100,687 research outputs found
Biometria, dormência e germinação de sementes de Butia eriospatha (Martius ex Drude) Beccari
No full textProjeto acadêmico (graduação) - Universidade Federal de Santa Catarina. Campus Curitibanos. Ciências Rurais.Butia eriospantha (Martius ex Drude) Beccari conhecido popularmente como butiá-da-serra é uma espécie nativa do bioma Mata Atlântica, encontrada no sul do Brasil, pertencente à família Arecaceae. Por ser uma palmeira que possui diferentes finalidades, esta passou a ser motivo de comércio ilegal nacional e internacional, e, por consequência da grande exploração e pouca regeneração natural, além da predação por bovinos e por apresentar uma germinação lenta, B. eriospatha encontra-se atualmente na lista das espécies brasileiras ameaçadas de extinção. Pouco se sabe sobre sua germinação e os mecanismos envolvidos nesse processo, assim como pouco se conhece sobre as características biométricas de seus frutos e sementes. Desse modo o principal objetivo deste trabalho é desenvolver metodologias para testes em laboratório que avaliam o processo de germinação e o vigor de sementes de B. eriospatha. Serão coletados frutos de sete matrizes (palmeiras), localizadas no município de Curitibanos/ SC, após as análises biométrica dos frutos, pirênios e sementes, serão realizados os testes de germinação, iniciando com o teste para a verificação da dormência, na sequência, teste para a verificação do substrato mais adequado, além disso, serão analisados também os efeitos das temperaturas de 25 e 30ºC sob a germinação, e a curva de embebição será determinada. Ainda, as matrizes serão avaliadas quanto ao vigor das sementes, através do desenvolvimento de metodologias para testes de condutividade elétrica e tetrazólio. Espera-se após as análises dos experimentos, recomendar metodologias adequadas para os testes em laboratório, que auxiliarão na diferenciação de lotes de sementes, bem como nos programas de multiplicação em viveiros, através do qual serão obtidas mudas de melhor qualidade, o que possibilita a retirada desta espécie da lista de espécies ameaçadas de extinção
In-fixture calibration of an S-parameter measuring system by means of time domain reflectometry
No full textWe present a technique which resorts to the time domain capabilities of a vector network analyzer and to the network synthesia tools, in order to perform an in-fixture calibration of the S-parameter measurement system directly to the ports of the device under test. The effects of the customer's non ideal fixtures can be removed without requiring the insertion of standard components or particular loads, which can affect the calibration efectiveness. The inaccuracies due to the precision of the actual loads and to the connection repeatability are also avoided. Some simulation reeults demonstrate the very good capability of the technique. Experimental tests were also carried out on an actual microstrip transistor fixture, showing a very satisfactoty launcher modeling and de-embeddin
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Promoter characterization and structure of the gene encoding mouse lysosomal alpha-d-mannosidase
No full textMouse lysosomal alpha-d-mannosidase (EC 3.2.1.24) is an enzyme involved in the catabolism of N-linked glycoproteins. The gene is differentially expressed in mouse tissues, and the highest level of mRNA is found in the epididymis. The expression of mannosidase in the epididymis may be hormonally regulated, since its activity increases with age. To understand the factors affecting the expression of mouse mannosidase, we isolated and characterized the promoter and determined the exon-intron structure. The gene is about 15 kb, consists of 24 exons, and the 5' flanking region contains GC-rich regions, TATA boxes, CAAT boxes, and putative binding sites for the transcription factors Sp1, AP2, and PEA3. PEA3 factor may participate in the transcriptional control of mannosidase expression in the mouse epididymis. In fact, it has been demonstrated that the PEA3 motif is spatially and temporally expressed within the mouse epididymis, and its accumulation is controlled by androgens and testicular factors. A 1279-bp fragment from the initiation codon had the strongest promoter activity, and three different transcription start sites were identified at positions -131, -149, and -174
Calcium ionophore A-23187 inhibits the secretion of β-hexosaminidase from the GG2EE mouse macrophage cell line
No full textSecretion of the lysosomal enzyme β-N-acetylhexosaminidase is inhibited by calcium ionophore A-23187 in the GG2EE macrophage cell line. Such inhibition is time and dose dependent. Calcium ionophore A-23187 treatment causes a change in the pattern of hexosaminidase isoenzymes detectable in the cell extract, as assessed by DEAE-cellulose chromatography. In particular, control cells show two hexosaminidase isoenzymes corresponding to hexosaminidase A and B, whereas cells treated with calcium ionophore A-23187 express a third isoenzyme form with properties similar to hexosaminidase S
Infra-red measurement of temperature during the Friction Stir Welding process and correlation with numerical simulation
No full textA smoothness criterion for monotonicity-preserving subdivision
No full textIn this paper we study subdivision schemes that both interpolate and preserve the monotonicity of the input data, and we derive a simple ratio condition that guarantees the continuous differentiability of the limit function. We then show that the condition holds for both a scheme of Kuijt and van Damme, based on rational functions, and a scheme of Sabin and Dodgson, based on square roots
Lysosomal enzyme activities as possible CSF biomarkers of synucleinopathies
No full textMutations on the GBA gene, encoding for the lysosomal enzyme β-glucocerebrosidase (GCase), have been identified as the most common genetic risk factor involved in the development of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), indicating a direct contribution of this enzyme to the pathogenesis of synucleinopathies. Decreased GCase activity has been observed repeatedly in brain tissues and biological fluids of both GBA mutation carrier and non-carrier PD and DLB patients, suggesting that lower GCase activity constitutes a typical feature of these disorders. Additional genetic, pathological and biochemical data on other lysosomal enzymes (e.g., Acid sphingomyelinase, Cathepsin D, α-galactosidase A and β-hexosaminidase) have further strengthened the evidence of a link between lysosomal dysfunction and synucleinopathies. A few studies have been performed for assessing the potential value of lysosomal enzyme activities in cerebrospinal fluid (CSF) as biomarkers for synucleinopathies. The reduction of GCase activity in the CSF of PD and DLB patients was validated in several of them, whereas the behaviour of other lysosomal enzyme activities was not consistently reliable among the studies. More in-depth investigations on larger cohorts, following stringent standard operating procedures should be committed to really understand the diagnostic utility of lysosomal enzymes as biomarkers for synucleinopathies. In this review, we reported the evidences of the association between the defective function of lysosomal proteins and the pathogenesis of synucleinopathies, and examined the role of lysosomal enzyme activities in CSF as reliable biomarkers for the diagnosis of PD and related neurodegenerative disorders
Dwarfs walking in a row. The filamentary nature of the NGC 3109 association.
No full textWe re-consider the association of dwarf galaxies around NGC 3109, whose known members were NGC 3109, Antlia, Sextans A,
and Sextans B, based on a new updated list of nearby galaxies and the most recent data. We find that the original members of the
NGC 3109 association, together with the recently discovered and adjacent dwarf irregular Leo P, form a very tight and elongated
configuration in space. All these galaxies lie within 100 kpc of a line that is ' 1070 kpc long, from one extreme (NGC 3109) to the
other (Leo P), and they show a gradient in the Local Group standard of rest velocity with a total amplitude of 43 km s
Elevated beta-N-acetylhexosaminidase activity in focal dystonia fibroblasts
No full textSpecific activities of beta-D-hexosaminidase, alpha-D-mannosidase, beta-D-galactosidase and beta-D-glucuronidase were determined in fibroblasts of patients with writer's cramp and torticollis. These diseases show degenerative neurological disorders similar to those observed in lysosomal diseases. Hexosaminidase specific activities, determined using 4-methylumbelliferyl-beta-N-acetylglucopyranoside and 4-methylumbelliferyl-beta-N-acetylglucopyranoside-6-sulphate as substrates, were significantly higher in the fibroblasts of patients than in controls. No significant differences were observed in the specific activities of the other lysosomal enzymes. The increased hexosaminidase specific activities in torticollis and writer's cramp may be additional markers for these diseases
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