Postantibiotic effect and postantibiotic sub-MIC effect of LTX-109 and mupirocin on Staphylococcus aureus blood isolates

The development of new synthetic antimicrobial peptides like LTX-109 provides a new class of drugs for the treatment of Staphylococcus aureus infections. We evaluated LTX-109 and mupirocin for pharmacodynamic parameters against 10 methicillin-resistant S. aureus isolates. The postantibiotic effect (PAE) is defined as the length of time that bacterial growth is suppressed following a brief exposure to an antibiotic. We also determined the sub-MIC effect (SME) which measures the direct effect of subinhibitory levels on strains that have not previously been exposed to antibiotics. The postantibiotic sub-MIC effect (PA-SME) is a combination of the PAE and SME. LTX-109 had an average PAE of 5·51 h vs 1·04 h for mupirocin. The PA-SME of LTX-109 ranged from 2·51 to 9·33 h as the concentration increased from 0·2 to 0·4 times the minimal inhibitory concentration (MIC). The PA-SME range for mupirocin was 0·93-2·58 h. LTX-109, as compared to mupirocin, demonstrated prolonged time of effect for these pharmacodynamic parameters, which supports persistent activity for several hours after the drug is no longer present or is below the MIC. The pharmacodynamic parameters studied here suggest that LTX-109 is less likely than mupirocin to generate resistance to S. aureus.

SIGNIFICANCE AND IMPACT OF THE STUDY

Resistant bacterial infections continue to be a challenge for clinicians. Identification of antibiotics with pharmacodynamic advantages may be beneficial in the treatment of these infections. An antibiotic with a longer postantibiotic effect may be able to be administered less frequently resulting in improved adherence. In this study, a new synthetic antimicrobial peptide, LTX-109, demonstrated a more prolonged time for LTX-109 than mupirocin against methicillin-resistant Staphylococcus aureus.

Crack detection in riveted lap joints using fiber laser acoustic emission sensors

Fiber laser ultrasonic sensors are demonstrated to be capable of measuring acoustic emission generated by cracks in aluminum panels. A single laser sensor is integrated into a riveted lap joint, which is subject to accelerated fatigue. Acoustic emission generated by crack formation in the panel in addition to other acoustic events due to fretting within the joint are clearly resolved by the laser sensor. Localization of an acoustic emission event is demonstrated with a multiplexed array of three laser sensors. This manuscript also calculates the fundamental limit to displacement resolution of the fiber laser sensor and presents measurements of the directional response to Lamb waves. The high measurement resolution and multiplexing capability of the fiber laser ultrasonic sensor makes it an ideal candidate for structural health monitoring applications.

Exercise Interventions for Preserving Physical Function Among Cancer Survivors in Middle to Late Life

The purpose of this review was to evaluate randomized controlled trials aiming to preserve the functional status, i.e. physical capabilities, of middle-aged and older cancer survivors through a structured, physical exercise intervention. The study team performed a thorough search of the literature using six online databases. This literature search limited included studies to randomized controlled trials which implemented a structured physical activity intervention for middle- and older-aged adults diagnosed with cancer. Studies were also required include at least one objective measure of physical function as a dependent outcome. This literature search yielded thirty-eight studies. The majority of the literature reviewed was successful in improving several functional outcomes including time needed to rise from a chair or distance covered during the six-minute walk test. A large number of published trials also suggest that exercise is effective in decreasing fatigue. However, a lack of trials investigating outcomes in older populations (≥ 65 years) was noted in this review. The results of this review suggest that a structured exercise program may be physically beneficial for middle-aged to older cancer survivors. Particularly, such interventions could preserve the functional status of cancer patients and, consequently, improve their long-term health outcomes. Future implications include further investigation into strictly older cancer patient populations, as outcomes related to exercise might differ between older and middle-aged adults.

Screening for Atrial Fibrillation

Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country- and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.

Long-term satellite tracking reveals variable seasonal migration strategies of basking sharks in the north-east Atlantic

Animal migration is ubiquitous in nature with individuals within a population often exhibiting varying movement strategies. The basking shark (Cetorhinus maximus) is the world's second largest fish species, however, a comprehensive understanding of their long-term wider-ranging movements in the north-east Atlantic is currently lacking. Seventy satellite tags were deployed on basking sharks over four years (2012-2015) off the west coast of Scotland and the Isle of Man. Data from 28 satellite tags with attachment durations of over 165 days reveal post-summer ranging behaviours. Tagged sharks moved a median minimum straight-line distance of 3,633 km; achieving median displacement of 1,057 km from tagging locations. Tagged individuals exhibited one of three migration behaviours: remaining in waters of UK, Ireland and the Faroe Islands; migrating south to the Bay of Biscay or moving further south to waters off the Iberian Peninsula, and North Africa. Sharks used both continental shelf areas and oceanic habitats, primarily in the upper 50-200 m of the water column, spanning nine geo-political zones and the High Seas, demonstrating the need for multi-national cooperation in the management of this species across its range.

Effect of expiratory positive airway pressure on tidal volume during non-invasive ventilation

During non-invasive ventilation (NIV), tidal volume ( V_t) will depend upon the difference between inspiratory and expiratory positive airway pressure (IPAP and EPAP, respectively), provided the respiratory muscles are relaxed and the lungs and chest wall therefore move along their passive pressure-volume curves. To test this hypothesis, we studied the effect of increasing EPAP during pressure-controlled modes of NIV in 30 long-term ventilator users (10 each with scoliosis, obesity hypoventilation or neuromuscular disorders). While maintaining the same IPAP, addition of 5 cmH₂O of EPAP reduced mean V_t by 167 ml; 10 cmH₂O reduced V_t by 367 ml. This pattern was seen in all three patient groups. EPAP has several potential advantages, for example maintaining upper airway patency, preventing basal atelectasis and facilitating triggering. EPAP does, however, appear to reduce V_t. Decreasing EPAP is an alternative to increasing IPAP if measurements of gas exchange during NIV indicate that ventilation is inadequate.

Pathways for Transformation: Disaster Risk Management to Enhance Resilience to Extreme Events

Disaster risk from extreme events and development are intimately linked. Disaster risk management influences and is affected by local development strategies. Trade-offs made in policy and implementation determine winners and losers on the basis of unequal capacity, susceptibility and hazard exposure. Transformation has been introduced as a concept opening new policy space for fundamental shifts in development trajectories. Though policy neutral, when combined with normative frameworks such as the Sustainable development goals it can open up leverage points for determining development trajectories. There is limited empirical evidence on which to base understanding of transformative disaster risk management policy though some work has been done in sister domains such as climate change mitigation and adaptation. This study asks whether transformation pathways for disaster risk management can be observed, offering an initial qualitative analysis to inform policy development. It is based on five case studies drawn from diverse locations exposed to a range of extreme events, examined through a conceptual framework offering five indicators of transformation to aid analysis: intense interaction between actors; the intervention of external actors; system level change extending beyond efficiency to governance and goals; behavior beyond established coping strategies; and behavior extending beyond established institutions. Core characteristics of transformative pathways for disaster risk reduction are identified, including pathway competition, pathway experimentation, pathway scale effects and pathway lock-in. These characteristics are seen to determine the extent to which the disruption consequent on extreme events leads to either transformatory change or relative stasis. The study concludes that transformative disaster risk management, both intentional and incidental can be observed. It is seen that transformations occur primarily at local level. Where policy level change occurs this generally played out at local level too. The particular insight of the study is to suggest that most often the burden of transformation is carried at the local level through the behavior of individuals, populations and civil society. This observation raises an important question for further work: How can the burden of undertaking transformation be shared across scales?