717 research outputs found
A note on ensiling characteristics of the tropical grass Setaria sphacelata var. splendida (Stapf).
The objective of this study was to evaluate the ensiling characteristics of Setaria sphacelata var. splendida (S. splendida) and to identify ensilability limiting factors of this tropical grass, locally produced
Characteristic functions of differential equations with deviating arguments
The material here is motivated by the discussion of solutions of linear homogeneous and autonomous differential equations with deviating arguments. If and are real and is real-valued and continuous, an example with these parameters is
\begin{equation} u'(t) = \big\{a u(t) + b
u(t+\check{\tau}_1) + c u(t+\check{\tau}_2) \big\} { \red +}
\int_{\check{\tau}_3}^{\check{\tau}_4} {{\gamma}_\natural}(s) u(t+s)
ds \tag{\hbox{\rd{\star}}} .
\end{equation}
A wide class of equations (\rd{\star}), or of similar type, can be written in the {\lq\lq}canonical{\rq\rq} form
\begin{equation} u'(t) =\DSS
\int_{\tau_{\rd \min}}^{\tau_{\rd \max}} u(t+s) d\sigma(s) \quad (t \in \Rset),
\hbox{ for a suitable choice of } {\tau_{\rd \min}}, {\tau_{\rd \max}}
\tag{\hbox{{\rd \star\star}}} \end{equation}
where is of bounded variation and the integral is a Riemann-Stieltjes integral. For equations written in the form ({\rd{\star\star}}), there is a
corresponding characteristic function \begin{equation} \chi(\zeta) ):= \zeta -
\DSS
\int_{\tau_{\rd \min}}^{\tau_{\rd \max}} \exp(\zeta s) d\sigma(s) \quad (\zeta \in
\Cset), \tag{\hbox{{\rd{\star\star\star}}}}
\end{equation}
%%()
whose zeros (if one considers appropriate subsets of equations ({\rd \star\star}) -- the literature provides additional information on the subsets to which we refer) play a r\^ole in the study of oscillatory or non-oscillatory solutions, or of bounded or unbounded solutions. We show that the related discussion of the zeros of is facilitated by observing and exploiting some simple and fundamental properties of characteristic functions
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Volcanic constraints on the unzipping of Africa from South America: Insights from new geochronological controls along the Angola margin
The breakup of Africa from South America is associated with the emplacement of the Paraná-Etendeka flood basalt province from around 134 Ma and the Tristan da Cunha plume. Yet many additional volcanic events occur that are younger than the main pulse of the Paraná-Etendeka and straddle the rift to drift phases of the main breakup. This contribution reports on new geochronological constraints from the Angolan part of the African Margin. Three coastal and one inland section have been sampled stretching across some 400 Km, with 39Ar/40Ar, U-Pb and Palaeontology used to provide age constraints. Ages from the new data range from ~100 to 81 Ma, with three main events (cr. 100, 91 and 82-81 Ma). Volcanic events are occurring within the Early to Late Cretaceous, along this part of the margin with a general younging towards Namibia. With the constraints of additional age information both onshore and offshore Angola, a clear younging trend at the early stages of rift to drift is recorded in the volcanic events that unzip from North to South. Similar age volcanic events are reported from the Brazilian side of the conjugate margin, and highlight the need to fully incorporate these relatively low volume volcanic pulses into the plate tectonic breakup models of the South Atlantic Margin
Mixing Bandt-Pompe and Lempel-Ziv approaches: another way to analyze the complexity of continuous-states sequences
In this paper, we propose to mix the approach underlying Bandt-Pompe
permutation entropy with Lempel-Ziv complexity, to design what we call
Lempel-Ziv permutation complexity. The principle consists of two steps: (i)
transformation of a continuous-state series that is intrinsically multivariate
or arises from embedding into a sequence of permutation vectors, where the
components are the positions of the components of the initial vector when
re-arranged; (ii) performing the Lempel-Ziv complexity for this series of
`symbols', as part of a discrete finite-size alphabet. On the one hand, the
permutation entropy of Bandt-Pompe aims at the study of the entropy of such a
sequence; i.e., the entropy of patterns in a sequence (e.g., local increases or
decreases). On the other hand, the Lempel-Ziv complexity of a discrete-state
sequence aims at the study of the temporal organization of the symbols (i.e.,
the rate of compressibility of the sequence). Thus, the Lempel-Ziv permutation
complexity aims to take advantage of both of these methods. The potential from
such a combined approach - of a permutation procedure and a complexity analysis
- is evaluated through the illustration of some simulated data and some real
data. In both cases, we compare the individual approaches and the combined
approach.Comment: 30 pages, 4 figure
Nucleotides, β-glucans, ascorbic acid, α-tocoferol, and different concentrations of a vitamin-mineral premix promote growth of Nile tilapia juveniles
ABSTRACT Feed additives, such as β-glucans, nucleotides, ascorbic acid (vitamin C), and α-tocopherol (vitamin E) can improve fish immunity and contribute to enhanced zootechnical performance of the fish. This study aimed to evaluate the effect of different concentrations of vitamin- mineral premix with or without the inclusion of an immunostimulant boost (β-glucans, nucleotides and vitamins C and E) on the zootechnical performance, hemato-immunological parameters, histological changes, and survival of Nile tilapia juveniles. To this end, isocaloric and isoproteic diets were prepared with three different concentrations of vitamin-mineral premix (1.0, 1.5, and 2.0 kg ton-1); additionally, the effects of 4% immunostimulant boost in the diet were examined considering six diets (without the immunostimulant boost: 0.1%, 0.15%, and 0.2%, and with the immunostimulant boost: 0.1% I, 0.15% I, and 0.2% I). We used 24 experimental units, each including 15 fish. Nile tilapia juveniles (1.88 g±0.25) were fed for 50 d with supplemented diets. Further, zootechnical indexes; histological changes in the liver, spleen, and intestine; intestinal morphology; and hemato-immunological parameters were evaluated. The fish that received supplementation showed higher zootechnical values, compared to those that did not receive the supplementation of immunostimulant reinforcement. Weight gain (30.45g±3.06), daily weight gain (0.60g±0.06), final weight (32.41g±3.15) and feed conversion (0.95±0.06) were higher in tilapia fed with an inclusion concentration of 0.2%. Hematological parameters were not affected by either the pre-mix concentrations or the booster of the immunostimulant. There was an increase in the number of intestinal folds, length of the fold, total area and number of goblet cells in the group supplemented with immunostimulant reinforcement. Supplementation with the immunostimulant promoted growth and improved intestinal morphology and immunological parameters of Nile tilapia juveniles
The impact of low-frequency and rare variants on lipid levels
Using a genome-wide screen of 9.6 million genetic variants achieved through 1000 Genomes Project imputation in 62,166 samples, we identify association to lipid traits in 93 loci, including 79 previously identified loci with new lead SNPs and 10 new loci, 15 loci with a low-frequency lead SNP and 10 loci with a missense lead SNP, and 2 loci with an accumulation of rare variants. In six loci, SNPs with established function in lipid genetics (CELSR2, GCKR, LIPC and APOE) or candidate missense mutations with predicted damaging function (CD300LG and TM6SF2) explained the locus associations. The low-frequency variants increased the proportion of variance explained, particularly for low-density lipoprotein cholesterol and total cholesterol. Altogether, our results highlight the impact of low-frequency variants in complex traits and show that imputation offers a cost-effective alternative to resequencing
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