Maastrichtian microfossils of the Shallow Marine Umir Formation, Northeastern Colombia

During the Late Cretaceous, northern South America was characterized by broad epicontinental seas, with variable surface productivity and changing bottom-water oxygenation. Global sea-level fluctuations and local tectonic shifts caused their disappearance in the latest Cretaceous. We present an integrated micropaleontological and geochemical study of a section comprising the Umir Formation and its lower stratigraphic contact with the La Luna Formation, in the Middle Magdalena Valley, northeastern Colombia. Foraminiferal assemblages were moderately diverse and mainly dominated by benthic taxa, characterizing the biozones Siphogenerinoides bramlettei and Ammobaculites colombiana (Maastrichtian). Planktonic foraminiferal assemblages were less diversified, being species assigned to Heterohelicidae and scarce keeled forms (Globotruncana spp.) the most recurrent taxa. Ostracod recovery was very scarce, and we could only identify the genus Actinocythereis. In contrast, calcareous nannofossil assemblages were moderately diversified along the section, and composed of typical Late Cretaceous low-latitude taxa such as Micula staurophora, Cribrosphaerella ehrenbergii, Gartnerago segmentatum. The identified microfossils indicate a transition from middle-inner shelf conditions, with moderately oxygenated bottom waters within the La Luna Formation, to a shallower marine setting within the Umir Formation. This interpretation is supported by Sr/Ba and log(Fe/Ca) ratios measured in bulk sediment, which indicate increased continental runoff and terrigenous input in the upper part of the section. Moreover, a significant biotic turnover was identified at the base of the section, suggesting the presence of a xenoconformity at the La Luna-Umir contact, which has been previously described and proposed as a regional stratigraphic feature. El Cretácico Tardío del norte de Sudamérica estuvo dominado por mares epicontinentales extensos, con fluctuaciones de la productividad superficial y oxigenación del agua de fondo. Cambios en los regímenes tectónicos locales y descensos globales en el nivel del mar, llevaron a la desaparición de dichos ambientes hacia fines del Cretácico. Presentamos un estudio micropaleontológico y geoquímico integrado de una sección de la Formación Umir y su contacto basal con la Formación La Luna en el Valle Medio del Magdalena, noreste de Colombia. Las asociaciones de foraminíferos fueron moderadamente diversas y estuvieron dominadas por formas bentónicas que definen las biozonas de asociación locales Siphogenerinoides bramlettei y Ammobaculites colombiana (Maastrichtiano). Las formas planctónicas, menos diversas, incluyeron ejemplares de Heterohelicidae y escasas formas quilladas (Globotruncana spp.). El registro de ostrácodos fue muy escaso, sólo pudimos reconocer al género Actinocythereis. En contraste, las asociaciones de nanofósiles calcáreos fueron moderadamente diversas y comprendieron formas típicas de bajas latitudes del Cretácico Tardío como Micula staurophora, Cribrosphaerella ehrenbergii, Gartnerago segmentatum. Las asociaciones de microfósiles indican una transición de condiciones de plataforma media-interna, moderadamente oxigenada en la Formación La Luna, a un ambiente más somero en la Formación Umir. Esta interpretación es corroborada por las relaciones de Sr/Ba y log(Fe/Ca) del sedimento que indican un aumento en la escorrentía continental y el aporte de terrígenos hacia la parte superior de la sección. De igual forma, la variación significativa en las asociaciones de microfósiles hacia la base sugiere la presencia de una xenoconformidad en el contacto La Luna-Umir, que fue previamente reportada como de carácter regional

Paleocene Radiolaria from DSDP Leg 36-Site 329, Maurice Ewing Bank, Malvinas Plateau: biostratigraphic response

The carbonatic succession of the Maurice Ewing Bank in the Malvinas Plateau, presents records of remarkable paleoceanographic changes in the South Atlantic Ocean, and documents the interval between its opening and the stabilization of the circumpolar current. A report of the Paleocene radiolarian fauna recovered in the Cores 33 and 32 (Section 4) of the DSDP Leg 36-Site 329 is presented herein. The samples, composed mainly by micritic limestones, were chemically treated with a solution of hydrogen peroxide (H2O2) and sodium hexametaphosphate (Na16P14O43). Afterward, they were soaked in a solution of chloridric acid (HCl). The studied microfauna shows low diversity and abundance and is composed by the genera Amphisphaera, Haliomma, Amphymenium, Spongodiscus, Lithelius, Dictyomitra, Dendrospyris, Bathropyramis and Siphocampe. The original biostratigraphic framework proposed for the DSDP Leg 36-Site 329 (based on nannofossils and foraminifers) assigns a Paleocene age to the rocks of the Cores 33 and 32 (Section 4). Radiolarian absence in the Paleocene-Oligocene interval is due to the poor preservation of the specimens. However, the co-occurrence of Amphisphaera priva (Foreman) Hollis and Dictyomitra andersoni (Campbell and Clark) Foreman allows us to sustain at least a Late Paleocene age for the Core 33. The assemblages recovered in the Cores 33 and 32 (Section 4) exhibit some similarity with Paleocene faunas reported in the New Zealand region. Forthcoming studies based on this radiolarian microfauna can provide relevant paleoceanographic data about the South Atlantic Ocean during the Late Paleocene.Simposio VI: Microfósiles del Mesozoico y Cenozoico de América del Sur y Antártida. Nuevas aplicaciones y problemáticas asociadasFacultad de Ciencias Naturales y Muse

Sistemas de cultivo sobre a podridão comum de raízes e mal-do-pé do trigo

The effect of cultivation systems on the intensity of common root rot and take-all in wheat (Triticum aestivum L.) fields was determined in Rio Grande do Sul in 1980 and 1981. Common root rot occurred in all surveyed fields. Its intensity was high in fields cropped annually to wheat and in those maintained out of wheat for one and two years regardless of the other crops grown. Disease was much less intense in fields that had been left fallow for three or four years or that were planted to wheat for the first time. Cochliobolus sativus (Ito & Kurib.) Drechsl. ex Dastur was the dominant pathogen isolated from lesioned wheat roots. Take-all occurred in about 30% of the fields annually cropped to wheat or that either had been left fallow or planted to a non-host crop such as flax, lupine, oats, or rapeseed for one year. It was not found in wheat following two or more years of oats, fallow, or a combination of fallow and a non-host crop. The average disease ratings in 1980 and 1981 were 60% and 71%, respectively.Determinou-se o efeito de sistemas de cultivo sobre a intensidade da podridão comum e do mal-do-pé do trigo (Triticum aestivum L.) em lavouras do Estado do Rio Grande do Sul, em 1980 e 1981. A podridão comum ocorreu em todas as lavouras avaliadas. Sua intensidade foi alta em lavouras de plantio anual de trigo ou em lavouras de um a dois anos de pousio ou rotação, independentemente das culturas usadas na rotação. A intensidade da doença foi baixa nas lavouras com pousio de três a quatro anos e nas plantadas com trigo pela primeira vez. Cochliobolus sativus (Ito & Kurib.) Drechsl. ex Dastur foi o principal patógeno isolado das raízes de trigo infectadas. O mal-do-pé ocorreu em, aproximadamente, 30% das lavouras de plantio anual de trigo e de um ano de pousio ou de cultivo com culturas não suscetíveis, como linho, tremoço, aveia ou colza. Esta doença, entretanto, não foi encontrada em lavouras com dois ou mais anos de aveia, pousio, ou de uma combinação de pousio com uma cultura não suscetível. A média do grau de infecção das podridões radiculares das lavouras avaliadas em 1980 e 1981 foi de 60% e 71%, respectivamente

Efeito de métodos de aplicação de calcário sobre o rendimento de grãos de soja, em plantio direto.

bitstream/item/134555/1/ID11951-1993-1994sojaresultados-p72-78.pdfTrabalho apresentado na XXII Reunião de Pesquisa de Soja da Região Sul, Cruz Alta, 1994

The Middle to Late Miocene “Carbonate Crash” in the Equatorial Indian Ocean

We integrate benthic foraminiferal stable isotopes, X‐ray fluorescence elemental ratios, and carbonate accumulation estimates in a continuous sedimentary archive recovered at International Ocean Discovery Program Site U1443 (Ninetyeast Ridge, Indian Ocean) to reconstruct changes in carbonate deposition and climate evolution over the interval 13.5 to 8.2 million years ago. Declining carbonate percentages together with a marked decrease in carbonate accumulation rates after ~13.2 Ma signal the onset of a prolonged episode of reduced carbonate deposition. This extended phase, which lasted until ~8.7 Ma, coincides with the middle to late Miocene carbonate crash, originally identified in the eastern equatorial Pacific Ocean and the Caribbean Sea. Interocean comparison reveals that intense carbonate impoverishment at Site U1443 (~11.5 to ~10 Ma) coincides with prolonged episodes of reduced carbonate deposition in all major tropical ocean basins. This implies that global changes in the intensity of chemical weathering and riverine input of calcium and carbonate ions into the ocean reservoir were instrumental in driving the carbonate crash. An increase in U1443 Log (Ba/Ti) together with a change in sediment color from red to green indicate a rise in organic export flux to the sea floor after ~11.2 Ma, which predates the global onset of the biogenic bloom. This early rise in export flux from biological production may have been linked to increased advection of nutrients and intensification of upper ocean mixing, associated with changes in the seasonality and intensity of the Indian Monsoon

Serum levels of S100B and NSE proteins in Alzheimer's disease patients

<p>Abstract</p> <p>Background</p> <p>Alzheimer's disease is the most common dementia in the elderly, and the potential of peripheral biochemical markers as complementary tools in the neuropsychiatric evaluation of these patients has claimed further attention.</p> <p>Methods</p> <p>We evaluated serum levels of S100B and neuron-specific enolase (NSE) in 54 mild, moderate and severe Alzheimer's disease (AD) patients and in 66 community-dwelling elderly. AD patients met the probable NINCDS-ADRDA criteria. Severity of dementia was ascertained by the Clinical Dementia Rating (CDR) scale, cognitive function by the Mini Mental State Examination (MMSE), and neuroimage findings with magnetic resonance imaging. Serum was obtained from all individuals and frozen at -70°C until analysis.</p> <p>Results</p> <p>By comparing both groups, serum S100B levels were lower in AD group, while serum NSE levels were the same both groups. In AD patients, S100B levels were positively correlated with CDR scores (rho = 0.269; p = 0.049) and negatively correlated with MMSE scores (rho = -0.33; <it>P </it>= 0.048). NSE levels decreased in AD patients with higher levels of brain atrophy.</p> <p>Conclusions</p> <p>The findings suggest that serum levels of S100B may be a marker for brain functional condition and serum NSE levels may be a marker for morphological status in AD.</p

Antiparasitic efficacy and blood effects of formalin on Arapaima gigas (Pisces: Arapaimidae).

This study evaluated the in vitro and in vivo antiparasitic efficacy of formalin against Dawestrema cycloancistrium, the effects on the physiological response of Arapaima gigas and the residual action on fish muscle after 96h of exposure. As regards the in vitro assay, 0, 22, 44, 66, 88, 110, 330, 660 and 880 mg L-1 formalin were tested. After 1h of exposure to 660 and 880 mg L-1 formalin, there was a 100% mortality of D. cycloancistrium as well as after 2h of exposure at 330 and 110 mg L-1 and 3h of exposure at 44, 66 and 88 mg L-1. Concerning the in vivo test, when fish were exposed to formalin at 0, 220, 330, 440 and 550 mg L-1, there was 100% survival at all concentrations and exposure times evaluated. Baths of 1h with 440 and 550 mg L-1 formalin showed 93.3% and 99.3% efficacy respectively. However, the baths of 12h with 55 and 66 mg L-1 formalin had the efficacy of 44.5% and 55.5% respectively. In 1h baths with 220, 330, 440 and 550 mg L-1 formalin, hematocrit, hemoglobin, number of total erythrocytes, mean corpuscular volume, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, plasma glucose levels, cortisol, total proteins, chloride, calcium, sodium, potassium and magnesium of the fish presented no differences in relation to the control values. However, in baths of 12h with 33, 44, 55 and 66 mg L-1 formalin, there was a decrease in hematocrit, plasma levels of calcium and chloride, and increased levels of glucose and cortisol, depending on the concentration of formalin used. In the fish muscle, the formalin residue decreased after 96h in all concentrations and periods evaluated, returning to values close to the control ones. The results indicate that formalin had its efficacy successfully proved in the treatment against D. cycloancistrium at higher concentrations such as 440 and 550 mg L-1 formalin and shorter exposure time (1h) without compromising fish homeostasis and consumer food safety. Statement of relevance: The manuscript represents original research on use of formalin in vitro and in vivo for treating infection by monogenoidean Dawestrema cycloancistrium in Arapaima gigas, the giant fish from Amazon. In the fish, muscle the residue levels of formalin after exposure was also investigated. Formalin have efficacy in the treatment against D. cycloancistrium at higher concentrations (440 and 550 mg.L-1) of formalin and shorter exposure time (1h) and without compromising A. gigas homeostasis and consumer food safety

Gestão conservacionista de solo e de água em escala de microbacia hidrográfica: estudo de caso.

bitstream/CNPT-2010/40705/1/p-do87.pd

The Middle to Late Miocene “Carbonate Crash” in the Equatorial Indian Ocean

金沢大学理工研究域地球社会基盤学系We integrate benthic foraminiferal stable isotopes, X-ray fluorescence elemental ratios, and carbonate accumulation estimates in a continuous sedimentary archive recovered at International Ocean Discovery Program Site U1443 (Ninetyeast Ridge, Indian Ocean) to reconstruct changes in carbonate deposition and climate evolution over the interval 13.5 to 8.2 million years ago. Declining carbonate percentages together with a marked decrease in carbonate accumulation rates after ~13.2 Ma signal the onset of a prolonged episode of reduced carbonate deposition. This extended phase, which lasted until ~8.7 Ma, coincides with the middle to late Miocene carbonate crash, originally identified in the eastern equatorial Pacific Ocean and the Caribbean Sea. Interocean comparison reveals that intense carbonate impoverishment at Site U1443 (~11.5 to ~10 Ma) coincides with prolonged episodes of reduced carbonate deposition in all major tropical ocean basins. This implies that global changes in the intensity of chemical weathering and riverine input of calcium and carbonate ions into the ocean reservoir were instrumental in driving the carbonate crash. An increase in U1443 Log (Ba/Ti) together with a change in sediment color from red to green indicate a rise in organic export flux to the sea floor after ~11.2 Ma, which predates the global onset of the biogenic bloom. This early rise in export flux from biological production may have been linked to increased advection of nutrients and intensification of upper ocean mixing, associated with changes in the seasonality and intensity of the Indian Monsoon. ©2019. American Geophysical Union. All Rights Reserved.Embargo Period 6 month