Modification of narrow‐spectrum peptidomimetic polyurethanes with fatty acid chains confers broad‐spectrum antibacterial activity

Each year, thousands of patients die from antimicrobial‐resistant bacterial infections that fail to respond to conventional antibiotic treatment. Antimicrobial polymers are a promising new method of combating antibiotic‐resistant bacterial infections. We have previously reported the synthesis of a series of narrow‐spectrum peptidomimetic antimicrobial polyurethanes that are effective against Gram‐negative bacteria, such as Escherichia coli; however, these polymers are not effective against Gram‐positive bacteria, such as Staphylococcus aureus. With the aim of understanding the correlation between chemical structure and antibacterial activity, we have subsequently developed three structural variants of these antimicrobial polyurethanes using post‐polymerization modification with decanoic acid and oleic acid. Our results show that such modifications converted the narrow‐spectrum antibacterial activity of these polymers into broad‐spectrum activity against Gram‐positive species such as S. aureus, however, also increasing their toxicity to mammalian cells. Mechanistic studies of bacterial membrane disruption illustrate the differences in antibacterial action between the various polymers. The results demonstrate the challenge of balancing antimicrobial activity and mammalian cell compatibility in the design of antimicrobial polymer compositions. © 2019 Society of Chemical Industry     

Hydromorphological,hydraulic and ecological effects of restored wood: findings and reflections from an academic partnership approach

Large wood (re)introduction can deliver multiple benefits in river restoration, but there is a dearth of the detailed and longer‐term post‐project monitoring and evaluation required for improving best practice. We present findings from an academic partnership approach to post‐project evaluation, based on successive MSc research projects on restored large wood in the Loddon catchment, UK. Field and modelling data reveal: (i) key differences in large wood features between restored and natural reaches; (ii) increased hydraulic retention and changes to mesohabitats associated with large wood; (iii) differences in macroinvertebrate community composition around large wood but a lack of site‐level effects; (iv) interactions between macrophytes and large wood that may be specific to restored reaches; (v) a need for further field and modelling studies to inform the accurate representation of large wood in hydraulic models. Some key challenges in partnership working are identified to aid planning and effectiveness of future collaborations.     

Herd life,lifetime production,and profitability of Viking Red-sired and Montbéliarde-sired crossbred cows compared with their Holstein herdmates

The first 2 generations from a 3-breed rotation of the Viking Red (VR), Montbéliarde (MO), and Holstein (HO) breeds were compared with their HO herdmates in high-performance commercial herds in Minnesota. The designed study enrolled pure HO females in 2008 to initiate a comparison of 3-breed rotational crossbreds with their HO herdmates. Sires of cows were proven artificial insemination bulls selected for high genetic merit in each of the 3 breeds. The first-generation cows calved for a first time from 2010 to 2014 and had 376 VR × HO and 358 MO × HO crossbreds to compare with their 640 HO herdmates. The second-generation cows calved for a first time from 2012 to 2014 and had 109 VR × MO/HO and 117 MO × VR/HO crossbreds to compare with their 250 HO herdmates. Collection of data ceased on December 31, 2017, and all cows studied had the opportunity for 45 mo in the herd after first calving. Production of milk, fat, and protein (kg) during lifetimes of cows was estimated from test-day observations with best prediction. The lifetime profit function included revenue and cost. Revenue was from production, calves, and slaughter of cull cows. Costs included feed cost during lactation, lactating overhead cost, dry cow cost (including feed cost during dry periods), replacement cost, health treatment cost, insemination cost, fertility hormone cost, pregnancy diagnosis cost, hoof trimming cost, and carcass disposal cost. For individual cows with herd life longer than 45 mo after first calving, survival of cows was projected beyond 45 mo after first calving to estimate herd life, production, and profitability. The 2-breed crossbreds had +158 d longer herd life and the 3-breed crossbreds had +147 d longer herd life compared with their respective HO herdmates. Also, 12.4% of the 2-breed crossbreds died up to 45 mo after first calving compared with 16.3% of their HO herdmates. Furthermore, approximately 29% of both the 2-breed and 3-breed crossbreds lived beyond 45 mo after first calving compared with approximately 18% of their respective HO herdmates. On a lifetime basis, the 2-breed and 3-breed crossbreds provided +$122 and +$134, respectively, more cull cow revenue compared with their HO herdmates. For lifetime replacement cost, the 2-breed crossbreds did not differ from their HO herdmates; however, the 3-breed crossbreds had ?$28 less lifetime replacement cost compared with their HO herdmates because of their younger age at first calving. The combined 2-breed crossbreds had +$0.473 (+13%) more daily profit (ignoring potential differences for feed efficiency) and the combined 3-breed crossbreds had +$0.342 (+9%) more daily profit compared with their respective HO herdmates. This resulted in +$173 more profit/cow annually for the combined 2-breed crossbreds and +$125 more profit/cow annually for the combined 3-breed crossbreds compared with their respective HO herdmates.     

Usability assessment of text-to-speech synthesis for additional detail in an automated telephone banking system

This paper describes a comprehensive usability evaluation of an automated telephone banking system which employs text-to-speech (TTS) synthesis in offering additional detail on customers’ account transactions. The paper describes a series of four experiments in which TTS was employed to offer an extra level of detail to recent transactions listings within an established banking service which otherwise uses recorded speech from a professional recording artist. Results from the experiments show that participants welcome the added value of TTS in being able to provide additional detail on their account transactions, but that TTS should be used minimally in the service.     

Deconstructing disaster: Psycho-social impact of building deconstruction in Post-Katrina New Orleans

This phenomenological study inquired into the psycho-social impact of building deconstruction in disaster response. Nine building owners participating in a Mercy Corps’ sponsored building deconstruction program in Post-Katrina New Orleans (2005–2008), engaged in extensive interviews about their experience. The core phenomenon they shared was empowerment arising from a synthesis of positive social interaction and material discovery. Dedicated, local, Mercy Corps trained contractors brought immediate relief to these distressed participants by facilitating “a dignified end” to their buildings and by proxy to the lives they held before the catastrophe. Deconstruction allowed participants to reclaim wealth that would have been scrapped for landfill waste by federal mandate. Participants reported a sudden psychological shift from despair to enthusiasm as they regained control of their property and then discovered value out of the ruined buildings. Data indicated that merely possessing reclaimed material did not explain the psychological transformation. Four of nine informants (including impoverished individuals) experienced psychological transformation by giving all of their reclaimed material away. The sharing of material was described as akin to “donating organs” giving life to their critically injured community. Data indicated the program also promoted more environmentally sustainable behavior. Previously, deconstruction has only been addressed in terms of technical, mechanical, economic, or environmental outcomes. This study adds a new component by seeing the human side of that technical process. This report is a companion study to another; Deconstructing Disaster; Economic and Environmental Impacts of Deconstruction in Post-Katrina New Orleans, which provides a quantitative analysis of material salvage from the Mercy Corps program.     

Crystallization of poly(3‐hydroxybutyrate) by exfoliated graphite nanoplatelets

Poly(3‐hydroxybutyrate) (PHB) has been shown to be efficiently nucleated by exfoliated graphite nanoplatelets (xGnP). The nucleating effect of xGnP was investigated using differential scanning calorimetry, optical microscopy and atomic force microscopy. Nonisothermal crystallization of PHB from the melt required lower activation energies for PHB containing 1 wt % and 3 wt % xGnP (?214 and ?102 kJ/mol respectively) than for pure PHB (?60 kJ/mol). A kinetic study of the PHB/xGnP crystallization employing a modified form of the Avrami equation revealed that the presence of xGnP increased the PHB crystallization temperature, as well as the crystallization rates, and generated smaller and more numerous spherulites. Optical microscopy and atomic force microscopy confirmed the incorporation of xGnP into the lamellar structure of the PHB spherulites and provided insight into the influence of xGnP on spherulite size and lamellae thickness. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Identification of platinum and palladium particles emitted from vehicles and dispersed into the surface environment

Platinum, palladium, and rhodium are emitted from vehicle catalytic converters. Until now, the form of precious metal particles in road dust and urban waste has not been identified. This study has located, imaged, and analyzed these particles in road dust and gully waste. Two fragments of catalytic converter have been observed in road dust. They are 40-80 μm in size and covered in many minute particles (<0.3 μm) of either platinum with minor rhodium or palladium. One fragment identified in gully sediment is smaller, 25 μm in diameter, hosting only one attached particle of palladium with minor rhodium. As fragments are washed off roads they begin to disintegrate and the precious metals become detached. Also precious metal-bearing particles have been located in incinerated sewage ash including a 20 μm diameter cluster of <3 μm sized platinum particles that may be the remains of a catalytic converter fragment that has survived incineration. The form of these precious metal-bearing particles described here reveals that as they are dispersed from roads they are likely to be present predominantly as two particle sizes. Either they are attached to larger fragments of catalytic converter or they are released as individual detached tiny <0.3 μm to nanoparticle sizes.     

How does cognitive therapy prevent relapse in residual depression? Evidence from a controlled trial.

This study examined the cognitive mediation of relapse prevention by cognitive therapy (CT) in a trial of 158 patients with residual depression. Scores based on agreement with item content of 5 questionnaires of depression-related cognition provided no evidence for cognitive mediation. A measure of the form of response to those questionnaires, the number of times patients used extreme response categories ("totally agree" and "totally disagree"), showed significant and substantial prediction of relapse, differential response to CT, and conformity to mediational criteria. CT reduced relapse through reductions in absolutist, dichotomous thinking style. CT may prevent relapse by training patients to change the way that they process depression-related material rather than by changing belief in depressive thought content. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Food allergy,a summary of eight cases in the UK criminal and civil courts: effective last resort for vulnerable consumers?

Food allergy has a forensic context. The authors describe eight cases in the UK courts involving fatalities, personal injury or criminal non‐compliance with food law from mainly ‘grey’ literature sources. The potentially severe consequences for people with food allergy of contraventions of labelling law have led to enforcement action up to criminal prosecution for what might otherwise be regarded as ‘trivial’ non‐compliance. The authors suggest there should be central collation of such cases. Non‐compliances should be followed up in a more rapid and robust manner. Evidence of fraud in the catering supply chain supports recent calls for zero tolerance of food fraud. Businesses must guard against gaps in allergen management, for which there are readily available sources of training and guidance, but also against fraudulent substitution in the supply chain, about which training and guidance should be developed. New allergen labelling legislation and case law appear to place responsibility on food businesses even for the forensically problematic area of allergen cross‐contamination. The courts can be an effective last resort for vulnerable consumers; however, there is evidence of knowledge and skill gaps in both the investigation and prosecution of potentially serious incidents of food allergen mismanagement and mislabelling. Thorough investigation of food allergy deaths is required with a tenacious and skilled approach, including early realisation that samples of the food and/or stomach contents from a post mortem examination should be retained and analysed. The supply chain must be rigorously examined to find out where adulteration or contamination with the fatal allergen occurred. © 2014 Society of Chemical Industry