Effect of genotype on duodenal expression of nutrient transporter genes in dairy cows

peer-reviewedBackground Studies have shown clear differences between dairy breeds in their feed intake and production efficiencies. The duodenum is critical in the coordination of digestion and absorption of nutrients. This study examined gene transcript abundance of important classes of nutrient transporters in the duodenum of non lactating dairy cows of different feed efficiency potential, namely Holstein-Friesian (HF), Jersey (JE) and their F1 hybrid. Duodenal epithelial tissue was collected at slaughter and stored at -80°C. Total RNA was extracted from tissue and reverse transcribed to generate cDNA. Gene expression of the following transporters, namely nucleoside; amino acid; sugar; mineral; and lipid transporters was measured using quantitative real-time RT-PCR. Data were statistically analysed using mixed models ANOVA in SAS. Orthogonal contrasts were used to test for potential heterotic effects and spearman correlation coefficients calculated to determine potential associations amongst gene expression values and production efficiency variables. Results While there were no direct effects of genotype on expression values for any of the genes examined, there was evidence for a heterotic effect (P < 0.05) on ABCG8, in the form of increased expression in the F1 genotype compared to either of the two parent breeds. Additionally, a tendency for increased expression of the amino acid transporters, SLC3A1 (P = 0.072), SLC3A2 (P = 0.081) and SLC6A14 (P = 0.072) was also evident in the F1 genotype. A negative (P < 0.05) association was identified between the expression of the glucose transporter gene SLC5A1 and total lactational milk solids yield, corrected for body weight. Positive correlations (P < 0.05) were also observed between the expression values of genes involved in common transporter roles. Conclusion This study suggests that differences in the expression of sterol and amino acid transporters in the duodenum could contribute towards the documented differences in feed efficiency between HF, JE and their F1 hybrid. Furthermore, positive associations between the expression of genes involved in common transporter roles suggest that these may be co-regulated. The study identifies potential candidates for investigation of genetic variants regulating nutrient transport and absorption in the duodenum in dairy cows, which may be incorporated into future breeding programmes

Quantitative analysis of ruminal methanogenic microbial populations in beef cattle divergent in phenotypic residual feed intake (RFI) offered contrasting diets

peer-reviewedBackground Methane (CH4) emissions in cattle are an undesirable end product of rumen methanogenic fermentative activity as they are associated not only with negative environmental impacts but also with reduced host feed efficiency. The aim of this study was to quantify total and specific rumen microbial methanogenic populations in beef cattle divergently selected for residual feed intake (RFI) while offered (i) a low energy high forage (HF) diet followed by (ii) a high energy low forage (LF) diet. Ruminal fluid was collected from 14 high (H) and 14 low (L) RFI animals across both dietary periods. Quantitative real time PCR (qRT-PCR) analysis was conducted to quantify the abundance of total and specific rumen methanogenic microbes. Spearman correlation analysis was used to investigate the association between the relative abundance of methanogens and animal performance, rumen fermentation variables and diet digestibility. Results Abundance of methanogens, did not differ between RFI phenotypes. However, relative abundance of total and specific methanogen species was affected (P < 0.05) by diet type, with greater abundance observed while animals were offered the LF compared to the HF diet. Conclusions These findings suggest that differences in abundance of specific rumen methanogen species may not contribute to variation in CH4 emissions between efficient and inefficient animals, however dietary manipulation can influence the abundance of total and specific methanogen species.Funding for the development and main work of this research was provided under the National Development Plan, through the Research Stimulus Fund, administered by the Department of Agriculture, Fisheries & Food, Ireland RSF 05 224

Intelligent and adaptive tutoring for active learning and training environments

Active learning facilitated through interactive and adaptive learning environments differs substantially from traditional instructor-oriented, classroom-based teaching. We present a Web-based e-learning environment that integrates knowledge learning and skills training. How these tools are used most effectively is still an open question. We propose knowledge-level interaction and adaptive feedback and guidance as central features. We discuss these features and evaluate the effectiveness of this Web-based environment, focusing on different aspects of learning behaviour and tool usage. Motivation, acceptance of the approach, learning organisation and actual tool usage are aspects of behaviour that require different evaluation techniques to be used

An examination of the molecular mechanisms controlling the tissue accumulation of conjugated linoleic acid (CLA) in cattle

End of project reportLong chain n-3 polyunsaturated fatty acids (n-3 PUFA) and conjugated linoleic acid (CLA) have demonstrable and potential human health benefits in terms of preventing cancer, diabetes, chronic inflammation, obesity and coronary heart disease. Supplementation of cattle diets with a blend of oils rich in n-3 PUFA and linoleic acid have a synergistic effect on the accumulation of ruminal and tissue concentrations of trans vaccenic acid (TVA), the main substrate for ?-9 desaturase which is responsible for de novo tissue synthesis of the cis 9, trans 11 isomer of CLA. This dietary strategy translates into increases in milk concentrations of CLA in dairy cows; however, concentrations in the muscle of beef animals have not always been increased. There is an apparent paradox in that n-3 PUFA supplementation enhances ruminal synthesis of trans-vaccenic acid (TVA), but then inhibits its conversion to CLA possibly through altering the activity of ?-9 desaturase. Recently, the promoter regions of the bovine ?- 9 desaturase gene has been isolated and analysed and has been shown to contain a conserved PUFA response region

Clinical and magnetic resonance imaging characteristics of thoracolumbar intervertenral disk extrusions and protrusions in large breed dogs

It has recently been shown that the fat-derived hormone adiponectin has the ability to decrease hyperglycemia and to reverse insulin resistance. However, bacterially produced full-length adiponectin is functionally inactive. Here, we show that endogenous adiponectin secreted by adipocytes is post-translationally modified into eight different isoforms, as shown by two-dimensional gel electrophoresis. Carbohydrate detection revealed that six of the adiponectin isoforms are glycosylated. The glycosylation sites were mapped to several lysines (residues 68, 71, 80, and 104) located in the collagenous domain of adiponectin, each having the surrounding motif of GXKGE(D). These four lysines were found to be hydroxylated and subsequently glycosylated. The glycosides attached to each of these four hydroxylated lysines are possibly glucosylgalactosyl groups. Functional analysis revealed that full-length adiponectin produced by mammalian cells is much more potent than bacterially generated adiponectin in enhancing the ability of subphysiological concentrations of insulin to inhibit gluconeogenesis in primary rat hepatocytes, whereas this insulin-sensitizing ability was significantly attenuated when the four glycosylated lysines were substituted with arginines. These results indicate that full-length adiponectin produced by mammalian cells is functionally active as an insulin sensitizer and that hydroxylation and glycosylation of the four lysines in the collagenous domain might contribute to this activity.link_to_subscribed_fulltex

Benchmarking calculations of excitonic couplings between bacteriochlorophylls

Excitonic couplings between (bacterio)chlorophyll molecules are necessary for simulating energy transport in photosynthetic complexes. Many techniques for calculating the couplings are in use, from the simple (but inaccurate) point-dipole approximation to fully quantum-chemical methods. We compared several approximations to determine their range of applicability, noting that the propagation of experimental uncertainties poses a fundamental limit on the achievable accuracy. In particular, the uncertainty in crystallographic coordinates yields an uncertainty of about 20% in the calculated couplings. Because quantum-chemical corrections are smaller than 20% in most biologically relevant cases, their considerable computational cost is rarely justified. We therefore recommend the electrostatic TrEsp method across the entire range of molecular separations and orientations because its cost is minimal and it generally agrees with quantum-chemical calculations to better than the geometric uncertainty. We also caution against computationally optimizing a crystal structure before calculating couplings, as it can lead to large, uncontrollable errors. Understanding the unavoidable uncertainties can guard against striving for unrealistic precision; at the same time, detailed benchmarks can allow important qualitative questions--which do not depend on the precise values of the simulation parameters--to be addressed with greater confidence about the conclusions

Semiotika Pesan Instagram Ani Yudhoyono dalam Perspektif Etika Komunikasi

Content's messages in social media have hidden and visible meanings, that can cause differences in interpretation between people who view it, and affect the communication interaction from the perspective of communication ethics. This research aims to analyze Ani Yudhoyono's Instagram account content and the communication interaction between her and her account viewers and then examined using the perspective of communication ethics. This research uses Roland Barthes's semiotic analysis to find denotative and connotative meanings contained in the communication interaction between Ani Yudhoyono and her account viewers on the controversial content of her Instagram account. Data collection was done by observation on Ani Yudhoyono's Instagram account and relevant news on online websites, and followed by relevant data selection, such as images and texts. Collected data then analyzed using Roland Barthes's semiotic analysis to find the visible and hidden meanings of the content on communication interaction between Ani Yudhoyono and her account viewers, and also to find visible myth concerning power on the interaction. Furthermore, these findings were reviewed using the perspective of communication ethics to see if they meet the principles of communication ethics. The results of this research indicates that there are differences between Ani Yudhoyono and her account viewers on interpreting her Instagram account content which caused a conflict between them. As the result, this conflict affected their interaction and also people's opinion towards Ani Yudhoyono and the institutions that she represents