The Universal Cloud and Aerosol Sounding System (UCASS): a low-cost miniature optical particle counter for use in dropsonde or balloon-borne sounding systems

© Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License. An earlier version of this work was published in Atmospheric Measurement Techniques Discussions: https://dx.doi.org/10.5194/amt-2019-70.A low-cost miniaturized particle counter has been developed by The University of Hertfordshire (UH) for the measurement of aerosol and droplet concentrations and size distributions. The Universal Cloud and Aerosol Sounding System (UCASS) is an optical particle counter (OPC), which uses wide-angle elastic light scattering for the high-precision sizing of fluid-borne particulates. The UCASS has up to 16 configurable size bins, capable of sizing particles in the range 0.4–40 µm in diameter. Unlike traditional particle counters, the UCASS is an open-geometry system that relies on an external air flow. Therefore, the instrument is suited for use as part of a dropsonde, balloon-borne sounding system, as part of an unmanned aerial vehicle (UAV), or on any measurement platform with a known air flow. Data can be logged autonomously using an on-board SD card, or the device can be interfaced with commercially available meteorological sondes to transmit data in real time. The device has been deployed on various research platforms to take measurements of both droplets and dry aerosol particles. Comparative results with co-located instrumentation in both laboratory and field settings show good agreement for the sizing and counting ability of the UCASS.Peer reviewe

SUMO-1 possesses DNA binding activity

<p>Abstract</p> <p>Background</p> <p>Conjugation of small ubiquitin-related modifiers (SUMOs) is a frequent post-translational modification of proteins. SUMOs can also temporally associate with protein-targets via SUMO binding motifs (SBMs). Protein sumoylation has been identified as an important regulatory mechanism especially in the regulation of transcription and the maintenance of genome stability. The precise molecular mechanisms by which SUMO conjugation and association act are, however, not understood.</p> <p>Findings</p> <p>Using NMR spectroscopy and protein-DNA cross-linking experiments, we demonstrate here that SUMO-1 can specifically interact with dsDNA in a sequence-independent fashion. We also show that SUMO-1 binding to DNA can compete with other protein-DNA interactions at the example of the regulatory domain of Thymine-DNA Glycosylase and, based on these competition studies, estimate the DNA binding constant of SUMO1 in the range 1 mM.</p> <p>Conclusion</p> <p>This finding provides an important insight into how SUMO-1 might exert its activity. SUMO-1 might play a general role in destabilizing DNA bound protein complexes thereby operating in a bottle-opener way of fashion, explaining its pivotal role in regulating the activity of many central transcription and DNA repair complexes.</p

Neoliberalism and University Education in Sub-Saharan Africa

This article reviews the history of university development in Sub-Saharan Africa (SSA) and discusses the impact of neoliberal policies. This will be followed by an examination of the problems facing universities in the region. The following questions will be explored: (a) Are the existing universities in SSA serving the development needs of the region? (b) Are these universities up to the task of moving SSA out of the predicaments it faces such as famine, HIV/AIDS, poverty, diseases, debt, and human rights abuses? Finally, the article argues that for universities to play a role in the development of the region, a new paradigm that makes university education a public good should be established

Investigating the potential of novel nonwoven fabrics for efficient pollination control in plant breeding

Plant breeding is achieved through the controlled self- or cross-pollination of individuals and typically involves isolation of floral parts from selected parental plants. Paper, cellulose or synthetic materials are used to avoid self pollination or cross contamination. Low seed set limits the rate of breeding progress and increases costs. We hypothesized that a novel ‘nonwoven’ fabric optimal for both pollination and seed set in multiple plant species could be developed. After determining the baseline pollen characteristics and usage requirements we established iterative three phase development and biological testing. This determined (1) that white fabric gave superior seed return and informed the (2) development of three non-woven materials using different fibre and layering techniques. We tested their performance in selfing and hybridisation experiments recording differences in performance by material type within species. Finally we (3) developed further advanced fabrics with increased air permeability and tested biological performance. An interaction between material type and species was observed and environmental decoupling investigated, showing that the non-woven fabrics had superior water vapour transmission and temperature regulation compared to controls. Overall, non-woven fabrics outperformed existing materials for both pollination and seed set and we found that different materials can optimize species-specific, rather than species-generic performance

Complex SUMO-1 Regulation of Cardiac Transcription Factor Nkx2-5

Reversible post-translational protein modifications such as SUMOylation add complexity to cardiac transcriptional regulation. The homeodomain transcription factor Nkx2-5/Csx is essential for heart specification and morphogenesis. It has been previously suggested that SUMOylation of lysine 51 (K51) of Nkx2-5 is essential for its DNA binding and transcriptional activation. Here, we confirm that SUMOylation strongly enhances Nkx2-5 transcriptional activity and that residue K51 of Nkx2-5 is a SUMOylation target. However, in a range of cultured cell lines we find that a point mutation of K51 to arginine (K51R) does not affect Nkx2-5 activity or DNA binding, suggesting the existence of additional Nkx2-5 SUMOylated residues. Using biochemical assays, we demonstrate that Nkx2-5 is SUMOylated on at least one additional site, and this is the predominant site in cardiac cells. The second site is either non-canonical or a “shifting” site, as mutation of predicted consensus sites and indeed every individual lysine in the context of the K51R mutation failed to impair Nkx2-5 transcriptional synergism with SUMO, or its nuclear localization and DNA binding. We also observe SUMOylation of Nkx2-5 cofactors, which may be critical to Nkx2-5 regulation. Our data reveal highly complex regulatory mechanisms driven by SUMOylation to modulate Nkx2-5 activity

Uncovering Ubiquitin and Ubiquitin-like Signaling Networks

Microscopic imaging and technolog