4,740 research outputs found
First demonstration of effective spatial training for near-transfer to spatial performance and far-transfer to a range of mathematics skills at 8 years
There is evidence that spatial thinking is malleable, and that spatial and mathematical skills are associated (Mix et al. [2016] Journal of Experimental Psychology: General, 145, 1206; Mix et al. [2017] Journal of Cognition and Development, 18, 465; Uttal et al. [2013] Psychological Bulletin, 139, 352). However, few studies have investigated transfer of spatial training gains to mathematics outcomes in children, and no known studies have compared different modes of spatial instruction (explicit vs. implicit instruction). Based on a sample of 250 participants, this study compared the effectiveness of explicit and implicit spatial instruction in eliciting near transfer (to the specific spatial skills trained), intermediate transfer (to untrained spatial skills) and far transfer (to mathematics domains) at age 8. Spatial scaling and mental rotation skills were chosen as training targets as previous studies have found, and proposed explanations for, associations between these skills and mathematics in children of this age (Journal of Experimental Psychology: General, 145, 2016 and 1206). In this study, spatial training led to near, intermediate and far transfer of gains. Mental visualization and proportional reasoning were proposed to explain far transfer from mental rotation and spatial scaling skills respectively. For most outcomes, except for geometry, there was no difference in the effectiveness of implicit (practice with feedback) compared to explicit instruction (instructional videos). From a theoretical perspective, the study identified a specific causal effect of spatial skills on mathematics skills in children. Practically, the results also highlight the potential of instructional videos as a method of introducing spatial thinking into the classroom
Portfolio Management - The key to successful business - A longitudinal case study of a construction company
Title Portfolio Management - The key to successful business A case study of a construction company Authors Britta Ek Thomas - Master of Science in Technology Management Filip Eliasson - Master of Science in Biotechnology Engineering with Technology Management Elin Skoghagen - Master of Science in Technology Management Advisors Charlotta Johnsson, Associate Professor Department of Automatic Control, Faculty of Engineering, Lund University Thomas Kalling, Professor Institute of Economic Research, Lund School of Economics and Management, Lund University Supervisor A, Product Manager The Mother Company Supervisor B, Director of Product Development The Mother Company Issue of Study Managing product portfolios in today’s business environment is highly complex; there are a number of orthogonal dimensions to consider in order to be successful. Theories within the area of portfolio management are often single tracked and lack the comprehensive picture of what vital aspects to consider to achieve portfolio management excellence. Purpose The purpose of the study is to increase the understanding of the mechanisms impacting portfolio management in an increasingly complex competitive and corporate environment. Methodology A longitudinal case study was chosen as research design since the authors aimed for a thorough and deep understanding of the case company’s strategic portfolio management over time. Initially, a literature review was conducted to increase the knowledge of portfolio management and the surrounding context of internal processes and the external environment. The chosen theories; portfolio management theory, PESTLE, Porter’s five forces, Porter’s generic strategies, Resource-based view and strategy process theory, were then composed into a unique theoretical framework. In the next step, empirical data from the case company was gathered through interviews, questionnaires, databases, observations and following of relevant employees. Finally, the theoretical framework and empirical conclusions were synchronized by using pattern matching. The conclusions drawn resulted in an increased understanding of the mechanisms impacting portfolio management in an increasingly complex competitive and corporate environment. The findings were visualized in Cheez - a generic portfolio management framework applicable in acquisition focused, capital and technology intensive industry companies operating within multinational B2B contexts. Conclusion The output of the study accentuates an amplified importance of internal company-specific processes, intrinsic barriers and driving forces to consider when managing product portfolios in an increasingly complex competitive and corporate environment. Further, deep understanding of the company’s internal and external market environment is required. Depending on the company’s portfolio management prerequisites, different aspects of the environment and the corporate processes have to been considered when striving for enhanced portfolio performance. To visualize the logic of the impacting mechanisms, the generic portfolio management framework Cheez has been developed, applicable on acquisition focused, capital and technology intensive industry companies operating within multinational B2B contexts
Functional consequences of subunit diversity in RNA polymerases II and V
SummaryMultisubunit RNA polymerases IV and V (Pol IV and Pol V) evolved as specialized forms of Pol II that mediate RNA-directed DNA methylation (RdDM) and transcriptional silencing of transposons, viruses, and endogenous repeats in plants. Among the subunits common to Arabidopsis thaliana Pols II, IV, and V are 93% identical alternative ninth subunits, NRP(B/D/E)9a and NRP(B/D/E)9b. The 9a and 9b subunit variants are incompletely redundant with respect to Pol II; whereas double mutants are embryo lethal, single mutants are viable, yet phenotypically distinct. Likewise, 9a or 9b can associate with Pols IV or V but RNA-directed DNA methylation is impaired only in 9b mutants. Based on genetic and molecular tests, we attribute the defect in RdDM to impaired Pol V function. Collectively, our results reveal a role for the ninth subunit in RNA silencing and demonstrate that subunit diversity generates functionally distinct subtypes of RNA polymerases II and V
Nanomechanical IR spectroscopy for fast analysis of liquid-dispersed engineered nanomaterials
AbstractThe proliferated use of engineered nanomaterials (ENMs), e.g. in nanomedicine, calls for novel techniques allowing for fast and sensitive analysis of minute samples. Here we present nanomechanical IR spectroscopy (NAM-IR) for chemical analysis of picograms of ENMs. ENMs are nebulized directly from dispersion and efficiently collected on nanomechanical string resonators through a non-diffusion limited sampling method. Even very small amounts of sample can convert absorbed IR light into a measurable frequency detuning of the string through photothermal heating. An IR absorption spectrum is thus readily obtained by recording this detuning of the resonator over a range of IR wavelengths. Results recorded using NAM-IR agree well with corresponding results obtained through ATR-FTIR, and remarkably, measurement including sample preparation takes only a few minutes, compared to ∼2 days sample preparation for ATR-FTIR. Resonator dimensions play an important role in NAM-IR, a relationship which will be elaborated here
The Entomopathogenic Fungal Endophytes Purpureocillium lilacinum (Formerly Paecilomyces lilacinus) and Beauveria bassiana Negatively Affect Cotton Aphid Reproduction under Both Greenhouse and Field Conditions
The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus), were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae), through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum) were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA) media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i) the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii) subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii) that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of using these endophytes for the biological control of aphids and other herbivores under greenhouse and field conditions
Gradient nonlinearity correction to improve apparent diffusion coefficient accuracy and standardization in the american college of radiology imaging network 6698 breast cancer trial
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113725/1/jmri24883.pd
Maternal neurofascin-specific autoantibodies bind to structures of the fetal nervous system during pregnancy, but have no long term effect on development in the rat
Neurofascin was recently reported as a target for axopathic autoantibodies in patients with multiple sclerosis (MS), a response that will exacerbate axonal pathology and disease severity in an animal model of multiple sclerosis. As transplacental transfer of maternal autoantibodies can permanently damage the developing nervous system we investigated whether intrauterine exposure to this neurofascin-specific response had any detrimental effect on white matter tract development. To address this question we intravenously injected pregnant rats with either a pathogenic anti-neurofascin monoclonal antibody or an appropriate isotype control on days 15 and 18 of pregnancy, respectively, to mimic the physiological concentration of maternal antibodies in the circulation of the fetus towards the end of pregnancy. Pups were monitored daily with respect to litter size, birth weight, growth and motor development. Histological studies were performed on E20 embryos and pups sacrificed on days 2, 10, 21, 32 and 45 days post partum. Results: Immunohistochemistry for light and confocal microscopy confirmed passively transferred anti-neurofascin antibody had crossed the placenta to bind to distinct structures in the developing cortex and cerebellum. However, this did not result in any significant differences in litter size, birth weight, or general physical development between litters from control mothers or those treated with the neurofascin-specific antibody. Histological analysis also failed to identify any neuronal or white matter tract abnormalities induced by the neurofascin-specific antibody. Conclusions: We show that transplacental transfer of circulating anti-neurofascin antibodies can occur and targets specific structures in the CNS of the developing fetus. However, this did not result in any pre- or post-natal abnormalities in the offspring of the treated mothers. These results assure that even if anti-neurofascin responses are detected in pregnant women with multiple sclerosis these are unlikely to have a negative effect on their children
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