Explore the vast range of titles available.

The present review will present the recent published results and discuss the main effects of nutrients, mainly fatty acids, on the expression of genes involved in lipid metabolism. In this sense, the review focuses in two phases: prenatal life and finishing phase, showing how nutrients can modulate gene expression affecting marbling and fatty acid profile in meat from ruminants. Adiposity in ruminants starts to be affected by nutrients during prenatal life when maternal nutrition affects the differentiation and proliferation of adipose cells enhancing the marbling potential. Therefore, several fetal programming studies were carried out in the last two decades in order to better understand how nutrients affect long-term expression of genes involved in adipogenesis and lipogenesis. In addition, during the finishing phase, marbling becomes largely dependent on starch digestion and glucose metabolism, being important to create alternatives to increase these metabolic processes, and modulates gene expression. Different lipid sources and their fatty acids may also influence the expression of genes responsible to encode enzymes involved in fat tissue deposition, influencing meat quality. In conclusion, the knowledge shows that gene expression is a metabolic factor affecting marbling and fatty acid profile in ruminant meat and diets and their nutrients have direct effect on how these genes are expressed.

Studies have shown that intramuscular adipogenesis and fibrogenesis may concomitantly occur in skeletal muscle of beef cattle. Thus, we hypothesized that the discrepancy of intramuscular fat content in beef from Nellore and Angus was associated with differences in intramuscular adipogenesis and fibrogenesis during the finishing phase. To test our hypothesis, longissimus muscle samples of Nellore (n = 6; BW = 372.5 ± 37.3 kg) and Angus (n = 6; BW = 382.8 ± 23.9 kg) cattle were collected for analysis of gene and protein expression, and quantification of intramuscular fat and collagen. Least-squares means were estimated for the effect of Breed and differences were considered at P ≤ 0.05. A greater intramuscular fat content was observed in skeletal muscle of Angus compared to Nellore cattle (P≤0.05). No differences were observed for mRNA expression of lipogenic and lipolytic markers ACC, FAS, FABP4, SERBP–1, CPT–2, LPL, and ACOX (P > 0.05) in skeletal muscle of Nellore and Angus cattle. Similarly, no differences were observed in mRNA expression of adipogenic markers Zfp423, PPARγ, and C/EBPα (P>0.05) However, a greater PPARγ protein content was observed in skeletal muscle of Angus compared to Nellore cattle (P≤0.05). A greater abundance of adipo/fibrogenic cells, evaluated by the PDGFRα content, was observed in skeletal muscle of Angus than Nellore cattle (P≤0.05). No differences in fibrogenesis were observed in skeletal muscle of Angus and Nellore cattle, which is in accordance with the lack of differences in intramuscular collagen content in beef from both breeds (P>0.05). These findings demonstrate that difference in intramuscular fat content is associated with a slightly enhanced adipogenesis in skeletal muscle of Angus compared to Nellore cattle, while no difference in fibrogenesis.

New porphyrin–pyrrolidine/pyrroline conjugates were prepared by revisiting 1,3-dipolar cycloaddition reactions between a porphyrinic azomethine ylide and a series of dipolarophiles. Cationic conjugates obtained by alkylation of the pyrrolidine/pyrroline cycloadducts showed ability to generate singlet oxygen and to produce iodine in presence of KI when irradiated with visible light. Some of the cationic derivatives showed photobactericidal properties towards a Gram-negative bioluminescent E. coli. In all cases, these features were significantly improved using KI as coadjutant, allowing, under the tested conditions, the photoinactivation of the bacterium until the detection limit of the method with a drastic reduction of the required photosensitizer concentration and irradiation time. The obtained results showed a high correlation between the ability of the cationic porphyrin derivative to produce singlet oxygen and iodine and its E. coli photoinactivation profile.

The use of digital images could be a faster and cheaper alternative technique to assess BW, HCW, and body composition of beef cattle. The objective of this study was to develop equations to predict body and carcass weight and body fat content of young bulls using digital images obtained through a Microsoft Kinect device. Thirty-five bulls with an initial BW of 383 (±5.38) kg (20 Black Angus, 390 [±7.48] kg initial BW, and 15 Nellore, 377 [±8.66] kg initial BW) were used. The Kinect sensor, installed on the top of a cattle chute, was used to take infrared light-based depth videos, recorded before the slaughter. For each animal, a quality control was made, running and pausing the video at the moment that the animal was standing with its body and head in line. One frame from recorded videos was selected and used to analyze the following body measurements: chest width, thorax width, abdomen width, body length, dorsal height, and dorsal area. From these body measurements, 23 indexes were generated and tested as potential predictors. The BW and HCW were assessed with a digital scale, whereas empty body fat (EBF) was estimated through ground samples of all tissues. To better understand the relationship among the measurements, the correlations between final BW (488 [±10.4] kg), HCW (287 [±12.5] kg), EBF (14 [±0.610] % empty BW) content, body measurements (taken through digital images), and developed indexes were evaluated. The REG procedure was used to develop the regressions, and the important independent variables were identified using the options STEPWISE and Mallow's Cp in the SELECTION statement. Chest width was the trait most related to weights and the correlations between this measurement and BW and HCW were above 0.85. The analysis of linear regressions between observed and predicted values showed that all models pass through the origin and have a slope of unity (null hypothesis [H]: = 0 and = 1; ≥ 0.993). The models to estimate BW and HCW of Angus and Nellore presented between 0.69 and 0.84 ( < 0.001), whereas from equations to estimate the EBF were lower ( = 0.43-0.45; ≤ 0.006). Index I5 [(chest width) × body length], related to the animal volume, was significant in all models created to estimate BW and HCW, and it explained more than 70% of the variation. This study indicates that digital images taken through a Microsoft Kinect system have the potential to be used as a tool to estimate body and carcass weight of beef cattle.

Abstract Medicinal plant species are genetically engineered to obtain higher production of biomass and specific secondary metabolites, which can be used in the pharmaceutical industry. The aim of the present study was to evaluate the effect of Pfaffia glomerata (Spreng.) Pedersen tetraploid hydroalcoholic extract on the liver of adult Swiss mice. The extract was prepared from the plant roots and given to the animals by gavage, for 42 days. The experimental groups were treated with water (control), Pfaffia glomerata tetraploid hydroalcoholic extract (100, 200 and 400 mg/kg) and Pfaffia glomerata tetraploid hydroalcoholic extract discontinuously (200 mg/kg). The last group received the extract every 3 days, for 42 days. The oxidative status, mineral dynamics, and cell viability were analysed. The liver weight and the number of viable hepatocytes were reduced, despite the increased cell’s number. Increased levels of malondialdehyde and nitric oxide, and changes in iron, copper, zinc, potassium, manganese and sodium levels were observed. aspartate aminotransferase levels were increased while alanine aminotransferase levels were decreased due to BGEt intake. Our results showed that BGEt induced alterations of oxidative stress biomarkers leading to liver injury, which was associated with a reduction in the number of hepatocytes. Resumo Espécies de plantas medicinais são geneticamente modificadas para obter maior produção de biomassa e metabólitos secundários específicos, que podem ser utilizados na indústria farmacêutica. O objetivo do presente estudo foi avaliar o efeito do extrato hidroalcoólico tetraploide de Pfaffia glomerata no fígado de camundongos suíços adultos. O extrato foi preparado a partir das raízes das plantas e administrado aos animais por gavagem, por 42 dias. Os grupos experimentais foram tratados com água (controle), extrato hidroalcoólico de Pfaffia glomerata tetraploide (100, 200 e 400 mg/kg) e extrato hidroalcoólico de Pfaffia glomerata tetraploide de forma descontinua (200 mg/kg). O último grupo recebeu o extrato a cada 3 dias, durante 42 dias. O estado oxidativo, a dinâmica mineral e a viabilidade celular foram analisados. O peso do fígado e o número de hepatócitos foram reduzidos, apesar do aumento do número de células. Observou-se aumento dos níveis de malondialdeído e óxido nítrico e alterações nos níveis de Ferro, Cobre, Zinco, potássio, Magnésio e sódio. Os níveis de aspartato aminotransferase aumentaram, enquanto os níveis de alanina aminotransferase diminuíram devido à ingestão do extrato. Nossos resultados mostraram que BGEt induziu alterações de biomarcadores de estresse oxidativo levando a lesão hepática, que foi associada a uma redução no número de hepatócitos.

In this article, we examine the oscillator system developed by Kaplan that generates electrocardiogram signals ECG. The system consists of two sets coupled in a ring. Each set has a Van der Pol oscillator, a differential delay equation and a low-pass half-wave filter. The ECG is composed of the P wave, the QRS complex and the T wave. The Kaplan oscillator generates only the QRS complex, this with two different amplitudes of the R-wave and non-uniform time spacing. The damping parameter of the Van der Pol oscillator, epsilon ε and the filter’s T parameter were analysed, by means of bifurcation diagrams, in order to generate the other ECG oscillations. We created a new parameter, called gamma γ, which was included in the mathematical model. This reduces the amplitude of the Van der Pol oscillator signal derivative and consequently affects the filter performance and the differential delay equation. Our new configuration obtained through analysis generates the QRS complex with constant R-wave amplitude and also constant time spacing, in addition to generating the P and T waveforms on ECG. The results are compared numerically with the actual ECG. The work resulted in advances in oscillator models that can generate heart signals.

In an increasingly digital world, almost anything can now be done through a computer or smartphone. Digital entrepreneurship is capitalizing on this trend, which brings numerous advantages to firms and society at large. However, the determinants of digital entrepreneurship’s success are still unclear, as well as how they relate to each other. This study sought to develop a fuzzy cognitive map (FCM) to identify and analyze the determinants of digital entrepreneurship. Two group sessions were held with a panel of decision makers who deal with the digital entrepreneurship phenomenon every day. Based on their shared experience and knowledge, an FCM was developed and validated for this research context. Static and dynamic analyses facilitated a deeper understanding of the cause-and-effect relationships between the determinants of digital entrepreneurship, resulting in a well-informed framework that was validated by the panel members. This methodological procedure enabled an objective analysis of the dynamics behind digital entrepreneurship. The advantages and limitations of our constructivist framework are also discussed.

The objective of this study was to evaluate the effects of dietary addition of ground oilseed sources on the quality, fatty acid profile, and CLA content of meat from zebu steers. Thirty-one zebu steers with an initial average age of 23 mo and an initial BW of 365 kg were used in this study. The experimental period was 84 d, which was preceded by an adaption period of 28 d. The diet was provided ad libitum with a forage:concentrate ratio of 40:60. Corn silage was used as the forage source. Four different concentrates were formulated for each treatment: without additional lipids (control) or with ground soybeans (SB), ground cottonseed (CS), or ground linseed (LS). The SB, CS, and LS diets were formulated to have 6.5% ether extract on a total dietary DM basis. The experiment was set up as a completely randomized design. After slaughter, samples were taken from the longissimus thoracis muscle for the measurement of fatty acid concentration and the evaluation of meat quality. The luminosity index was greater in the control and LS diets (P < 0.01). The greatest percentages of myristic acid (C14:0), palmitic acid (C16:0), trans octadecenoic acid (C18:1 trans-10, trans-11, or trans-12), and SFA in the subcutaneous fat were observed in the CS treatment (P < 0.01). Moreover, the least percentages of oleic acid (C18:1 cis-9) and total unsaturated fatty acids in the subcutaneous fat were observed in the CS diet (P < 0.01). The meat linoleic acid and α-linolenic acid percentages were greatest in the SB and LS treatments, respectively (P < 0.001). The unsaturated fatty acid:SFA ratio was smallest for the CS diet (P < 0.01). A gradual increase in oxidation was observed as a function of storage time; however, the diets did not affect the rancidity of the meat (P > 0.05). The fatty acid profile of subcutaneous fat was impaired by the addition of CS. Supplying ground oilseeds did not increase the content of CLA in the meat.

The objective of this study was to evaluate the fatty acid profile and qualitative characteristics of meat from feedlot young bulls fed ground soybean or ground cottonseed, with or without supplementation of vitamin E. A total of 40 Red Norte young bulls, with an initial average age of 20 months, and an initial average BW of 339±15 kg, were allotted in a completely randomized design using a 2×2 factorial arrangement, with two oilseeds, and daily supplementation or not of 2500 IU of vitamin E. The experimental period was for 84 days, which was preceded by an adaptation period of 28 days. The treatments were ground soybean (SB), ground soybean plus vitamin E (SBE), ground cottonseed (CS) and ground cottonseed plus vitamin E (CSE). The percentage of cottonseed and soybean in the diets (dry matter basis) was 24% and 20%, respectively. Diets were isonitrogenous (13% CP) and presented similar amount of ether extract (6.5%). The animals were slaughtered at average live weight of 464±15 kg, and samples were taken from the longissimus dorsi muscle for the measurement of fatty acid concentration and the evaluation of lipid oxidation and color of the beef. Before fatty acid extraction, muscle tissue and subcutaneous fat of the longissimus dorsi were separated to analyze fatty acid profile in both tissues. Supplementation of vitamin E did not affect fatty acid concentration, lipid oxidation and color (P>0.05). Subcutaneous fat from animals fed CS diet had greater C12:0, C16:0 and C18:0 contents (P<0.03). In addition, CS diets reduced the C18:1 and C18:2 cis-9, trans-11 contents in subcutaneous fat (P<0.05). The muscle from animals fed CS tended to higher C16:0 and C18:0 contents (P<0.11), and decreased C18:1, C18:2 cis-9, trans-11 and C18:3 contents (P<0.05) compared with SB. The Δ9-desaturase index was greater in muscle from animals fed SB (P<0.01). At 42 days of age, meat from cattle fed SB had a greater lipid oxidation rate (P<0.05). Meat from animals fed SB diets had less lightness and redness indices than meat from animals fed CS diets after 14 days of age. In conclusion, the addition of ground cottonseed in the finishing diets did increase the saturated fatty acid content of the longissimus dorsi. However, animals fed cottonseed exhibited greater lightness and redness of beef. In this study, the addition of vitamin E did not affect qualitative characteristics of meat.

The objectives of this study were to test the interaction of breed (Nellore or Angus) and diet (whole shelled corn [WSC] or ground corn [GC] with silage) on growth performance, carcass characteristics, and ruminal pH of young bulls. Thirty-six bulls (18 Nellore and 18 Angus) with the range in age of 18 to 22 mo and BW of 381 ± 12 kg were used in a completely randomized design experiment with a 2 × 2 factorial arrangement of treatments (2 breeds and 2 diets). Experimental diets (DM basis) included 1) a GC diet containing 30% corn silage and 70% GC- and soybean meal-based concentrate and 2) a WSC diet containing 85% WSC and 15% of a soybean meal- and mineral-based pelleted supplement. An additional 8 bulls were slaughtered at the beginning of the experimental period for determination of initial carcass weight. The treatments were Nellore fed the GC diet, Nellore fed the WSC diet, Angus fed the GC diet, and Angus fed the WSC diet. Greater DMI ( < 0.01), ADG ( < 0.01), and G:F ( < 0.01) were observed in Angus bulls compared with Nellore bulls, regardless of diet. Lower average ruminal pH ( = 0.04), maximum ruminal pH (P = 0.02), and DMI ( < 0.01) were observed in bulls fed the WSC diet than in those fed the GC diet. In addition, bulls fed the WSC diet had greater G:F ( < 0.01). The WSC diet led to greater variation in DMI compared with the GC diet ( < 0.01). Omasum and large intestine percentage was affected by diets only in the Angus breed ( < 0.02) and were greater when bulls were fed the GC diet. The WSC diet without forage may be useful for feedlots because this diet promoted greater G:F than the GC diet, regardless of breed. However, special care must be exercised in feed management during adaptation and throughout the feeding of Nellore animals to avoid digestive disorders and fluctuations in DMI.