A Langmuir approach on monolayer interactions to investigate surface active peptides

The Langmuir Blodgett apparatus provides a versatile system for studying the interfacial properties of peptides and peptide-membrane interactions under controlled conditions. Using amphiphilic α-helical peptides to highlight studies undertaken, here we discuss the use of this system to provide information on the surface activity of peptides and describe the insights these studies give into biological functio

The nature of emotional support and counselling provision for people with sight loss in the United Kingdom

People with sight loss in the United Kingdom are known to have lower levels of emotional wellbeing and to be at higher risk of depression. Consequently ‘having someone to talk to’ is an important priority for people with visual impairment. An on-line survey of the provision of emotional support and counselling for people affected by sight loss across the UK was undertaken. The survey was distributed widely and received 182 responses. There were more services offering ‘emotional support’, in the form of listening and information and advice giving, than offered ‘counselling’. Services were delivered by providers with differing qualifications in a variety of formats. Waiting times were fairly short and clients presented with a wide range of issues. Funding came from a range of sources, but many felt their funding was vulnerable. Conclusions have been drawn about the need for a national standardised framework for the provision of emotional support and counselling services for blind and partially sighted people in the U

A theoretical analysis of secondary structural characteristics of anticancer peptides

Here, cluster analysis showed that a database of 158 peptides formed 21 clusters based on net positive charge, hydrophobicity and amphiphilicity. In general these clusters showed similar median toxicities (p = 0.176) against eukaryotic cell lines and no single combination of these properties was found optimal for efficacy. The database contained 14 peptides, which showed selectivity for tumour cell lines only (ACPCT), 123 peptides with general toxicity to eukaryotic cells (ACPGT) and 21 inactive peptides (ACPI). Hydrophobic arc size analysis showed that there was no significant difference across the datasets. Even though there was no correlation there was no correlation observed, peptides with wide hydrophobic arcs (> 270°) appeared less toxic. Extended hydrophobic moment plot analysis predicted that over 50% of ACPCT and ACPGT peptides would be surface active, which led to the suggestion that amphiphilicity is a key driver of the membrane interactions for these peptides but probably plays a role in their efficacy rather than their selectivity. This analysis also predicted that only 14% of ACPCT peptides compared to 45% of ACPGT peptides were candidates for tilted peptide formation. This implies that those peptides with non-specific activity may have a tendency towards the utilisation of membrane disruptive structures such as tilt peptides which led to the suggestion that the absence of this structure may support cancer cell selectivity. However, these analyses predicted that ACPI peptides, which possess no anticancer activity, would also form surface active and tilted a-helices, clearly showing that other factors are involved in determining the efficacy and selectivity of ACPs

The Dutch aren’t turning against immigration – the salience of the immigration issue is what drives Wilders’ support

The key story in the 2017 Dutch election campaign so far has been the high levels of support for Geert Wilders’ PVV in opinion polls. But what explains the PVV’s ability to attract voters? James Dennison, Andrew Geddes and Teresa Talò write that although Wilders’ success is frequently linked to hardening views on immigration, attitudes toward immigration in the Netherlands have actually remained fairly stable. The real root of the PVV’s support lies in the salience of the immigration issue itself, partially heightened by media coverage of recent increases in the numbers of migrants entering the country

Why immigration has the potential to upend the Italian election

The failure of Marine Le Pen and Geert Wilders to cause an upset in 2017 has prompted some observers to argue that Europe's 'populist right' is now in retreat. But as James Dennison, Andrew Geddes and Matthew Goodwin highlight, the apparent fall in support for anti-immigration populism elsewhere in Europe has not been seen in Italy ahead of the country's general election in March. Immigration has risen from a non-issue to the second most important for Italian voters, and polls have shown growing support for the increasingly anti-immigration Forza Italia and Lega Nord

Photoelectric Charging by Ultraviolet Light of a Lunar Dust Simulant in a Microgravity Environment

A microgravity experiment to test the electrostatic behavior of a lunar dust simulant being charged through the photoelectric effect will expand understanding of the charging characteristics of dust particles and may lead to a possible mitigation solution. With a design based upon Robert Milikan\u27s oil-drop experiment, this experiment is designed to observe the interactions of a lunar dust simulant without the conflicting effects of a dominant gravitational force. The dust particles will be charged by means of a lamp capable of photon energies necessary to emit electrons by the photoelectric effect. In the presence of an axial electric field, the photo-electrons and charged dust will be attracted to opposing sides of a capacitor and the net charge over time as well as physical trajectories of the particles can be determined

Textural Analysis and Substrate Classification in the Nearshore Region of Lake Superior Using High-Resolution Multibeam Bathymetry

University of Minnesota M.S. thesis. September 2017. Major: Earth Sciences. Advisor: Nigel Wattrus. 1 computer file (PDF); xii, 236 pages + 2 supplementary zip files.Classification of the seafloor substrate can be done with a variety of methods. These methods include Visual (dives, drop cameras); mechanical (cores, grab samples); acoustic (statistical analysis of echosounder returns). Acoustic methods offer a more powerful and efficient means of collecting useful information about the bottom type. Due to the nature of an acoustic survey, larger areas can be sampled, and by combining the collected data with visual and mechanical survey methods provide greater confidence in the classification of a mapped region. During a multibeam sonar survey, both bathymetric and backscatter data is collected. It is well documented that the statistical characteristic of a sonar backscatter mosaic is dependent on bottom type. While classifying the bottom-type on the basis on backscatter alone can accurately predict and map bottom-type, i.e a muddy area from a rocky area, it lacks the ability to resolve and capture fine textural details, an important factor in many habitat mapping studies. Statistical processing of high-resolution multibeam data can capture the pertinent details about the bottom-type that are rich in textural information. Further multivariate statistical processing can then isolate characteristic features, and provide the basis for an accurate classification scheme. The development of a new classification method is described here. It is based upon the analysis of textural features in conjunction with ground truth sampling. The processing and classification result of two geologically distinct areas in nearshore regions of Lake Superior; off the Lester River,MN and Amnicon River, WI are presented here, using the Minnesota Supercomputer Institute's Mesabi computing cluster for initial processing. Processed data is then calibrated using ground truth samples to conduct an accuracy assessment of the surveyed areas. From analysis of high-resolution bathymetry data collected at both survey sites is was possible to successfully calculate a series of measures that describe textural information about the lake floor. Further processing suggests that the features calculated capture a significant amount of statistical information about the lake floor terrain as well. Two sources of error, an anomalous heave and refraction error significantly deteriorated the quality of the processed data and resulting validate results. Ground truth samples used to validate the classification methods utilized for both survey sites, however, resulted in accuracy values ranging from 5 -30 percent at the Amnicon River, and between 60-70 percent for the Lester River. The final results suggest that this new processing methodology does adequately capture textural information about the lake floor and does provide an acceptable classification in the absence of significant data quality issues