910 resultados para Missing samples
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This report describes 4 patients presenting with multiple teeth affected by invasive cervical resorption (ICR). The cases came to our attention between 2006 and 2008; previously, no cases of multiple ICR (mICR) had been reported in Switzerland. Characteristics common to all 4 cases included progression of disease over time, similar clinical and radiographic appearance of lesions, and obscure etiology. The histologically assessed teeth showed a similar pattern of tooth destruction, with resorptive lesions being confined to the cervical region. Howship's lacunae and multinucleated, tartrate-resistant acid phosphatase-positive odontoclasts were detected. None of the teeth presented with internal resorption. The positive pulp sensitivity corresponded to the histologic findings, indicating that the pulp tissue resisted degradation even in advanced stages of resorptive lesions. Although mICR is rare in humans, a similar disease known as feline odontoclastic resorptive lesions (FORL) is common in domestic, captive, and wild cats. The etiology of FORL, like that of mICR, remains largely unknown. Because FORL has been associated with feline viruses, we asked our mICR patients whether they had had contact with cats, and interestingly, all patients reported having had direct (2 cases) or indirect (2 cases) contact. In addition, blood samples were taken from all patients for neutralization testing of feline herpes virus type 1 (FeHV-1). Indeed, the sera obtained were able to neutralize (2 cases) or partly inhibit (2 cases) replication of FeHV-1, indicating transmission of feline viruses to humans. Future studies on mICR (and FORL) should evaluate the possible role of a (feline) virus as an etiologic (co-)factor in this disease.
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Surface mineralogical compositions and their association to modern processes are well known from the east Atlantic and south-west Indian sectors of the Southern Ocean, but data from the interface of these areas - the Prydz Bay-Kerguelen region - is still missing. The objective of our study was to provide mineralogical data of reference samples from this region and to relate these mineralogical assemblages to hinterland geology, weathering, transport and depositional processes. Clay mineral assemblages were analysed by means of X-ray diffraction technique. Heavy mineral assemblages were determined by counting of gravity-separated grains under a polarizing microscope. Results show that by use of clay mineral assemblages four mineralogical provinces can be subdivided: i) continental shelf, ii) continental slope, iii) deep sea, iv) Kerguelen Plateau. Heavy mineral assemblages in the fine sand fraction are relatively uniform except for samples taken from the East Antarctic shelf. Our findings show that mineralogical studies on sediment cores from the study area have the potential to provide insights into past shifts in ice-supported transport and activity and provenance of different water masses (e.g. Antarctic slope current and deep western boundary current) in the Prydz Bay-Kerguelen region.
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Restudy of Deep Sea Drilling Project Sites 536 and 540 in the southeast Gulf of Mexico gives evidence for a giant wave at Cretaceous-Tertiary boundary time. Five units are recognized: (1) Cenomanian limestone underlies a hiatus in which the five highest Cretaceous stages are missing, possibly because of catastrophic K-T erosion. (2) Pebbly mudstone, 45 m thick, represents a submarine landslide possibly of K-T age. (3) Current-bedded sandstone, more than 2.5 m thick, contains anomalous iridium, tektite glass, and shocked quartz; it is interpreted as ejecta from a nearby impact crater, reworked on the deep-sea floor by the resulting tsunami. (4) A 50-cm interval of calcareous mudstone containing small Cretaceous planktic foraminifera and the Ir peak is interpreted as the silt-size fraction of the Cretaceous material suspended by the impact-generated wave. (5) Calcareous mudstone with basal Tertiary forams and the uppermost tail of the Ir anomaly overlies the disturbed interval, dating the impact and wave event as K-T boundary age. Like Beloc in Haiti and Mimbral in Mexico, Sites 536 and 540 are consistent with a large K-T age impact at the nearby Chicxulub crater.
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A Mediterranean composite sedimentary record was analyzed for Ba/Ca ratios on carbonate shells of Orbulina universa planktonic foraminifer (Ba/Ca)carb providing the opportunity to study and assess the extent of freshwater inputs on the basin and possible impacts on its dynamics during the Tortonian to Recent period. A number of scanning electron microscope analyses and auxiliary trace element measurements (Mn, Sr, and Mg), obtained from the same samples, exclude important diagenetic effects on the studied biogenic carbonates and corroborate the reliability of (Ba/Ca)carb ratios in foraminifera calcite as indicators of seawater source components during the studied interval. A long-term trend with (Ba/Ca)carb values shifting from ~7 to 3 µmol/mol from the base of the Tortonian to the top of the Messinian is observed. The interval of the late Messinian salinity crisis, where biogenic carbonates are missing or strongly diagenized, represents a crucial passage not monitored in our record. At the base of the Pliocene, up to about 4.7 Ma, the (Ba/Ca)carb record shows a decreasing trend from ~4 µmol/mol stabilizing itself to an about constant value of 0.9 ± 0.3 µmol/mol for the whole Plio-Pleistocene interval. These results suggest a dramatic change in the continental runoff values, up to ~3-16 times higher during part of the late Neogene (Tortonian-early Pliocene), with a possible profound modification in the physical dynamics of the Mediterranean basin. First-order mass balance equations used to estimate barium and salinity budgets in the Mediterranean Sea during the late Miocene-early Pliocene interval support the hypothesis of an active connection of the basin with the Paratethys region and of a definitive restriction at the base of the Pliocene after about 0.7 Ma from the well-known Messinian Lagomare phase. They also open intriguing scenarios on possible circulation shifts during the Neogene.
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From the DSDP Legs 1, 11, 13, 17, 25, 27, 32, 36, 41, 43, 44, 50, and 62 the Lower Cretaceous foraminifers have been investigated for biostratigraphical, taxonomical, and palaeoecological purposes. An overview of the cored Lower Cretaceous sections of Leg 1-80 is given. In the Northern Atlantic Ocean characteristic foraminiferal faunas are missing from the Upper Tithonian to the Valanginian due to a marked regression which caused hiatuses. In areas without black shale conditions Valanginian to Barremian medium rich to poor microfaunas with Praedorothia ouachensis (Sigal) of the Praedorothia ouachensis Zone (Valanginian-Hauterivian). The Hauterivian-Aptian interval is characterized by zones of Gavelinella barrerniana, Gaudryina dividens, and Conorotalites aptiensis. During the Albian a world-wide fauna consisting of agglutinated and calcareous foraminifers of the Pseudoclavulina gaultina Zone is established in areas lacking the wide-spread black-shale conditions. The Upper Albian and the Cenomanian are represented by the Gavelinella eenomanica Zone. Some ornamented species of the nodosariids (Citharina, Lenticulina), Gavelinella, Conorotatites, Pleurostomella, Vatvulineria, and Osangularia are of some importance for the biostratigraphy of the Berriasian-Albian interval. The Berriasian to Albian zones introduced for the Tethys and the DSDP by Moullade (1984) could only be of some local importance due to the long stratigraphical range of the foraminiferal species used. In the Indian Ocean an exact stratigraphical age cannot be assigned to the few Neocomian foraminiferal faunas of a cooler sea water (Site 261). These faunas mainly contain primitive agglutinated foraminifers, because in most cases the calcareous tests are dissolved or redeposited. In the Pacific Ocean most of the Berriasian to Aptian microfaunas are of minor biostratigraphical and palaeoecological importance for reasons of poor core recoveries, contaminations or original foraminiferal poverty (black shales). Since the Albian there are somewhat higher-diverse faunas of calcareous and agglutinated foraminifers with index species of the Pseudoclavulina gaultina Zone. As a rule, the boundary Albian/Cenomanian is set by means of planktonic foraminifers because no other foraminifer has its first appearance datum during this interval, except Gavelinella cenornanica. During the Albian very uniform, world-wide foraminiferal faunas without a marked provincialism are obvious.
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A high-resolution stratigraphy is essential toward deciphering climate variability in detail and understanding causality arguments of events in earth history. Because the highly dynamic middle to late Eocene provides a suitable testing ground for carbon cycle models for a waning warm world, an accurate time scale is needed to decode climate-driving mechanisms. Here we present new results from ODP Site 1260 (Leg 207) which covers a unique expanded middle Eocene section (magnetochrons C18r to C20r, late Lutetian to early Bartonian) of the tropical western Atlantic including the chron C19r transient hyperthermal event and the Middle Eocene Climate Optimum (MECO). To establish a detailed cyclostratigraphy we acquired a distinctive iron intensity records by XRF scanning Site 1260 cores. We revise the shipboard composite section, establish a cyclostratigraphy and use the exceptional eccentricity modulated precession cycles for orbital tuning. The new astrochronology revises the age of magnetic polarity chrons C19n to C20n, validates the position of very long eccentricity minima at 40.2 and 43.0 Ma in the orbital solutions, and extends the Astronomically Tuned Geological Time Scale back to 44 Ma. For the first time the new data provide clear evidence for an orbital pacing of the chron C19r event and a likely involvement of the very long eccentricity cycle contributing to the evolution of the MECO.
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Dissolved organic carbon (DOC) distribution and dynamics are investigated at the DYFAMED site (central Ligurian Sea, NW Mediterranean) in relation to hydrological and biological contexts, using a 4-year time-series dataset (1991-1994). The DYFAMED site is regarded as a one-dimensional station where simple hydrological mechanisms prevail and where the ecosystem is quite well understood. An average vertical profile of DOC concentration ([DOC]) indicates that maximal concentrations and variability are concentrated in the surface layers. For depths >800 m, the annual variations are on average similar to the analytical standard deviation (~2 µM). The "composite" [DOC] distribution (average distribution over a typical year, integrating about 40 monthly profiles) for surface waters (0-200 m) is closely related to hydrological and phytoplanktonic forcings. It exhibits summer DOC accumulation in surface waters, due to spring-summer stratification and successive phytoplanktonic events such as spring and summer blooms, and winter DOC removal to deeper waters, due to intense vertical mixing. The analysis of vertical [DOC] gradient at 100-m depth as a function of the integrated DOC content in the 0-100-m layer makes it possible to objectively distinguish three specific periods: the winter vertical mixing period, the period of stratification and spring phytoplankton bloom, and the period of stratification re-inforcement and summer-fall phytoplankton bloom. We recalculate the vertical DOC fluxes to deep waters using a larger original dataset, after the first direct calculation (Deep-Sea Res. 40 (10) (1993) 1963, 1972) that was reproduced for other oceanic areas. The seasonal variations of the "composite" [DOC] distribution in surface waters are significantly correlated to the apparent oxygen utilization distribution, but the biogeochemical significance of such a correlation is still under examination. The global significance of our local findings is presented and the role of the oceanic DOC in the global carbon cycle is emphasized, especially with respect to several current issues, such as the oceanic "missing sink" and the equivalence between new production and exported production.
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Glacially deformed pieces of wood, organic lake sediments and clasts of reworked peat have been collected in front of Alpine glaciers since AD 1990. The palaeoglaciological interpretation of these organic materials is related to earlier phases of glacier recession surpassing that of today's shrunken glaciers and to tree growth and peat accumulation in the valleys now occupied by the glaciers. Glacial transport of the material is indicated by wood anatomy, incorporated silt, sand and gravel particles, missing bark and deformed treerings. A total of 65 samples have been radiocarbon dated so far, and clusters of dates provide evidence of eight phases of glacier recession: 9910-9550, 9010-7980, 7250-6500, 6170-5950, 5290-3870, 3640-3360, 2740-2620 and 1530-1170 calibrated years BP. Allowing for the timelag between climatic fluctuations, glacier response and vegetation colonization, these recession phases may lag behind climatic changes by 100-200 years.
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Exploratory analysis of petroleum geochemical data seeks to find common patterns to help distinguish between different source rocks, oils and gases, and to explain their source, maturity and any intra-reservoir alteration. However, at the outset, one is typically faced with (a) a large matrix of samples, each with a range of molecular and isotopic properties, (b) a spatially and temporally unrepresentative sampling pattern, (c) noisy data and (d) often, a large number of missing values. This inhibits analysis using conventional statistical methods. Typically, visualisation methods like principal components analysis are used, but these methods are not easily able to deal with missing data nor can they capture non-linear structure in the data. One approach to discovering complex, non-linear structure in the data is through the use of linked plots, or brushing, while ignoring the missing data. In this paper we introduce a complementary approach based on a non-linear probabilistic model. Generative topographic mapping enables the visualisation of the effects of very many variables on a single plot, while also dealing with missing data. We show how using generative topographic mapping also provides an optimal method with which to replace missing values in two geochemical datasets, particularly where a large proportion of the data is missing.
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To detect the presence of male DNA in vaginal samples collected from survivors of sexual violence and stored on filter paper. A pilot study was conducted to evaluate 10 vaginal samples spotted on sterile filter paper: 6 collected at random in April 2009 and 4 in October 2010. Time between sexual assault and sample collection was 4-48hours. After drying at room temperature, the samples were placed in a sterile envelope and stored for 2-3years until processing. DNA extraction was confirmed by polymerase chain reaction for human β-globin, and the presence of prostate-specific antigen (PSA) was quantified. The presence of the Y chromosome was detected using primers for sequences in the TSPY (Y7/Y8 and DYS14) and SRY genes. β-Globin was detected in all 10 samples, while 2 samples were positive for PSA. Half of the samples amplified the Y7/Y8 and DYS14 sequences of the TSPY gene and 30% amplified the SRY gene sequence of the Y chromosome. Four male samples and 1 female sample served as controls. Filter-paper spots stored for periods of up to 3years proved adequate for preserving genetic material from vaginal samples collected following sexual violence.
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Infections of the central nervous systems (CNS) present a diagnostic problem for which an accurate laboratory diagnosis is essential. Invasive practices, such as cerebral biopsy, have been replaced by obtaining a polymerase chain reaction (PCR) diagnosis using cerebral spinal fluid (CSF) as a reference method. Tests on DNA extracted from plasma are noninvasive, thus avoiding all of the collateral effects and patient risks associated with CSF collection. This study aimed to determine whether plasma can replace CSF in nested PCR analysis for the detection of CNS human herpesvirus (HHV) diseases by analysing the proportion of patients whose CSF nested PCR results were positive for CNS HHV who also had the same organism identified by plasma nested PCR. In this study, CSF DNA was used as the gold standard, and nested PCR was performed on both types of samples. Fifty-two patients with symptoms of nervous system infection were submitted to CSF and blood collection. For the eight HHV, one positive DNA result-in plasma and/or CSF nested PCR-was considered an active HHV infection, whereas the occurrence of two or more HHVs in the same sample was considered a coinfection. HHV infections were positively detected in 27/52 (51.9%) of the CSF and in 32/52 (61.5%) of the plasma, difference not significant, thus nested PCR can be performed on plasma instead of CSF. In conclusion, this findings suggest that plasma as a useful material for the diagnosis of cases where there is any difficulty to perform a CSF puncture.
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The taxonomic position of a bacterium isolated from water samples from the Rio Negro, in Amazon, Brazil, was determined by using a polyphasic approach. The organism formed a distinct phyletic line in the Chromobacterium 16S rRNA gene tree and had chemotaxonomic and morphological properties consistent with its classification in this genus. It was found to be closely related to Chromobacterium vaccinii DSM 25150(T) (98.6 % 16S rRNA gene similarity) and shared 98.5 % 16S rRNA gene similarity with Chromobacterium piscinae LGM 3947(T). DNA-DNA relatedness studies showed that isolate CBMAI 310(T) belongs to distinct genomic species. The isolate was readily distinguished from the type strain of these species using a combination of phenotypic and chemotaxonomic properties. Thus, based on genotypic and phenotypic data, it is proposed that isolate CBMAI 310(T) (=DSM 26508(T)) be classified in the genus Chromobacterium as the type strain of a novel species, namely, Chromobacterium amazonense sp. nov.
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Ammonium nitrate fuel oil (ANFO) is an explosive used in many civil applications. In Brazil, ANFO has unfortunately also been used in criminal attacks, mainly in automated teller machine (ATM) explosions. In this paper, we describe a detailed characterization of the ANFO composition and its two main constituents (diesel and a nitrate explosive) using high resolution and accuracy mass spectrometry performed on an FT-ICR-mass spectrometer with electrospray ionization (ESI(±)-FTMS) in both the positive and negative ion modes. Via ESI(-)-MS, an ion marker for ANFO was characterized. Using a direct and simple ambient desorption/ionization technique, i.e., easy ambient sonic-spray ionization mass spectrometry (EASI-MS), in a simpler, lower accuracy but robust single quadrupole mass spectrometer, the ANFO ion marker was directly detected from the surface of banknotes collected from ATM explosion theft.