Streptomycin is an aminoglycoside antibiotic used in apiculture to protect bees against a variety of brood diseases. Brazilian authorities have included it in the National Regulatory Monitoring ...Program for honey production. A simple and reliable method using liquid chromatography–tandem mass spectrometry has been developed and validated for the determination of streptomycin in honey. The chromatography separation was performed on a Gemini 5
μm C18 (50
mm
×
2
mm) column using 5
mM heptafluorbutiric acid/acetonitrile (85:15) as the mobile phase at a flow rate of 0.2
mL
min
−1. The detection of the analyte was achieved by positive ionization electrospray in multiple reaction-monitoring modes. Two characteristic transitions were monitored for streptomycin. Some analytical parameters were validated according to the guidelines laid down by European Commission Decision 2002/657/EC: decision limit, detection capability, recovery, precision and ruggedness. The recoveries of streptomycin from honey fortified at 2.5, 10, 15 and 20
μg
kg
−1 levels are around 100%. The decision limit and detection capability of streptomycin was 3
μg
kg
−1 and 4.7
μg
kg
−1 respectively.
•Grapevine leaves were used to develop machine learning models.•A cultivar classification model based on morpho-colorimetry was highly accurate.•A second cultivar classification model based on NIR ...spectroscopy had similar accuracy.•Comparisons between these two models and techniques were provided.
The application of computer vision algorithms and chemometric fingerprinting using near-infrared spectrometry (NIR) of plant leaves, offers enhanced capabilities for ampelography by providing more accurate methods to discriminate leaves based on morphological parameters, and chemometrics, respectively. This paper showed that machine learning algorithms based on morpho-colorimetric parameters and NIR analysis separately, were able to automatically classify leaves of 16 grapevine cultivars. The artificial neural network (ANN) model developed with morpho-colorimetric parameters as inputs (Model 1), and 16 cultivars as targets, rendered an accuracy of 94% to classify leaves for all cultivars studied. The ANN model obtained with the NIR spectra per leaf as inputs (Model 2), and the real classification as targets, rendered 92% accuracy. The automatic extraction of morpho-colorimetric data, NIR chemical fingerprinting and machine learning modelling rendered rapid, accurate and non-destructive methods for cultivar classification, which can aid management practices.
The number of dairy farms adopting automatic milking systems (AMS) has considerably increased around the world aiming to reduce labor costs, improve cow welfare, increase overall performance, and ...generate a large amount of daily data, including production, behavior, health, and milk quality records. In this context, this study aimed to (1) estimate genomic-based variance components for milkability traits derived from AMS in North American Holstein cattle based on random regression models; and (2) derive and estimate genetic parameters for novel behavioral indicators based on AMS-derived data. A total of 1,752,713 daily records collected using 36 milking robot stations and 70,958 test-day records from 4,118 genotyped Holstein cows were used in this study. A total of 57,600 SNP remained after quality control. The daily-measured traits evaluated were milk yield (MY, kg), somatic cell score (SCS, score unit), milk electrical conductivity (EC, mS), milking efficiency (ME, kg/min), average milk flow rate (FR, kg/min), maximum milk flow rate (FRM, kg/min), milking time (MT, min), milking failures (MFAIL), and milking refusals (MREF). Variance components and genetic parameters for MY, SCS, ME, FR, FRM, MT, and EC were estimated using the AIREMLF90 software under a random regression model fitting a third-order Legendre orthogonal polynomial. A threshold Bayesian model using the THRGIBBS1F90 software was used for genetically evaluating MFAIL and MREF. The daily heritability estimates across days in milk (DIM) ranged from 0.07 to 0.28 for MY, 0.02 to 0.08 for SCS, 0.38 to 0.49 for EC, 0.45 to 0.56 for ME, 0.43 to 0.52 for FR, 0.47 to 0.58 for FRM, and 0.22 to 0.28 for MT. The estimates of heritability (± SD) for MFAIL and MREF were 0.02 ± 0.01 and 0.09 ± 0.01, respectively. Slight differences in the genetic correlations were observed across DIM for each trait. Strong and positive genetic correlations were observed among ME, FR, and FRM, with estimates ranging from 0.94 to 0.99. Also, moderate to high and negative genetic correlations (ranging from −0.48 to −0.86) were observed between MT and other traits such as SCS, ME, FR, and FRM. The genetic correlation (± SD) between MFAIL and MREF was 0.25 ± 0.02, indicating that both traits are influenced by different sets of genes. High and negative genetic correlations were observed between MFAIL and FR (−0.58 ± 0.02) and MFAIL and FRM (−0.56 ± 0.02), indicating that cows with more MFAIL are those with lower FR. The use of random regression models is a useful alternative for genetically evaluating AMS-derived traits measured throughout the lactation. All the milkability traits evaluated in this study are heritable and have demonstrated selective potential, suggesting that their use in dairy cattle breeding programs can improve dairy production efficiency in AMS.
Alterações histológicas em brânquias de tilápia nilotica Oreochromis niloticus causadas pelo cádmio Garcia-Santos, S.(Universidade de Trás-os-Montes e Alto Douro Centro de Estudos Tecnológicos, do Ambiente e da Vida); Monteiro, S.M.(Universidade de Trás-os-Montes e Alto Douro Centro de Estudos Tecnológicos, do Ambiente e da Vida); Carrola, J.(Universidade de Trás-os-Montes e Alto Douro Centro de Estudos Tecnológicos, do Ambiente e da Vida) ...
Arquivo brasileiro de medicina veterinária e zootecnia,
2007, Letnik:
59, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Os efeitos histopatológicos do cádmio nas brânquias de tilápia Oreochromis niloticus foram estudados por microscopia óptica, usando 25mgl-1 de CdCl2 durante quatro dias, com o objetivo de identificar ...seus efeitos agudos na estrutura das brânquias. A morfologia geral das brânquias de O. niloticus é idêntica à de outros teleósteos, apresentando quatro pares de arcos branquiais com filamentos bem desenvolvidos. Situadas lateralmente, encontram-se as lamelas provenientes do eixo central dos filamentos. No epitélio filamentar foi possível identificar células de cloro, pavimentosas e mucosas. Os peixes expostos ao cádmio mostraram sinais de lesões epiteliais; edema intersticial, vasodilatação das lamelas, destacamento do epitélio lamelar e proliferação do epitélio filamentar. As alterações observadas também incluíram fusão nas lamelas como resultado de hiperplasia e hipertrofia epitelial, ruptura do sistema de células pilar, aneurismas e necroses.
The histopathogical effects of cadmium on the gills of tilapia Oreochromis niloticus were studied by light microscopy, using 25mgl-1 of CdCl2 during four days to identified the effects of short-term exposure on gills structure. The general morphology of O. niloticus gills is similar to the other teleostean fishes, showing four pairs of gills arches with well developed filaments. Bilaterally situated, secondary lamellae branches are found from the central axis of the filaments. The filamentar epithelium showed the chloride cells, the pavement cells and mucous cells. Fish exposed to cadmium showed signs of epithelial lesion, namely the interstitial edema, swollen of the lamellae, lifting and cellular proliferation of the filamentar epithelium. The changes of the gills also included lamellar fusion as a result of epithelial hyperplasia and hypertrophy, the breakdown of pillar cell system, and aneurisms with some ruptures and necrosis, especially in the filamentar epithelium.
Key message
This work shows that overexpression of the
WUS
gene from
Arabidopsis
enhanced the expression of embryogenic competence and triggered organogenesis from some cells of the regenerated ...embryo-like structures
.
Agrobacterium
-mediated genetic transformation of cotton was described in the late 1980s, but is still time consuming and largely genotype dependant due to poor regeneration. To help solve this bottleneck, we over-expressed the
WUSCHEL
(
WUS
) gene, a homeobox transcription factor cloned in
Arabidopsis thaliana
, known to stimulate organogenesis and/or somatic embryogenesis in
Arabidopsis
tissues cultured in vitro. The
AtWUS
gene alone, and
AtWUS
gene fused to the
GFP
marker were compared to the
GFP
gene alone and to an empty construct used as a control. Somatic embryogenesis was improved in
WUS
expressed calli, as the percentage of explants giving rise to embryogenic tissues was significantly higher (×3) when
WUS
gene was over-expressed than in the control. An interesting result was that
WUS
embryogenic lines evolved in green embryo-like structures giving rise to ectopic organogenesis never observed in any of our previous transformation experiments. Using our standard in vitro culture protocol, the overexpression of
AtWUS
in tissues of a recalcitrant variety did not result in the production of regenerated plants. This achievement will still require the optimization of other non-genetic factors, such as the balance of exogenous phytohormones. However, our results suggest that targeted expression of the
WUS
gene is a promising strategy to improve gene transfer in recalcitrant cotton cultivars.
In the present work, we analyzed the linear and nonlinear model suitabilities for adsorption data from aqueous As(III) removal by manganese ferrite nanoparticles (NPs). Hence, As(III) adsorption onto ...ferrite NPs was formerly analyzed by the intraparticle diffusion model (IPD). Then, adsorption kinetics was described by the pseudo-first-order (PFO), pseudo-second-order (PSO), and Elovich models, while equilibrium adsorption was fitted to the Freundlich and Langmuir isotherms. Linear and nonlinear kinetic and isotherm models were solved and compared. The nonlinear data fitting was applied through the
lsqcurvefit
user-defined function (Matlab ver. 7.10.0). The initial adsorption rate was influenced by intraparticle diffusion and surface or film diffusion from the arsenic bulk solution to ferrite NPs, according to the IPD model. Adsorption kinetics of As(III) on manganese ferrite NPs was better described by the PSO model, followed by the Elovich model and then the PFO model. Equilibrium adsorption data were only worthily described by the Freundlich isotherm model. While the PSO, Elovich and Freundlich linear models showed even better fit than the nonlinear models, determinant bias was depicted for the PFO and Langmuir linear models. Thus, to use nonlinear adsorption models is highly advisable, having the Matlab
lsqcurvefit
function been proven very useful to face such task.
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