Shelf-Ocean material exchange influencing the Atlantic chemical composition off NW Iberian margin since the last glaciation

Rivers are the main conduit of sediment to the shelf. The basin geology, the drainage area and the discharge rate are the major factors that determine their sediment load (Milliman and Syvistski, 1992). Besides suspended particles, dissolved components may also give some information on the eroded crust. Sr isotopes in carbonate shells of biological organisms have been used to study, in the geological record, the influence exerted by the chemical weathering of the continental crust on the seawater composition (Macdougall, 1991). In this work, Sr isotope ratios obtained in tests of foraminifera representing the last 40 ka are presented and discussed in the scope of the palaeogeographical evolution of NW Iberia. This work aims to present and discuss the results of Sr isotope analyses (performed, by TIMS, in the Isotope Geology Laboratory of the University of Aveiro) of tests of two species of foraminifera, from nine samples taken along the OMEX core KC 024-19 (181 cm; 42°08’98’’N, 10°29´96’’W, and 2765m), collected in the Galicia Bank area, off Galicia. Taking into account that Sr contained in the carbonate tests is usually considered as preserving the signature of the contemporaneous seawater, one planktonic species (Globigerina bulloides) and one benthic species (Cibicides wuellerstorfi) were selected in order to try to detect Sr isotope variations both through time and between two different levels of the water column. The core age model, which records the last 40 ka, is based on a combination of oxygen isotope stratigraphy, eight AMS 14C datings and the synchronisation of the last four Heinrich Events in the Iberian Margin sedimentary records. As a whole, the obtained 87Sr/86Sr ratios vary between 0.709209 and 0.709108, with a mean 2σ error of 0.000025. These values lie within the range of modern marine Sr isotope ratios (0.70910-0.70922), as previously defined using analyses of both seawater and marine carbonates (see compilation by Faure and Mensing, 2005). Despite their small variation, the 87Sr/86Sr ratios obtained in G. bulloides seem to indicate that Sr dissolved in seawater at the KC 024-19 core site became slightly less radiogenic after the Last Glacial Maximum (LGM). This decrease is concomitant with diminishing amounts of the detrital components in the sediments (Fig. 1). Therefore, both the composition of dissolved Sr, as revealed by results on tests of planktonic foraminifera, and the proportions of suspended terrigenous particulate material arriving at the KC 024-19 site point to a decreasing importance of the contribution of the erosion of the Iberian Variscan crust since the Last Glacial Maximum and in the Holocene. The 87Sr/86Sr ratios measured in tests of benthic foraminifera (C. wuellerstorfi) are more erratic and no correlation can be established with palaeogeographical/palaeoclimatic constraints. The difference between the behaviour of Sr compositions in G. bulloides and C. wuellerstorfi may indicate that whilst the planktonic foraminifera should reproduce very closely the seawater composition, the benthic organisms should, in addition to the major role of seawater, also be affected by some sort of interaction with the sediments. As such, planktonic foraminifera are probably more reliable indicators of seawater composition in studies involving very small periods and corresponding very slight variations of the 87Sr/86Sr ratios. Taking into account that G. bulloides is a common planktonic species (living mostly in the first 50m of the water column), whose tests seem to be in equilibrium with sea water composition, variations in its 87Sr/86Sr ratios can be related with changes in the chemical composition of the water of the Atlantic Ocean off NW Iberian Margin. The highest 87Sr/86Sr values are contemporaneous with a period of low sea level (about -140 m; Dias et al., 2000) during the LGM. According to Dias et al. (2000) at 18 ka BP the shoreline was close to the shelf break. The summital parts of the Gerês and Estrela mountains were covered by local glaciers and close to the coast freezing occurred frequently. The river catchments, which extended far to the shelf, received more rainfall due to a longer, compared to present day conditions, wet season, which promoted both physical and chemical weathering. Higher pluviosity combined with the effect of spring ice melting maintained high river discharge and consequently caused very important sediment supply to the coastal zone. The extremely narrow shelf was a very energetic environment due to sea bottom inclination and very limited long wave refraction. Therefore, at that time, a long wet season and very competent rivers should have caused important erosion of the Variscan basement in NW Iberia. Additionally, then, the shoreline was much closer to the KC 024-19 site. The combination of all these factors favoured an important deposition of terrigenous sediments and the local slight enrichment in radiogenic Sr of the seawater. With sea level rise, after the deglaciation and during the Holocene, the river estuaries became progressively far away from the shelf break. Their competence of transport also became progressively reduced and the offshore transport of detrital sediments became progressively lower. Conversely the biogenic carbonate proportion in the sediments increased, due to lower dilution by the terrigenous particles. Simultaneously, the values of 87Sr/86Sr in the seawater at the KC 024-19 site became lower, as a consequence of a complete homogenization with the ocean global composition, which was now more effective with the increasing distance towards shoreline

Explantes foliares de pupunheira (Bactris gasipaes H.B.K.) submetidos a combinações fatoriais de 2,4-D e BAP.

O objetivo deste trabalho foi desenvolver protocolos para indução de calos em explantes foliares de B. gasipaes submetidos a combinações fatoriais de 2,4-D e BAP

Non-Small Cell Lung Cancer: Screening, Diagnosis, and Staging

Lung cancer is the leading cause of cancer deaths worldwide. Tobacco consumption is the primary cause of lung cancer, accounting for more than 85% 90% of all lung cancer deaths. Non-small cell lung cancer accounts for about 85% of all lung cancers. Several studies have shown that low-dose helical CT of the lung detects more nodules and lung cancers, including early-stage cancers, than does chest radiography. The National Lung Cancer Screening Trial results show that three annual rounds of low-dose CT screening reduce mortality from lung cancer. Despite the great debate around lung cancer screening, recently the National Comprehensive Cancer Network has come out in favor of lung cancer screening in an updated set of guidelines. All patients who present with suspect lung cancer should have a complete and meticulous history and physical examination performed to identify symptoms or physical findings suggestive of locally extensive or metastatic disease, assess pulmonary health status, identify significant comorbidities, and assess overall health status. Tissue sampling is required to confirm a diagnosis in all patients with suspected lung cancer. Non-surgical approaches, surgical approaches, or both may be used to obtain a tissue sample. Evaluation of the mediastinal lymph nodes is a key step in the further staging of the patient. The best way of evaluating mediastinal lymph nodes is still a matter of debate. The tumor node metastasis (TNM) International Staging System provides useful prognostic information and is used to stage all patients with non-small cell lung cancer. Recent trials added new data on screening and diagnostic approach. Those data will be reviewed in this paper

Calogênese em insulina vegetal (Cissus verticillata(L.) Nicolson & C. E. Jarvis).

O objetivo foi desenvolver um protocolo para a indução de calos em explantes foliares de Cissus verticillata (L.) Nicolson & C. E. Jarvis e quantificar a massa fresca obtida visando à produção de metabólitos secundários

The distance to the LMC cluster NGC 1866 and the surrounding field

We use the Main Sequence stars in the LMC cluster NGC 1866 and of Red Clump stars in the local field to obtain two independent estimates of the LMC distance. We apply an empirical Main Sequence-fitting technique based on a large sample of subdwarfs with accurate {\sl Hipparcos} parallaxes in order to estimate the cluster distance modulus, and the multicolor Red Clump method to derive distance and reddening of the LMC field. We find that the Main Sequence-fitting and the Red Clump distance moduli are in significant disagreement; NGC 1866 distance is equal to $\rm (m-M)_{0,NGC 1866}=18.33\pm$0.08 (consistent with a previous estimate using the same data and theoretical Main Sequence isochrones), while the field stars provide $\rm (m-M)_{0,field}=18.53\pm$0.07. This difference reflects the more general dichotomy in the LMC distance estimates found in the literature. Various possible causes for this disagreement are explored, with particular attention paid to the still uncertain metallicity of the cluster and the star formation history of the field stars.Comment: 5 pages, incl. 1 figure, uses emulateapj.sty, ApJ accepte

Calogênese em explantes de foliares de pupunheira (Bactris gasipaes H.B.K.) submetidos a meio de cultivo com diferentes níveis de PH.

O objetivo deste trabalho foi desenvolver protocolos para indução de calos em explantes foliares de B. gasipaes submetidos a diferentes níveis de pH do meio de cultivo em combinações fatoriais com 2,4-D

Calogênese em explantes foliares de pupunheira (Bactris gasipaes H.B.K.) submetidos a diferentes concentrações de nitrato de amônio.

O objetivo deste trabalho foi desenvolver protocolos para indução de calos em explantes foliares de B. gasipaes submetidos a diferentes concentrações de nitrato de amônio em combinação fatorial com 2,4-D

Cardiomiopatia de Takotsubo: uma complicação rara, mas grave, de crises epilépticas

Takotsubo cardiomyopathy (TKC) is a reversible, yet potentially fatal, syndrome triggered by stressful conditions, including seizures, with increasing recognition in clinical practice. We report a TKC in a patient with unexplained sinus tachycardia and troponin elevation after generalized seizures