732 research outputs found

    Decomposing Dual Scale Soil Surface Roughness for Microwave Remote Sensing Applications

    Get PDF
    Soil surface roughness, as investigated in this study, is decomposed in a dual scale process. Therefore, we investigated photogrammetrically acquired roughness information over different agricultural fields in the size of 6-22 m(2) and decomposed them into a dual scale process by using geostatistical techniques. For the characterization of soil surface roughness, we calculated two different roughness indices (the RMS height s and the autocorrelation length l) differing significantly for each scale. While we could relate the small scale roughness pattern clearly to the seedbed rows, the larger second scale pattern could be related to the appearance of wheel tracks of the tillage machine used. As a result, major progress was made in the understanding of the different scales in soil surface roughness characterization and its quantification possibilities

    Study of temperature-growth interactions of entomopathogenic fungi with potential for control of Varroa destructor (Acari: Mesostigmata) using a nonlinear model of poikilotherm development

    Get PDF
    Aims: To investigate the thermal biology of entomopathogenic fungi being examined as potential microbial control agents of Varroa destructor , an ectoparasite of the European honey bee Apis mellifera . Methods and Results: Colony extension rates were measured at three temperatures (20, 30 and 35degreesC) for 41 isolates of entomopathogenic fungi. All of the isolates grew at 20 and 30degreesC but only 11 isolates grew at 35degreesC. Twenty-two isolates were then selected on the basis of appreciable growth at 30-35degreesC (the temperature range found within honey bee colonies) and/or infectivity to V. destructor , and their colony extension rates were measured at 10 temperatures (12.5-35degreesC). This data were then fitted to Schoolfield et al . [J Theor Biol (1981)88:719-731] re-formulation of the Sharpe and DeMichele [J Theor Biol (1977)64:649-670] model of poikilotherm development. Overall, this model accounted for 87.6-93.9% of the data variance. Eleven isolates exhibited growth above 35degreesC. The optimum temperatures for extension rate ranged from 22.9 to 31.2degreesC. Only three isolates exhibited temperature optima above 30degreesC. The super-optimum temperatures (temperature above the optimum at which the colony extension rate was 10% of the maximum rate) ranged from 31.9 to 43.2degreesC. Conclusions: The thermal requirements of the isolates examined against V. destructor are well matched to the temperatures in the broodless areas of honey bee colonies, and a proportion of isolates, should also be able to function within drone brood areas. Significance and Impact of the Study: Potential exists for the control of V. destructor with entomopathogenic fungi in honey bee colonies. The methods employed in this study could be utilized in the selection of isolates for microbial control prior to screening for infectivity and could help in predicting the activity of a fungal control agent of V. destructor under fluctuating temperature conditions

    Microbial biopesticides for integrated crop management : an assessment of environmental and regulatory sustainability

    Get PDF
    Herbivorous insects and mites, plant diseases and weeds are major impediments to the production of food crops and are increasingly difficult to control with conventional chemicals. This paper focuses on microbial control agents with an emphasis on augmentation. There are marked differences in the availability of products in different countries which can be explained in terms of differences in their regulatory systems. Regulatory failure arises from the application of an inappropriate synthetic pesticides model. An understanding of regulatory innovation is necessary to overcome these problems. Two attempts at remedying regulatory failure in the UK and the Netherlands are assessed. Scientific advances can feed directly into the regulatory process and foster regulatory innovation

    The acute transcriptome response of the midbrain/diencephalon to injury in the adult mummichog (\u3cem\u3eFundulus heteroclitus\u3c/em\u3e)

    Get PDF
    Adult fish produce new cells throughout their central nervous system during the course of their lives and maintain a tremendous capacity to repair damaged neural tissue. Much of the focus on understanding brain repair and regeneration in adult fish has been directed at regions of the brainstem and forebrain; however, the mesencephalon (midbrain) and diencephalon have received little attention. We sought to examine differential gene expression in the midbrain/diencephalon in response to injury in the adult fish using RNA-seq. Using the mummichog (Fundulus heteroclitus), we administered a mechanical lesion to the midbrain/diencephalon and examined differentially expressed genes (DEGs) at an acute recovery time of 1 h post-injury. Comparisons of whole transcriptomes derived from isolated RNA of intact and injured midbrain/diencephalic tissue identified 404 DEGs with the vast majority being upregulated. Using qPCR, we validated the upregulation of DEGs pim-2-like, syndecan-4-like, and cd83. Based on genes both familiar and novel regarding the adult brain response to injury, these data provide an extensive molecular profile giving insight into a range of cellular processes involved in the injury response of a brain regenerative-capable vertebrate

    The acute transcriptome response of the midbrain/diencephalon to injury in the adult mummichog (\u3cem\u3eFundulus heteroclitus\u3c/em\u3e)

    Get PDF
    Adult fish produce new cells throughout their central nervous system during the course of their lives and maintain a tremendous capacity to repair damaged neural tissue. Much of the focus on understanding brain repair and regeneration in adult fish has been directed at regions of the brainstem and forebrain; however, the mesencephalon (midbrain) and diencephalon have received little attention. We sought to examine differential gene expression in the midbrain/diencephalon in response to injury in the adult fish using RNA-seq. Using the mummichog (Fundulus heteroclitus), we administered a mechanical lesion to the midbrain/diencephalon and examined differentially expressed genes (DEGs) at an acute recovery time of 1 h post-injury. Comparisons of whole transcriptomes derived from isolated RNA of intact and injured midbrain/diencephalic tissue identified 404 DEGs with the vast majority being upregulated. Using qPCR, we validated the upregulation of DEGs pim-2-like, syndecan-4-like, and cd83. Based on genes both familiar and novel regarding the adult brain response to injury, these data provide an extensive molecular profile giving insight into a range of cellular processes involved in the injury response of a brain regenerative-capable vertebrate

    Commercials, careers and culture: travelling salesmen in Britain 1890s-1930s

    Get PDF
    Within the lower middle-class, British commercial travellers established a strong fraternal culture before 1914. This article examines their interwar experiences in terms of income, careers, and associational culture. It demonstrates how internal labour markets operated, identifies the ways in which commercial travellers interpreted their role, and explores their social and political attitudes

    Detection of Viruses from Bioaerosols Using Anion Exchange Resin

    Get PDF
    This protocol demonstrates a customized bioaerosol sampling method for viruses. In this system, anion exchange resin is coupled with liquid impingement-based air sampling devices for efficacious concentration of negatively-charged viruses from bioaerosols. Thus, the resin serves as an additional concentration step in the bioaerosol sampling workflow. Nucleic acid extraction of the viral particles is then performed directly from the anion exchange resin, with the resulting sample suitable for molecular analyses. Further, this protocol describes a custom-built bioaerosol chamber capable of generating virus-laden bioaerosols under a variety of environmental conditions and allowing for continuous monitoring of environmental variables such as temperature, humidity, wind speed, and aerosol mass concentration. The main advantage of using this protocol is increased sensitivity of viral detection, as assessed via direct comparison to an unmodified conventional liquid impinger. Other advantages include the potential to concentrate diverse negatively-charged viruses, the low cost of anion exchange resin (~$0.14 per sample), and ease of use. Disadvantages include the inability of this protocol to assess infectivity of resin-adsorbed viral particles, and potentially the need for the optimization of the liquid sampling buffer used within the impinger

    Binge-Like Alcohol Exposure During Adolescence Disrupts Dopaminergic Neurotransmission in the Adult Prelimbic Cortex

    Get PDF
    Repeated binge-like exposure to alcohol during adolescence has been reported to perturb prefrontal cortical development, yet the mechanisms underlying these effects are unknown. Here we report that adolescent intermittent ethanol exposure induces cellular and dopaminergic abnormalities in the adult prelimbic cortex (PrL-C). Exposing rats to alcohol during early-mid adolescence (PD28–42) increased the density of long/thin dendritic spines of layer 5 pyramidal neurons in the adult PrL-C. Interestingly, although AIE exposure did not alter the expression of glutamatergic proteins in the adult PrL-C, there was a pronounced reduction in dopamine (DA) D1 receptor modulation of both intrinsic firing and evoked NMDA currents in pyramidal cells, whereas D2 receptor function was unaltered. Recordings from fast-spiking interneurons also revealed that AIE reduced intrinsic excitability, glutamatergic signaling, and D1 receptor modulation of these cells. Analysis of PrL-C tissue of AIE-exposed rats further revealed persistent changes in the expression of DA-related proteins, including reductions in the expression of tyrosine hydroxylase and catechol-O-methyltransferase (COMT). AIE exposure was associated with hypermethylation of the COMT promoter at a conserved CpG site in exon II. Taken together, these findings demonstrate that AIE exposure disrupts DA and GABAergic transmission in the adult medial prefrontal cortex (mPFC). As DA and GABA work in concert to shape and synchronize neuronal ensembles in the PFC, these alterations could contribute to deficits in behavioral control and decision-making in adults who abused alcohol during adolescence

    Proneness to Guilt, Shame, and Pride in Children with Autism Spectrum Disorders and Neurotypical Children

    Get PDF
    Self‐conscious emotions (e.g., guilt, shame, and pride) are complex emotions that require self‐reflection and self‐evaluation, and are thought to facilitate the maintenance of societal norms and personal standards. Despite the importance of self‐conscious emotions, most research has focused on basic emotion processing in children with Autism Spectrum Disorders (ASD). Therefore, in the present study, we used the Test of Self‐Conscious Affect for Children (TOSCA‐C) to assess proneness to, or propensity to experience, the self‐conscious emotions guilt, shame, and pride in children with ASD and neurotypical children. The TOSCA‐C is designed to capture a child\u27s natural tendency to experience a given emotion across a range of everyday situations [Tangney, Stuewig, & Mashek, 2007]. We also assessed how individual characteristics contribute to the development of proneness to self‐conscious emotions, including theory of mind (ToM) and ASD symptomatology. In comparison to neurotypical children, children with ASD showed less proneness to guilt, although all children showed relatively high levels of proneness to guilt. Greater ToM ability was related to more proneness to guilt and authentic pride in children with ASD. Additionally, we found that children with ASD with more severe symptomatology were more prone to hubristic pride. Our results provide evidence of differences in proneness to self‐conscious emotions in children with ASD, as well as highlight important mechanisms contributing to how children with ASD may experience self‐conscious emotions
    • 

    corecore