1,305 research outputs found
Spectrally resolved white light interferometer for measuring dispersion in the visible and near infrared range
We design a spectrally resolved interferometer to measure the refractive
index of transparent samples over a broad spectral range between 400 and 550
nm. The measuring device consists of a Michelson interferometer whose output is
analysed by means of three fibre spectrometers: a homemade prism spectrometer
which obtains the interferogram generated by the sample between 400 and 1050
nm, a homemade transmission grating spectrometer that measures the
interferogram in between 950 and 1550 nm, and a commercial Czerny Turner
spectrometer used to make high precision measurements of the displacement
between the Michelson mirrors. The whole system is illuminated by a white light
source with an emission spectrum similar to that of a black body. We test the
instrument on solid and liquid samples achieving accuracy of up to 0.0001 in
the refractive index after fitting it with the Cauchy formula.Comment: 18 pages, 11 figures, 3 table
Revealing hidden clonal complexity in Mycobacterium tuberculosis infection by qualitative and quantitative improvement of sampling
AbstractThe analysis of microevolution events, its functional relevance and impact on molecular epidemiology strategies, constitutes one of the most challenging aspects of the study of clonal complexity in infection by Mycobacterium tuberculosis. In this study, we retrospectively evaluated whether two improved sampling schemes could provide access to the clonal complexity that is undetected by the current standards (analysis of one isolate from one sputum). We evaluated in 48 patients the analysis by mycobacterial interspersed repetitive unit–variable number tandem repeat of M. tuberculosis isolates cultured from bronchial aspirate (BAS) or bronchoalveolar lavage (BAL) and, in another 16 cases, the analysis of a higher number of isolates from independent sputum samples. Analysis of the isolates from BAS/BAL specimens revealed clonal complexity in a very high proportion of cases (5/48); in most of these cases, complexity was not detected when the isolates from sputum samples were analysed. Systematic analysis of isolates from multiple sputum samples also improved the detection of clonal complexity. We found coexisting clonal variants in two of 16 cases that would have gone undetected in the analysis of the isolate from a single sputum specimen. Our results suggest that analysis of isolates from BAS/BAL specimens is highly efficient for recording the true clonal composition of M. tuberculosis in the lungs. When these samples are not available, we recommend increasing the number of isolates from independent sputum specimens, because they might not harbour the same pool of bacteria. Our data suggest that the degree of clonal complexity in tuberculosis has been underestimated because of the deficiencies inherent in a simplified procedure
Authorship, Authority: Issues about Women's Writing
Authorship, authority, female author, poetess, are just some of the insufficient words for the desire for literature of female writers of all times. Language, this living organism, urgently needs to be modified to manage the writing of women in the global south. Here, where Eurocentric constructs do not reach the diversity of existences, it seems little to accept the consolation prizes of a stern, excluding and white-hetero-cis-patriarchal canon. So if their text calls for a different posture from theory, a commitment from the body of criticism that glimpses estrangement, this article seeks to dig some conceptions regarding the theme “authorship” in order to undo, unlearn, disrespect and from there create epistemologies in the light of theorists such as María Lugones (2020), Ochy Curiel (2020) and Conceição Evaristo (2019) to understand the writing of women. Heeding Gloria Anzaldúa's call, it is necessary for these women to write, in any place and time, it is not possible to wait for the perfect conditions to arrive. It's necessary to dare to exist. At the end of this study, we let some of our writers talk about listening and learning processes that do not conclude in this article.Autoria, autoridade, autora, feminino, poetisa, são apenas alguns dos vocábulos insuficientes para o desejo de literatura de escritoras de todos os tempos. A língua, esse organismo vivo, urge ser modificada para dar conta da escrita de mulheres ao sul global. Aqui, onde os construtos eurocentrados não alcançam a diversidade de existências, parece pouco aceitar os prêmios de consolação de um cânone sisudo, excludente e branco-hetero-cis-patriarcal. Então se o texto delas pede uma postura diferente da teoria, um empenho do corpo da crítica que vislumbra o estranhamento, este artigo procura escavar algumas concepções a respeito do tema “autoria” para desfazer, desaprender, desrespeitar e a partir daí criar epistemologias à luz de teóricas como María Lugones (2020), Ochy Curiel (2020) e Conceição Evaristo (2019) para compreender a escrita de mulheres. Atendendo ao chamado de Glória Anzaldúa, é preciso que essas mulheres escrevam, em qualquer lugar e tempo, não dá para esperar as condições perfeitas chegarem. É preciso ousar existir. Ao final deste estudo, deixamos que algumas de nossas escritoras se digam em processos de escuta e aprendizado que não se encerram neste artigo
Transgene inheritances and genetic similarities of near isogenic lines of genetically modifi ed common beans
O objetivo do presente trabalho foi determinar a herança e a estabilidade de transgenes de uma linhagem de feijoeiro-comum com expressão dos genes rep-trap-ren, do Bean golden mosaic virus, e do gene bar. Foram realizados cruzamentos entre a linhagem transgênica e quatro cultivares comerciais de feijão, seguidos de quatro retrocruzamentos. As progênies de cada cruzamento foram avaliadas quanto à presença dos transgenes, com aplicação do glifosinato de amônia nas folhas e por meio da reação da polimerase em cadeia com uso de oligonucleotídeos específicos. O vírus do mosaico comum necrótico do feijoeiro, Bean common mosaic necrosis virus (BCMNV), foi inoculado mecanicamente nas gerações avançadas. Os transgenes foram herdados em padrão mendeliano nos quatro cruzamentos estudados. As linhagens analisadas apresentaram cerca de 80% das características do parental recorrente, conforme determinado por análises com uso de marcadores de DNA, além de manter caracteres importantes, tais como resistência ao BCMNV. A presença do transgene não causou efeitos indesejáveis que pudessem ser detectados nas progênies avaliadas.The objective of the present work was to determine the inheritance and stability of transgenes of a transgenic bean line expressing the genes rep-trap-ren from Bean golden mosaic virus and the bar gene. Crosses were done between the transgenic line and four commercial bean cultivars, followed by four backcrosses to the commercial cultivars. Progenies from each cross were evaluated for the presence of the transgenes by brushing the leaves with glufosinate ammonium and by polymerase chain reaction using specific oligonucleotides. Advanced generations were rub-inoculated with an isolate of Bean common mosaic necrosis virus (BCMNV). The transgenes were inherited consistently in a Mendelian pattern in the four crosses studied. The analyzed lines recovered close to 80% of the characteristics of the recurrent parent, as determined by the random amplified DNA markers used, besides maintaining important traits such as resistance to BCMNV. The presence of the transgene did not cause any detectable undesirable effect in the evaluated progenies
Anharmonic transitions in nearly dry L-cysteine I
Two special dynamical transitions of universal character have been recently
observed in macromolecules at K and K.
Despite their relevance, a complete understanding of the nature of these
transitions and their consequences for the bio-activity of the macromolecule is
still lacking. Our results and analysis concerning the temperature dependence
of structural, vibrational and thermodynamical properties of the orthorhombic
polymorph of the amino acid L-cysteine (at a hydration level of 3.5%) indicated
that the two referred temperatures define the triggering of very simple and
specific events that govern all the biochemical interactions of the
biomolecule: activation of rigid rotors (), phonon-phonon interactions
with phonons of water dimer (), and water rotational barriers
surpassing ().Comment: 4 pages, 4 figures, submitted to Physical Review Letter
Palisadegrass effects on N fertilizer dynamic in intercropping systems with corn.
Corn grain yield, nitrogen (N) fertilizer efficiency and distribution to corn alone and three forms of corn and palisadegrass (Urochloa spp.) intercropping implantation was investigated. A field experiment with 15N labeling fertilizer was performed in randomized block design. No form of palisadegrass intercropping implantation affected corn grain yield, total N accumulation and N use efficiency (NUE), which were 8.7 t ha-1, 205 kg ha-1 and 37% respectively. The palisadegrass produced on average 1.9 t of dry mass, absorbing a maximum of 6 kg ha-1 or 5.5% of N fertilizer during corn growing. Furthermore, the palisadegrass did not affect N fertilizer distribution in soil-plant system, in which 28.2% was recovered in the soil and 40.4% in the plants (corn + palisadegrass). The results show that for the three intercropping implantation methods the palisadegrass did not compete with corn for N fertilizer
Factors that control the geochemical evolution of hydrothermal systems of alkaline water in granites in Central Pyrenees (Spain)
La evolución geoquímica de las soluciones de los sistemas hidrotermales de Caldas de Boí, Artiés, Tredós y Les, situados en el Pirineo Central (Spain), muestra diferencias reflejadas en la concentración de sólidos disueltos y en la presencia de una situación de equilibrio o desequilibrio en profundidad de las soluciones respecto a la albita. La datación (14C) de las aguas pertenecientes a los distintos sistemas hidrotermales ha puesto de manifiesto que el tiempo de residencia no es el factor de control determinante de las diferencias existentes en el grado de evolución geoquímica alcanzado por las mismas, teniendo que contemplarse otro tipo de factores relacionados con la cinética de disolución de los minerales, como responsables de estas diferencias. El análisis de la influencia de los principales factores que controlan la tasa de disolución de los minerales y, más en concreto, de los feldespatos, muestra como las diferencias de temperatura de las soluciones en profundidad son capaces de justificar el distinto grado de evolución geoquímica, incluso en soluciones con tiempos de residencia muy similares
Grain yield, efficiency and the allocation of foliar N applied to soybean canopies.
Soybean [Glycine max (L.) Merr.] grain yield is closely associated with the level of optimal nitrogen (N) supply, especially during the reproductive stages. Foliar fertilization with low rates of N have been considered as a strategy for furnishing additional N and enhancing grain yields. Field studies using 15N tracer were conducted over two growing seasons to investigate the impact of foliar N fertilization on grain yield, plant N content, the amount of N derived from fertilizer (NDFF) and N recovery efficiency (NRE). Four foliar N rates (0, 1300, 2600 and 3900 g ha?1) were supplied by two equal split applications at the R1 and R3 stages. Foliar N fertilization of soybean canopies did not affect grain yield, grain N content, shoot N content nor plant N content. Total NDFF was increased from 0.7 to 2.0 kg ha?1 across the N rates. Nonetheless, NRE was unaffected by foliar N fertilization, which averaged 53 %. Soybean plants allocated the same amount of N fertilizer to both grains and shoots. No significant effects of low rate foliar N fertilization were registered on soybean grain yield nor plant N content, despite considerable N fertilizer recovery by plant organs
Resposta do milho a fontes e modos de aplicação de fosforo durante três cultivos sucessivos em solo da região do cerrado.
Objetivou-se comparar fertilizantes fosfatados em diferentes modos de aplicação, durante três cultivos sucessivos de milho, num Argissolo Vermelho já adubado anteriormente. Foi utilizado um fatorial 4 x 2+1, envolvendo quatro fontes de P (superfosfato triplo - ST, termofosfato magnesiano - TM, fosfato reativo de Arad - FR e fosfato natural de Araxá - FA), duas formas de aplicação (a lanço ou no sulco de plantio), e uma testemunha (sem P) como tratamento adicional. Foram fornecidos 180 kg ha-1 de P7O5 no primeiro cultivo, com base nos teores totais das fontes. Para os cultivos seguintes, não foi feito preparo do solo. Determinaram-se os teores de nutrientes no solo e nas folhas de milho e a produção de grãos. As respostas aos tratamentos foram mais discrepantes inicialmente e tenderam à eqüidade com os cultivos sucessivos. Nas duas primeiras safras, as fontes de maior solubilidade (ST e TM) ocasionaram as maiores produções. Os fosfatos naturais (FR e FA) apresentaram aumento de eficiência com o tempo. A aplicação localizada do FR proporcionou alta produtividade na terceira safra. O residual de antigas adubações e as condições climáticas influenciaram os efeitos dos tratamentos
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