Ma. 3. Chemical weathering is stronger for Miocene paleosol samples than for the Plio-Pleistocene ones, showing warmer/more humid climatic conditions with a stronger summer monsoon in the Miocene. However, chemical weathering is typical of Ca-Na removal stage, suggesting a climate range from semiarid to subhumid conditions. These support the notion about the formation of a semi-arid to semi-humid monsoonal regime by the early Miocene, as is consistent with earlier studies.

Prioridades de pesquisa com a cultura da alfafa no Brasil.

Áreas prioritárias de pesquisa com alfafa ; Melhoramento vegetal ; Produção de sementes ; Pastejo em alfafa ; Irrigação ; Controle de plantas daninhas ; Rotação de culturas ; Nutrição e adubação ; Pragas e doenças ; Avaliação econômica ; Priorização de linhas de pesquisa em alfafa.

Protocolos para estabelecimento e caracterização de sítio específico experimental.

2007

Estabelecimento de sítios-específicos experimentais visando imposição e monitoramento de estresse hídrico para fenotipagem de cereais.

2005

Laboratório móvel para monitoramento, avaliação e gerência de atributos de sistemas de produção agrícola.

2005

Informes da avaliação de genótipos de girassol 2005/2006 e 2006.

Características gerais da Rede Oficial de Avaliação de Genótipos de Girassol; Resultados dos ensaios finais de primeiro e segundo ano; Lista dos genótipos de girassol avaliados e registrados no Ministério da Agricultura, Pecuária e Abastecimento - MAPA.

Levantamento de reconhecimento dos solos do Estado do Paraná.

O conhecimento pormenorizado das propriedades morfológicas, físicas, químicas e mineralógicas dos solos, constitui fonte de informação básica para a compreensão e solução dos problemas que afetam a pesquisa agropecuária.

Solos do Estado de Santa Catarina.

2004

Os solos do Vale dos Vinhedos.

INTRODUÇÃO. CARACTERIZAÇÃO DA ÁREA. MATERIAL E MÉTODOS. RESULTADOS. CONSIDERAÇÕES FINAIS. REFERÊNCIAS. ANEXOS: Anexo I - Mapa impresso; Mapa de solos do Vale dos Vinhedos, RS. Anexo II - CD-ROM. Anexo IIA - Arquivos digitais para reprodução de cópias impressas - formato pdf (portable document file). Anexo IIB - Arquivos digitais estruturados para uso em SIG - formato shape file. Anexo IIC - Descrição dos perfis do levantamento detalhado de solos do Vale dos Vinhedos, RS

Influencia de distintas citocininas en el cultivo in vitro de apices caulinares de Fragaria x ananassa y F. virginiana

p.65-70

Estrategia didáctica para favorecer el desarrollo de la competencia organizar e interpretar el conocimiento matemático en los estudiantes de la carrera Ingeniería Informática de la Universidad de Camagüey

La estrategia didáctica es uno de los resultados de la investigación que realiza el grupo de matemática educativa de la Universidad de Camagüey. Tiene como objetivo diseñar una estrategia didáctica para favorecer la formación y el desarrollo de la competencia organizar e interpretar el conocimiento matemático en los estudiantes de la carrera Ingeniería Informática de la Universidad de Camagüey. La misma centra sus resultados científicos fundamentales en un modelo teórico para la formación y desarrollo de la competencia organizar e interpretar el conocimiento matemático. En esta estrategia didáctica para favorecer la formación y el desarrollo de la competencia organizar e interpretar el conocimiento matemático en los estudiantes de la carrera Ingeniería Informática presenta un set de instrumentos e indicadores para evaluar la formación y el desarrollo de la competencia organizar e interpretar el conocimiento matemático. En el desarrollo de la investigación se utilizaron diferentes métodos, y la implementación se realizó en dos grupos de esta facultad con resultados satisfactorios. Con esta investigación se contribuye al Perfeccionamiento de la Educación Superior.

Assessing the potential of autonomous submarine gliders for ecosystem monitoring across multiple trophic levels (plankton to cetaceans) in shallow shelf seas

A combination of scientific, economic, technological and policy drivers is behind a recent upsurge in the use of marine autonomous systems (and accompanying miniaturized sensors) for environmental mapping and monitoring. Increased spatial–temporal resolution and coverage of data, at reduced cost, is particularly vital for effective spatial management of highly dynamic and heterogeneous shelf environments. This proof-of-concept study involves integration of a novel combination of sensors onto buoyancy-driven submarine gliders, in order to assess their suitability for ecosystem monitoring in shelf waters at a variety of trophic levels. Two shallow-water Slocum gliders were equipped with CTD and fluorometer to measure physical properties and chlorophyll, respectively. One glider was also equipped with a single-frequency echosounder to collect information on zooplankton and fish distribution. The other glider carried a Passive Acoustic Monitoring system to detect and record cetacean vocalizations, and a passive sampler to detect chemical contaminants in the water column. The two gliders were deployed together off southwest UK in autumn 2013, and targeted a known tidal-mixing front west of the Isles of Scilly. The gliders’ mission took about 40 days, with each glider travelling distances of >1000 km and undertaking >2500 dives to depths of up to 100 m. Controlling glider flight and alignment of the two glider trajectories proved to be particularly challenging due to strong tidal flows. However, the gliders continued to collect data in poor weather when an accompanying research vessel was unable to operate. In addition, all glider sensors generated useful data, with particularly interesting initial results relating to subsurface chlorophyll maxima and numerous fish/cetacean detections within the water column. The broader implications of this study for marine ecosystem monitoring with submarine gliders are discussed.

Decomposition of in situ particulate absorption spectra

A global dataset of in situ particulate absorption spectra has been decomposed into component functions representing absorption by phytoplankton pigments and non-algal particles. The magnitudes of component Gaussian functions, used to represent absorption by individual or groups of pigments, are well correlated with pigment concentrations determined using High Performance Liquid Chromatography. We are able to predict the presence of chlorophylls a,ba,b, and cc, as well as two different groups of summed carotenoid pigments with percent errors between 30% and 57%. Existing methods of analysis of particulate absorption spectra measured in situ provide for only chlorophyll aa; the method presented here, using high spectral resolution particulate absorption, shows the ability to obtain the concentrations of additional pigments, allowing for more detailed studies of phytoplankton ecology than currently possible with in-situ spectroscopy.

Assessing the potential of autonomous submarine gliders for ecosystem monitoring across multiple trophic levels (plankton to cetaceans) in shallow shelf seas

A combination of scientific, economic, technological and policy drivers is behind a recent upsurge in the use of marine autonomous systems (and accompanying miniaturized sensors) for environmental mapping and monitoring. Increased spatial–temporal resolution and coverage of data, at reduced cost, is particularly vital for effective spatial management of highly dynamic and heterogeneous shelf environments. This proof-of-concept study involves integration of a novel combination of sensors onto buoyancy-driven submarine gliders, in order to assess their suitability for ecosystem monitoring in shelf waters at a variety of trophic levels. Two shallow-water Slocum gliders were equipped with CTD and fluorometer to measure physical properties and chlorophyll, respectively. One glider was also equipped with a single-frequency echosounder to collect information on zooplankton and fish distribution. The other glider carried a Passive Acoustic Monitoring system to detect and record cetacean vocalizations, and a passive sampler to detect chemical contaminants in the water column. The two gliders were deployed together off southwest UK in autumn 2013, and targeted a known tidal-mixing front west of the Isles of Scilly. The gliders’ mission took about 40 days, with each glider travelling distances of >1000 km and undertaking >2500 dives to depths of up to 100 m. Controlling glider flight and alignment of the two glider trajectories proved to be particularly challenging due to strong tidal flows. However, the gliders continued to collect data in poor weather when an accompanying research vessel was unable to operate. In addition, all glider sensors generated useful data, with particularly interesting initial results relating to subsurface chlorophyll maxima and numerous fish/cetacean detections within the water column. The broader implications of this study for marine ecosystem monitoring with submarine gliders are discussed.

Analysis about the society of 'Pa Negre' (Agustí Villaronga, 2010)

This article has developed with the intention of analyzing how the stereotypes, prejudices and lies can influence the education of the children. Formation, that usually comes from family and teachers, who sometimes move for extremist ideologies. There exist multiple fictions in which we observe these social archetypes, but it is the case of the movie Pa negre (Agustí Villaronga, 2010), where the principal personage evolves psychologically, because of that its eyes observe and the ideas that the people transmit him on its family, in the rural environments, where the tradition of the rumors coexists.