169 research outputs found
The Role of Cytonemes and Diffusive Transport in the Establishment of Morphogen Gradients
Spatial distributions of morphogens provide positional information in
developing systems, but how the distributions are established and maintained
remains an open problem. Transport by diffusion has been the
traditional mechanism, but recent experimental work has shown that cells can
also communicate by filopodia-like structures called cytonemes that make
direct
cell-to-cell contacts. Here we investigate the roles each may play
individually in a complex tissue and how they can jointly establish a
reliable
spatial distribution of a morphogen.Comment: 36 pages, 16 figure
Blade root moment sensor failure detection based on multibeam LIDAR for fault-tolerant individual pitch control of wind turbines
Detection of blade root moment sensor failures is an important problem for fault-tolerant individual pitch control, which plays a key role in reduction of uneven blade loads of large wind turbines. A new method for detection of blade root moment sensor failures which is based on variations induced by a vertical wind shear is described in this paper. The detection is associated with monitoring of statistical properties of the difference between amplitudes of the first harmonic of the blade load, which is calculated in two different ways. The first method is based on processing of the load sensor signal, which contains a number of harmonics. The first harmonic is recovered via least squares estimation of the blade load signal with harmonic regressor and strictly diagonally dominant (SDD) information matrix. The second method is a model-based method of estimation of the first harmonic, which relies on the blade load model and upwind speed measurements provided by multibeam Light Detection and Ranging (LIDAR). This is a new application for future LIDAR-enabled wind turbine technologies. Moreover, adaptation of the load model in a uniform wind field is proposed. This adaptation improves accuracy of the load estimation and hence the performance of the blade load sensor failure detection method
The anti-civic effects of popular culture on American teenagers
Civic participation and civic awareness is essential to the
maintenance of American democracy. Strong civic communities
serve to promote prosperity, ensure the resolution of
collective problems, and act as a check upon the power of
the state. But in 2002, there is little doubt that, across a wide
range of indicators, America’s civic culture is in decline.
Voting rates have fallen rapidly over the past several decades,
and so too has trust in government. Equally troubling
Ec002
Massachusetts Department
of Education
[email protected]
Massachusetts Department
of Education
Massachusetts Department
of Education
Massachusetts Department
of Education
[email protected]
Anders Lewis
Jennifer Butler
Melanie
Winklosky
Sandra Stotsky
ESE Nº002 2002
is the disconcerting dearth of civic knowledge among American
youths and the drop in participation, among all Americans,
in numerous civic organizations, from church-affiliated
groups to voluntary and fraternal organizations as
well as women’s auxiliaries and unions. There are many causes
for these trends. This paper examines how popular culture
affects civic participation and civic awareness among a
group of particularly active teenagers in Massachusetts. We
found that popular culture has a generally negative influence
on civic life but that its effects are not one-sided
and that it can be mitigated by strong families and quality
schools committed to an academic and civic education
Run-in periods and clinical outcomes of antipsychotics in dementia:A meta-epidemiological study of placebo-controlled trials
PURPOSE: Run-in periods are used to identify placebo-responders and washout. Our aim was to assess the association of run-in periods with clinical outcomes of antipsychotics in dementia. METHODS: We searched randomized placebo-controlled trials of conventional and atypical antipsychotics for neuropsychiatric symptoms (NPS) in dementia in electronic sources and references of selected articles. We extracted (a) the presence of a run-in period, use of placebo/investigated drug during run-in (versus washout only), and run-in duration (1 week or more) and (b) the reduction in NPS, number of participants with somnolence, extrapyramidal symptoms (EPS), and deaths per treatment group. We pooled clinical outcomes comparing antipsychotic and placebo groups in trials with and without run-in. RESULTS: We identified 35 trials. Twenty-nine trials used run-in. The pooled standardized mean difference in the reduction of NPS was -0.170 (95% CI, -0.227 to -0.112) in trials with run-in and -0.142 (95% CI, -0.331 to 0.047) in trials without run-in. The pooled odds ratio for somnolence was 2.8 (95% CI, 2.3-3.5) in trials with run-in and 3.5 (95% CI, 1.2-10.7) in trials without run-in; for EPS, these ORs were 1.8 (95% CI, 1.4-2.2) and 2.0 (95% CI, 1.3-3.1) respectively, and for mortality 1.4 (95% CI, 1.0-2.0) and 1.6 (95% CI, 0.7-3.4). The use of placebo/investigated drug during run-in and run-in duration did not affect the estimates in a consistent way. CONCLUSIONS: The use of run-in in trials might have led to overestimated efficacy and especially underestimated risks of side effects of antipsychotics compared with placebo for NPS in dementia
Measuring the capability to raise revenue process and output dimensions and their application to the Zambia revenue authority
The worldwide diffusion of the good governance agenda and new public management has triggered a renewed focus on state capability and, more specifically, on the capability to raise revenue in developing countries. However, the analytical tools for a comprehensive understanding of the capability to raise revenue remain underdeveloped. This article aims at filling this gap and presents a model consisting of the three process dimensions ‘information collection and processing’, ‘merit orientation’ and ‘administrative accountability’. ‘Revenue performance’ constitutes the fourth capability dimension which assesses tax administration’s output. This model is applied to the case of the Zambia Revenue Authority. The dimensions prove to be valuable not only for assessing the how much but also the how of collecting taxes. They can be a useful tool for future comparative analyses of tax administrations’ capabilities in developing countries.Die weltweite Verbreitung der Good-Governance- und New-Public-Management-Konzepte hat zu einer zunehmenden Konzentration auf staatliche Leistungsfähigkeit und, im Besonderen, auf die Leistungsfähigkeit der Steuererhebung in Entwicklungsländern geführt. Allerdings bleiben die analytischen Werkzeuge für ein umfassendes Verständnis von Leistungsfähigkeit unterentwickelt. Dieser Artikel stellt hierfür ein Modell vor, das die drei Prozess-Dimensionen „Sammeln und Verarbeiten von Informationen“, „Leistungsorientierung der Mitarbeiter“ und „Verantwortlichkeit der Verwaltung“ beinhaltet. „Einnahmeperformanz“ ist die vierte Dimension und erfasst den Output der Steuerverwaltung. Das mehrdimensionale Modell wird für die Analyse der Leistungsfähigkeit der Steuerbehörde Zambias (Zambia Revenue Authority) genutzt. Es erweist sich nicht nur für die Untersuchung des Wieviel, sondern auch des Wie des Erhebens von Steuern als wertvoll. Die vier Dimensionen können in Zukunft zur umfassenden und vergleichenden Analyse der Leistungsfähigkeit verschiedener Steuerverwaltungen in Entwicklungsländern genutzt werden
ОСТАНОВКА КРОВООБРАЩЕНИЯ С УСПЕШНОЙ РЕАНИМАЦИЕЙ И ПРОФИЛАКТИКОЙ РЕЦИДИВА У БОЛЬНОГО С СИНДРОМОМ БРУГАДА (КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ)
We report the clinical case and data on the delayed annualmonitoring of a patient with the Brugada syndrome, complicated with the clinical deathПриводится клиническое наблюдение и данные отсроченного годичного контроля пациента с синдромом Бругада, осложненным клинической смертью
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