354 research outputs found

    Plant Species Distribution Along Topographic Gradients in Tallgrass Prairies of Eastern Nebraska.

    Get PDF
    Plant species composition was evaluated along a slope gradient in two native tallgrass prairies of eastern Nebraska. Forb cover differed significantly (P\u3c0.05) along the topographic gradient at both sites, however, grass covered differed only at one site (P\u3c0.05). A site-by-site comparison by topographic location indicates significant differences between lower slopes for grass and between upper slopes for forbs. Big bluestem (Andropogon gerardii Vitman) dominated all topographic locations at both sites (average cover = 64%) with no significant differences in the topographic distribution. Kentucky bluegrass (Poa pratensis L.), little bluestem (Andropogon scoparius Michx.), false boneset Kuhnia eupatorioides L.) prairie wild rose (Rosa arkansana Porter), prairie violet (Viola pedatifida G. Don), and sedge (Carex L. spp.) also show the no significant topographic preference at either site. Mid-slope locations contained the greatest number of species that differed significantly along the topographic gradient. Leadplant (Amorpha canescens Pursh) and indiangrass (Sorghastrum nutans (L.) Nash) were the two most common species showing high canopy cover values in mid-slope locations at both sites. Significant topographic distributions were also noted for scoring rush (Equisetum lawvigatum A. Br.) at both sites and for finger coreopsis (Coreopsis palmata Nutt.) found only at one site. Flowering spurge (Euphobia corollate L.) and sideoats grama (Bouteloua curtipendula (Michx.) Torr.) were significantly higher on the hilltop locations of one site

    Genomic Prediction of Testcross Performance in Canola (Brassica napus)

    Get PDF
    The work was funded by Deutsche Forschungsgemeinschaft (DFG) grant SN14/16-1 to RS and funding to RN, RS, and HJ from the European Union FP7 Marie Curie Initial Training Network INTERCROSSING

    Understanding the control of a vitamin B12 riboswitch

    Get PDF
    Within the life sciences switching mechanisms are pervasive at all levels, from molecules to cells and tissues. Their operation can be a key determinant of health or disease. Whilst the existence and importance of switches is widely acknowledged within the biological literature, many life scientists do not deal explicitly with the switching behaviour. Frequently, steady-state behaviour before and after switching is the primary focus. Here methods for analysis of switched systems from control engineering are applied to the modelling and analysis of a riboswitch. The model has been developed by studying the dynamics of the vitamin B12 riboswitch. The simulation results have been validated using in vivo experiments by checking the bacterial growth when using Escherichia coli and Salmonella enterica where the action of the vitamin B12 riboswitch is known to be a determinant of system behaviour. The paper first describes a simple model for the B12-riboswitch regulatory network in E. coli and applies the same analysis when changing the strain to S. enterica. Validation of the simulation results has been undertaken by linking the dynamics of the riboswitch to bacterial growth

    Slicing Strategies for the Generalised Type-2 Mamdani Fuzzy Inferencing System

    Get PDF
    The final publication is available at Springer via http://dx.doi.org/[insert DOI]".As a three-dimensional object, there are a number of ways of slicing a generalised type-2 fuzzy set. In the context of the Mamdani Fuzzy Inferencing System, this paper concerns three accepted slicing strategies, the vertical slice, the wavy slice, and the horizontal slice or alpha -plane. Two ways of de ning the generalised type-2 fuzzy set, vertical slices and wavy slices, are presented. Fuzzi cation and inferencing is presented in terms of vertical slices. After that, the application of all three slicing strategies to defuzzi cation is described, and their strengths and weaknesses assessed

    Exploration of 2-deoxy-D-ribose and 17β-Estradiol as alternatives to exogenous VEGF to promote angiogenesis in tissue-engineered constructs

    Get PDF
    Aim: In this study, we explored the angiogenic potential and proangiogenic concentration ranges of 2-deoxy-D-ribose (2dDR) and 17β-Estradiol (E2) in comparison with VEGF. The 2dDR and E2 were then loaded into tissue engineering (TE) scaffolds to investigate their proangiogenic potential when released from fibers. Materials & methods:Ex ovo chick chorioallantoic membrane (CAM) assay was used to evaluate angiogenic activity of 2dDR and E2. Both factors were then introduced into scaffolds via electrospinning to assess their angiogenic potential when released from fibers. Results: Both factors were approximately 80% as potent as VEGF and showed a dose-dependent angiogenic response. The sustained release of both agents from the scaffolds stimulated neovascularization over 7 days in the chorioallantoic membrane assay. Conclusion: We conclude that both 2dDR and E2 provide attractive alternatives to VEGF for the functionalization of tissue engineering scaffolds to promote angiogenesis in vivo

    Multifactorial causes of chronic mortality in juvenile sturgeon (Huso huso)

    Get PDF
    This investigation focused on an episode of chronic mortality observed in juvenile Huso huso sturgeons. The examined subjects underwent pathological, microbiological, molecular, and chemical investigations. Grossly severe body shape deformities, epaxial muscle softening, and multifocal ulcerative dermatitis were the main observed findings. The more constant histopathologic findings were moderate to severe rarefaction and disorganization of the lymphohematopoietic lymphoid tissues, myofiber degeneration, atrophy and interstitial edema of skeletal epaxial muscles, and degeneration and atrophy of the gangliar neurons close to the myofibers. Chemical investigations showed a lower selenium concentration in affected animals, suggesting nutritional myopathy. Other manifestations were nephrocalcinosis and splenic vessel wall hyalinosis. Septicemia due to bacteria such as Aeromonas veronii, Shewanella putrefaciens, Citrobacter freundii, Chryseobacterium sp., and pigmented hyphae were found. No major sturgeon viral pathogens were detected by classical methods. Next-generation sequencing (NGS) analysis confirmed the absence of viral pathogens, with the exception of herpesvirus, at the order level; also, the presence of Aeromonas veronii and Shewanella putrefaciens was confirmed at the family level by the metagenomic classification of NGS data. In the absence of a primary yet undetected biological cause, it is supposed that environmental stressors, including nutritional imbalances, may have led to immune system impairment, facilitating the entry of opportunistic bacteria and mycotic hyphae

    The association of aggressive and chronic periodontitis with systemic manifestations and dental anomalies in a jordanian population: a case control study

    Get PDF
    <p>Abstract</p> <p><b>Background</b></p> <p>The relationship between dental anomalies and periodontitis has not been documented by earlier studies. Although psychological factors have been implicated in the etiopathogenesis of periodontitis, very little information has so far been published about the association of anxiety and depression with aggressive periodontitis. The aim of this study was to investigate the association of chronic periodontitis and aggressive periodontitis with certain systemic manifestations and dental anomalies.</p> <p><b>Methods</b></p> <p>A total of 262 patients (100 chronic periodontitis, 81 aggressive periodontitis and 81 controls), attending the Periodontology clinics at Jordan University of Science and Technology, Dental Teaching Centre) were included. All subjects had a full periodontal and radiographic examination to assess the periodontal condition and to check for the presence of any of the following dental anomalies: dens invaginatus, dens evaginatus, congenitally missing lateral incisors or peg-shaped lateral incisors. Participants were interrogated regarding the following: depressive mood, fatigue, weight loss, or loss of appetite; and their anxiety and depression status was assessed using the Hospital Anxiety and Depression (HAD) scale.</p> <p><b>Results</b></p> <p>Patients with aggressive periodontitis reported more systemic symptoms (51%) than the chronic periodontitis (36%) and control (30%) patients (<it>p </it>< 0.05). Aggressive periodontitis patients had a higher tendency for both anxiety and depression than chronic periodontitis and control patients. Dental anomalies were significantly (<it>p </it>< 0.05) more frequent among both of chronic and aggressive periodontitis patients (15% and 16%, respectively), compared to controls.</p> <p><b>Conclusion</b></p> <p>In this group of Jordanians, systemic symptoms were strongly associated with aggressive periodontitis, and dental anomalies were positively associated with both aggressive and chronic periodontitis.</p
    • …
    corecore