153 research outputs found

    Tunable Fiber Bragg Grating Ring Lasers using Macro Fiber Composite Actuators

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    The research reported herein includes the fabrication of a tunable optical fiber Bragg grating (FBG) fiber ring laser (FRL)1 from commercially available components as a high-speed alternative tunable laser source for NASA Langley s optical frequency domain reflectometer (OFDR) interrogator, which reads low reflectivity FBG sensors. A Macro-Fiber Composite (MFC) actuator invented at NASA Langley Research Center (LaRC) was selected to tune the laser. MFC actuators use a piezoelectric sheet cut into uniaxially aligned rectangular piezo-fibers surrounded by a polymer matrix and incorporate interdigitated electrodes to deliver electric fields along the length of the piezo-fibers. This configuration enables MFC actuators to produce displacements larger than the original uncut piezoelectric sheet. The FBG filter was sandwiched between two MFC actuators, and when strained, produced approximately 3.62 nm of wavelength shift in the FRL when biasing the MFC actuators from 500 V to 2000 V. This tunability range is comparable to that of other tunable lasers and is adequate for interrogating FBG sensors using OFDR technology. Three different FRL configurations were studied. Configuration A examined the importance of erbium-doped fiber length and output coupling. Configuration B demonstrated the importance of the FBG filter. Configuration C added an output coupler to increase the output power and to isolate the filter. Only configuration C was tuned because it offered the best optical power output of the three configurations. Use of Plastic Optical Fiber (POF) FBG s holds promise for enhanced tunability in future research

    New Zealand: The State of Liberal Democracy

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    This article is a brief report on constitutional developments and cases in New Zealand in 2017. The authors discuss several topics including the operation of New Zealand’s Mixed-Member Proportional voting system, New Zealand’s constitutional commitment to liberal democracy, and the issue of prisoner voting

    Experiences of dental behaviour support techniques: a qualitative systematic review

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    Background Little is known about patients' or carers' reported experiences of dental care provided using dental behaviour support (DBS) techniques. Qualitative literature can provide unique insight into these experiences. Aim To explore and synthesize qualitative literature related to patient experience of dental behaviour support. Methods A PROSPERO-registered systematic review of qualitative articles was undertaken. Studies were identified through MEDLINE, Embase and PsycINFO. Abstracts were screened by two reviewers and data were extracted to summarize the qualitative findings included within them. A thematic summary approach was used to synthesize the qualitative data identified. Results Twenty-three studies were included. Studies primarily explored experiences of dental care of children by speaking to their parents (n = 16), particularly regarding paediatric dental general anaesthesia (DGA) (n = 8). Studies of adults' experiences of DBS (n = 7) covered a range of techniques. Nine studies explored broader dental care experiences and did not study specific DBS approaches. A thematic synthesis identified five themes applicable across the studies identified: Trust and the therapeutic alliance supporting effective care delivery; considered information sharing often alleviated anticipatory anxiety; control and autonomy-reduced anxieties; variations in the perceived treatment successes and failures of DBS techniques; and DBS techniques produced longer positive and negative impacts on patients beyond direct care provision. Conclusion Qualitative research has been under-utilized in research on DBS techniques. Care experiences of most DBS techniques outside of paediatric DGA are poorly understood. Building trust with patients and enabling autonomy appear to support positive patient-reported experiences of care

    Physician decision making in selection of second-line treatments in immune thrombocytopenia in children.

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    Immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder which presents with isolated thrombocytopenia and risk of hemorrhage. While most children with ITP promptly recover with or without drug therapy, ITP is persistent or chronic in others. When needed, how to select second-line therapies is not clear. ICON1, conducted within the Pediatric ITP Consortium of North America (ICON), is a prospective, observational, longitudinal cohort study of 120 children from 21 centers starting second-line treatments for ITP which examined treatment decisions. Treating physicians reported reasons for selecting therapies, ranking the top three. In a propensity weighted model, the most important factors were patient/parental preference (53%) and treatment-related factors: side effect profile (58%), long-term toxicity (54%), ease of administration (46%), possibility of remission (45%), and perceived efficacy (30%). Physician, health system, and clinical factors rarely influenced decision-making. Patient/parent preferences were selected as reasons more often in chronic ITP (85.7%) than in newly diagnosed (0%) or persistent ITP (14.3%, P = .003). Splenectomy and rituximab were chosen for the possibility of inducing long-term remission (P < .001). Oral agents, such as eltrombopag and immunosuppressants, were chosen for ease of administration and expected adherence (P < .001). Physicians chose rituximab in patients with lower expected adherence (P = .017). Treatment choice showed some physician and treatment center bias. This study illustrates the complexity and many factors involved in decision-making in selecting second-line ITP treatments, given the absence of comparative trials. It highlights shared decision-making and the need for well-conducted, comparative effectiveness studies to allow for informed discussion between patients and clinicians

    Rational Design and Synthesis of Large Stokes Shift 2,6-Sulphur-Disubstituted BODIPYs for Cell Imaging

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    Five new disubstituted 2,6-thioaryl-BODIPY dyes were synthesized via selective aromatic electrophilic substitution from commercially available thiophenols. The analysis of the photophysical properties via absorption and emission spectroscopy showed unusually large Stokes shifts for BODIPY fluorophores (70&ndash;100 nm), which makes them suitable probes for bioimaging. Selected compounds were evaluated for labelling primary immune cells as well as different cancer cell lines using confocal fluorescence microscopy

    A scoping review of interventions and outcome measures in trials of dental behavior support

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    Background Dental behavior support (DBS) describes all techniques used by dental professionals to ensure that dental care is safe, effective, and acceptable. There is a need to standardize outcome measures across DBS techniques to reduce heterogeneity, limit selective reporting, promote consistency, and optimize outcomes across DBS research. A comprehensive review of existing measures is a prerequisite to understanding potential outcomes related to the area of interest. Aim This review had three aims: first, to identify the outcome measures (OMs) reported in trials of dental behavior support; second, to categorize the component DBS techniques reported within interventions according to emerging agreed terminology; and, third, to map outcome measures to intervention type. Methods A scoping review of trials evaluating DBS techniques was undertaken from 2012 to 2022. The review was prospectively registered. Studies were identified through Medline, Embase, and PsycINFO. Study abstracts were screened by two reviewers. Data were extracted by single selector. Outcome measures were sorted according to measurement domains (physiological, behavioral, psychological, and treatment). Responses were assimilated and summed to produce a refined list of distinguishable outcome measures. Intervention types were categorized according to accepted descriptors. Frequencies were presented; associations between outcome domain and DBS type were also reported (Chi-square test of independence). Results A total of 344 trials were included in the review from an initial 14,793 titles / title and abstracts screened. Most involved children (n = 215), most were from India (n = 104), involving basic dental care (n = 117). The median number of outcome measures per trial was four (range = 1–12); 1,317 individual outcomes were reported, categorized as: psychological (n = 501, 38.0%); physiological (n = 491, 37.3%), behavioral (n = 123, 9.3%) or, treatment-related (n = 202, 15.3%). DBS interventions were split between 239 (45.7%) pharmacological and 283 (54.1%) non-pharmacological; 96.6% of interventions mapped to accepted descriptors. A significant relationship was noted between the type of intervention and the outcome domain reported. Conclusion The findings demonstrate massive variation in outcome measures of DBS interventions that likely lead to unnecessary heterogeneity, selective reporting, and questionable relevance in the literature. A large range of DBS interventions were mapped according to BeSiDe list. There is a need for consensus on a core outcome set across the spectrum of DBS techniques

    Putting Guidelines into Practice: Using Co-design to Develop a Complex Intervention Based on NG48 to Enable Care Staff to Provide Daily Oral Care to Older People Living in Care Homes

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    Objectives: 1) Explore the challenges of providing daily oral care in care homes; 2) Understand oral care practices provided by care home staff; 3) Co-design practical resources supporting care home staff in these activities. Methods: Three Sheffield care homes were identified via the ‘ENRICH Research Ready Care Home Network’ and three to six staff per site were recruited as co-design partners. Design researchers led three co-design workshops exploring care home staff’s experiences of providing daily oral care, including challenges, coping strategies and the role of current guidelines. New resources were prototyped to support the use of guidelines in practice. The design researchers developed final resources to enable the use of these guidelines in-practice-in-context. Findings: Care home staff operate under time and resource constraints. The proportion of residents with dementia and other neurodegenerative conditions is rapidly increasing. Care home staff face challenges when residents adopt ‘refusal behaviours’ and balancing daily oral care needs with resident and carer safety becomes complex. Care home staff have developed many coping strategies to navigate ‘refusal behaviours’. Supporting resources need to ‘fit’ within the complexities of practice-in-context. Conclusions: The provision of daily oral care practices in care homes is complex and challenging. The co-design process revealed care home staff have a ‘library’ of context-specific practical knowledge and coping strategies. This study offers insights into the process of making guidelines usable for professionals in their contexts of practice, exploring the agenda of implementing evidence-based guidelines

    Planar lightwave integrated circuits with embedded actives for board and substrate level optical signal distribution

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    © 2004 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.DOI: 10.1109/TADVP.2004.831894As the data rate of integrated circuits dramatically increases, interconnection speed at the backplane and board levels are beginning to limit system performance, which drives investigations into alternative interconnection technologies. Critical factors to consider when evaluating alternative interconnection approaches include interconnect speed, power consumption, area, and compatibility with current backplane and board integration technologies. Optical interconnections can achieve very high speed with a significant reduction in interconnect footprint compared to transmission lines, robust signal quality in high-density interconnection systems because of immunity to electromagnetic interference, and potentially simple to design (compared to transmission lines) lines with materials which can be postprocessed onto printed wiring boards or integrated into the board structure. This paper explores design options for planar optical interconnections integrated onto boards, discusses fabrication options for both beam turning and embedded interconnections to optoelectronic devices, describes integration processes for creating embedded planar optical interconnections, and discusses measurement results for a number of integration schemes that have been demonstrated by the authors. In the area of optical interconnections with beams coupled to and from the board, the topics covered include integrated metal-coated polymer mirrors and volume holographic gratings for optical beam turning perpendicular to the board. Optical interconnections that utilize active thin film (approximately 1-5 µm thick) optoelectronic components embedded in the board are also discussed, using both Si and high temperature FR-4 substrates. Both direct and evanescent coupling of optical signals into and out of the waveguide are discussed using embedded optical lasers and photodetectors

    El Conocimiento Didáctico del Contenido en ciencias: estado de la cuestión

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    This paper gives a descriptive overview of the literature related to Pedagogical Content Knowledge - PCK - in the sciences. It is expected that this review can contribute to a better understanding of PCK, pointing out what has been investigated about this concept. Specifically, we analyze: a) how PCK is defined, what are its main features and how it has been appropriated by teachers; b) the relationship between PCK, knowledge of the contents to be taught and students learning; c) how PCK was actually used in teachers' training and teachers' evaluation; and, d) the scientific areas in which PCK has been studied. It concludes that PCK is an essential tool for improving the quality of teacher training

    Immunosuppressive therapy for pediatric aplastic anemia: a North American Pediatric Aplastic Anemia Consortium study

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    Quality of response to immunosuppressive therapy and long-term outcomes for pediatric severe aplastic anemia remain incompletely characterized. Contemporary evidence to inform treatment of relapsed or refractory severe aplastic anemia for pediatric patients is also limited. The clinical features and outcomes for 314 children treated from 2002 to 2014 with immunosuppressive therapy for acquired severe aplastic anemia were analyzed retrospectively from 25 institutions in the North American Pediatric Aplastic Anemia Consortium. The majority of subjects (n=264) received horse anti-thymocyte globulin (hATG) plus cyclosporine (CyA) with a median 61 months follow up. Following hATG/CyA, 71.2% (95%CI: 65.3,76.6) achieved an objective response. In contrast to adult studies, the quality of response achieved in pediatric patients was high, with 59.8% (95%CI: 53.7,65.8) complete response and 68.2% (95%CI: 62.2,73.8) achieving at least a very good partial response with a platelet count ≥50×109L. At five years post-hATG/CyA, overall survival was 93% (95%CI: 89,96), but event-free survival without subsequent treatment was only 64% (95%CI: 57,69) without a plateau. Twelve of 171 evaluable patients (7%) acquired clonal abnormalities after diagnosis after a median 25.2 months (range: 4.3-71 months) post treatment. Myelodysplastic syndrome or leukemia developed in 6 of 314 (1.9%). For relapsed/refractory disease, treatment with a hematopoietic stem cell transplant had a superior event-free survival compared to second immunosuppressive therapy treatment in a multivariate analysis (HR=0.19, 95%CI: 0.08,0.47; P=0.0003). This study highlights the need for improved therapies to achieve sustained high-quality remission for children with severe aplastic anemia
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