PARAFAC under non-negativity constraint is adapted to recover the underlying Beer-Lambert law of the excitation-emission fluorescence matrix measurements acquired from analyte-triggered semiconductor QDs photoluminescence modulation. When and why?

BACKGROUND: Analyte-triggered semiconductor quantum dots (QDs) modulation in the presence of non-consistently responsive fluorescent species represents a challenging analytical issue in concrete multi-way data handling. QDs with heterogeneous sizes and/or uneven distribution of functional moieties on their surfaces exhibit significant fluctuations in the fluorescent response components, known as chemical rank, across different excitation/emission modes. This phenomenon may lead to a substantial deviation from the proportionality prescribed by Beer-Lambert law. Nonetheless, even in the presence of such deviation, a multi-way model may be successfully selected after determining a proper chemical rank in a QDs system. RESULTS: We show that in a valid PARAllel FACtor (PARAFAC) model under properly determined chemical rank, meaningfully resolved pure spectral profiles can be reached for each fluorescent responsive constituent in the original excitation-emission fluorescence matrix (EEFM) measurements. This was thoroughly illustrated by applying PARAFAC trilinear decomposition of a three-way data array of two distinct datasets acquired from semiconductor QDs sensing systems with low-rank trilinear assumption. The first dataset, presented here for the first time, comprises EEFM measurements of the ligand-driven quenching of thiomalic acid (TMA)-capped AgInS2 (AIS) QDs by vomitoxin. The second dataset, employed for illustrative purposes, comprises EEFM measurements of the quenching, via cation bridging, of glutathione (GSH)-capped CdTe QDs by Pb(II). The results of this study enabled the determination of vomitoxin at a ppb level in real samples of fish feeds, showcasing the efficacy of the PARAFAC model in resolving spectral signatures (loadings) and pure concentration profiles (scores). SIGNIFICANCE: PARAFAC under a properly examined chemical rank can be easily adapted for retrieval the underlying Beer-Lambert law of the original EEFM measurements with a low-rank trilinear structure through the chemically meaningful information either when (i) no deviation of Beer-Lambert law was observed as deeply discussed in connection with the dataset acquired from vomitoxin-driven molecular sensing through TMA-capped AIS QDs, or when (ii) substantial deviations of the Beer-Lambert law are evident, as discussed in connection with the dataset collected from sensing ionic species through Pb(II) bridging of GSH-capped CdTe QDs.

Maturation and antioxidant activity of 'Giombo' and 'Rama Forte' persimmons produced in the Brazilian semiarid.

The objective of this work was characterizing persimmons of the 'Giombo' and 'Rama Forte' cultivars harvested at different ripening stages in the Brazilian semiarid. Fruits were harvested at three ripening stages - green, semi-ripe and ripe - then evaluated for the following characteristics: fruit weight and diameter, skin and pulp color, fruit firmness, pulp pH, soluble solids content, titratable acidity, SSC/TA ratio, total soluble sugars, reducing sugars, astringency index, and the contents of tannin, vitamin C, carotenoid, ß-carotene, and total extractable polyphenols. Also, total antioxidant activity by the DPPH and ABTS methods and pectin methylesterase, and polygalacturonase enzyme activities were evaluated. Two experiments were carried out in a completely randomized design, one for each cultivar, with treatments consisting of different stages of maturation, with five replications of three fruits each. Data were submitted to analysis of variance and the differences between the means were compared using the Tukey test at 5% probability. Fruit firmness and soluble solids content did not vary between maturation stages for any of the cultivars. However, the skin color index increased with advancing maturation for both 'Giombo' and 'Rama Forte'. The astringency index, the content of total extractable polyphenols, soluble tannins and the antioxidant capacity were lower in fruits harvested at the ripe stage, for both cultivars. It can be concluded that persimmons of the 'Giombo' and 'Rama Forte' cultivars present better physicochemical quality characteristics when harvested when ripe, with a totally yellow skin.

A tutorial on multi-way data processing of excitation-emission fluorescence matrices acquired from semiconductor quantum dots sensing platforms.

This tutorial demonstrates how to exploit the second-order advantage on excitation-emission fluorescence matrices (EEFMs) acquired from sensing platforms based on analyte-triggered semiconductor quantum dots (QDs) fluorescence modulation (quenching/enhancing). The advantage in processing such second-order EEFMs data from complex samples, seeking successful quantification, is comprehensively addressed. It is worth emphasizing that, aiming to exploit the second-order advantage, the selection of the most appropriate advanced chemometric model should rely on the matching between the data structure and the physicochemical chemometric model assumption. In this sense, the achievement of second-order advantage after EEFMs' processing is extensively addressed throughout this tutorial taking into consideration three different analytical situations, each involving a specific data structure: i) parallel factor analysis (PARAFAC), which is applied in a real dataset stacked in a three-way data array containing a trilinear data structure acquired from QDs-based detection with non-selective species; ii) multivariate curve resolution - alternating least-squares (MCR-ALS), which is also employed in a real dataset arranged in an augmented data matrix containing non-trilinear data structure acquired from QDs-based detection with a single breaking mode caused by background signals; iii) unfolded partial least-squares with residual bilinearization (U-PLS/RBL), which is applied in a dataset containing non-trilinear data acquired from a classical fluorescence system with two breaking modes caused by inner filter effect (IFE) in both instrumental modes (excitation and emission). The latter challenging data structure can be acquired via fluorescence quenching from IFE-based sensing platforms and chemometrically handled in two main steps. First, a set of calibration EEFMs data is converted into an unfolded data matrix during the unfolding process, followed by applying U-PLS model. Second, a post-calibration procedure using RBL analysis is applied to a test sample of EEFM maintained in its matrix form, in order to handle potential interferents. In the last section, the state-of-the-art of second-order EEFMs data acquired from semiconductor QDs-based sensing platforms and coupled to multi-way fluorescence data processing to accomplish a successful quantification, even with substantial interfering species, is critically reviewed.

Three-way calibration using PARAFAC and MCR-ALS with previous synchronization of second-order chromatographic data through a new functional alignment of pure vectors for the quantification in the presence of retention time shifts in peak position and shape.

In the present contribution is shown the application of the recently developed functional alignment of pure vectors (FAPV) as a proper algorithm to align second-order chromatographic data with severe retention time shifts in peak position and shape. FAPV decomposed a three-way chromatographic data array in their three modes (sample, spectral and elution time vectors), using a basis function to pre-process the non-linear mode (elution time) and then it aligns the functionalized pure vectors and reshapes the transformed vectors into matrices, restoring the trilinearity of second-order chromatographic data. The well-aligned three-way chromatographic data array is then successfully decomposed by advanced chemometric models such as parallel factor analysis (PARAFAC) and multivariate curve resolution - alternating least-squares (MCR-ALS) with the trilinearity constraint. The performance of this innovative analytical strategy based on PARAFAC and MCR-ALS with previous synchronization of data through FAPV algorithm is properly evaluated using real second-order chromatographic data with multiple artifacts, i.e., shifts in peak position and shape for the simultaneous quantification of amoxicillin and potassium clavulanate in commercial medicinal drugs. The present contribution compares some analytical results achieved by: (1) the usual MCR-ALS as a bilinear model applied in augmented data matrix without previous synchronization and with interval correlation optimized shifting (ICOSHIFT) and FAPV and (2) trilinear models using PARAFAC with ICOSHIFT and FAPV and trilinearity constraint in MCR-ALS with FAPV. Available results suggest that these strongly shifted and warped elution time profiles cause for the loss of trilinearity, which can be adequately restored by FAPV algorithm. PARAFAC performed a successful trilinear decomposition of three-way chromatographic data array with law values of relative prediction error (REP) in the order of 1.34-1.42% in both analytes.

Portable and benchtop Raman spectrometers coupled to cluster analysis to identify quinine sulfate polymorphs in solid dosage forms and antimalarial drug quantification in solution by AuNPs-SERS with MCR-ALS.

This paper proposes for the first time: (a) a qualitative analytical method based on portable and benchtop backscattering Raman spectrometers coupled to hierarchical cluster analysis (HCA) and multivariate curve resolution - alternating least-squares (MCR-ALS) to identify two polymorphs of antimalarial quinine sulfate in commercial pharmaceutical tablets in their intact forms and (b) a quantitative analytical method based on gold nanoparticles (AuNPs) as active substrates for surface-enhanced Raman scattering (SERS) in combination with MCR-ALS to quantify quinine sulfate in commercial pharmaceutical tablets in solution. The pure concentration and spectral profiles recovered by MCR-ALS proved that both formulations present different polymorphs. These results were also confirmed by two clusters observed in the HCA model, according to their similarities within and among the samples that provided useful information about the homogeneity of different pharmaceutical manufacturing processes. AuNPs-SERS coupled to MCR-ALS was able to quantify quinine sulfate in the calibration range from 150.00 to 200.00 ng mL-1 even with the strong overlapping spectral profile of the background SERS signal, proving that it is a powerful ultrahigh sensitivity analytical method. This reduced linearity was validated throughout a large calibration range from 25.00 to 175.00 µg mL-1 used in a reference analytical method based on high performance liquid chromatography with a diode array detector (HPLC-DAD) coupled to MCR-ALS for analytical validation purposes, even in the presence of a coeluted compound. The analytical methods developed herein are fast, because second-order chromatographic data and first-order SERS spectroscopic data were obtained in less than 6 and 2 min, respectively. Concentrations of quinine sulfate were estimated with low root mean square error of prediction (RMSEP) values and a low relative error of prediction (REP%) in the range 1.8-4.5%.

Random regression models for the evaluation of the growth of goats of the Anglonubian breed / Modelos de regressão aleatória para avaliação do crescimento de caprinos da raça Anglonubiana

A total of 6593 weight records collected from 796 male and female Anglo-Nubian goats aged up to 130 days, offspring from 29 sires and 225 dams, were used to compare models and estimate genetic parameters throughout the growth curve by applying random regression models. Direct and maternal additive genetic effects and direct and maternal permanent environmental effects were included as random in the models. The contemporary groups were included as fixed effects and goat age at kidding was included as a covariable (linear and quadratic). The choice of the best model was based on the AIC, BIC and AICc criteria. Variance estimates of the four random effects increased as the animals aged. Direct heritability (h2) rose from 0.13 to 0.40 with age, whereas maternal heritability showed a low value. Genetic correlations of weight between closer ages were high. The most suitable random regression model to compare the fitting of random effects was that which employed the Legendre polynomials of quadratic order with homogeneous variance (3333-1).(AU)

Utilizaram-se 6593 pesos de 796 caprinos da raça Anglonubiana, coletados em machos e fêmeas com idade até 130 dias, descendentes de 29 reprodutores e 225 matrizes, com o objetivo de se compararem modelos e de se estimarem parâmetros genéticos ao longo da curva de crescimento com aplicação de modelos de regressão aleatória. Nos modelos, incluíram-se os efeitos genéticos aditivos diretos e maternos e os de ambiente permanente diretos e maternos como aleatórios; os grupos de contemporâneos foram incluídos como efeitos fixos, e a idade da cabra ao parto como covariável (linear e quadrática). A escolha do melhor modelo foi realizada pela avaliação dos critérios AIC, BIC e AICc. As estimativas de variâncias dos quatro efeitos aleatórios cresceram de acordo com o aumento da idade. A herdabilidade direta (h2) aumentou de 0,13 a 0,40 com a idade, e a materna apresentou baixo valor. As correlações genéticas do peso entre idades mais próximas foram altas. O modelo de regressão aleatório mais adequado ao se comparar o ajuste dos efeitos aleatórios foi o que empregou polinômios de Legendre de ordem quadrática com variância homogênea (3333-1).(AU)

Dual-emission CdTe/AgInS2 photoluminescence probe coupled to neural network data processing for the simultaneous determination of folic acid and iron (II).

This work focused on the combination of CdTe and AgInS2 quantum dots in a dual-emission nanoprobe for the simultaneous determination of folic acid and Fe(II) in pharmaceutical formulations. The surface chemistry of the used QDs was amended with suitable capping ligands to obtain appropriate reactivity in terms of selectivity and sensitivity towards the target analytes. The implementation of PL-based sensing schemes combining multiple QDs of different nature, excited at the same wavelength and emitting at different ones, allowed to obtain a specific analyte-response profile. The first-order fluorescence data obtained from the whole emission spectra of the CdTe/AgInS2 combined nanoprobe upon interaction with folic acid and Fe(II) were processed by using chemometric tools, namely partial least-squares (PLS) and artificial neural network (ANN). This enabled to circumvent the selectivity issues commonly associated with the use of QDs prone to indiscriminate interaction with multiple species, which impair reliable and accurate quantification in complex matrices samples. ANN demonstrated to be the most efficient chemometric model for the simultaneous determination of both analytes in binary mixtures and pharmaceutical formulations due to the non-linear relationship between analyte concentration and fluorescence data that it could handle. The R2P and SEP% obtained for both analytes quantification in pharmaceutical formulations through ANN modelling ranged from 0.92 to 0.99 and 5.7-9.1%, respectively. The obtained results revealed that the developed approach is able to quantify, with high reliability and accuracy, more than one analyte in complex mixtures and real samples with pharmaceutical interest.

Detection of melamine and sucrose as adulterants in milk powder using near-infrared spectroscopy with DD-SIMCA as one-class classifier and MCR-ALS as a means to provide pure profiles of milk and of both adulterants with forensic evidence: A short communication.

The present short communication reports a promising analytical method for authentication of milk based on first-order near-infrared (NIR) spectroscopic data coupled to data driven soft independent modeling of class analogy (DD-SIMCA). This one-class classifier was able to correctly classify all samples of genuine milk powder as members of the target class from samples of milk powder adulterated with melamine and sucrose in a concentration range of 0.8-2% (w/w) and 1-3% (w/w), respectively. Multivariate curve resolution - alternating least-squares (MCR-ALS) was applied as a complementary chemometric model to DD-SIMCA aimed at retrieving pure profiles, allowing to identify the chemical composition of samples properly attributed in the target class or not, providing further investigation from forensic point of view. In order to extend the prime focus of the present report, which was aimed at developing an appropriate chemometric model for authentication purposes, the quantification analysis was also performed. This was done by successful bilinear data decomposition of NIR spectra into pure profiles for the contributing components contained in the system studied (milk and adulterants), allowing to quantify analytes with strong overlapping profiles, even in the presence of an uncalibrated interferent, as demonstrated in this short communication using MCR-ALS under various constraints in order to decrease the rotational ambiguity.

Correção de medida ultrassonográfica de carcaça em coelhos usando modelo linear misto com covariáveis / Correction ultrasonographic measurement of carcass in rabbits using mixed linear Model with covariates

Objetivou-se avaliar a correção da medida ultrassonográfica da área do músculo Longissimus dorsi, em coelhos da raça Nova Zelândia, pela análise de covariância usando modelos mistos. Foram realizadas análises em delineamento em blocos completos ao acaso, com cinco tratamentos (operadores) e seis blocos (animais), considerando na análise: a inexistência de covariáveis; a covariável comprimento de olho de lombo; a covariável profundidade de olho de lombo; e as duas covariáveis juntas. Como os animais são uma amostra aleatória, o efeito de bloco foi considerado como aleatório. Consideraram-se as covariáveis como medidas com efeito fixo sem erro, independentemente do tratamento e do comportamento linear. As estatísticas de critério de decisão CV%, R ² e R ¯ ² evidenciaram relação direta entre si e podem ser consideradas para avaliar a precisão experimental em ensaios com avaliação de carcaças. Os valores das estatísticas AIC, BIC e AICC apresentam coerência com a interpretação dos critérios de decisão e indicam que o modelo com duas covariáveis proporciona resultados acurados. A inclusão das covariáveis complementa o controle de local com melhoria na precisão do experimento. A utilização das medidas ultrassonográficas de profundidade e comprimento corrige a média da área do músculo Longissimus dorsi avaliado por diferentes operadores.(AU)

The objective of this study was to evaluate the correction ultrasonographic measurement of area the Longissimus dorsi muscle in New Zealand rabbits by covariance analysis using mixed linear models. The analyzes were performed in randomized block design with 5 treatments (operators) and 6 blocks (animals), considering in the analysis: absence of covariates; rib eye length as covariate; rib eye depth as covariate; the two covariates together. As the animals are a random sample, the block effect was considered to be random. The covariates were considered as measures of fixed effect without error, independent of treatment and linear comportment. The decision criterion statistics CV%, R², and R ¯ ²showed a direct relationship between them and can be taken into consideration to evaluate the experimental accuracy in tests with carcass evaluation. The AIC, BIC, and AICC statistics are consistent with the interpretation of the decision criteria and indicate that the two covariates in model provides accurate results. The inclusion of covariates complements the local control to improve the accuracy of the experiment. The use of ultrasound measurements of depth and length corrects the mean area of the Longissimus dorsi muscle evaluated by different operators.(AU)

At-line green synthesis monitoring of new pharmaceutical co-crystals lamivudine:theophylline polymorph I and II, quantification of polymorph I among its APIs using FT-IR spectroscopy and MCR-ALS.

This paper, reports for the first time the green synthesis of the polymorphs I and II of new pharmaceutical co-crystals lamivudine:theophylline in solid-phase, through the mixture between lamivudine and theophylline (both active pharmaceutical ingredients-APIs) in the proportion of 1:1 by neat grinding and liquid assisted grinding (10 µL ethanol). Fourier transform-infrared (FT-IR) spectroscopy and multivariate curve resolution with alternating least-squares (MCR-ALS) were employed as non-invasive analytical methodology for the at-line green synthesis monitoring of the novels lamivudine:theophylline co-crystals. By MCR-ALS it was possible to identify each component present in a complex matrix, with strong spectral overlapping, containing lamivudine, theophylline, and the novel lamivudine:theophylline co-crystal with high confidence based on the comparison of the pure and recovered spectral and concentration profiles. This model allowed to identify the end of the reaction and understand the mechanism involved in the synthesis through the identification of the intermediates present in the synthesis process. Also, MCR-ALS model estimated the concentration of co-crystal polymorph I with a root mean square error of prediction (RMSEP) and the percentage relative error of prediction (REP%) equal to 3.323 (w/w) and 9.9%, respectively. These were good results since the spectral profile of cocrystal and the physical mixture of its APIs present strong spectral overlapping in their spectral domain. Therefore, the quantification of the co-crystal between its APIs (lamivudine and theophylline) certified that the co-crystal as final product was obtained, collaborating with the results obtained by differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD).

Variabilidade genética de 12 loci de microssatélites em galinhas crioulas Canela-Preta / Genetic variability of twelve microsatellite loci in native Canela-Preta chickens

Esta pesquisa foi realizada com o objetivo de se conhecer a variabilidade genética de 12 loci de microssatélites em galinhas crioulas Canela-Preta. Foram coletadas amostras de sangue de 118 galinhas crioulas Canela-Preta, provenientes de três municípios do estado do Piauí (Oeiras, Queimada Nova e Teresina). Após extração do DNA, foram utilizados marcadores para 12 loci de microssatélites: LEI0192, LEI0209, LEI0212, LEI0217, LEI0221, LEI0234, LEI0237, LEI0248, LEI0258, MCW0081, MCW0183 e MCW0213, que foram amplificados pela técnica de reação em cadeia da polimerase (PCR). Foram obtidos 408 alelos (somando os alelos dos 12 loci), com os fragmentos variando entre 50 e 460 pares de bases. O número de alelos variou de 15 (MCW0081) a 52 (LEI0212), com média de 31,5 alelos por locus. A média de heterozigosidade esperada e o conteúdo de informações polimórficas foram, respectivamente, 0,887 e 0,909. Foram observados desvios no equilíbrio de Hardy-Weinberg e valores positivos do índice de fixação com excesso de homozigotos. Os microssatélites utilizados mostraram-se polimórficos e podem ser usados para investigações genéticas em galinhas Canela-Preta. As galinhas dos plantéis avaliados apresentam grande variabilidade gênica, o que as qualifica como importante fonte de recursos genéticos e, consequentemente, faculta a utilização delas em programas de melhoramento genético animal.(AU)

The aim of this study was to analyze the genetic variability of twelve microsatellite loci in native Canela-Preta chickens. Blood samples were collected from 118 chickens of the breed from five properties in three cities (Oeiras, Queimada Nova and Teresina) of Piauí state. After the DNA extraction, markers were used for twelve microsatellite loci: LEI0192, LEI0209, LEI0212, LEI0217, LEI0221, LEI0234, LEI0237, LEI0248, LEI0258, MCW0081, MCW0183, and MCW0213 that were amplified by polymerase chain reaction technique (PCR). The results showed a total of 408 alleles (adding alleles from the 12 loci) with the fragments ranging between 50 and 460 base pairs, the number of alleles ranged from 15 (MCW0081) to 52 (LEI0212) with an average of 31,5 alleles per locus. The average expected heterozygosity and PIC were, respectively, 0.887 and 0.909. Deviations were observed in the Hardy-Weinberg equilibrium and positive values of the fixation index with excess of homozygotes. It is concluded that the used microsatellites are polymorphic and can, therefore, be used for genetic research in Canela-Preta chickens. The birds of the analyzed cores present great genetic variability, which qualifies them as an important source of genetic resources, which could be used for future animal breeding programs.(AU)

Random regression models for the estimation of genetic and environmental covariance functions for growth traits in Santa Ines sheep.

Polynomial functions of different orders were used to model random effects associated with weight of Santa Ines sheep from birth to 196 days. Fixed effects included in the models were contemporary groups, age of ewe at lambing, and fourth-order Legendre polynomials for age to represent the average growth curve. In the random part, functions of different orders were included to model variances associated with direct additive and maternal genetic effects and with permanent environmental effects of the animal and mother. Residual variance was fitted by a sixth-order ordinary polynomial for age. The higher the order of the functions, the better the model fit the data. According to the Akaike information criterion and likelihood ratio test, a continuous function of order, five, five, seven, and three for direct additive genetic, maternal genetic, animal permanent environmental, and maternal permanent environmental effects (k = 5573), respectively, was sufficient to model changes in (co)variances with age. However, a more parsimonious model of order three, three, five, and three (k = 3353) was suggested based on Schwarz's Bayesian information criterion for the same effects. Since it was a more flexible model, model k = 5573 provided inconsistent genetic parameter estimates when compared to the biologically expected result. Predicted breeding values obtained with models k = 3353 and k = 5573 differed, especially at young ages. Model k = 3353 adequately fit changes in variances and covariances with time, and may be used to describe changes in variances with age in the Santa Ines sheep studied.

Aspectos ambientais e genéticos da prolificidade em caprinos utilizando modelos bayesianos de limiar e linear / Environmental and genetic aspects of litter size in goats using linear and threshold bayesian models

Foram estimados os componentes de variância e os parâmetros genéticos da característica prolificidade, utilizando-se inferência bayesiana sob modelo animal linear e de limiar. A prolificidade de cabras mestiças foi estudada com informações referentes ao período de oito anos consecutivos. As análises foram realizadas com cadeias de 500.000 ciclos. Considerou-se burn-in dos 15.000 valores iniciais, sendo tomados valores a cada 250 ciclos, para se obter a distribuição a posteriori com 1.940 amostras. Os efeitos do mês de cobrição e da ordem de parto e o efeito linear do peso à cobrição foram significativos. As herdabilidades foram de 0,03 e 0,18 para o modelo linear e o modelo de limiar, respectivamente. O uso do modelo de limiar mostrou-se adequado, produzindo estimativas superiores acerca dos parâmetros estimados.

Variance components and genetic parameters of the litter size trait, using Bayesian inference under linear and threshold animal model were estimated. The litter size of crossbred goats was studied with information regarding a period of eight consecutive years. Analyses were performed with 500,000 cycle chains. The burn-in of the 15,000 baseline values was considered and these were taken every 250 cycles to obtain a posteriori distribution with 1,940 effective samples. Statistical analyses showed that the effects of coverage month, delivery order and linear effect of weight on coverage were significant. The heritabilities were 0.03 and 0.18 for linear and threshold models respectively. The threshold model proved to be suitable, producing higher estimates regarding the estimated parameters.

Dinâmica da fermentação ruminal de coprodutos do babaçu por meio da técnica in vitro semiautomática de produção de gases / Dynamics of the ruminal fermentation of coproducts of babassu (Orbignya martiniana) through the half-automatic in vitro gas production technique

Avaliou-se a cinética de fermentação ruminal da matéria seca (MS) e da fibra em detergente neutro (FDN) do farelo e da torta de babaçu (Orbignya martiniana), por meio da técnica in vitro semiautomática de produção de gases. As leituras de pressão e volume foram realizadas às três, seis, nove, 12, 15, 21, 27, 33, 39, 48, 60, 72 e 96 horas. Para a degradação da MS e da FDN, quantificou-se o resíduo após 96h de incubação. As curvas de produção cumulativa de gases foram ajustadas utilizando-se o modelo logístico bicompartimental. Para a MS, houve efeito (P<0,05) do alimento sobre o volume de gases da fração solúvel de rápida degradação (Vf1). O volume de gases da fração insolúvel de lenta degradação (Vf2) foi maior para o farelo de babaçu. O farelo apresentou o maior tempo de colonização, e a torta a menor degradação. Quanto ao Vf1 da fração de FDN, não houve diferença (P>0,05) entre os alimentos, e a fração Vf2 foi maior para a torta. A produção cumulativa de gases produzidos até 96h foi alta tanto para o farelo como para a torta, 120 e 140mL, respectivamente. O farelo e a torta de babaçu podem ser utilizados como alimentos alternativos para ruminantes por apresentarem boa qualidade do ponto de vista fermentativo.

The kinetic ruminal fermentation of the dry substance (MS) and the fraction in neutral detergent (FDN) of the meal and the palm cake of babassu was evaluated through the half-automatic in vitro gas production technique. The pressure readings and measurements of volume were been carried through at 3, 6, 9, 12, 15, 21, 27, 33, 39, 48, 60, 72 and 96h. For the degradation of the MS and FDN residue was quantified after 96h of incubation. The curves of cumulative production of gases had been adjusted using the bicompartimental logistic model. For the MS it had the effect (P<0,05) of food for the volume of gases of the soluble fraction of fast degradation (Vf1). The volume of gases in the insoluble fraction of slow degradation (Vf2) was superior (P<0,05) for the babassu meal. The "Lag time" of the meal was bigger (P<0,05) that that of the palm babassu cake. The palm babassu cake presented minor degradation. The Vf1 of the FDN fraction did not have difference (P>0,05) between foods. The Vf2 fraction was bigger for the palm babassu cake. The cumulative production of gases produced up to 96h was high for the meal and for the palm babassu cake, 120 and 140mL, respectively. The babassu meal and cake can be used as alternative foods for ruminants to present good quality from the fermentation point of view.

Genetic and environmental effects on age at first farrowing in sows in southeastern Brazil.

We evaluated genetic and environmental factors affecting age at first farrowing of sows in the Brazilian southeast. For this purpose, 466 observations regarding the age at first farrowing were made for Dalland-C40© animals belonging to two herds. The effects of the environmental factors on this trait were assessed by means of a model that included, as random effects, the influence of the sow's father and mother and, as fixed effects, the influence the year of birth, the herd and the birth season, along with the covariable litter size at birth. The variance components were estimated using the derivative-free restricted maximum likelihood method. The estimated mean was 354.8 ± 25.87 days, with a coefficient of variation of 7.29%. Significant effects on the trait were observed for the herd, the year and the season of birth; but a linear effect of litter size at birth on the age at first farrowing was not observed. The boar did not significantly contribute to the variation occurring among the sows, whereas the sow's mother caused significant variation. The heritability estimate for the age at first farrowing was 0.44 ± 0.15, which is considered high. We concluded that herd effect and year and season of birth should be taken into consideration for an accurate genetic comparison; consequently, the animals should be joined into contemporary groups.

Avaliação dos modelos logístico bicompartimental e de Gompertz na estimativa da dinâmica de fermentação ruminal in vitro do farelo e da torta de babaçu (Orbignya martiana) / Avaliation of bicompartimental logistic and Gompertz mathematical models to estimate gas production from babassu (Orbignya martiana) meal and pie using the semi-automated in vitro technique

Utilizaram-se dois modelos matemáticos para avaliar a produção de gases do farelo e da torta de babaçu, pela técnica in vitro semiautomática de produção de gases. Foram utilizados o modelo logístico e o de Gompertz. Os parâmetros de validação usados foram o quadrado médio do erro (QME), o coeficiente de determinação (R²), o desvio médio absoluto dos resíduos (DMA) e a análise gráfica dos resíduos. O modelo logístico bicompartimental apresentou menores valores (P<0,05) para o QME e o DMA em relação ao de Gompertz, e não houve diferença (P>0,05) quanto ao R². Os gráficos de dispersão mostraram semelhanças nos ajustes dos dois modelos. Na análise gráfica dos resíduos, os dois modelos descreveram bem cinética de produção de gases da matéria seca. No entanto, o modelo logístico apresentou melhor valor de QME. Para avaliação da cinética de fermentação ruminal do farelo e da torta de babaçu pela técnica in vitro semiautomática de produção de gases, recomenda-se adotar o modelo logístico.

Two mathematical models were used to evaluate gas production from the meal and pie of babassu using the semi-automated gas production technique. The logistic and Gompertz models were used and the validation parameters for both models were the residual mean square (RMS), the coefficient of determination (R 2 ), the absolute average residual (AAR), and the graphical analysis of residues. The logistic model showed lower RMS (P<0.05) and AAR in comparison to Gompertz model. Both Gompertz and logistic models showed similar R 2 . The dispersion graphics showed similarity for both models and graphics analyses demonstrated that both models describe well the kinetic of gas production of dry matter. However, the bicompartimental logistic model showed the best RMS value. Logistic models are recommended to describe the kinetic of gas production from babassu foods using the semi-automated in vitro technique.

Efeitos genéticos e não-genéticos sobre o intervalo de parto em fêmeas suínas no Sudeste do Brasil / Genetic and environmental effects on the farrowing interval in sows in the southeastern region of Brazil

The effect of environmental and genetic effects on the farrowing interval in Dalland (C-40) sows in the Southeast of Brazil was studied. Data consisting of 1,013 farrowing intervals recorded in two herds were analyzed, using a model that included the sire and the dam as random effects and the year of farrowing, the herd and the farrowing season as fixed effects, plus the covariables sow's age at farrowing, litter size at birth, lactation length and weaning-estrus interval. For the farrowing interval first only, variance components were estimated by REML, with an animal model that included, as fixed effect, a contemporary group and, as random effects, the additive genetic variance and the error. The mean farrowing interval was 140.9+5.7 days, with a 4.0 percent coefficient of variation. Variance analysis showed no effect of either year, season of farrowing or herd on the farrowing interval. The sire effect was not important for the farrowing interval, but the dam represented an important source of variation. The total number of piglets born and the sow's age at farrowing had no influence on the farrowing interval. The length of lactation exerted an influence on the farrowing interval, accounting for 19.4 percent of the total variation of this trait. Likewise, the linear regression of the weaning-estrus interval in relation to the farrowing interval was highly significant, accounting for 51.7 percent of the total variation. The heritability estimate was 0.00, suggesting that no genetic gain can be obtained by selection for a shorter farrowing interval.