418 research outputs found
“The great source” microplastic abundance and characteristics along the river Thames
This study focused on quantifying the abundance of microplastics within the surface water of the River Thames, UK. Ten sites in eight areas were sampled within the tidal Thames, starting from Teddington and ending at Southend-on-Sea. Three litres of water was collected monthly at high tide from land-based structures from each site from May 2019 to May 2021. Samples underwent visual analysis for microplastics categorised based on type, colour and size. 1041 pieces were tested using Fourier transform spectroscopy to identify chemical composition and polymer type. 6401 pieces of MP were found during sampling with an average MP of 12.27 pieces L⁻¹ along the river Thames. Results from this study show that microplastic abundance does not increase along the river
TOPS++FATCAT: Fast flexible structural alignment using constraints derived from TOPS+ Strings Model
<p>Abstract</p> <p>Background</p> <p>Protein structure analysis and comparison are major challenges in structural bioinformatics. Despite the existence of many tools and algorithms, very few of them have managed to capture the intuitive understanding of protein structures developed in structural biology, especially in the context of rapid database searches. Such intuitions could help speed up similarity searches and make it easier to understand the results of such analyses.</p> <p>Results</p> <p>We developed a TOPS++FATCAT algorithm that uses an intuitive description of the proteins' structures as captured in the popular TOPS diagrams to limit the search space of the aligned fragment pairs (AFPs) in the flexible alignment of protein structures performed by the FATCAT algorithm. The TOPS++FATCAT algorithm is faster than FATCAT by more than an order of magnitude with a minimal cost in classification and alignment accuracy. For beta-rich proteins its accuracy is better than FATCAT, because the TOPS+ strings models contains important information of the parallel and anti-parallel hydrogen-bond patterns between the beta-strand SSEs (Secondary Structural Elements). We show that the TOPS++FATCAT errors, rare as they are, can be clearly linked to oversimplifications of the TOPS diagrams and can be corrected by the development of more precise secondary structure element definitions.</p> <p>Software Availability</p> <p>The benchmark analysis results and the compressed archive of the TOPS++FATCAT program for Linux platform can be downloaded from the following web site: <url>http://fatcat.burnham.org/TOPS/</url></p> <p>Conclusion</p> <p>TOPS++FATCAT provides FATCAT accuracy and insights into protein structural changes at a speed comparable to sequence alignments, opening up a possibility of interactive protein structure similarity searches.</p
Private Equity Minority Investments in Large Family Firms: What Influences the Attitude of Family Firm Owners?
This paper extends research in the field of private equity investments in family firms. It contributes to the literature by fundamentally analyzing the decision criteria of family firm owners for using minority investments of private equity investors. This type of financing might be of great interest to family firms, as the family firm owner is able to secure majority ownership and control over the family business. Likewise, minority investments might be attractive for private equity investors, as they are mostly not leveraged and therefore independent from capital market turbulences. Using data from 21 case studies, we identify challenges induced by the family or the business that lead to the phenomenon of private equity minority investments in family firms. We find that perceived benefits and drawbacks of private equity investments are influenced by business and family characteristics. Based on pecking-order theory, resource-based view and the strategy paradigm, propositions as well as a conceptual framework are developed
Evolutionary Views on Entrepreneurial Processes: Managerial and Policy Implications
In this paper we outline an evolutionary framework of entrepreneurial processes where by firms are started, grow, and exit from the market. We explain the important of such a framework in explaining both what contextual factor affects entrepreneurial processes and in explaining the distinction and interaction between self-employment and high-potential entrepreneurship. We highlight the implications from prior empirical work using this evolutionary framework for management and policy making: Three broad implications relevant for managers and entrepreneurs interested in understanding how they can leverage their chances to position their firms as ripe for growth, and six detailed implications relevant for policy makers interested in understanding and affecting the structural conditions where by entrepreneurship can lead to enhanced growth and job creation
The Importance of Equity Finance for R&D Activity – Are There Differences Between Young and Old Companies?
This paper analyzes the importance of equity finance for the R&D activity of small and medium-sized enterprises. We use information on almost 6000 German SMEs from a company survey. Using the intensity of banking competition at the district level as instrument to control for endogeneity, we find that a higher equity ratio is conducive to more R&D for young but not for old companies. Equity may be a constraining factor for young companies which have to rely on the original equity investment of their owners since they have not yet accumulated retained earnings and can relay less on outside financing. The positive influence is found for R&D intensity but not for the decision whether to perform R&D. Equity financing is therefore especially important for the most innovative, young companies
Post-Translational Modifications and Lipid Binding Profile of Insect Cell-Expressed Full-Length Mammalian Synaptotagmin 1
ABSTRACT: Synaptotagmin 1 (Syt1) is a Ca2+ sensor for SNARE-mediated, Ca2+-triggered synaptic vesicle fusion in neurons. It is composed of luminal, transmembrane, linker, and two Ca2+-binding (C2) domains. Here we describe expression and purification of full-length mammalian Syt1 in insect cells along with an extensive biochemical characterization of the purified protein. The expressed and purified protein is properly folded and has increased α-helical content compared to the C2AB fragment alone. Post-translational modifications of Syt1 were analyzed by mass spectrometry, revealing the same modifications of Syt1 that were previously described for Syt1 purified from brain extract or mammalian cell lines, along with a novel modification of Syt1, tyrosine nitration. A lipid binding screen with both full-length Syt1 and the C2AB fragments of Syt1 and Syt3 isoforms revealed new Syt1−lipid interactions. These results suggest a conserved lipid binding mechanism in which Ca2+-independent interactions are mediated via a lysine rich region of the C2B domain while Ca2+-dependent interactions are mediated via the Ca2+-binding loops
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