Differential cross section for neutron-proton bremsstrahlung

The neutron-proton bremsstrahlung process $(np \to np\gamma)$ is known to be sensitive to meson exchange currents in the nucleon-nucleon interaction. The triply differential cross section for this reaction has been measured for the first time at the Los Alamos Neutron Science Center, using an intense, pulsed beam of up to 700 MeV neutrons to bombard a liquid hydrogen target. Scattered neutrons were observed at six angles between 12$^\circ$ and 32$^\circ$, and the recoil protons were observed in coincidence at 12$^\circ$, 20$^\circ$, and 28$^\circ$ on the opposite side of the beam. Measurement of the neutron and proton energies at known angles allows full kinematic reconstruction of each event. The data are compared with predictions of two theoretical calculations, based on relativistic soft-photon and non-relativistic potential models.Comment: 5 pages, 3 figure

The heme sensing response regulator HssR in Staphylococcus aureus but not the homologous RR23 in Listeria monocytogenes modulates susceptibility to the antimicrobial peptide plectasin

<p>Abstract</p> <p>Background</p> <p>Host defence peptides (HDPs), also known as antimicrobial peptides (AMPs), have emerged as potential new therapeutics and their antimicrobial spectrum covers a wide range of target organisms. However, the mode of action and the genetics behind the bacterial response to HDPs is incompletely understood and such knowledge is required to evaluate their potential as antimicrobial therapeutics. Plectasin is a recently discovered HDP active against Gram-positive bacteria with the human pathogen, <it>Staphylococcus aureus </it>(<it>S. aureus</it>) being highly susceptible and the food borne pathogen, <it>Listeria monocytogenes </it>(<it>L. monocytogenes</it>) being less sensitive. In the present study we aimed to use transposon mutagenesis to determine the genetic basis for <it>S. aureus </it>and <it>L. monocytogenes </it>susceptibility to plectasin.</p> <p>Results</p> <p>In order to identify genes that provide susceptibility to plectasin we constructed bacterial transposon mutant libraries of <it>S. aureus </it>NCTC8325-4 and <it>L. monocytogenes </it>4446 and screened for increased resistance to the peptide. No resistant mutants arose when <it>L. monocytogenes </it>was screened on plates containing 5 and 10 fold Minimal Inhibitory Concentration (MIC) of plectasin. However, in <it>S. aureus</it>, four mutants with insertion in the heme response regulator (<it>hssR</it>) were 2-4 fold more resistant to plectasin as compared to the wild type. The <it>hssR </it>mutation also enhanced resistance to the plectasin-like defensin eurocin, but not to other classes of HDPs or to other stressors tested. Addition of plectasin did not influence the expression of <it>hssR </it>or <it>hrtA</it>, a gene regulated by HssR. The genome of <it>L. monocytogenes </it>LO28 encodes a putative HssR homologue, RR23 (in <it>L. monocytogenes </it>EGD-e lmo2583) with 48% identity to the <it>S. aureus </it>HssR, but a mutation in the <it>rr23 </it>gene did not change the susceptibility of <it>L. monocytogenes </it>to plectasin.</p> <p>Conclusions</p> <p><it>S. aureus </it>HssR, but not the homologue RR23 from <it>L. monocytogenes</it>, provides susceptibility to the defensins plectasin and eurocin. Our data suggest that a functional difference between response regulators HssR and RR23 is responsible for the difference in plectasin susceptibility observed between <it>S. aureus </it>and <it>L. monocytogenes</it>.</p

All Doors Lead to the Kitchen – Sustainability and Wellbeing Challenges in a Shared Centrepiece of Living

The kitchen figures a central place in the home where a significant share of a household’s resource consumption takes place. Sharing the kitchen between multiple households has potential to bring positive sustainability effects due to more efficient use of both material resources and energy. The concept of shared kitchens has, however, thus far had a limited diffusion. This paper explores the potential of shared kitchens as a future sustainable living environment by studying user experiences from a Living Lab setting. It builds the base for an overarching larger European collaboration on how future shared kitchens should be designed in order to support everyday practices while optimising the conditions for achieving positive impact on both sustainability and wellbeing. Findings are presented from five focus areas concerning different use contexts: (1) accessing, (2) cooking, (3) living and socialising, (4) storing, and (5) cleaning

Managing professional jurisdiction and domestic energy use

Professionals involved in organizing and undertaking domestic works, such as extensions, maintenance and refurbishment, have an important role in influencing how homes are configured and how occupants live within them. Despite this, the professional identities of these actors, and their impact on domestic energy use, is often overlooked. In response, this paper argues that one useful way of examining their influence is to consider how professional identities shape everyday working practices in relation to clients. Data from two UK interview and observation studies are combined: one with heating installers and the other with architects. The data are analysed using concepts from Abbott’s ‘system of professions’ framework that focuses on how the routine working practices of professional groups are born of how they see themselves and the tasks for which they are responsible. This comparison provides insights into how these two groups manage their professional ‘jurisdictions’ during their client interactions and what this means for policy-makers and industry representatives hoping to influence their work in pursuit of less carbon-intensive living. It also points to the value of further in-depth studies that explore how the routine management of professional jurisdiction impacts upon domestic energy use in a range of contexts

Would You Help Me Voluntarily for the Next Two Years? Evaluating Psychological Persuasion Techniques in Human-Robot Interaction. First results of an empirical investigation of the door-in-the-face technique in human-robot interaction

Human-robot communication scenarios are becoming increasingly important. In this paper, we investigate the differences between human-human and human-robot communication in the context of persuasive communication. We ran an experiment using the door-in-the-face technique in a hu-manrobot context. In our experiment, participants communicated with a robot that performed the door-in-the-face technique, in which the communicating agent asks for an "extreme" favor first and a for a small favor shortly after to increase affirmative response to the second request. Our results show a surprisingly high acceptance rate for the extreme request and a smaller acceptance rate for the small request compared to the original study of Cialdini et al., so our results differ from the classical human-human door-in-the-face experiments. This suggests that human-robot persuasive communication differs from human-human communication, which is surprising given related work. We discuss potential reasons for our observations and outline the next research steps to answer the question whether the door-in-the-face and similar persuasive techniques would be effective if applied by robots. © 2023 Copyright for this paper by its authors

Recruitment, augmentation and apoptosis of rat osteoclasts in 1,25-(OH)2D3 response to short-term treatment with 1,25-dihydroxyvitamin D3in vivo

Background Although much is known about the regulation of osteoclast (OC) formation and activity, little is known about OC senescence. In particular, the fate of of OC seen after 1,25-(OH)2D3 administration in vivo is unclear. There is evidence that the normal fate of OC is to undergo apoptosis (programmed cell death). We have investigated the effect of short-term application of high dose 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on OC apoptosis in an experimental rat model. Methods OC recruitment, augmentation and apoptosis was visualised and quantitated by staining histochemically for tartrate resistant acid phosphatase (TRAP), double staining for TRAP/ED1 or TRAP/DAPI, in situ DNA fragmentation end labelling and histomorphometric analysis. Results Short-term treatment with high-dose 1,25-(OH)2D3 increased the recruitment of OC precursors in the bone marrow resulting in a short-lived increase in OC numbers. This was rapidly followed by an increase in the number of apoptotic OC and their subsequent removal. The response of OC to 1,25-(OH)2D3 treatment was dose and site dependent; higher doses producing stronger, more rapid responses and the response in the tibiae being consistently stronger and more rapid than in the vertebrae. Conclusions This study demonstrates that (1) after recruitment, OC are removed from the resorption site by apoptosis (2) the combined use of TRAP and ED1 can be used to identify OC and their precursors in vivo (3) double staining for TRAP and DAPI or in situ DNA fragmentation end labelling can be used to identify apoptotic OC in vivo

The antimicrobial lysine-peptoid hybrid LP5 inhibits DNA replication and induces the SOS response in Staphylococcus aureus

BACKGROUND: The increase in antibiotic resistant bacteria has led to renewed interest in development of alternative antimicrobial compounds such as antimicrobial peptides (AMPs), either naturally-occurring or synthetically-derived. Knowledge of the mode of action (MOA) of synthetic compounds mimicking the function of AMPs is highly valuable both when developing new types of antimicrobials and when predicting resistance development. Despite many functional studies of AMPs, only a few of the synthetic peptides have been studied in detail. RESULTS: We investigated the MOA of the lysine-peptoid hybrid, LP5, which previously has been shown to display antimicrobial activity against Staphylococcus aureus. At concentrations of LP5 above the minimal inhibitory concentration (MIC), the peptoid caused ATP leakage from bacterial cells. However, at concentrations close to the MIC, LP5 inhibited the growth of S. aureus without ATP leakage. Instead, LP5 bound DNA and inhibited macromolecular synthesis. The binding to DNA also led to inhibition of DNA gyrase and topoisomerase IV and caused induction of the SOS response. CONCLUSIONS: Our data demonstrate that LP5 may have a dual mode of action against S. aureus. At MIC concentrations, LP5 binds DNA and inhibits macromolecular synthesis and growth, whereas at concentrations above the MIC, LP5 targets the bacterial membrane leading to disruption of the membrane. These results add new information about the MOA of a new synthetic AMP and aid in the future design of synthetic peptides with increased therapeutic potential