312 research outputs found

    Gravitational self-torque and spin precession in compact binaries

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    We calculate the effect of self-interaction on the "geodetic" spin precession of a compact body in a strong-field orbit around a black hole. Specifically, we consider the spin precession angle ψ\psi per radian of orbital revolution for a particle carrying mass μ\mu and spin s≪(G/c)μ2s \ll (G/c) \mu^2 in a circular orbit around a Schwarzschild black hole of mass M≫μM \gg \mu. We compute ψ\psi through O(μ/M)O(\mu/M) in perturbation theory, i.e, including the correction δψ\delta\psi (obtained numerically) due to the torque exerted by the conservative piece of the gravitational self-field. Comparison with a post-Newtonian (PN) expression for δψ\delta\psi, derived here through 3PN order, shows good agreement but also reveals strong-field features which are not captured by the latter approximation. Our results can inform semi-analytical models of the strong-field dynamics in astrophysical binaries, important for ongoing and future gravitational-wave searches.Comment: 5 pages, 1 table, 1 figure. Minor changes to match published versio

    An Exploration of the Role of Substance Misuse Nurses in Scotland

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    Executive Summary Background With the increase of drug misuse over the past two decades, the role of the Substance Misuse Nurse has increased dramatically. Research on the role of nurses working in this field is minimal and there is little known about what they do, what they think about their clients and their role, and how they approach treatment. A pilot study on substance misuse nurses in Grampian indicated that nurses may be key gatekeepers to specialist services and some nurses appeared to have an important role in clinical decision making. However, clinical decision making and other key aspects of nurse practice may vary across services in different geographical areas. This research was designed to gain a better understanding of the role of the substance misuse nurse in Scotland. Aims and Objectives The aim of this research was to describe and analyse the role of substance misuse nurses working with drug misusers in Scotland. The objectives were: • to identify the population of specialist nurses working directly in the management of illicit drug users in Scotland and gain baseline data on their demography, caseload, services provided and level of interaction with other health professionals; • to compare their attitudes to drug misusers with those of other health professionals; • to explore their beliefs about the effectiveness of different treatment options; • to examine their role in the initial client assessment and subsequent management; • to describe their interaction with the client; • to explore their relationship with other professionals. Methods Mixed quantitative and qualitative methods were used. The population of Substance Misuse Nurses and midwives working specifically with drug misusers across Scotland were identified and posted a comprehensive questionnaire. The questionnaire covered issues including qualifications, training, attitudes and beliefs about treatment and aspects of practice such as caseloads, services provided and relationships with other health and social professionals. Face-to-face interviews were conducted with a sub-sample of nurses including a range of gender, experience, and NHS areas. Interviews covered nurses’ assessment and decision making regarding treatment and relationships with other professionals. Observations of specialist nurse and client consultations allowed for some insight into the general structure of the consultation, the setting where the consultation took place and the roles of nurse and client in assessment and treatment planning. Characteristics of SMS nurses and services • A scoping exercise indentified 272 nurses. Of these 244 were sent a questionnaire (the remainder having left or being on sick leave). Of these, 79% responded. • Seventy percent (70%) were Grade G or above indicating a senior level workforce. • Most nurses were employed in substance misuse services (48%) or, similarly, drug and alcohol services (30%). • Formal training (university certificate/diploma) in substance misuse had been undertaken by 40% of nurses, induction training (i.e. at the start of employment) by 62% of nurses. • The median caseload was 38 clients. • The majority of consultations took place in clinical consultation rooms but this was not observed to influence the consultation. • Nurses reported that the average length of a consultation was 38 minutes. All of the observed consultations were scheduled for 30 minutes but half over-ran. Motivation, attitudes and beliefs • The challenging nature of working with drug misusers was a positive motivating factor for nurses working in this field. • Seventy-seven percent (77%) of nurses considered working with drug misusers to be rewarding, although 79% also considered that this population were not easy to deal with. Opinion was split about whether drug misusers could be manipulative in consultations. Initial assessment of clients • Waiting times for assessment were generally an issue of concern to nurses. • A detailed assessment was almost always conducted at the first consultation. • An SMR24 was almost always completed at the first consultation. • Interviews and observation of nurse-client consultations found that the approach to assessment seemed consistent across geographical areas. • Assessment included: brief physical examination, urine sampling, detailed exploration of drug use, exploration of physical problems, discussion of social and family support, housing and employment status and history of involvement in the criminal justice system. • Consultations were often brought to a close by discussing treatment expectations. • Initial assessment could take place over more than one appointment and several appointments could be required before a treatment plan was implemented. Making treatment decisions • Clients were actively encouraged to participate in treatment decisions. • Although 84% of nurses reported they were expected to follow a treatment protocol only 44% said they always did (for any treatment). • Eighty-six percent (86%) of nurses had seen the National Clinical Guidelines (DoH, 1999), and those who were interviewed felt that these provided a good framework for treatment, although they were perhaps lacking in detail. • Nurses reported that they often consulted widely with other health professionals but, most frequently, with the client, before making a treatment decision. • A third of nurses reported writing prescriptions for a doctor to sign. • Seventy percent (70%) of respondents felt nurses should be able write prescriptions but only if they were experienced nurses with appropriate training. Comparing beliefs of nurses with those of GPs and pharmacists Nurses were asked some questions which had been asked of GPs and pharmacists in previous national surveys conducted in 2000. This allowed for comparisons to be made: • When making treatment decisions nurses were less influenced than GPs by the attitude and behaviour of drug misusers. • When making treatment decisions nurses were more influenced than GPs by societal factors such as reducing the transmission of infectious disease. • Nurses were less likely than GPs to favour detoxification as a treatment approach, although 83% of nurses agreed that a community based detoxification programme was an effective tool for the treatment of drug misuse. • Nurses were more confident than GPs about their ability to successfully manage polydrug users. • Nurses and GPs were split in their beliefs about the effectiveness of dihydrocodeine. • Nurses believed more strongly than pharmacists that maintenance prescribing could stop the use of illicit drugs. • Fewer nurses than pharmacists believed that controlled drug dispensing should take place in central clinics rather than community pharmacies. Multidisciplinary working • Over half of nurses considered their relationship with pharmacists, GPs, health visitors/community nurses, hospital doctors and social workers to be good. • Opportunities to discuss services with local policy makers were considered insufficient. • Relationships with GPs seemed positive because nurses felt GPs valued their specialist knowledge. • Nurses had frequent contact with pharmacists and respected the difficulties of a pharmacist’s work. • Relationships with social services were variable. Some nurses felt undervalued by their social work colleagues, or felt there was a lack of joint planning for individual client care. • Nurses were clear about what circumstances should lead to a break in confidentiality between services and of how to go about this. • Integrated drug services were seen as potentially beneficial but there were specific concerns about the implications for clients of sharing information with other agencies and practical concerns about the size of joint assessment tools. Health and Safety at work • Sixty-four percent (64%) of nurses reported that they had been physically or verbally abused by clients, and half of those who had been subject to abuse felt current safety provision in their service was insufficient. Nurses in most areas said that the safety of staff was considered to be a high service priority, but there was evidence from interviews this was still lacking in some areas. • Greater use of personal alarms and alarms in consultation rooms, use of mobile phones, and specialised training were suggested as ways of improving safety. • Nurses said that the majority of their consultations take place in clinics/consultation rooms rather than clients’ homes. • The feeling was commonly expressed among interviewees that their work could be stressful, and this was seen as due to paperwork, excessive caseloads and working in isolation. Discussion of Findings This study provides baseline information which can be used to inform individual nurses, services, policy makers and researchers. Some individual nurses reading this report might find an element that is simply describing what they already know. This is inevitable but it is hoped individual nurses will still find interest in the views and practice of others within their profession. The value of this report is that it has quantified these findings on a national basis, providing robust data for workforce planning and needs assessment. It has not been possible to compare findings, and thus the practice of substance misuse nurses in Scotland, with other areas or countries because there is no comparable published work. It is also not possible to give guidelines or examples of ‘good practice’ as this would have involved data collection from clients and other professionals which was outwith this study’s remit. This study has found a reassuring consistence of practice across Scotland. Although many substance misuse nurses work in some degree of isolation there is an apparently high level of discussion and consultation with other service colleagues which provides support. The role of the nurse in the initial assessment and treatment plan is critical. Nevertheless, decisions regarding treatment plans were made largely between nurses and clients, with nurses making use of service protocols/guidelines. Some might question whether a nurse is the most appropriate person to undertake these tasks. Ability to conduct physical examination, some knowledge of pharmacology, mental health and psychology as well as an ability to explore the wider social context is required. On reflection a nurse, with mental health qualifications seems to have the most appropriate skills for this. There is a willingness by nurses to take on the role of prescribing albeit in a limited capacity, and only by very experienced nurses with appropriate training. Currently, a minority of nurses reported writing prescriptions to be signed by doctors, which is possible for doctors with handwriting exemptions. This raises issues about clinical governance. In signing the prescription a GP is still taking responsibility even though s/he may know little about the patient’s current condition. An important strand of a substance misuse nurse’s practice is ongoing support or counselling for clients. This raises issues about models of counselling followed and nurses’ competencies in doing this. The nature or model of counselling used by nurses was not explicitly covered in this research and further exploration of counselling would be an area for future research. Relationships with other professionals, were generally reported to be good. Nurses generally believed GPs valued their role. Comparison of attitudes of substance misuse nurses with earlier surveys of pharmacists and GPs indicates they are more positive in general and about treatment outcomes in particular. Nurses viewed the challenging aspect of working with drug misusers more positively than pharmacists and GPs. Nurses were less positive about their ability to influence policy. Currently substance misuse nurses have little input at policy level. At a local level, through Drug and Alcohol Action Teams (DAATs) this could improve the feeling of ownership towards service developments related to the Joint Future agenda. Service managers are currently the key link between nurses and DAATs. Perhaps a service nurse with more client contact should also attend to provide client feedback. At a national level greater nursing input into policy could give this specialist group a greater feeling of professional cohesion as well as keeping policy makers informed. Concerns about health and safety at work need to be considered at a national professional level as well as locally. Whether these issues should be addressed through the involvement of an organisation such as the Association of Nurses in Substance Abuse (ANSA) or an appointed individual is for discussion. Recommendations • All substance misuse nurses should receive induction training prior to commencing their post. Greater time should be protected to allow participation in training. • There should be further exploration of what models of counselling, if any, are followed to assess whether current training is adequate. • Appointment scheduling may need review as there was evidence that consultation time was routinely underestimated. Frequency of missed appointments needs to be considered at the same time. • Staffing of substance misuse nurses should be expanded in order to reduce: excessive caseloads; lengthy waiting lists; insufficient cover for holidays, training and absences; and occupational stress. • Nurses could be involved in GP training to share their experience of managing difficult cases such as poly-drug users and widen GPs perspective of the social benefits of drug misuse treatment. • Nurses should be kept aware of developments on integrated care for drug misusers. This would allow them to understand the principles behind integrated care and be aware of how their service fits into the overall plan. • Extending the role of senior substance misuse nurses to include the prescribing of controlled drugs should be considered. • A clearer job title should be given to nurses working in substance misuse so that they may be easily identified and representable at both DAAT and Scottish Executive level, e.g. Specialist Nurse in Substance Misuse. • Efforts should be made to improve substance misuse nurses’ opportunities to influence policy. • All substance misuse nurses should be provided with appropriate on going training, procedures and practices to allow them to carry out their work safely

    Quasi-local contribution to the scalar self-force: Non-geodesic Motion

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    We extend our previous calculation of the quasi-local contribution to the self-force on a scalar particle to general (not necessarily geodesic) motion in a general spacetime. In addition to the general case and the case of a particle at rest in a stationary spacetime, we consider as examples a particle held at rest in Reissner-Nordstrom and Kerr-Newman space-times. This allows us to most easily analyse the effect of non-geodesic motion on our previous results and also allows for comparison to existing results for Schwarzschild spacetime.Comment: 11 pages, 1 figure, corrected typo in Eq. 2.

    Broadscale landscape mapping provides insight into the Commonwealth of Dominica and surrounding islands offshore environment

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    A lack of data hinders effective marine management strategies for developing island states. This is a particularly acute problem for the Commonwealth of Dominica. Here we use publicly available remote sensing and model data to map their relatively unstudied waters. Two study areas were selected; a smaller area focussing on the nearshore marine environment, and a larger area to capture broader spatial patterns and context. Three broadscale landscape maps were created, using geophysical and oceanographic data to classify the marine environment based on its abiotic characteristics. Principal component analysis (PCA) was performed on each area, followed by K-means clustering. The larger area PCA revealed three eigenvalues > 1, and one eigenvalue of 0.980. Therefore, two maps were created for this area, to assess the significance of including the fourth principal component (PC). We demonstrate that including too many PCs could lead to an increase in the confusion index of final output maps. Overall, the marine landscape maps were used to assess the spatial characteristics of the benthic environment and to identify priority areas for future high-resolution study. Through defining and analysing existing conditions and highlighting important natural areas in the Dominican waters, these study results can be incorporated into the Marine Spatial Planning process

    Improving the triple bottom line returns from smallholder tree farms in the Philippines: A systems approach

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    This paper outlines the application of systems thinking in investigating ways to improve the returns to smallholder tree farmers in the Philippines. The paper illustrates how a systems approach was used in the conceptualisation of the project and how systems thinking facilitated a shared understanding of the how each individual’s research contributed to the broader project activities. Systems thinking has also been used in the design and implementation of various project activities. Three examples are provided. The first example illustrates how a systems diagram was developed which outlined the direct and indirect linkages between biophysical data on tree farms and various activities designed to increase returns. The second example illustrates how the suggested approach for improving the flow of information concerning tree registration, harvest and transportation regulations and approval mechanisms link with various project activities and have been informed by a series of action research workshops. The third example illustrates how systems thinking has been applied to understand the factors affecting the production of high quality tree seedlings and to investigate the effect of policy interventions on improving the quality of seedlings available to smallholders

    Managing the symptoms of neuropathic pain: An exploration of patients' experiences

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    The debilitating effects of chronic neuropathic pain on everyday life are considerable but little is known about how individual sufferers manage these effects. Virtually nothing is known about what patients prefer, what measures they take themselves, when, or in what combinations. The aim of this study was to explore patients’ reports of how they managed their neuropathic pain symptoms. Three focus groups including 10 participants were used to generate qualitative data on both individual and shared experiences of managing their symptoms of neuropathic pain. Discussions were recorded and transcribed verbatim. Data were analysed using thematic analysis, identifying categories and broader themes of importance to patients. The most common management strategy was the use of conventional medications, often associated with poor effectiveness and unpleasant side-effects. Complementary and alternative medicine was ineffective but many found resting or retreating helpful. They exhibited a repeated cycle of seeking help to manage the pain, with each unsuccessful attempt followed by new attempts. Some had tried to accept their pain, but there was insufficient psychological, social, emotional and practical support to allow them to do this successfully. This exploratory study provides a basis from which to develop a larger study to validate and extend the findings. Other issues meriting research are the effectiveness of cognitive behavioural therapies for those with neuropathic pain; and an exploration and subsequent evaluation of different types of social, practical and emotional support needed to help live with neuropathic pain

    Spin–orbit precession for eccentric black hole binaries at first order in the mass ratio

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    We consider spin–orbit ('geodetic') precession for a compact binary in strong-field gravity. Specifically, we compute ψ, the ratio of the accumulated spin-precession and orbital angles over one radial period, for a spinning compact body of mass m 1 and spin s 1, with s1≪Gm12/c{{s}_{1}}\ll Gm_{1}^{2}/c , orbiting a non-rotating black hole. We show that ψ can be computed for eccentric orbits in both the gravitational self-force and post-Newtonian frameworks, and that the results appear to be consistent. We present a post-Newtonian expansion for ψ at next-to-next-to-leading order, and a Lorenz-gauge gravitational self-force calculation for ψ at first order in the mass ratio. The latter provides new numerical data in the strong-field regime to inform the effective one-body model of the gravitational two-body problem. We conclude that ψ complements the Detweiler redshift z as a key invariant quantity characterizing eccentric orbits in the gravitational two-body problem

    Glycoprotein Ib activation by thrombin stimulates the energy metabolism in human platelets

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    <div><p>Thrombin-induced platelet activation requires substantial amounts of ATP. However, the specific contribution of each ATP-generating pathway <i>i</i>.<i>e</i>., oxidative phosphorylation (OxPhos) versus glycolysis and the biochemical mechanisms involved in the thrombin-induced activation of energy metabolism remain unclear. Here we report an integral analysis on the role of both energy pathways in human platelets activated by several agonists, and the signal transducing mechanisms associated with such activation. We found that thrombin, Trap-6, arachidonic acid, collagen, A23187, epinephrine and ADP significantly increased glycolytic flux (3–38 times <i>vs</i>. non-activated platelets) whereas ristocetin was ineffective. OxPhos (33 times) and mitochondrial transmembrane potential (88%) were increased only by thrombin. OxPhos was the main source of ATP in thrombin-activated platelets, whereas in platelets activated by any of the other agonists, glycolysis was the principal ATP supplier. In order to establish the biochemical mechanisms involved in the thrombin-induced OxPhos activation in platelets, several signaling pathways associated with mitochondrial activation were analyzed. Wortmannin and LY294002 (PI3K/Akt pathway inhibitors), ristocetin and heparin (GPIb inhibitors) as well as resveratrol, ATP (calcium-release inhibitors) and PP1 (Tyr-phosphorylation inhibitor) prevented the thrombin-induced platelet activation. These results suggest that thrombin activates OxPhos and glycolysis through GPIb-dependent signaling involving PI3K and Akt activation, calcium mobilization and protein phosphorylation.</p></div

    Do trauma cue exposure and/or PTSD symptom severity intensify selective approach bias toward cannabis cues in regular cannabis users with trauma histories?

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    Trauma cue-elicited activation of automatic cannabis-related cognitive biases are theorized to contribute to comorbid posttraumatic stress disorder and cannabis use disorder. This phenomenon can be studied experimentally by combining the trauma cue reactivity paradigm (CRP) with cannabis-related cognitive processing tasks. In this study, we used a computerized cannabis approach-avoidance task (AAT) to assess automatic cannabis (vs. neutral) approach bias following personalized trauma (vs. neutral) CRP exposure. We hypothesized that selective cannabis (vs. neutral) approach biases on the AAT would be larger among participants with higher PTSD symptom severity, particularly following trauma (vs. neutral) cue exposure. We used a within-subjects experimental design with a continuous between-subjects moderator (PTSD symptom severity). Participants were exposed to both a trauma and neutral CRP in random order, completing a cannabis AAT (cannabis vs. neutral stimuli) following each cue exposure. Current cannabis users with histories of psychological trauma (n = 50; 34% male; mean age = 37.8 years) described their most traumatic lifetime event, and a similarly-detailed neutral event, according to an established interview protocol that served as the CRP. As hypothesized, an AAT stimulus type x PTSD symptom severity interaction emerged (p = .042) with approach bias greater to cannabis than neutral stimuli for participants with higher (p = .006), but not lower (p = .36), PTSD symptom severity. Contrasting expectations, the stimulus type x PTSD symptoms effect was not intensified by trauma cue exposure (p = .19). Selective cannabis approach bias may be chronically activated in cannabis users with higher PTSD symptom severity and may serve as an automatic cognitive mechanism to help explain PTSD-CUD co-morbidity.</p
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