224 research outputs found

    Ultrafast nonlocal control of spontaneous emission

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    Solid-state cavity quantum electrodynamics systems will form scalable nodes of future quantum networks, allowing the storage, processing and retrieval of quantum bits, where a real-time control of the radiative interaction in the cavity is required to achieve high efficiency. We demonstrate here the dynamic molding of the vacuum field in a coupled-cavity system to achieve the ultrafast nonlocal modulation of spontaneous emission of quantum dots in photonic crystal cavities, on a timescale of ~200 ps, much faster than their natural radiative lifetimes. This opens the way to the ultrafast control of semiconductor-based cavity quantum electrodynamics systems for application in quantum interfaces and to a new class of ultrafast lasers based on nano-photonic cavities.Comment: 15 pages, 4 figure

    Predictive value of subclinical autistic traits at age 14–15 months for behavioural and cognitive problems at age 3–5 years

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    It is unclear whether subclinical autistic traits at very young age are transient or stable, and have clinical relevance. This study investigated the relationship between early subclinical autistic traits and the occurrence of later developmental and behavioural problems as well as problems in cognitive and language functioning. Parents of infants aged 14–15 months from the general population completed the Early Screening of Autistic Traits Questionnaire (ESAT). Three groups of children with high, moderate, and low ESAT-scores (total n = 103) were selected. Follow-up assessments included the CBCL 1½–5 at age 3 years, and the SCQ, the ADI-R, the ADOS-G, a non-verbal intelligence test, and language tests for comprehension and production at age 4–5 years. None of the children met criteria for autism spectrum disorder at follow-up. Children with high ESAT-scores at 14–15 months showed significantly more internalizing and externalizing problems at age 3 years and scored significantly lower on language tests at age 4–5 years than children with moderate or low ESAT-scores. Further, significantly more children with high ESAT-scores (14/26, 53.8%) than with moderate and low ESAT-scores (5/36, 13.9% and 1/41, 2.4%, respectively) were in the high-risk/clinical range on one or more outcome domains (autistic symptoms, behavioural problems, cognitive and language abilities). Subclinical autistic traits at 14–15 months predict later behavioural problems and delays in cognitive and language functioning rather than later ASD-diagnoses. The theoretical implications of the findings lie in the pivotal role of early social and communication skills for the development of self-regulation of emotions and impulses. The practical implications bear on the early recognition of children at risk for behavioural problems and for language and cognitive problems

    Current use and barriers and facilitators for implementation of standardised measures in physical therapy in the Netherlands

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    In many countries, the need for physical therapists to use standardised measures has been recognised and is recommended in clinical practice guidelines. Research has shown a lack of clinimetric knowledge and clinical application of measurement instruments in daily practice may hamper implementation of these guidelines. The aims of this study are 1) to investigate the current use of measurement instruments by Dutch physical therapists; 2) to investigate the facilitators and barriers in using measurement instruments

    Three dimensional evaluation of posture in standing with the PosturePrint: an intra- and inter-examiner reliability study

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    Abstract Background Few digitizers can measure the complexity of upright human postural displacements in six degrees of freedom of the head, rib cage, and pelvis. Methods In a University laboratory, three examiners performed delayed repeated postural measurements on forty subjects over two days. Three digital photographs (left lateral, AP, right lateral) of each of 40 volunteer participants were obtained, twice, by three examiners. Examiners placed 13 markers on the subjects before photography and chose 16 points on the photographic images. Using the PosturePrint® internet computer system, head, rib cage, and pelvic postures were calculated as rotations (Rx, Ry, Rz) in degrees and translations (Tx, Tz) in millimeters. For reliability, two different types (liberal = ICC3,1 & conservative = ICC2,1) of inter- and intra-examiner correlation coefficients (ICC) were calculated. Standard error of measurements (SEM) and mean absolute differences within and between observers' measurements were also determined. Results All of the "liberal" ICCs were in the excellent range (> 0.84). For the more "conservative" type ICCs, four Inter-examiner ICCs were in the interval (0.5–0.6), 10 ICCs were in the interval (0.61–0.74), and the remainder were greater than 0.75. SEMs were 2.7° or less for all rotations and 5.9 mm or less for all translations. Mean absolute differences within examiners and between examiners were 3.5° or less for all rotations and 8.4 mm or less for all translations. Conclusion For the PosturePrint® system, the combined inter-examiner and intra-examiner correlation coefficients were in the good (14/44) and excellent (30/44) ranges. SEMs and mean absolute differences within and between examiners' measurements were small. Thus, this posture digitizer is reliable for clinical use

    Course and prognosis of recovery for chronic non-specific low back pain: design, therapy program and baseline data of a prospective cohort study

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    Background: There has been increasing focus on factors predicting the development of chronic musculoskeletal disorders. For patients already experiencing chronic non-specific low back pain it is also relevant to investigate which prognostic factors predict recovery. We present the design of a cohort study that aims to determine the course and prognostic factors for recovery in patients with chronic non-specific low back pain. Methods/Design. All participating patients were recruited (Jan 2003-Dec 2008) from the same rehabilitation centre and were evaluated by means of (postal) questionnaires and physical examinations at baseline, during the 2-month therapy program, and at 5 and 12 months after start of therapy. The therapy protocol at the rehabilitation centre used a bio-psychosocial approach to stimulate patients to adopt adequate (movement) behaviour aimed at physical and functional recovery. The program is part of regular care and consists of 16 sessions of 3 hours each, over an 8-week period (in total 48 hours), followed by a 3-month self-management program. The primary outcomes are low back pain intensity, disability, quality of life, patient's global perceived effect of recovery, and participation in work. Baseline characteristics include information on socio-demographics, low back pain, employment status, and additional clinical items status such as fatigue, duration of activities, and fear of kinesiophobia. Prognostic variables are determined for recovery at short-term (5 months) and long-term (12 months) follow-up after start of therapy. Discussion. In a routine clinical setting it is important to provide patients suffering from chronic non-specific low back pain with adequate information about the prognosis of their complaint

    Advances in Quantitative Hepcidin Measurements by Time-of-Flight Mass Spectrometry

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    Assays for the detection of the iron regulatory hormone hepcidin in plasma or urine have not yet been widely available, whereas quantitative comparisons between hepcidin levels in these different matrices were thus far even impossible due to technical restrictions. To circumvent these limitations, we here describe several advances in time-of flight mass spectrometry (TOF MS), the most important of which concerned spiking of a synthetic hepcidin analogue as internal standard into serum and urine samples. This serves both as a control for experimental variation, such as recovery and matrix-dependent ionization and ion suppression, and at the same time allows value assignment to the measured hepcidin peak intensities. The assay improvements were clinically evaluated using samples from various patients groups and its relevance was further underscored by the significant correlation of serum hepcidin levels with serum iron indices in healthy individuals. Most importantly, this approach allowed kinetic studies as illustrated by the paired analyses of serum and urine samples, showing that more than 97% of the freely filtered serum hepcidin can be reabsorbed in the kidney. Thus, the here reported advances in TOF MS-based hepcidin measurements represent critical steps in the accurate quantification of hepcidin in various body fluids and pave the way for clinical studies on the kinetic behavior of hepcidin in both healthy and diseased states

    HACCP-based quality risk management approach to udder health problems on dairy farms

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    Against the background of prevailing udder health problems on dairy farms, this paper discusses a new approach to mastitis control. Current udder health control programmes, such as the 'five-point plan', are highlighted and their drawbacks indicated. The concept and principles of hazard analysis critical control points (HACCP) are introduced. The eight core elements of this concept are dealt with by using the example of a dairy herd with a mastitis problem due to Staphylococcus aureus. The various steps to be taken in the development of a HACCP-based quality risk management programme are illustrated through the application of core elements. Finally, it is shown that the HACCP key words, structure, organisation, planning, communication and formalisation; which do not frequently appear in conventional herd health and production management programmes can contribute to better udder health. The role of the veterinarian can be paramount and of added value, if he/she is willing to invest in new knowledge and skills, such as the HACCP concept, farm economics, animal nutrition, and particularly the role of coach to the dairy farmer in the implementation of preventative measures in relation to udder health

    Inter-rater reliability and stability of diagnoses of autism spectrum disorder in children identified through screening at a very young age

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    To examine the inter-rater reliability and stability of autism spectrum disorder (ASD) diagnoses made at a very early age in children identified through a screening procedure around 14 months of age. In a prospective design, preschoolers were recruited from a screening study for ASD. The inter-rater reliability of the diagnosis of ASD was measured through an independent assessment of a randomly selected subsample of 38 patients by two other psychiatrists. The diagnoses at 23 months and 42 months of 131 patients, based on the clinical assessment and the diagnostic classifications of standardised instruments, were compared to evaluate stability of the diagnosis of ASD. Inter-rater reliability on a diagnosis of ASD versus non-ASD at 23 months was 87% with a weighted κ of 0.74 (SE 0.11). The stability of the different diagnoses in the autism spectrum was 63% for autistic disorder, 54% for pervasive developmental disorder, not otherwise specified (PDD-NOS), and 91% for the whole category of ASD. Most diagnostic changes at 42 months were within the autism spectrum from autistic disorder to PDD-NOS and were mainly due to diminished symptom severity. Children who moved outside the ASD category at 42 months made significantly larger gains in cognitive and language skills than children with a stable ASD diagnosis. In conclusion, the inter-rater reliability and stability of the diagnoses of ASD established at 23 months in this population-based sample of very young children are good

    Efficacy and safety of acupuncture for the treatment of non-specific acute low back pain: a randomised controlled multicentre trial protocol [ISRCTN65814467]

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    BACKGROUND: Low back pain and its associated incapacitating effects constitute an important healthcare and socioeconomic problem, as well as being one of the main causes of disability among adults of working age. The prevalence of non-specific low back pain is very high among the general population, and 60–70% of adults are believed to have suffered this problem at some time. Nevertheless, few randomised clinical trials have been made of the efficacy and efficiency of acupuncture with respect to acute low back pain. The present study is intended to assess the efficacy of acupuncture for acute low back pain in terms of the improvement reported on the Roland Morris Questionnaire (RMQ) on low back pain incapacity, to estimate the specific and non-specific effects produced by the technique, and to carry out a cost-effectiveness analysis. METHODS/DESIGN: Randomised four-branch controlled multicentre prospective study made to compare semi-standardised real acupuncture, sham acupuncture (acupuncture at non-specific points), placebo acupuncture and conventional treatment. The patients are blinded to the real, sham and placebo acupuncture treatments. Patients in the sample present symptoms of non specific acute low back pain, with a case history of 2 weeks or less, and will be selected from working-age patients, whether in paid employment or not, referred by General Practitioners from Primary Healthcare Clinics to the four clinics participating in this study. In order to assess the primary and secondary result measures, the patients will be requested to fill in a questionnaire before the randomisation and again at 3, 12 and 48 weeks after starting the treatment. The primary result measure will be the clinical relevant improvement (CRI) at 3 weeks after randomisation. We define CRI as a reduction of 35% or more in the RMQ results. DISCUSSION: This study is intended to obtain further evidence on the effectiveness of acupuncture on acute low back pain and to isolate the specific and non-specific effects of the treatment

    Expectations and needs of patients with a chronic disease toward self-management and eHealth for self-management purposes

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    Background: Self-management is considered as an essential component of chronic care by primary care professionals. eHealth is expected to play an important role in supporting patients in their self-management. For effective implementation of eHealth it is important to investigate patients’ expectations and needs regarding self-management and eHealth. The objectives of this study are to investigate expectations and needs of people with a chronic condition regarding self-management and eHealth for self-management purposes, their willingness to use eHealth, and possible differences between patient groups regarding these topics. Methods: Five focus groups with people with diabetes (n = 14), COPD (n = 9), and a cardiovascular condition (n = 7) were conducted in this qualitative research. Separate focus groups were organized based on patients’ chronic condition. The following themes were discussed: 1) the impact of the chronic disease on patients’ daily life; 2) their opinions and needs regarding self-management; and 3) their expectations and needs regarding, and willingness to use, eHealth for self-management purposes. A conventional content analysis approach was used for coding. Results: Patient groups seem to differ in expectations and needs regarding self-management and eHealth for self-management purposes. People with diabetes reported most needs and benefits regarding self-management and were most willing to use eHealth, followed by the COPD group. People with a cardiovascular condition mentioned having fewer needs for self-management support, because their disease had little impact on their life. In all patient groups it was reported that the patient, not the care professional, should choose whether or not to use eHealth. Moreover, participants reported that eHealth should not replace, but complement personal care. Many participants reported expecting feelings of anxiety by doing measurement themselves and uncertainty about follow-up of deviant data of measurements. In addition, many participants worried about the implementation of eHealth being a consequence of budget cuts in care. Conclusion: This study suggests that aspects of eHealth, and the way in which it should be implemented, should be tailored to the patient. Patients’ expected benefits of using eHealth to support self-management and their perceived controllability over their disease seem to play an important role in patients’ willingness to use eHealth for self-management purposes
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