1,350 research outputs found
Apple Pomace Consumption Favorably Alters Hepatic Lipid Metabolism in Young Female Sprague-Dawley Rats Fed a Western Diet
Apple pomace, which is a waste byproduct of processing, is rich in several nutrients, particularly dietary fiber, indicating potential benefits for diseases that are attributed to poor diets, such as non-alcoholic fatty liver disease (NAFLD). NAFLD affects over 25% of United States population and is increasing in children. Increasing fruit consumption can influence NAFLD. The study objective was to replace calories in standard or Western diets with apple pomace to determine the effects on genes regulating hepatic lipid metabolism and on risk of NAFLD. Female Sprague-Dawley rats were randomly assigned (n = 8 rats/group) to isocaloric diets of AIN-93G and AIN-93G/10% w/w apple pomace (AIN/AP) or isocaloric diets of Western (45% fat, 33% sucrose) and Western/10% w/w apple pomace (Western/AP) diets for eight weeks. There were no significant effects on hepatic lipid metabolism in rats fed AIN/AP. Western/AP diet containing fiber-rich apple pomace attenuated fat vacuole infiltration, elevated monounsaturated fatty acid content, and triglyceride storage in the liver due to higher circulating bile and upregulated hepatic DGAT2 gene expression induced by feeding a Western diet. The study results showed the replacement of calories in Western diet with apple pomace attenuated NAFLD risk. Therefore, apple pomace has the potential to be developed into a sustainable functional food for human consumption
Autonomous three-dimensional formation flight for a swarm of unmanned aerial vehicles
This paper investigates the development of a new guidance algorithm for a formation of unmanned aerial vehicles. Using the new approach of bifurcating potential fields, it is shown that a formation of unmanned aerial vehicles can be successfully controlled such that verifiable autonomous patterns are achieved, with a simple parameter switch allowing for transitions between patterns. The key contribution that this paper presents is in the development of a new bounded bifurcating potential field that avoids saturating the vehicle actuators, which is essential for real or safety-critical applications. To demonstrate this, a guidance and control method is developed, based on a six-degreeof-freedom linearized aircraft model, showing that, in simulation, three-dimensional formation flight for a swarm of unmanned aerial vehicles can be achieved
A Novel Flow-Perfusion Bioreactor Supports 3D Dynamic Cell Culture
Background. Bone engineering requires thicker three-dimensional constructs than the maximum thickness supported by standard cell-culture techniques (2 mm). A flow-perfusion bioreactor was developed to provide chemotransportation to thick (6 mm) scaffolds.
Methods. Polyurethane scaffolds, seeded with murine preosteoblasts, were loaded into a novel bioreactor. Control scaffolds remained in static culture. Samples were harvested at days 2, 4, 6, and 8 and analyzed for cellular distribution, viability, metabolic activity, and density at the periphery and core. Results. By day 8, static scaffolds had a periphery cell density of 67% ± 5.0%, while in the core it was 0.3% ± 0.3%. Flow-perfused scaffolds demonstrated peripheral cell density of 94% ± 8.3% and core density of 76% ± 3.1% at day 8. Conclusions. Flow perfusion provides chemotransportation to thick scaffolds. This system may permit high throughput study of 3D tissues in vitro and enable prefabrication of biological constructs large enough to solve clinical problems
Gene discovery and comparative analysis of X-degenerate genes from the domestic cat Y chromosome☆☆Sequence data from this article have been deposited with the EMBL/GenBank Data Libraries under Accession No. EU879967-EU879988.
AbstractMammalian sex chromosomes are the remnants of an ancient autosomal pair present in the ancestral mammalian karyotype. As a consequence of random decay and chromosome rearrangements over evolutionary time, Y chromosome gene repertoires differ between eutherian lineages. To investigate the gene repertoire and transcriptional analysis of the domestic cat Y chromosome, and their potential roles in spermatogenesis, we obtained full-length cDNA sequences for all known Y genes and their X chromosome gametologues and used those sequences to create a BAC-based physical map of the X-degenerate region. Our results indicate the domestic cat Y chromosome has retained most X-degenerate genes that were present on the ancestral eutherian Y chromosome. Transcriptional analysis revealed that most feline X-degenerate genes have retained housekeeping functions shared by their X chromosome partners and have not been specialized for testis-specific functions. Physical mapping data indicate that the cat SRY gene is present as multiple functional copies and that very little of the felid Y chromosome may be single copy. X-Y gene divergence time estimates obtained using Bayesian methods confirm an early origin of Stratum 1 genes prior to the origin of therian mammals. We observed no statistical difference in the ages of Stratum 2 and Stratum 3 gene pairs, suggesting that eutherian and marsupial Stratum 2 genes may have been independently retained in each lineage
Using On-Farm Demonstrations to Evaluate Newly Developed Cool-Season Forages in the Southeastern USA
Multiple demonstration sites throughout Florida were designed to evaluate and provide hands-on producer and county faculty access to newly developed cool-season winter forage crops that can be grown in the southeastern United States. Research funding for these projects was provided by the Dairy Research and Education Project, supported through the Georgia/Florida Dairy Industry check-off dollars. Early adopter producers interested in evaluating forages were identified for this cooperation. Long-term goals are to have the early adopter producer aid in the trialing and dissemination of information about improved varieties.
Cool-season forages for use on southeastern US livestock operations benefit the producer in providing highly nutritional greenchop or silage crop for livestock, winter cover to provide erosion and leaching protection on cultivated acreage, potentially recycle nutrients or remove significant nutrients from the forage system, and serve as a sentinel plots to help identify new or emerging pest problems related to forage production.
We also focus developing forages for both low and high end input systems that address environmental issues related to N and P in the soils. In the southeastern U.S. particularly in Florida, nitrogen and phosphorus accumulate in many production fields and these nutrients impact surface and ground water resources. We participate with the Florida Department of Agriculture and the dairy and beef cattle industry to develop “best management practices” (BMPs) that guide producers to lessen their negative impacts on the environment and improve upon their operation’s sustainability and economic returns. This effort has led to the release of new cultivars from the University of Florida’s Forage Program. While we focus, primarily, on cool-season small grains and ryegrass, our program also includes breeding other subtropical forage species for adaptation to our environment and to improve adoption of BMPs
Lifespan extension and the doctrine of double effect
Recent developments in biogerontology—the study of the biology of ageing—suggest that it may eventually be possible to intervene in the human ageing process. This, in turn, offers the prospect of significantly postponing the onset of age-related diseases. The biogerontological project, however, has met with strong resistance, especially by deontologists. They consider the act of intervening in the ageing process impermissible on the grounds that it would (most probably) bring about an extended maximum lifespan—a state of affairs that they deem intrinsically bad. In a bid to convince their deontological opponents of the permissibility of this act, proponents of biogerontology invoke an argument which is grounded in the doctrine of double effect. Surprisingly, their argument, which we refer to as the ‘double effect argument’, has gone unnoticed. This article exposes and critically evaluates this ‘double effect argument’. To this end, we first review a series of excerpts from the ethical debate on biogerontology in order to substantiate the presence of double effect reasoning. Next, we attempt to determine the role that the ‘double effect argument’ is meant to fulfil within this debate. Finally, we assess whether the act of intervening in ageing actually can be justified using double effect reasoning
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De novo assembly of the cattle reference genome with single-molecule sequencing.
BackgroundMajor advances in selection progress for cattle have been made following the introduction of genomic tools over the past 10-12 years. These tools depend upon the Bos taurus reference genome (UMD3.1.1), which was created using now-outdated technologies and is hindered by a variety of deficiencies and inaccuracies.ResultsWe present the new reference genome for cattle, ARS-UCD1.2, based on the same animal as the original to facilitate transfer and interpretation of results obtained from the earlier version, but applying a combination of modern technologies in a de novo assembly to increase continuity, accuracy, and completeness. The assembly includes 2.7 Gb and is >250× more continuous than the original assembly, with contig N50 >25 Mb and L50 of 32. We also greatly expanded supporting RNA-based data for annotation that identifies 30,396 total genes (21,039 protein coding). The new reference assembly is accessible in annotated form for public use.ConclusionsWe demonstrate that improved continuity of assembled sequence warrants the adoption of ARS-UCD1.2 as the new cattle reference genome and that increased assembly accuracy will benefit future research on this species
Identification of a bifunctional lipopolysaccharide sialyltransferase in Haemophilus influenzae - Incorporation of disialic acid
The lipopolysaccharide (LPS) of non-typeable Haemophilus influenzae (NTHi) can be substituted at various positions by N-acetylneuraminic acid (Neu5Ac). LPS sialylation plays an important role in pathogenesis. The only LPS sialyltransferase characterized biochemically to date in H. influenzae is Lic3A, an alpha-2,3-sialyltransferase responsible for the addition of Neu5Ac to a lactose acceptor (Hood, D. W., Cox, A. D., Gilbert, M., Makepeace, K., Walsh, S., Deadman, M. E., Cody, A., Martin, A., Mansson, M., Schweda, E. K., Brisson, J.R., Richards, J.C., Moxon, E.R., and Wakarchuk, W.W. (2001) Mol. Microbiol. 39, 341-350). Here we describe a second sialyltransferase, Lic3B, that is a close homologue of Lic3A and present in 60% of NTHi isolates tested. A recombinant form of Lic3B was expressed in Escherichia coli and purified by affinity chromatography. We used synthetic fluorescent acceptors with a terminal lactose or sialyllactose to show that Lic3B has both alpha-2,3- and alpha-2,8-sialyltransferase activities. Structural analysis of LPS from lic3B mutant strains of NTHi confirmed that only monosialylated species were detectable, whereas disialylated species were detected upon inactivation of lic3A. Furthermore, introduction of lic3B into a lic3B-deficient strain background resulted in a significant increase in sialylation in the recipient strain. Mass spectrometric analysis of LPS indicated that glycoforms containing two Neu5Ac residues were evident that were not present in the LPS of the parent strain. These findings characterize the activity of a second sialyltransferase in H. influenzae, responsible for the addition of di-sialic acid to the LPS. Modification of the LPS by di-sialylation conferred increased resistance of the organism to the killing effects of normal human serum, as compared with mono-sialylated or non-sialylated species, indicating that this modification has biological significance
Kepler-16: A Transiting Circumbinary Planet
We report the detection of a planet whose orbit surrounds a pair of low-mass
stars. Data from the Kepler spacecraft reveal transits of the planet across
both stars, in addition to the mutual eclipses of the stars, giving precise
constraints on the absolute dimensions of all three bodies. The planet is
comparable to Saturn in mass and size, and is on a nearly circular 229-day
orbit around its two parent stars. The eclipsing stars are 20% and 69% as
massive as the sun, and have an eccentric 41-day orbit. The motions of all
three bodies are confined to within 0.5 degree of a single plane, suggesting
that the planet formed within a circumbinary disk.Comment: Science, in press; for supplemental material see
http://www.sciencemag.org/content/suppl/2011/09/14/333.6049.1602.DC1/1210923.Doyle.SOM.pd
BACH2 regulates CD8(+) T cell differentiation by controlling access of AP-1 factors to enhancers.
T cell antigen receptor (TCR) signaling drives distinct responses depending on the differentiation state and context of CD8(+) T cells. We hypothesized that access of signal-dependent transcription factors (TFs) to enhancers is dynamically regulated to shape transcriptional responses to TCR signaling. We found that the TF BACH2 restrains terminal differentiation to enable generation of long-lived memory cells and protective immunity after viral infection. BACH2 was recruited to enhancers, where it limited expression of TCR-driven genes by attenuating the availability of activator protein-1 (AP-1) sites to Jun family signal-dependent TFs. In naive cells, this prevented TCR-driven induction of genes associated with terminal differentiation. Upon effector differentiation, reduced expression of BACH2 and its phosphorylation enabled unrestrained induction of TCR-driven effector programs
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