598 research outputs found

    A MEMS Dual Vertical Electrometer and Electric Field-Mill

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    Presented is the first iteration of a Microelectromechanical System (MEMS) dual vertical electrometer and electric field-mill (EFM). The device uses a resonating structure as a variable capacitor that converts the presence of a charge or field into an electric signal. Previous MEMS electrometers are lateral electrometers with laterally spaced electrodes that resonate tangentially with respect to each other. Vertical electrometers, as the name suggests, have vertically spaced electrodes that resonate transversely with respect to each other. The non-tangential movement reduces damping in the system. Both types demonstrate comparable performance, but the vertical electrometer does so at a fraction of the size. In addition, vertical electrometers can efficiently operate as an electric field sensor. The electric field sensor simulations did not compare as well to other MEMS electric field sensors. However, the dual nature of this device makes it appealing. These devices can be used in missiles and satellites to monitor charge buildup in electronic components and the atmosphere [11]. Future iterations can improve these devices and give way to inexpensive, high-resolution electrostatic charge and field sensors

    MEMS Variable Area Capacitor for Room Temperature Electrometry

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    This paper introduces a new way to detect charge using MEMS variable capacitors for extremely sensitive, room temperature electrometry. It is largely based on the electrometers introduced by Riehl et al. [1] except variable capacitance is created by a changing area, not a changing gap. The new scheme will improve MEMS electrometers by eliminating the effects of squeeze-film damping and by theoretically increasing the maximum charge resolution by 70%. The charge conversion gain (the increase in output voltage per input unit charge) for this system is derived. The result show good agreement with MATLAB calculations

    Letter from R[obert] U[nderwood] Johnson to John Muir, 1897 Feb 6.

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    R. W. GILDER, EDITOR.R. U. JOHNSON,ASSOCIATE EDITOR.C. C. BUEL,ASSISTANT EDITOR.February 6th, 1897My dear Muir:-The inclosed letter from Senator Perkins will interest you. Will you please consider it confidential, though it is not marked personal . It seems to me that it is well for the friends of recession to know that the Senator is with us.Yours Faithfully R. U. Johnson,Mr. John MuirMartinex, Cal.02235 United States Senate,WASHINGTON, D. C, Feb 3d. 1897.R.U. Johnson. Esq., Century Magazine, New York City, N. Y.My dear Sir:-I am in receipt of yours of the 1st inst., relating to the transfer of the Yosemite Reservation to the United States, I agree with you perfectly with respect to the advisability of such action, but I am of the opinion that the State Legislature should take action before the matter is brought before Congress. I should not feel at liberty to bring the matter to the notice of the Senate unless authorized by the California Legislature. I therefore suggest that you write to Hon. Warren Olney, 101 Sansome St. San Francisco, who is a lawyer and a member of the Sierra Club, and solicit his aid in securing proper action in California.Yours very truly,Geo [George] C. Perkins0223

    Autism and the U.K. secondary school experience

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    This research investigated the self-reported mainstream school experiences of those diagnosed on the autistic spectrum compared with the typically developing school population. Existing literature identifies four key areas that affect the quality of the school experience for students with autism: social skills, perceived relationships with teaching staff, general school functioning, and interpersonal strengths of the young person. These areas were explored in a mainstream U.K. secondary school with 14 students with autism and 14 age and gender matched students without autism, using self-report questionnaires and semi-structured interviews. Quantitative analyses showed consistent school experiences for both groups, although content analysis of interview data highlighted some differences in the ways in which the groups perceive group work, peers, and teaching staff within school. Implications for school inclusion are discussed, drawing attention to how staff awareness of autism could improve school experience and success for students with autism attending mainstream schools

    Surgical resident experience with common bile duct exploration and assessment of performance and autonomy with formative feedback

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    Background Common bile duct exploration (CBDE) is safe and effective for managing choledocholithiasis, but most US general surgeons have limited experience with CBDE and are uncomfortable performing this procedure in practice. Surgical trainee exposure to CBDE is limited, and their learning curve for achieving autonomous, practice-ready performance has not been previously described. This study tests the hypothesis that receipt of one or more prior CBDE operative performance assessments, combined with formative feedback, is associated with greater resident operative performance and autonomy. Methods Resident and attending assessments of resident operative performance and autonomy were obtained for 189 laparoscopic or open CBDEs performed at 28 institutions. Performance and autonomy were graded along validated ordinal scales. Cases in which the resident had one or more prior CBDE case evaluations (n = 48) were compared with cases in which the resident had no prior evaluations (n = 141). Results Compared with cases in which the resident had no prior CBDE case evaluations, cases with a prior evaluation had greater proportions of practice-ready or exceptional performance ratings according to both residents (27% vs. 11%, p = .009) and attendings (58% vs. 19%, p < .001) and had greater proportions of passive help or supervision only autonomy ratings according to both residents (17% vs. 4%, p = .009) and attendings (69% vs. 32%, p < .01). Conclusions Residents with at least one prior CBDE evaluation and formative feedback demonstrated better operative performance and received greater autonomy than residents without prior evaluations, underscoring the propensity of feedback to help residents achieve autonomous, practice-ready performance for rare operations

    An Advanced Trajectory-Based Operations Prototype Tool and Focus Group Evaluation

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    Trajectory-based operations (TBO) is a key concept in the Next Generation Air Transportation System transformation of the National Airspace System (NAS) that will increase the predictability and stability of traffic flows, support a common operational picture through the use of digital data sharing, facilitate more effective collaborative decision making between airspace users and air navigation service providers, and enable increased levels of integrated automation across the NAS. The National Aeronautics and Space Administration (NASA) has been developing trajectory-based systems to improve the efficiency of the NAS during specific phases of flight and is now also exploring Advanced 4-Dimensional Trajectory (4DT) operational concepts that will integrate these technologies and incorporate new technology where needed to create both automation and procedures to support gate-to-gate TBO. A TBO Prototype simulation toolkit has been developed that demonstrates initial functionality that may reside in an Advanced 4DT TBO concept. Pilot and controller subject matter experts (SMEs) were brought to the Air Traffic Operations Laboratory at NASA Langley Research Center for discussions on an Advanced 4DT operational concept and were provided an interactive demonstration of the TBO Prototype using four example scenarios. The SMEs provided feedback on potential operational, technological, and procedural opportunities and concerns. After viewing the interactive demonstration scenarios, the SMEs felt the operational capabilities demonstrated would be useful for performing TBO while maintaining situation awareness and low mental workload. The TBO concept demonstrated produced defined routings around weather which resulted in a more organized, consistent flow of traffic where it was clear to both the controller and pilot what route the aircraft was to follow. In general, the controller SMEs felt that traffic flow management should be responsible for generating and negotiating the operational constraints demonstrated, in cooperation with the Air Traffic Control System Command Center, while air traffic control should be responsible for the implementation of those constraints. The SMEs also indicated that digital data communications would be very beneficial for TBO operations and would result in less workload due to reduced communications, would eliminate issues due to language barriers and frequency problems, and would make receiving, loading, accepting, and executing clearances easier, less ambiguous, and more expeditious. This paper describes an Advanced 4DT operational concept, the TBO Prototype, the demonstration scenarios and methods used, and the feedback obtained from the pilot and controller SMEs in this focus group evaluation

    Unlocking Community Capabilities Across Health Systems in Low- and Middle-Income Countries: Lessons Learned from Research and Reflective Practice

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    The right and responsibility of communities to participate in health service delivery was enshrined in the 1978 Alma Ata declaration and continues to feature centrally in health systems debates today. Communities are a vital part of people-centred health systems and their engagement is critical to realizing the diverse health targets prioritised by the Sustainable Development Goals and the commitments made to Universal Health Coverage. Community members' intimate knowledge of local needs and adaptive capacities are essential in constructively harnessing global transformations related to epidemiological and demographic transitions, urbanization, migration, technological innovation and climate change. Effective community partnerships and governance processes that underpin community capability also strengthen local resilience, enabling communities to better manage shocks, sustain gains, and advocate for their needs through linkages to authorities and services. This is particularly important given how power relations mark broader contexts of resource scarcity and concentration, struggles related to social liberties and other types of ongoing conflicts.IS

    Doing implementation research on health governance: a frontline researcher’s reflexive account of field-level challenges and their management

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    BACKGROUND: Implementation Research (IR) in and around health systems comes with unique challenges for researchers including implementation, multi-layer governance, and ethical issues. Partnerships between researchers, implementers, policy makers and community members are central to IR and come with additional challenges. In this paper, we elaborate on the challenges faced by frontline field researchers, drawing from experience with an IR study on Village Health Sanitation and Nutrition Committees (VHSNCs). METHODS: The IR on VHSNC took place in one state/province in India over an 18-month research period. The IR study had twin components; intervention and in-depth research. The intervention sought to strengthen the VHSNC functioning, and concurrently the research arm sought to understand the contextual factors, pathways and mechanism affecting VHSNC functions. Frontline researchers were employed for data collection and a research assistant was living in the study sites. The frontline research assistant experienced a range of challenges, while collecting data from the study sites, which were documented as field memos and analysed using inductive content analysis approach. RESULTS: Due to the relational nature of IR, the challenges coalesced around two sets of relationships (a) between the community and frontline researchers and (b) between implementers and frontline researchers. In the community, the frontline researcher was viewed as the supervisor of the intervention and was perceived by the community to have power to bring about beneficial changes with public services and facilities. Implementers expected help from the frontline researcher in problem-solving in VHSNCs, and feedback on community mobilization to improve their approaches. A concerted effort was undertaken by the whole research team to clarify and dispel concerns among the community and implementers through careful and constant communication. The strategies employed were both managerial, relational and reflexive in nature. CONCLUSION: Frontline researchers through their experiences shape the research process and its outcome and they play a central role in the research. It demonstrates that frontline researcher resilience is very crucial when conducting health policy and systems research.Scopu

    Self-Reported Health-Promoting Behaviors of Black and White Caregivers

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    The purpose of this study was to describe the behaviors that caregivers report carrying out to maintain their own health, and to compare the health-promoting behaviors of Black and White caregivers. Although many studies have examined health-promoting behaviors, few have examined health promotion among caregivers. Reported studies of caregivers’ health-promoting behaviors have not compared cultural groups. The sample for this study was selected by random digit dialing, and included 136 Black and 257 White caregivers of frail elders. Content analysis of respondents’ answers to the open-ended question, “In general, what do you do to stay healthy?” was used to address the research questions. Most caregivers reported specific behaviors they engaged in for the purpose of staying healthy. Although most of their behaviors addressed physical health, caregivers also mentioned behaviors that contribute to mental and spiritual health. Both differences and similarities were found in Black and White caregivers’ self-reported health behaviors, which have important implications for nursing practice and research in the future.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69087/2/10.1177_01939459922044027.pd
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