1,052 research outputs found
Fertilizante de liberação lenta no desenvolvimento de mudas de Eucalyptus grandis.
Uma das ações mais importantes para aumentar a produção de mudas de essências florestais é a fertilização do substrato. A utilização de fertilizante de liberação lenta (FLL) pode contribuir para a obtenção de mudas de melhor qualidade. O objetivo do trabalho foi avaliar doses crescentes de FLL e fertilizante convencional (FC), bem como comparar esses fertilizantes no desenvolvimento de mudas de Eucalyptus grandis. O estudo foi realizado na região do Vale do Itajaí, SC. Os tratamentos foram a adição de FLL e FC para cada experimento nas seguintes doses de formulado: T1 ? 0 kg (testemunha); T2 ? 2 kg; T3 ? 4 kg; T4 ? 6 kg; T5 ? 8 kg e T6 ? 10 kg.m-3 de substrato-base. Decorridos 174 dias da semeadura, foram analisadas as variáveis altura total, diâmetro do colo, biomassa fresca da parte aérea, biomassa seca da parte aérea, biomassa seca da raiz, biomassa seca total, dose de máxima eficiência técnica e teores de nutrientes da parte aérea das mudas de cada tratamento. Em todos os tratamentos houve resposta positiva no desenvolvimento das mudas, entretanto as mudas tiveram melhor crescimento sob doses entre 9,1 e 12,9 kg.m-3 de fertilizante de liberação lenta
Fertilidade de um argissolo sob pomar de pêssego em função da irrigação e posição de amostragem.
Modulation of fecal clostridiales bacteria and butyrate by probiotic intervention with Lactobacillus paracasei DG varies among healthy adults
Background: The modulation of gut microbiota is considered to be the first target to establish probiotic efficacy in a healthy population. Objective: This study was conducted to determine the impact of a probiotic on the intestinal microbial ecology of healthy volunteers. Methods: High-throughput 16S ribosomal RNA gene sequencing was used to characterize the fecal microbiota in healthy adults (23-55 y old) of both sexes, before and after 4 wk of daily consumption of a capsule containing at least 24 billion viable Lactobacillus paracasei DG cells, according to a randomized, double-blind, crossover placebo-controlled design. Results: Probiotic intake induced an increase in Proteobacteria (P = 0.006) and in the Clostridiales genus Coprococcus (P = 0.009), whereas the Clostridiales genus Blautia (P = 0.036) was decreased; a trend of reduction was also observed for Anaerostipes (P = 0.05) and Clostridium (P = 0.06). We also found that the probiotic effect depended on the initial butyrate concentration. In fact, participants with butyrate >100 mmol/kg of wet feces had a mean butyrate reduction of 49 ± 21% and a concomitant decrease in the sum of 6 Clostridiales genera, namely Faecalibacterium, Blautia, Anaerostipes, Pseudobutyrivibrio, Clostridium, and Butyrivibrio (P = 0.021), after the probiotic intervention. In contrast, in participants with initial butyrate concentrations <25 mmol/kg of wet feces, the probiotic contributed to a 329 ± 255% (mean ± SD) increment in butyrate concomitantly with an ~55% decrease in Ruminococcus (P = 0.016) and a 150% increase in an abundantly represented unclassified Bacteroidales genus (P = 0.05). Conclusions: The intake of L. paracasei DG increased the Blautia:Coprococcus ratio, which, according to the literature, can potentially confer a health benefit on the host. The probiotic impact on themicrobiota and on short-chain fatty acids, however, seems to strictly depend on the initial characteristics of the intestinal microbial ecosystem. In particular, fecal butyrate concentrations could represent an important biomarker for identifying subjects who may benefit from probiotic treatment
Photo-physical properties of He-related color centers in diamond
Diamond is a promising platform for the development of technological
applications in quantum optics and photonics. The quest for color centers with
optimal photo-physical properties has led in recent years to the search for
novel impurity-related defects in this material. Here, we report on a
systematic investigation of the photo-physical properties of two He-related
(HR) emission lines at 535 nm and 560 nm created in three different diamond
substrates upon implantation with 1.3 MeV He+ ions and subsequent annealing.
The spectral features of the HR centers were studied in an "optical grade"
diamond substrate as a function of several physical parameters, namely the
measurement temperature, the excitation wavelength and the intensity of
external electric fields. The emission lifetimes of the 535 nm and 560 nm lines
were also measured by means of time-gated photoluminescence measurements,
yielding characteristic decay times of (29 +- 5) ns and (106 +- 10) ns,
respectively. The Stark shifting of the HR centers under the application of an
external electrical field was observed in a CVD diamond film equipped with
buried graphitic electrodes, suggesting a lack of inversion symmetry in the
defects' structure. Furthermore, the photoluminescence mapping under 405 nm
excitation of a "detector grade" diamond sample implanted at a 1x1010 cm-2 He+
ion fluence enabled to identify the spectral features of both the HR emission
lines from the same localized optical spots. The reported results provide a
first insight towards the understanding of the structure of He-related defects
in diamond and their possible utilization in practical applicationsComment: 9 pages, 3 figure
Comportamento produtivo de mamoneiras de porte baixo e porte médio em sistemas de plantio consorciado.
bitstream/CPATC-2009-09/20634/1/cot_81.pdfMeta 2008
On the Possibility of Measuring the Gravitomagnetic Clock Effect in an Earth Space-Based Experiment
In this paper the effect of the post-Newtonian gravitomagnetic force on the
mean longitudes of a pair of counter-rotating Earth artificial satellites
following almost identical circular equatorial orbits is investigated. The
possibility of measuring it is examined. The observable is the difference of
the times required to in passing from 0 to 2 for both senses of
motion. Such gravitomagnetic time shift, which is independent of the orbital
parameters of the satellites, amounts to 5 s for Earth; it is
cumulative and should be measured after a sufficiently high number of
revolutions. The major limiting factors are the unavoidable imperfect
cancellation of the Keplerian periods, which yields a constraint of 10
cm in knowing the difference between the semimajor axes of the satellites,
and the difference of the inclinations of the orbital planes which, for
, should be less than . A pair of spacecrafts
endowed with a sophisticated intersatellite tracking apparatus and drag-free
control down to 10 cm s Hz level might allow to meet
the stringent requirements posed by such a mission.Comment: LaTex2e, 22 pages, no tables, 1 figure, 38 references. Final version
accepted for publication in Classical and Quantum Gravit
The central role of Italy in the spatial spread of USUTU virus in Europe
USUTU virus (USUV) is an arbovirus maintained in the environment through a bird-mosquito enzootic cycle. Previous surveillance plans highlighted the endemicity of USUV in North-eastern Italy. In this work, we sequenced 138 new USUV full genomes from mosquito pools (Culex pipiens) and wild birds collected in North-eastern Italy and we investigated the evolutionary processes (phylogenetic analysis, selection pressure and evolutionary time-scale analysis) and spatial spread of USUV strains circulating in the European context and in Italy, with a particular focus on North-eastern Italy. Our results confirmed the circulation of viruses belonging to four different lineages in Italy (EU1, EU2, EU3 and EU4), with the newly sequenced viruses from the North-eastern regions, Veneto and Friuli Venezia Giulia, belonging to the EU2 lineage and clustering into two different sub-lineages, EU2-A and EU2-B. Specific mutations characterize each European lineage and geographic location seem to have shaped their phylogenetic structure. By investigating the spatial spread in Europe, we were able to show that Italy acted mainly as donor of USUV to neighbouring countries. At a national level, we identified two geographical clusters mainly circulating in Northern and North-western Italy, spreading both northward and southward. Our analyses provide important information on the spatial and evolutionary dynamics of USUTU virus that can help to improve surveillance plans and control strategies for this virus of increasing concern for human health
Conservative evaluation of the uncertainty in the LAGEOS-LAGEOS II Lense-Thirring test
We deal with the test of the general relativistic gravitomagnetic
Lense-Thirring effect currently ongoing in the Earth's gravitational field with
the combined nodes \Omega of the laser-ranged geodetic satellites LAGEOS and
LAGEOS II.
One of the most important source of systematic uncertainty on the orbits of
the LAGEOS satellites, with respect to the Lense-Thirring signature, is the
bias due to the even zonal harmonic coefficients J_L of the multipolar
expansion of the Earth's geopotential which account for the departures from
sphericity of the terrestrial gravitational potential induced by the
centrifugal effects of its diurnal rotation. The issue addressed here is: are
the so far published evaluations of such a systematic error reliable and
realistic? The answer is negative. Indeed, if the difference \Delta J_L among
the even zonals estimated in different global solutions (EIGEN-GRACE02S,
EIGEN-CG03C, GGM02S, GGM03S, ITG-Grace02, ITG-Grace03s, JEM01-RL03B, EGM2008,
AIUB-GRACE01S) is assumed for the uncertainties \delta J_L instead of using
their more or less calibrated covariance sigmas \sigma_{J_L}, it turns out that
the systematic error \delta\mu in the Lense-Thirring measurement is about 3 to
4 times larger than in the evaluations so far published based on the use of the
sigmas of one model at a time separately, amounting up to 37% for the pair
EIGEN-GRACE02S/ITG-Grace03s. The comparison among the other recent GRACE-based
models yields bias as large as about 25-30%. The major discrepancies still
occur for J_4, J_6 and J_8, which are just the zonals the combined
LAGEOS/LAGOES II nodes are most sensitive to.Comment: LaTex, 12 pages, 12 tables, no figures, 64 references. To appear in
Central European Journal of Physics (CEJP
Energetics and stability of nanostructured amorphous carbon
Monte Carlo simulations, supplemented by ab initio calculations, shed light
into the energetics and thermodynamic stability of nanostructured amorphous
carbon. The interaction of the embedded nanocrystals with the host amorphous
matrix is shown to determine in a large degree the stability and the relative
energy differences among carbon phases. Diamonds are stable structures in
matrices with sp^3 fraction over 60%. Schwarzites are stable in low-coordinated
networks. Other sp^2-bonded structures are metastable.Comment: 11 pages, 7 figure
Determining the reference range of blood presepsin in term and preterm neonates
Introduction Sepsis is still a major cause of morbidity and mortality in neonates, especially in preterm infants. Mortality can reach 60-70% in very low birth weight infants (birthweight 0.20). This reduced model explains 3.8% of the total sum of squares. After adjustment for all the factors in the model, presepsin levels appear to be significantly lower in twins (496 pg/ml \uf0b1 65.5 vs 655 pg/ml \uf0b1 11.8) and in neonates with Apgar at 1 min 658 (644 pg/ml \uf0b1 11.8 vs 774 pg/ml \uf0b1 56.2). So none of the above factors seems worth to be taken into account in determining the reference limits for presepsin blood levels in healthy term neonates. Preterm neonates. The largest differences in presepsin level are observed between small for gestational age (SGA) (903 pg/ml \uf0b1 57.1) and adequate for gestational age (AGA) neonates (703 pg/ml \uf0b1 26.7), between neonates with and without mechanical ventilation at blood sampling (1090 pg/ml \uf0b1 86.9 vs 711 pg/ml \uf0b1 24.7) and at delivery (855 pg/ml \uf0b1 87.3 vs 729 pg/ml \uf0b1 25.8), between neonates with and without venous catether (801 pg/ml \uf0b1 47.5 vs 716 pg/ml \uf0b1 28.9), between neonates who underwent blood sampling after the 4th day or before (797 pg/ml \uf0b1 46.2 vs 716 pg/ml \uf0b1 29.2), between males and females (778 pg/ml \uf0b1 35.1 vs 701 pg/ml \uf0b1 34.7). All these factors, when simultaneously introduced into a multivariable linear model, explain only 18.8% of the total sum of squares. A second multivariable linear model was fitted after removing the factors that showed the lowest effect on presepsin level (those associated with a p-value >0.50). This reduced model explains 13.4% of the total sum of squares. A third and more parsimonious multivariable linear model was fitted after removing the factors that showed the lowest effect on presepsin level (those associated with a p-value >0.20). This reduced model explains 12.3% of the total sum of squares. After adjustment for all the factors in the model, presepsin levels result to be significantly lower in AGA neonates (706 pg/ml \uf0b1 25.7 vs 890 pg/ml \uf0b1 55.0) and between neonates with and without mechanical ventilation at blood sampling (1074 pg/ml \uf0b1 85.3 vs 712 pg/ml \uf0b1 24.2). Even in this case, none of the above factors is expected to substantially affect the reference limits for presepsin blood levels in preterm neonates. Conclusion Presepsin blood levels seem to be quite independent of most of maternal and neonatal conditions examined in this study both in preterm and term neonates. The factors exerting significant effects (multiple birth and Apgar at 1 min, in term neonates, weight by gestational age and mechanical ventilation in preterm neonates) are expected to affect presepsin reference limits only to minor extent. References [1] Evaluation of a newly identified soluble CD14 subtype as a marker for sepsis. Yaegashi Y., Shirakawa K., Sato N., Suzuki Y., Kojika M., Imai S., Takahashi G., Miyata M., Furusako S., Endo S. J Infect Chemother. 2005;11:234-8. [2] CDC/NHSN surveillance definition of health care-associated infection and criteria for specific types of infection in the acute care setting. Horan T.C., Andrus M., Dudeck M.A. Am J Infect Control. 2008;36:309-32
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