1,708 research outputs found
The comprehensive cohort model in a pilot trial in orthopaedic trauma
Background: The primary aim of this study was to provide an estimate of effect size for the functional outcome of
operative versus non-operative treatment for patients with an acute rupture of the Achilles tendon using
accelerated rehabilitation for both groups of patients. The secondary aim was to assess the use of a
comprehensive cohort research design (i.e. a parallel patient-preference group alongside a randomised group) in
improving the accuracy of this estimate within an orthopaedic trauma setting.
Methods: Pragmatic randomised controlled trial and comprehensive cohort study within a level 1 trauma centre.
Twenty randomised participants (10 operative and 10 non-operative) and 29 preference participants (3 operative
and 26 non-operative). The ge range was 22-72 years and 37 of the 52 patients were men. All participants had an
acute rupture of their Achilles tendon and no other injuries. All of the patients in the operative group had a simple
end-to-end repair of the tendon with no augmentation. Both groups then followed the same eight-week
immediate weight-bearing rehabilitation programme using an off-the-shelf orthotic. The disability rating index (DRI;
primary outcome), EQ-5D, Achilles Total Rupture Score and complications were assessed ed at two weeks, six
weeks, three months, six months and nine months after initial injury.
Results: At nine months, there was no significant difference in DRI between patients randomised to operative or
non-operative management. There was no difference in DRI between the randomised group and the parallel
patient preference group. The use of a comprehensive cohort of patients did not provide useful additional
information as to the treatment effect size because the majority of patients chose non-operative management.
Conclusions: Recruitment to clinical trials that compare operative and non-operative interventions is notoriously
difficult; especially within the trauma setting. Including a parallel patient preference group to create a
comprehensive cohort of patients has been suggested as a way of increasing the power of such trials. In our
study, the comprehensive cohort model doubled the number of patients involved in the study. However, a strong
preference for non-operative treatment meant that the increased number of patients did not significantly increase
the ability of the trial to detect a difference between the two interventions
A Tunable Two-impurity Kondo system in an atomic point contact
Two magnetic atoms, one attached to the tip of a Scanning Tunneling
Microscope (STM) and one adsorbed on a metal surface, each constituting a Kondo
system, have been proposed as one of the simplest conceivable systems
potentially exhibiting quantum critical behaviour. We have succeeded in
implementing this concept experimentally for cobalt dimers clamped between an
STM tip and a gold surface. Control of the tip-sample distance with
sub-picometer resolution allows us to tune the interaction between the two
cobalt atoms with unprecedented precision. Electronic transport measurements on
this two-impurity Kondo system reveal a rich physical scenario which is
governed by a crossover from local Kondo screening to non-local singlet
formation due to antiferromagnetic coupling as a function of separation of the
cobalt atoms.Comment: 22 pages, 5 figure
Threshold for Synovial Cell Count and Neutrophil Differential in Diagnosis of Periprosthetic Knee Infection: A Multi-Institutional Study
Introduction:
Synovial fluid analysis is an important tool in the work-up of suspected periprosthetic joint infection (PJI). Yet, there is conflicting guidance for the analysis of synovial fluid aspiration, including a lack of uniform thresholds for white blood cell (WBC) count and neutrophil percentage (PMN%)1-3. Therefore, a multi-institutional study was undertaken to reassess these thresholds, compare preoperative versus intraoperative sample collection, and assess variation in results between institutions
Widespread distribution of Plasmodium vivax malaria in Mauritania on the interface of the Maghreb and West Africa.
BACKGROUND: Plasmodium vivax is very rarely seen in West Africa, although specific detection methods are not widely applied in the region, and it is now considered to be absent from North Africa. However, this parasite species has recently been reported to account for most malaria cases in Nouakchott, the capital of Mauritania, which is a large country at the interface of sub-Saharan West Africa and the Maghreb region in northwest Africa. METHODS: To determine the distribution of malaria parasite species throughout Mauritania, malaria cases were sampled in 2012 and 2013 from health facilities in 12 different areas. These sampling sites were located in eight major administrative regions of the country, within different parts of the Sahara and Sahel zones. Blood spots from finger-prick samples of malaria cases were processed to identify parasite DNA by species-specific PCR. RESULTS: Out of 472 malaria cases examined, 163 (34.5 %) had P. vivax alone, 296 (62.7 %) Plasmodium falciparum alone, and 13 (2.8 %) had mixed P. falciparum and P. vivax infection. All cases were negative for Plasmodium malariae and Plasmodium ovale. The parasite species distribution showed a broad spectrum, P. vivax being detected at six of the different sites, in five of the country's major administrative regions (Tiris Zemmour, Tagant, Brakna, Assaba, and the capital Nouakchott). Most cases in Nouakchott were due to P. vivax, although proportions vary significantly among different health facilities in the city. In the northern town of Zouérat, all cases were due to P. vivax, whereas almost all cases in the south of the country were due to P. falciparum. All P. vivax cases tested were Duffy blood group positive. CONCLUSIONS: It is important that P. vivax is recognized to be a widespread cause of malaria in Mauritania, occurring in diverse regions. This should be noted by the World Health Organization, as it has significant implications for diagnosis, treatment and control of malaria in the northwestern part of Africa
Native IYG: Improving Psychosocial Protective Factors for HIV/STI and Teen Pregnancy Prevention among Youth in American Indian/Alaska Native Communities
Background: Few HIV/STI and pregnancy prevention programs for youth in American Indian and Alaska Native (AI/AN) communities have been rigorously evaluated despite sexual health disparities in this population. This study reports the evaluation of a culturally adapted Internet-based HIV/STI and pregnancy prevention program for AI/AN youth, Native It’s Your Game (Native IYG).
Methods: A randomized study was conducted with 523 youth (12 to 14 years old), recruited from 25 tribal sites in Alaska, Arizona, and the Pacific Northwest. Participants were surveyed at baseline and upon completion of treatment or comparison interventions. Multivariable linear regression models were used to assess impact on short term psychosocial determinants of sexual initiation.
Results: A sample of 402 intervention (n=290) and comparison (n=112) youth completed the post-intervention survey (76.9% retention) from 1 to 462 days post-baseline (mean = 114, SD = ±96.67). Participants were 55.5% female, mean age of 13.0 (± 0.97) years with 86.1% self-reporting as AI/AN. Reasons not to have sex, STI knowledge, condom knowledge, condom availability self-efficacy, and condom use self-efficacy were significantly impacted (all P ≤ .01). Limitations included variability in intervention exposure and time between data collection time points.
Conclusions: Native IYG demonstrated efficacy to impact short-term psychosocial determinants of sexual behavior in a sample of predominantly AI/AN middle school youth
Paleophysical Oceanography with an Emphasis on Transport Rates
Paleophysical oceanography is the study of the behavior of the fluid ocean of the past, with a specific emphasis on its climate implications, leading to a focus on the general circulation. Even if the circulation is not of primary concern, heavy reliance on deep-sea cores for past climate information means that knowledge of the oceanic state when the sediments were laid down is a necessity. Like the modern problem, paleoceanography depends heavily on observations, and central difficulties lie with the very limited data types and coverage that are, and perhaps ever will be, available. An approximate separation can be made into static descriptors of the circulation (e.g., its water-mass properties and volumes) and the more difficult problem of determining transport rates of mass and other properties. Determination of the circulation of the Last Glacial Maximum is used to outline some of the main challenges to progress. Apart from sampling issues, major difficulties lie with physical interpretation of the proxies, transferring core depths to an accurate timescale (the “age-model problem”), and understanding the accuracy of time-stepping oceanic or coupled-climate models when run unconstrained by observations. Despite the existence of many plausible explanatory scenarios, few features of the paleocirculation in any period are yet known with certainty.National Science Foundation (U.S.) (grant OCE-0645936
Willingness to participate in future HIV prevention studies among gay and bisexual men in Scotland, UK: a challenge for intervention trials
This article examines willingness to participate in future HIV prevention research among gay and bisexual men in Scotland, UK. Anonymous, self-complete questionnaires and Orasure Gäó oral fluid samples were collected in commercial gay venues. 1,320 men were eligible for inclusion. 78.2% reported willingness to participate in future HIV prevention research; 64.6% for an HIV vaccine, 57.4% for a behaviour change study, and 53.0% for a rectal microbicide. In multivariate analysis, for HIV vaccine research, greater age, minority ethnicity, and not providing an oral fluid sample were associated with lower willingness; heterosexual orientation and not providing an oral fluid sample were for microbicides; higher education and greater HIV treatment optimism were for behaviour change. STI testing remained associated with being more willing to participate in microbicide research and frequent gay scene use remained associated with being more willing to participate in behaviour change research. Having an STI in the past 12 months remained significantly associated with being willing to participate in all three study types. There were no associations between sexual risk behaviour and willingness. Although most men expressed willingness to participate in future research, recruitment of high-risk men, who have the potential to benefit most, is likely to be more challenging
Under pressure: Response urgency modulates striatal and insula activity during decision-making under risk
When deciding whether to bet in situations that involve potential monetary loss or gain (mixed gambles), a subjective sense of pressure can influence the evaluation of the expected utility associated with each choice option. Here, we explored how gambling decisions, their psychophysiological and neural counterparts are modulated by an induced sense of urgency to respond. Urgency influenced decision times and evoked heart rate responses, interacting with the expected value of each gamble. Using functional MRI, we observed that this interaction was associated with changes in the activity of the striatum, a critical region for both reward and choice selection, and within the insula, a region implicated as the substrate of affective feelings arising from interoceptive signals which influence motivational behavior. Our findings bridge current psychophysiological and neurobiological models of value representation and action-programming, identifying the striatum and insular cortex as the key substrates of decision-making under risk and urgency
Supersymmetry with Light Stops
Recent LHC data, together with the electroweak naturalness argument, suggest
that the top squarks may be significantly lighter than the other sfermions. We
present supersymmetric models in which such a split spectrum is obtained
through "geometries": being "close to" electroweak symmetry breaking implies
being "away from" supersymmetry breaking, and vice versa. In particular, we
present models in 5D warped spacetime, in which supersymmetry breaking and
Higgs fields are located on the ultraviolet and infrared branes, respectively,
and the top multiplets are localized to the infrared brane. The hierarchy of
the Yukawa matrices can be obtained while keeping near flavor degeneracy
between the first two generation sfermions, avoiding stringent constraints from
flavor and CP violation. Through the AdS/CFT correspondence, the models can be
interpreted as purely 4D theories in which the top and Higgs multiplets are
composites of some strongly interacting sector exhibiting nontrivial dynamics
at a low energy. Because of the compositeness of the Higgs and top multiplets,
Landau pole constraints for the Higgs and top couplings apply only up to the
dynamical scale, allowing for a relatively heavy Higgs boson, including m_h =
125 GeV as suggested by the recent LHC data. We analyze electroweak symmetry
breaking for a well-motivated subset of these models, and find that fine-tuning
in electroweak symmetry breaking is indeed ameliorated. We also discuss a flat
space realization of the scenario in which supersymmetry is broken by boundary
conditions, with the top multiplets localized to a brane while other matter
multiplets delocalized in the bulk.Comment: 27 pages, 7 figure
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Cancer survivors' experience with telehealth: A systematic review and thematic synthesis
Background: Net survival rates of cancer are increasing worldwide, placing a strain on health service provision. There is a drive to transfer the care of cancer survivors—individuals living with and beyond cancer—to the community and encourage them to play an active role in their own care. Telehealth, the use of technology in remote exchange of data and communication between patients and health care professionals (HCPs), is an important contributor to this evolving model of care. Telehealth interventions are “complex,” and understanding patient experiences of them is important in evaluating their impact. However, a wider view of patient experience is lacking as qualitative studies detailing cancer survivor engagement with telehealth are yet to be synthesized.
Objective: To systematically identify, appraise, and synthesize qualitative research evidence on the experiences of adult cancer survivors participating in telehealth interventions, to characterize the patient experience of telehealth interventions for this group.
Methods: Medline (PubMed), PsychINFO, Cumulative Index for Nursing and Allied Health Professionals (CINAHL), Embase, and Cochrane Central Register of Controlled Trials were searched on August 14, 2015, and March 8, 2016, for English-language papers published between 2006 and 2016. Inclusion criteria were as follows: adult cancer survivors aged 18 years and over, cancer diagnosis, experience of participating in a telehealth intervention (defined as remote communication or remote monitoring with an HCP delivered by telephone, Internet, or hand-held or mobile technology), and reporting qualitative data including verbatim quotes. An adapted Critical Appraisal Skill Programme (CASP) checklist for qualitative research was used to assess paper quality. The results section of each included article was coded line by line, and all papers underwent inductive analysis, involving comparison, reexamination, and grouping of codes to develop descriptive themes. Analytical themes were developed through an iterative process of reflection on, and interpretation of, the descriptive themes within and across studies.
Results: Across the 22 included papers, 3 analytical themes emerged, each with 3 descriptive subthemes: (1) influence of telehealth on the disrupted lives of cancer survivors (convenience, independence, and burden); (2) personalized care across physical distance (time, space, and the human factor); and (3) remote reassurance—a safety net of health care professional connection (active connection, passive connection, and slipping through the net). Telehealth interventions represent a convenient approach, which can potentially minimize treatment burden and disruption to cancer survivors’ lives. Telehealth interventions can facilitate an experience of personalized care and reassurance for those living with and beyond cancer; however, it is important to consider individual factors when tailoring interventions to ensure engagement promotes benefit rather than burden.
Conclusions: Telehealth interventions can provide cancer survivors with independence and reassurance. Future telehealth interventions need to be developed iteratively in collaboration with a broad range of cancer survivors to maximize engagement and benefit
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