Thermoresponsive, well-defined, poly(vinyl alcohol) co-polymers

Thermoresponsive polymers have attracted huge interest as adaptable biomaterials based on their reversible solubility behaviour which can be exploited for controlled drug delivery or cellular uptake. The most famous and successful of these is poly(ethylene glycol) (PEG), but the thermal transition temperatures that are practically accessible are not physiologically useful. There are some notable examples of synthetic, responsive, polymers that are highly tunable over a physiologically relevant range, but there is still a need for these to be clinically validated in terms of toxicology and immunogenity for in vivo usage, in addition to their widely used in vitro applications. Poly(vinyl alcohol), PVA, is an appealing biocompatible polymer which is already used for a huge range of biomedical applications. Here, PVA is shown to be a highly tunable, thermoresponsive polymer scaffold. RAFT/MADIX polymerization is used to obtain a library of well-defined polymers between 8 and 50 kDa. Selective alkanoylation of the obtained PVA enabled the effect of side-chains, end-groups and molecular weight on the observable transition temperatures to be studied by turbidimetry. It was found that increasingly hydrophobic side chains (acetyl, propanoyl, butanoyl), or increasing their density led to corresponding decreases in cloud point. PVA with just 10 mol% butanoylation was shown to have a thermal transition temperature close to physiological temperatures (37 °C), compared to 70 mol% for acetylation, with temperatures in between accessible by controlling both the relative degree of functionalization, or by altering the chain length. Finally, a secondary response to esterase enzymes was demonstrated as a route to ‘turn off’ the responsive behaviour on demand. This study suggests that PVA-derived polymers may be a useful platform for responsive biomaterials

Assessment and behaviour of prestressed concrete bridge beams in shear with less than minimum shear reinforcement

The Queensland Department of Transport and Main Roads manages over 3300 bridges, and many bridges have less shear reinforcement than required by modern design codes. Concerns about accurately predicting the shear capacities and the ductility of bridge beams have become increasingly important in maintaining network operation and transport productivity given the large increases in the loads since the bridges were constructed. An experimental investigation was conducted to study the shear performance and cracking behaviour of three full-scale, prestressed concrete beams, similar to those manufactured for Queensland bridges. The shear reinforcement provided was less than the minimum requirements defined by modern design codes. The beams were tested under a simply supported three-point loading regime, until failure. The experimental ultimate shear strengths were compared with the shear provisions of a number of international codified prediction models, including; current and previous versions of Australian Standard (AS5100), Canadian Highway Bridge Design Code (S6), and the fib Model Code 2010 (MC2010). The experimental results showed that the ultimate shear strength was generally greater than the codified model. However, of particular concern was the sudden nature of the ultimate failure. This paper provides insightsinto the methodologies used to assess prestressed concrete bridge beams with less than minimum shear reinforcement and will inform the inspection and management of bridges with these beams

Identifying a new intermediate polar using \u3cem\u3eXMM-Newton\u3c/em\u3e and \u3cem\u3eINTEGRAL\u3c/em\u3e

The bright X-ray source 2XMMi J180438.7-145647 is fortunate to have long baseline observations in INTEGRAL that complement observations taken by other missions. Optical spectroscopy of this object has suggested a distance of ˜7 kpc and an identification with a low-mass X-ray binary. We instead use the X-ray data from 0.3 to 40 keV to identify the source as a bright intermediate polar (IP) with an estimate for the white dwarf mass of ˜0.60 M⊙. This identification is supported by the presence of an iron triplet, the component lines of which are some of the strongest seen in IPs, and the signature of the spin period of the white dwarf at ˜24 min. We note that the lack of broad-band variability may suggest that this object is a stream-fed IP, similar in many respects to the well-studied IP, V2400 Oph. Phase binning has allowed us to create spectra corresponding to the peaks and troughs of the light curve from which we determine that the spectra appear harder in the troughs, consistent with the behaviour of other IPs binned on their spin periods. This work strongly suggests a misidentification in the optical due to the presence of large columns of enshrouding material. We instead propose a distance to the source of \u3c2.5 kpc to be consistent with the luminosities of other IPs in the dim, hard state. The considerable flux of the source together with the strength of the iron lines may, in future, allow the source to be used to diagnose the properties of the shock-heated plasma and the reflected component of the emission

Physical science research needed to evaluate the viability and risks of marine cloud brightening

Marine cloud brightening (MCB) is the deliberate injection of aerosol particles into shallow marine clouds to increase their reflection of solar radiation and reduce the amount of energy absorbed by the climate system. From the physical science perspective, the consensus of a broad international group of scientists is that the viability of MCB will ultimately depend on whether observations and models can robustly assess the scale-up of local-to-global brightening in today\u27s climate and identify strategies that will ensure an equitable geographical distribution of the benefits and risks associated with projected regional changes in temperature and precipitation. To address the physical science knowledge gaps required to assess the societal implications of MCB, we propose a substantial and targeted program of research-field and laboratory experiments, monitoring, and numerical modeling across a range of scales

Acute Effects of Elastic Bands as Resistance or Assistance on EMG, Kinetics, and Kinematics During Deadlift in Resistance-Trained Men

The aim of the study was to compare neuromuscular activation, kinetics and kinematics in three variations of the deadlift: (1) free weights, (2) free weights with elastic bands as resistance (bands anchored to the ground) and (3) free weights with elastic bands as assistance (bands attached above the bar). Sixteen resistance-trained men performed one repetition of the three variations as fast as possible using a 2-repetition maximum load in randomized and counterbalanced order. Muscle activation (gluteus maximus, semitendinosus, biceps femoris, erector spinae, vastus lateralis, and vastus medialis), kinematics (average-, peak-, and time to peak velocity), and kinetics (average-, peak,-and time to peak force) were measured during the ascending movement. Resisted and assisted deadlifts led to higher average and peak force outputs (p < 0.001–0.037, ES = 0.29–0.58), and time to peak velocity was shorter when compared to the free weights deadlift (p = 0.005–0.010, ES = 0.83–1.01). However, peak force was achieved faster when using free weights (p < 0.001, ES = 1.58–2.10) and assisted deadlifts had a lower peak velocity compared to resisted and free weights deadlift (p = 0.004–0.046, ES = 0.43–0.60). There were no significant differences in muscle activation between the different conditions (p = 0.082–1.000). In conclusion, the assisted and resisted deadlift produced higher force when compared to free weights. However, free weight and resisted deadlift seem more favorable for the barbell velocity. These findings are of importance for athletes and coaches which should select exercise depending on the goal of the session.publishedVersio

The role of trunk training for physical fitness and sport-specific performance. Protocol for a Meta-Analysis.

The trunk (core) muscles are involved in daily functions (i. e., stabilizing the body in everyday tasks) and force generation of the limbs during athletic tasks such as kicking, throwing, or running. Even though trunk training is a popular means for improving physical fitness and athletic performance, the direct relationship of improved trunk function (i.e., stability, strength, or endurance), fitness and sport-specific performance is not conclusive. The aim of this proposed review is to evaluate the effects of trunk training on physical fitness and sport-specific performance, and to examine potential subject-related (e.g., age, sex) and trunk training-related moderator variables (e.g., training period, training frequency) for performance changes. We will conduct a systematic literature search in Web of Science, MEDLINE (via EBSCO) and SportDiscus. Relevant papers will be screened independently by two reviewers in two stages: (1) title and abstracts and (2) the full text of the remaining papers. A third reviewer will resolve possible disagreements. Data extraction and risk of bias of the included studies will be performed in addition to the PEDro scoring to judge the quality of the studies. A meta-analysis will be conducted to determine the efficacy of trunk training to increase physical fitness and sport-specific performance measures. In addition, subgroup univariate analyses were computed for subject-related (i.e., age, sex, performance level) and training-related moderator variables (i.e., training period, training frequency, training sessions, session duration). The results of this proposed systematic review and meta-analysis will assess the effects of trunk training on physical fitness and sport-specific and identify which subject-related and training-related moderate variables of trunk training modality might be beneficial for performance gains. This knowledge has potential importance for athletes and coaches in sports.publishedVersio

The effects of ten weeks resistance training on sticking region in chest-press exercises

The aim of the study was to compare the effects of a 10-week chest-press resistance training on lifting regions in a trained exercise and a none-trained exercise; the barbell bench press (BBP). Thirty-five resistance trained men with 4.2 (± 2.3) years of resistance training experience were recruited. The participants were randomized to attend a resistance program, performing the chest-press, twice per week using either, Smith machine, dumbbells or laying on Swiss ball using a barbell. A six-repetitions maximum (6RM) test was conducted pre- and post-training in the trained chest-press exercise and non-trained BBP to examine lifting velocity, load displacement and the time of the pre-sticking, sticking and post-sticking regions. Additionally, the muscle activity in pectoralis major, triceps brachii, biceps brachii and deltoid anterior was examined. In the post-test, all three chest-press groups decreased lifting velocity and increased the time to reach the sticking- and post-sticking region. Independent of the type of chest-press exercise trained, no differences were observed in vertical displacement or in the muscle activity for the three lifting regions. In general, similar changes in kinematics in trained exercise and those observed in the BBP were observed for all three groups. This indicates that none of the three chest-press exercises (Swiss ball, Smith machine or dumbbells) were specific regarding the lifting regions but displaced a transferability towards the non-trained BBP. However, improved strength altered the sticking region among resistance trained men.publishedVersio

A qualitative study of decision-making and safety in ambulance service transitions

Background Decisions made by front-line ambulance staff are often time critical and based on limited information, but wrong decisions in this context could have serious consequences for patients. There has been little research carried out in the ambulance service setting to identify areas of risk associated with decisions about patient care. Aim The aim of this study was to qualitatively examine potential system-wide influences on decision-making in the ambulance service setting and to identify useful areas for future research and intervention. Methods We used a multisite, multimethod qualitative approach across three ambulance service trusts. In phase 1 we carried out 16 interviews to contextualise the study and provide discussion points for phase 2. For phase 2, university and ambulance service researchers observed paramedics on 34 shifts and 10 paramedics completed ‘digital diaries’ that reported challenges to decision-making or to patient safety. Six focus groups were held, three with staff (n = 21) and three with service users (n = 23). From observation and diary data we developed a typology of decisions made at the scene. Data from these and other sources were also coded within a human factors framework and then thematically analysed to identify influences on those decisions. In phase 3, workshops were held at each site to allow participants and stakeholders (n = 45) to comment on the study findings. Participants were asked to rank influences on decisions using a ‘paired comparison’ method. Results Interviews provided the context for further qualitative exploration. Nine types of decision were identified from observations and digital diaries, ranging from emergency department conveyance and specialist emergency pathways to non-conveyance. A synthesis of findings from the observations, diaries and staff focus groups revealed seven overarching system influences on decision-making and potential risk factors: meeting increasing demand for emergency care; impacts of performance regime and priorities on service delivery; access to appropriate care options; disproportionate risk aversion; education, training and professional development for crews; communication and feedback to crews; and ambulance service resources. Safety culture issues were also identified. Data from the service user focus groups reflected similar issues to those identified from the staff focus groups. Service user concerns included call handling and communication, triage, patient involvement in decisions, balancing demand, resources, access to care, risk aversion, geographical location and vulnerable patients. Group discussions highlighted a lack of awareness by the public of how best to use emergency and urgent care services. Workshop attendees were satisfied that the findings reflected relevant issues. The two issues ranked highest for warranting attention were staff training and development and access to alternative care. Conclusions Multiple qualitative methods allowed a range of perspectives to be accessed and validation of issues across perspectives. Recommendations for future research include exploring effective ways of providing access to alternative care pathways to accident and emergency, assessing public awareness and expectations of ambulance and related services, exploring safe ways of improving telephone triage decisions and assessing the effects of different staff skill levels on patient safety

Images of survival, stories of destruction: Nuclear war on British screens from 1945 to the early 1960s

This article discusses a range of depictions and discussions of nuclear war, which appeared on British screens in the first half of the Cold War, in order to understand the changing way nuclear weapons were viewed within British culture. Using such screened images to understand how nuclear war was constructed and represented within British culture, the article argues that the hydrogen bomb, not the atomic bomb, was the true harbinger of the nuclear revolution that transformed cultural understandings of warfare and destruction. Although the atomic bomb created a great deal of anxiety within British popular culture, representations of atomic attack elided atomic destruction with that experienced in 1939-45, emphasising the 'survivability' of atomic war. In the thermonuclear era, the Second World War could not undertake the same symbolic work. The image of the city-destroying bomb was an imaginative as well as technological step-change. Screened representations stressed that a thermonuclear war would literally end the world. As such, they preceded, and indeed provided the cultural climate for, the rise of the Campaign for Nuclear Disarmament (CND). The Campaign exploited and further popularised this idea of the apocalyptic nuclear war as a key aspect of its political and moral standpoint. The article concludes, however, that the cultural hegemony of this vision of nuclear war equally helped underpin notions of nuclear deterrence. The basic assumptions about the nature of nuclear war constructed and circulated on British screens therefore formed part of CND's 'cultural' victory but the article also explains why this did not translate into the political realm. © Edinburgh University Press

DNA barcoding identifies cryptic animal tool materials

Funding: Biotechnology and Biological Sciences Research Council (BBSRC) (Grants BB/G023913/1 and BB/G023913/2 to C.R., and studentship to B.C.K.), the School of Biology at the University of St Andrews (studentships to M.P.S. and B.C.K.), and the Leverhulme Trust (Grant RPG-2015-273 to P.M.H.).Some animals fashion tools or constructions out of plant materials to aid foraging, reproduction, self-maintenance, or protection. Their choice of raw materials can affect the structure and properties of the resulting artifacts, with considerable fitness consequences. Documenting animals’ material preferences is challenging, however, as manufacture behavior is often difficult to observe directly, and materials may be processed so heavily that they lack identifying features. Here, we use DNA barcoding to identify, from just a few recovered tool specimens, the plant species New Caledonian crows (Corvus moneduloides) use for crafting elaborate hooked stick tools in one of our long-term study populations. The method succeeded where extensive fieldwork using an array of conventional approaches—including targeted observations, camera traps, radio-tracking, bird-mounted video cameras, and behavioral experiments with wild and temporarily captive subjects—had failed. We believe that DNA barcoding will prove useful for investigating many other tool and construction behaviors, helping to unlock significant research potential across a wide range of study systems.Publisher PDFPeer reviewe