GRAZING SELECTIVITY AND IN VIVO DIGESTIBILITY OF SWITCHGRASS STRAINS SELECTED FOR DIFFERING DIGESTIBILITY

Animal selectivity and digestibility differences among switchgrass strains selected for different in vitro dry matter digestibilities (IVDMD) were measured in a grazing trial with esophageally fistulated steers and a sheep digestion trial. Extrusa selected by esophageally fistulated steers grazing high-IVDMD (Trailblazer), Pathfinder and Iow-IVDMD strains of switchgrass were compared, as were top and whole plant hand-clipped samples from each strain. Trailblazer extrusa had higher (P \u3c .1) in vitro organic matter disappearance (IVOMD) and lower (P \u3c .1) NDF and ADF than Pathfinder extrusa. Extrusa from all three strains appeared to be of higher quality than top or whole plant hand-clipped samples. In vitro organic matter disappearance tended to be highest for Trailblazer top hand-clipped samples. Composition of hand-clipped samples among strains was not significantly different. Mature crossbred wethers were used to compare Trailblazer and P ~ switchgrass hay in a digestion trial. No differences (P \u3e .1) were detected between slrains for DMI or apparent digestibility of DM, NDF, ADF and CP. Extrusa from Trailblazer switchgrass that had been selected for whole plant IVDMD had higher IVOMD; however, there was no indication that steers selected a differentially higher IVOMD for one strain than another

Alkali-Labile Cell-Wall Phenolics and Forage Quality in Switchgrasses Selected for Differing Digestibility

Alkali-labile cell-wall phenolics have been implicated in previous research as factors that affect forage digestibility by ruminants. Alkali- labile cell-wall phenolics, in vitro dry matter digestibility (IVDMD), neutral-detergent fiber (NDF), acid-detergent fiber (ADF), lignin (permanganate-oxidation), and crude protein (CP) were determined in three switchgrass (Panicum virgatum L.) strains differing genetically for IVDMD to determine relationships between • these quality parameters and IVDMD during the grazing season. Grazed (upper 1/3 of grazed plants) and ungrazed (whole plants in caged exclosures) forage was collected weekly from replicated 0.4- ha pastures of \u27Trailblazer\u27 (high IVDMD), \u27Pathfinder\u27, and a low- IVDMD strain during three grazing seasons from 1983 to 1985. The principal alkali-labile phenolics (g kg-1 NDF) detected were p-coumaric acid (PCA) and ferulic acid (FA). Increased PCA concentration due to increased maturity averaged \u3e70°/o during each grazing season and corresponded with increased NDF, ADF, and lignin and decreased IVDMD, CP, and FA/PCA ratio. Ferulic acid concentration either declined slightly or remained unchanged. Averaged across 3 yr, Trailblazer had higher (P \u3c 0.06) IVDMD, lower (P \u3c 0.09) PCA and higher (P \u3c 0.10) FA/PCA ratio than a divergently selected low-IVDMD strain. Differences between strains in detergent-fiber constituents, FA, and CP were either not apparent or inconsistent with strain differences in IVDMD. Results were consistent with both grazed and ungrazed switchgrass and indicate that alkali-labile cell-wall phenolic composition in switchgrass is heritable and genetically correlated to IVDMD

A Netrin-3 Like Protein is Secreted from \u3ci\u3eTetrahymena thermophila\u3c/i\u3e

Netrin proteins are a family of laminin-related secreted proteins that provide signals for axonal growth and cell migration during vertebrate development. Netrin homologs are expressed throughout the animal kingdom; however, some animals do not express a homolog of any known netrin receptors. We have previously found that the ciliated protozoan, Tetrahymena thermophila, responds to netrin-1 peptide by showing avoidance behavior. In addition, Tetrahymena secrete a protein that is immunologically similar to netrin-1 as detected by ELISA. Since netrin-3, like netrin-1, is a guidance molecule for axons and overlaps signaling pathways with netrin-1 in vertebrates, we hypothesized that netrin-3 may also act as a chemorepellent in Tetrahymena. While behavioral assays did not confirm this hypothesis, growth assays indicate that netrin-3 peptide inhibits cell division in Tetrahymena. In addition, ELISA and Western blots indicate that a netrin-3 like protein of approximately 48 kDa is secreted from Tetrahymena. Immunolocalization of this protein within the cell shows that it appears in widely distributed throughout the cell, and co-localizes with the netrin-1 like protein. Using ER tracker™, we found that some of the netrin-3-like protein co-localizes with the endoplasmic reticulum, as might be expected for a secreted protein. Further experimentation is necessary to determine the mechanism by which netrin-3 peptide inhibits growth in Tetrahymena

Mapping Netrin Signaling in \u3cem\u3eTetrahymena thermophila\u3c/em\u3e

The netrin family of proteins, found throughout the animal kingdom, are well known for their roles in developmental signaling. Netrin-1, the best-studied member of this family, signals through four receptor types in vertebrates: the UNC-5 family, DCC, neogenin, and DSCAM. We have previously characterized a netrin-1-like protein in the ciliated protozoan, Tetrahymena thermophila. This protein is secreted from Tetrahymena, and functions as a chemorepellent. Since a netrin-like protein is produced by this organism, we hypothesized that some components of the vertebrate netrin signaling pathway might also be present in Tetrahymena. Through immunolocalization on the plasma membrane of the cell, we have found that Tetrahymena appear to have a UNC-5 like protein, as well as proteins that are immunologically similar to neogenin. A homolog of src-1, a tyrosine kinase involved in vertebrate netrin-1, is also present in Tetrahymena. Future experiments will allow us to make more comparisons between netrin signaling in Tetrahymena with netrin signaling in the animal kingdom, and will allow us to determine the suitability of Tetrahymena as a model system for this particular pathway

Halloween Storm Simulations with the Space Weather Modeling Framework

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77046/1/AIAA-2006-87-256.pd

Shifting perspectives on coastal impacts and adaptation

The Intergovernmental Panel on Climate Change reports reflect evolving attitudes in adapting to sea-level rise by taking a systems approach and recognizing that multiple responses exist to achieve a less hazardous coast.info:eu-repo/semantics/publishedVersio

Respiratory and sleep disorders in mucopolysaccharidosis

MPS encompasses a group of rare lysosomal storage disorders that are associated with the accumulation of glycosaminoglycans (GAG) in organs and tissues. This accumulation can lead to the progressive development of a variety of clinical manifestations. Ear, nose, throat (ENT) and respiratory problems are very common in patients with MPS and are often among the first symptoms to appear. Typical features of MPS include upper and lower airway obstruction and restrictive pulmonary disease, which can lead to chronic rhinosinusitis or chronic ear infections, recurrent upper and lower respiratory tract infections, obstructive sleep apnoea, impaired exercise tolerance, and respiratory failure. This review provides a detailed overview of the ENT and respiratory manifestations that can occur in patients with MPS and discusses the issues related to their evaluation and management. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10545-012-9555-1) contains supplementary material, which is available to authorized users

Notch ligation by Delta1 inhibits peripheral immune responses to transplantation antigens by a CD8⁺ cell–dependent mechanism

Notch signaling plays a fundamental role in determining the outcome of differentiation processes in many tissues. Notch signaling has been implicated in T versus B cell lineage commitment, thymic differentiation, and bone marrow hematopoietic precursor renewal and differentiation. Notch receptors and their ligands are also expressed on the surface of mature lymphocytes and APCs, but the effects of Notch signaling in the peripheral immune system remain poorly defined. The aim of the studies reported here was to investigate the effects of signaling through the Notch receptor using a ligand of the Delta-like family. We show that Notch ligation in the mature immune system markedly decreases responses to transplantation antigens. Constitutive expression of Delta-like 1 on alloantigen-bearing cells renders them nonimmunogenic and able to induce specific unresponsiveness to a challenge with the same alloantigen, even in the form of a cardiac allograft. These effects could be reversed by depletion of CD8⁺ cells at the time of transplantation. Ligation of Notch on splenic CD8⁺ cells results in a dramatic decrease in IFN-γ with a concomitant enhancement of IL-10 production, suggesting that Notch signaling can alter the differentiation potential of CD8⁺ cells. These data implicate Notch signaling in regulation of peripheral immunity and suggest a novel approach for manipulating deleterious immune responses

Frailty, lifestyle, genetics and dementia risk.

OBJECTIVE: To optimise dementia prevention strategies, we must understand the complex relationships between lifestyle behaviours, frailty and genetics. METHODS: We explored relationships between frailty index, healthy lifestyle and polygenic risk scores (all assessed at study entry) and incident all-cause dementia as recorded on hospital admission records and death register data. RESULTS: The analytical sample had a mean age of 64.1 years at baseline (SD=2.9) and 53% were women. Incident dementia was detected in 1762 participants (median follow-up time=8.0 years). High frailty was associated with increased dementia risk independently of genetic risk (HR 3.68, 95% CI 3.11 to 4.35). Frailty mediated 44% of the relationship between healthy lifestyle behaviours and dementia risk (indirect effect HR 0.95, 95% CI 0.95 to 0.96). Participants at high genetic risk and with high frailty had 5.8 times greater risk of incident dementia compared with those at low genetic risk and with low frailty (HR 5.81, 95% CI 4.01 to 8.42). Higher genetic risk was most influential in those with low frailty (HR 1.31, 95% CI 1.22 to 1.40) but not influential in those with high frailty (HR 1.09, 95% CI 0.92 to 1.28). CONCLUSION: Frailty is strongly associated with dementia risk and affects the risk attributable to genetic factors. Frailty should be considered an important modifiable risk factor for dementia and a target for dementia prevention strategies, even among people at high genetic risk