Effects of limonene on ruminal fusobacterium necrophorum concentrations, fermentation, and lysine degradation in cattle

Citation: Samii, S. S., Wallace, N., Nagaraja, T. G., Engstrom, M. A., Miesner, M. D., Armendariz, C. K., & Titgemeyer, E. C. (2016). Effects of limonene on ruminal fusobacterium necrophorum concentrations, fermentation, and lysine degradation in cattle. Journal of Animal Science, 94(8), 3420-3430. doi:10.2527/jas2016-0455Previous in vitro data showed that Fusobacterium necrophorum was inhibited by limonene. We further evaluated effects of limonene on growth of F. necrophorum in vitro as well as on ruminal concentrations of F. necrophorum in vivo. With in vitro cultivation in anaerobic brain-heart infusion broth, limonene decreased growth of F. necrophorum. Thymol also reduced growth of F. necrophorum, but it was less effective than limonene. Tylosin effectively reduced growth of F. necrophorum in vitro. Although the response over fermentation times and concentrations of antimicrobials differed somewhat between tylosin and limonene, the 2 antimicrobial agents yielded similar inhibitory effects on growth of F. necrophorum at concentrations ranging from 6 to 24 mg/L. The effects of limonene on ruminal F. necrophorum concentration in vivo were tested in 7 ruminally cannulated heifers (225 kg initial BW) used in a 7 × 4 Youden square design. Treatments included: 1) control, 2) limonene at 10 mg/kg diet DM, 3) limonene at 20 mg/kg diet DM, 4) limonene at 40 mg/kg diet DM, 5) limonene at 80 mg/kg diet DM, 6) CRINA-L (a blend of essential oil components) at 180 mg/kg diet DM, and 7) tylosin at 12 mg/kg diet DM. Each period included 11 d with 10 d washouts between periods. Samples of ruminal contents were collected before treatment initiation and after 4, 7, and 10 d of treatment for measuring F. necrophorum by the most probable number method using selective culture medium. Limonene linearly decreased (P = 0.03) ruminal F. necrophorum concentration, with the lowest concentration achieved with 40 mg of limonene/kg dietary DM. Limonene tended (P ? 0.07) to linearly reduce ruminal molar proportions of propionate and valerate while tending to linearly increase (P ? 0.10) those of butyrate and 2-methyl butyrate. Limonene did not affect ruminal NH3 concentrations or degradation rates of lysine. Neither CRINA-L (P = 0.52) nor tylosin (P = 0.19) affected ruminal F. necrophorum concentrations. CRINA-L significantly decreased ruminal concentrations of NH3 and molar proportions of 3-methyl butyrate, whereas tylosin significantly decreased molar proportions of propionate while increasing those of butyrate and tending to increase those of acetate. Limonene supplementation reduced ruminal concentrations of F. necrophorum suggesting that it may have the potential to reduce the prevalence of liver abscesses, although further research is needed to assess the effect of limonene in feedlot cattle. © 2016 American Society of Animal Science. All rights reserved

Loops versus lines and the compression stiffening of cells

Both animal and plant tissue exhibit a nonlinear rheological phenomenon known as compression stiffening, or an increase in moduli with increasing uniaxial compressive strain. Does such a phenomenon exist in single cells, which are the building blocks of tissues? One expects an individual cell to compression soften since the semiflexible biopolymer-based cytoskeletal network maintains the mechanical integrity of the cell and in vitro semiflexible biopolymer networks typically compression soften. To the contrary, we find that mouse embryonic fibroblasts (mEFs) compression stiffen under uniaxial compression via atomic force microscopy (AFM) studies. To understand this finding, we uncover several potential mechanisms for compression stiffening. First, we study a single semiflexible polymer loop modeling the actomyosin cortex enclosing a viscous medium modeled as an incompressible fluid. Second, we study a two-dimensional semiflexible polymer/fiber network interspersed with area-conserving loops, which are a proxy for vesicles and fluid-based organelles. Third, we study two-dimensional fiber networks with angular-constraining crosslinks, i.e. semiflexible loops on the mesh scale. In the latter two cases, the loops act as geometric constraints on the fiber network to help stiffen it via increased angular interactions. We find that the single semiflexible polymer loop model agrees well with our AFM experiments until approximately 35% compressive strain. We also find for the fiber network with area-conserving loops model that the stress-strain curves are sensitive to the packing fraction and size distribution of the area-conserving loops, thereby creating a mechanical fingerprint across different cell types. Finally, we make comparisons between this model and experiments on fibrin networks interlaced with beads as well as discuss the tissue-scale implications of cellular compression stiffening.Comment: 19 pages, 17 figure

Loads on a point-absorber wave energy converter in regular and focused extreme wave events

Accurate modeling and prediction of extreme loads for survivability is of crucial importance if wave energy is to become commercially viable. The fundamental differences in scale and dynamics from traditional offshore structures, as well as the fact that wave energy has not converged around one or a few technologies, implies that it is still an open question how the extreme loads should be modeled. In recent years, several methods to model wave energy converters in extreme waves have been developed, but it is not yet clear how the different methods compare. The purpose of this work is the comparison of two widely used approaches when studying the response of a point-absorber wave energy converter in extreme waves, using the open-source CFD software OpenFOAM. The equivalent design-waves are generated both as equivalent regular waves and as focused waves defined using NewWave theory. Our results show that the different extreme wave modeling methods produce different dynamics and extreme forces acting on the system. It is concluded that for the investigation of point-absorber response in extreme wave conditions, the wave train dynamics and the motion history of the buoy are of high importance for the resulting buoy response and mooring forces

Neurochemical Aftermath of Repetitive Mild Traumatic Brain Injury

IMPORTANCE: Evidence is accumulating that repeated mild traumatic brain injury (mTBI) incidents can lead to persistent, long-term debilitating symptoms and in some cases a progressive neurodegenerative condition referred to as chronic traumatic encephalopathy. However, to our knowledge, there are no objective tools to examine to which degree persistent symptoms after mTBI are caused by neuronal injury. OBJECTIVE: To determine whether persistent symptoms after mTBI are associated with brain injury as evaluated by cerebrospinal fluid biochemical markers for axonal damage and other aspects of central nervous system injury. DESIGN, SETTINGS, AND PARTICIPANTS: A multicenter cross-sectional study involving professional Swedish ice hockey players who have had repeated mTBI, had postconcussion symptoms for more than 3 months, and fulfilled the criteria for postconcussion syndrome (PCS) according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) matched with neurologically healthy control individuals. The participants were enrolled between January 2014 and February 2016. The players were also assessed with Rivermead Post Concussion Symptoms Questionnaire and magnetic resonance imaging. MAIN OUTCOMES AND MEASURES: Neurofilament light protein, total tau, glial fibrillary acidic protein, amyloid β, phosphorylated tau, and neurogranin concentrations in cerebrospinal fluid. RESULTS: A total of 31 participants (16 men with PCS; median age, 31 years; range, 22-53 years; and 15 control individuals [11 men and 4 women]; median age, 25 years; range, 21-35 years) were assessed. Of 16 players with PCS, 9 had PCS symptoms for more than 1 year, while the remaining 7 returned to play within a year. Neurofilament light proteins were significantly increased in players with PCS for more than 1 year (median, 410 pg/mL; range, 230-1440 pg/mL) compared with players whose PCS resolved within 1 year (median, 210 pg/mL; range, 140-460 pg/mL) as well as control individuals (median 238 pg/mL, range 128-526 pg/mL; P = .04 and P = .02, respectively). Furthermore, neurofilament light protein concentrations correlated with Rivermead Post Concussion Symptoms Questionnaire scores and lifetime concussion events (ρ = 0.58, P = .02 and ρ = 0.52, P = .04, respectively). Overall, players with PCS had significantly lower cerebrospinal fluid amyloid-β levels compared with control individuals (median, 1094 pg/mL; range, 845-1305 pg/mL; P = .05). CONCLUSIONS AND RELEVANCE: Increased cerebrospinal fluid neurofilament light proteins and reduced amyloid β were observed in patients with PCS, suggestive of axonal white matter injury and amyloid deposition. Measurement of these biomarkers may be an objective tool to assess the degree of central nervous system injury in individuals with PCS and to distinguish individuals who are at risk of developing chronic traumatic encephalopathy

The outflow in Mrk 509: A method to calibrate XMM-Newton EPIC-pn and RGS

We have analyzed three XMM-Newton observations of the Seyfert 1 galaxy Mrk 509, with the goal to detect small variations in the ionized outflow properties. Such measurements are limited by the quality of the cross-calibration between RGS, the best instrument to characterize the spectrum, and EPIC-pn, the best instrument to characterize the variability. For all three observations we are able to improve the relative calibration of RGS and pn consistently to 4 %. In all observations we detect three different outflow components and, thanks to our accurate cross-calibration we are able to detect small differences in the ionization parameter and column density in the highest ionized component of the outflow. This constrains the location of this component of the outflow to within 0.5 pc of the central source. Our method for modeling the relative effective area is not restricted to just this source and can in principle be extended to other types of sources as well.Comment: 11 pages, 9 figure

Maternal polymorphisms in glutathione-related genes are associated with maternal mercury concentrations and early child neurodevelopment in a population with a fish-rich diet

Introduction: Glutathione (GSH) pathways play a key role the metabolism and elimination of the neurotoxicant methylmercury (MeHg). We hypothesized that maternal genetic variation linked to GSH pathways could influence MeHg concentrations in pregnant mothers and children and thereby also affect early life development. Methods: The GCLM (rs41303970, C/T), GCLC (rs761142, T/G) and GSTP1 (rs1695, A/G) polymorphisms were genotyped in 1449 mothers in a prospective study of the Seychellois population with a diet rich in fish. Genotypes were analyzed in association with maternal hair and blood Hg, fetal blood Hg (cord blood Hg), as well as children's mental (MDI) and motor development (PDI; MDI and PDI assessed by Bayley Scales of Infant Development at 20 months). We also examined whether genotypes modified the association between Hg exposure and developmental outcomes. Results: GCLC rs761142 TT homozygotes showed statistically higher mean maternal hair Hg (4.12 ppm) than G carriers (AG 3.73 and GG 3.52 ppm) (p = 0.037). For the combination of GCLC rs761142 and GCLM rs41303970, double homozygotes TT + CC showed higher hair Hg (4.40 ppm) than G + T carriers (3.44 ppm; p = 0.018). No associations were observed between GSTP1 rs1695 and maternal hair Hg or between any genotypes and maternal blood Hg or cord blood Hg. The maternal GSTP1 rs1695 rare allele (G) was associated with a lower MDI among children (β = −1.48, p = 0.048). We also observed some interactions: increasing Hg in maternal and cord blood was associated with lower PDI among GCLC rs761142 TT carriers; and increasing Hg in hair was associated with lower MDI among GSTP1 rs1695 GG carriers. Conclusions: Maternal genetic variation in genes involved in GSH synthesis is statistically associated with Hg concentrations in maternal hair, but not in maternal or fetal blood. We observed interactions that suggest maternal GSH genetics may modify associations between MeHg exposure and neurodevelopmental outcomes

Orbit structure and (reversing) symmetries of toral endomorphisms on rational lattices

We study various aspects of the dynamics induced by integer matrices on the invariant rational lattices of the torus in dimension 2 and greater. Firstly, we investigate the orbit structure when the toral endomorphism is not invertible on the lattice, characterising the pretails of eventually periodic orbits. Next we study the nature of the symmetries and reversing symmetries of toral automorphisms on a given lattice, which has particular relevance to (quantum) cat maps.Comment: 29 pages, 3 figure

Circulating alpha1-antitrypsin in the general population: Determinants and association with lung function

BACKGROUND: Severe alpha1-antitrypsin (AAT) deficiency associated with low AAT blood concentrations is an established genetic COPD risk factor. Less is known about the respiratory health impact of variation in AAT serum concentrations in the general population. We cross-sectionally investigated correlates of circulating AAT concentrations and its association with FEV1. METHODS: In 5187 adults (2669 females) with high-sensitive c-reactive protein (CRP) levels < or = 10 mg/l from the population-based Swiss SAPALDIA cohort, blood was collected at the time of follow-up examination for measuring serum AAT and CRP. RESULTS: Female gender, hormone intake, systolic blood pressure, age in men and in postmenopausal women, as well as active and passive smoking were positively, whereas alcohol intake and BMI inversely correlated with serum AAT levels, independent of CRP adjustment. We observed an inverse association of AAT with FEV1 in the total study population (p < 0.001), that disappeared after adjustment for CRP (p = 0.28). In addition, the AAT and FEV1 association was modified by gender, menopausal status in women, and smoking. CONCLUSION: The results of this population-based study reflect a complex interrelationship between tobacco exposure, gender related factors, circulating AAT, systemic inflammatory status and lung function

On the calibration of a WEC-Sim model for heaving point absorbers

The outcomes of reliability based design methods applied to wave energy converters (WECs) in the early stages of development depend heavily on the uncertainty in the variables used to determine the loads acting on, and responses of, devices. Open source software has been developed in recent years to aid in the response modelling of devices such as NEMOH, WEC-Sim and OpenFOAM. Uncertainty in the estimation of the viscous drag forces acting on a device has been identified as a key source of error in diffraction and radiation based hydrodynamic models. Different methods of determining the drag coefficient are compared in the case of 2 heaving point absorbers in the absence of PTOs. This study uses physical model decay tests to try and quantify the viscous damping for the X-MED buoy and Uppsala University’s model WEC, a bottom referenced point absorber similar to the full scale Seabased device. The approach is then evaluated by applying the values obtained for the drag coefficients to the hydrodynamic model WECSim which is then compared to physical model tank tests in regular waves