582 research outputs found

    Transmission performance improvement using random DFB laser based Raman amplification and bidirectional second-order pumping

    Get PDF
    We demonstrate that a distributed Raman amplification scheme based on random distributed feedback (DFB) fiber laser enables bidirectional second-order Raman pumping without increasing relative intensity noise (RIN) of the signal. This extends the reach of 10 × 116 Gb/s DP-QPSK WDM transmission up to 7915 km, compared with conventional Raman amplification schemes. Moreover, this scheme gives the longest maximum transmission distance among all the Raman amplification schemes presented in this paper, whilst maintaining relatively uniform and symmetric signal power distribution, and is also adjustable in order to be highly compatible with different nonlinearity compensation techniques, including mid-link optical phase conjugation (OPC) and nonlinear Fourier transform (NFT)

    The physiological and behavioral responses of steers to gaseous ammonia in simulated long distance transport by ship.

    Get PDF
    Ammonia (NH3) can accumulate in high density cattle accommodation during live export shipments and could potentially threaten the animals' health and welfare. The effects of 4 NH3 concentrations, control ( 0.05) on hematological parameters or body weight. Twenty-eight days after exposure to NH3, the steers' pulmonary macrophage activity and neutrophil levels had returned to normal. It was concluded that ammonia concentrations of 30 and 45 ppm induced temporary inflammatory responses which indicate an adverse effect on the welfare of steers

    First experimental demonstration of nonlinear inverse synthesis transmission over transoceanic distances

    Get PDF
    We demonstrate for the first time, the transmission performance of 10Gbaud nonlinear inverse synthesis based signal over transoceanic distances, showing a significant improvement in data capacity x distance product (x12) compared with other NFT-based systems

    Insulin Response Genes in Different Stages of Periodontal Disease

    Get PDF
    Bacterial infections are known to alter glucose metabolism within tissues via mechanisms of inflammation. We conducted this study to examine whether insulin response genes are differentially expressed in gingival tissues, comparing samples from experimental gingivitis and periodontitis subjects to those from healthy individuals. Total RNA was extracted from gingival biopsies from 26 participants: 8 periodontally healthy, 9 experimental gingivitis, and 9 periodontitis subjects. Gene expression patterns were evaluated with a polymerase chain reaction array panel to examine 84 candidate genes involved with glucose metabolism, insulin resistance, and obesity. Array data were evaluated with a t test adjusted by the false discover rate (P < 0.05), and ingenuity pathway analysis was performed for statistical testing of pathways. Although tissue samples were not sufficient to enable protein quantification, we confirmed the upregulation of the key gene using lipopolysaccharide-stimulated primary gingival epithelial cells by Western blot. The mRNA expression patterns of genes that are associated with insulin response and glucose metabolism are markedly different in experimental gingivitis subjects compared with healthy controls. Thirty-two genes are upregulated significantly by at least 2-fold, adjusted for false discover rate (P < 0.05). Periodontitis subjects show similar but attenuated changes in gene expression patterns, and no genes meet the significance criteria. Ingenuity pathway analysis demonstrates significant activation of the carbohydrate metabolism network in experimental gingivitis but not in periodontitis. G6PD protein increases in response to lipopolysaccharide stimulation in primary gingival epithelial cells, which is in the same direction as upregulated mRNA in tissues. Acute gingival inflammation may be associated with tissue metabolism changes, but these changes are not evident in chronic periodontitis. This study suggests that acute gingival inflammation may induce localized changes that modify tissue insulin/glucose metabolism

    The vegetation of Lambusango Forest, Buton, Indonesia

    Get PDF
    The vegetation of Lambusango Forest, Buton, Indonesia. Reinwardtia 14(2): 265 – 286. ― Lambusango Forest is a tropical rainforest on the island of Buton, which lies close to south east Sulawesi. The forest covers an area of about 95.000 ha, with different parts of the forest having different levels of conservation protection. It lies on rocks of both calcareous (limestone) and non-calcareous (sandstone, conglomerate, peridotite and chert) nature, which give rise to soils with varying pH values, nutrient levels and water-holding capacities. The climate is seasonal, with a dry season of three months and considerable year-to-year variability due to El Niño and La Niña events. The vegetation on the different soils and in different habitats has been studied. Over 300 species of vascular plants found in the forest and surrounding areas are listed, including trees and shrubs, herbs, climbers, epiphytes, ferns and club-mosses. Two genera, Calam uswith 18 species and Ficus with 29 species, are particularly species-rich, apparently due to their ability to occupy numer-ous edaphic and ecological niches. Species of these two genera are also good colonists and so better able to reach Buton in the recent past than other species. The plants of the forest indicate that Buton is floristically very similar to Sulawesi, with at least 83% of the species found in the forest also being known from Sulawesi. Most of the plant fami-lies and genera present on Buton are common in SE Asia, indicating colonisation primarily from that continent. Many fewer families and genera have colonised from the Australasian continent. The conservation of plant diversity is neces-sary for the forest to continue as a functioning ecosystem, to the benefit of the animals of the forest and also the local people

    The effects of stakeholder integration on firm-level product innovativeness: Insights from small and medium-sized enterprises in Ghana

    Get PDF
    In spite of growing research on the influence of external stakeholders on firm outcomes, there is a paucity of research on how they influence innovation in emerging economies. In addition, the specific environmental factors that may influence the effect of stakeholder integration (SI) on firm innovation is less understood. Using data collected from 248 small and medium-sized enterprises (SMEs) in Ghana, this paper develops and tests a model that examines the relationship between SI and firm-level product innovativeness. The findings from the study indicate SI positively relates to product innovativeness. Moreover, under conditions of higher competitor pressure and greater customer expectations, the effect of SI on product innovativeness is amplified. Contributions for theory and practice are discussed

    Two-Dimensional Wigner Crystal in Anisotropic Semiconductor

    Full text link
    We investigate the effect of mass anisotropy on the Wigner crystallization transition in a two-dimensional (2D) electron gas. The static and dynamical properties of a 2D Wigner crystal have been calculated for arbitrary 2D Bravais lattices in the presence of anisotropic mass, as may be obtainable in Si MOSFETs with (110) surface. By studying the stability of all possible lattices, we find significant change in the crystal structure and melting density of the electron lattice with the lowest ground state energy.Comment: 4 pages, revtex, 4 figure

    Acute cocoa flavanol supplementation improves muscle macro- and microvascular but not anabolic responses to amino acids in older men

    Get PDF
    The anabolic effects of nutrition on skeletal muscle may depend on adequate skeletal muscle perfusion, which is impaired in older people. Cocoa flavanols have been shown to improve flow-mediated dilation, an established measure of endothelial function. However, their effect on muscle microvascular blood flow is currently unknown. Therefore, the objective of this study was to explore links between the consumption of cocoa flavanols, muscle microvascular blood flow and muscle protein synthesis (MPS) in response to nutrition in older men. To achieve this objective leg blood flow (LBF), muscle microvascular blood volume (MBV) and MPS were measured under postabsorptive and postprandial (I.V glamin, dextrose to sustain glucose ~7.5 mmol·l-1) conditions in 20 older men. Ten of these men were studied with no cocoa flavanol intervention and a further 10 were studied with the addition of 350 mg of cocoa flavanols at the same time as nutrition began. Leg [femoral artery] blood flow was measured by Doppler ultrasound, muscle MBV by contrast-enhanced ultrasound (CEUS) using DefinityTM perflutren contrast agent and MPS using [1, 2-13C2] leucine tracer techniques. Our results show that although older individuals do not show an increase in LBF or MBV in response to feeding, these absent responses are apparent when cocoa flavanols are given acutely with nutrition. However this restoration in vascular responsiveness is not associated with improved MPS responses to nutrition. We conclude that acute cocoa flavanol supplementation improves muscle macro- and microvascular responses to nutrition, independently of modifying muscle protein anabolism

    Increased dietary protein in the second trimester of gestation increases live weight gain and carcass composition in weaner calves to 6 months of age

    Get PDF
    Genetically similar nulliparous Polled Hereford heifers from a closed pedigree herd were used to evaluate the effects of dietary protein during the first and second trimester of gestation upon fetal, placental and postnatal growth. Heifers were randomly allocated into two groups at 35d post AI (35dpc) to a single bull and fed High (15.7%CP) or Low (5.9%CP) protein in the first trimester (T1). At 90dpc, half of each nutritional treatment group changed to a High or Low protein diet for the second trimester until 180dpc (T2). High protein intake in the second trimester increased birthweight in females (P = 0.05) but there was no effect of treatment upon birthweight when taken over both sexes. Biparietal diameter was significantly increased by high protein in the second trimester with the effect being greater in the female (P = 0.02) but also significant overall (P = 0.05). Placental weight was positively correlated with birth weight, fibroblast volume, and relative blood vessel volume (P < 0.05). Placental fibroblast density was increased and trophoblast volume decreased in the high protein first trimester treatment group (P <0.05). There was a trend for placental weight to be increased by high protein in the second trimester (P = 0.06). Calves from heifers fed the high protein treatment in the second trimester weighed significantly more on all occasions preweaning (at one month (P = 0.0004), 2 mths (P = 0.006), 3 mths (P = 0.002), 4 mths (P = 0.01), 5 mths (P = 41 0.03), 6 mths (P = 0.001)), and grew at a faster rate over the 6 month period. By 6 mths of age the calves from heifers fed high nutrition in the second trimester weighed 33kg heavier than those fed the low diet in the second trimester. These results suggest that dietary protein in early pregnancy alters the development of the bovine placenta and calf growth to weaning
    corecore