234 research outputs found
The RTL-46: A simulated commercial air transportation study
The RTL-46 provides an aircraft which utilizes advanced technology within the fictional Aeroworld market to better service the air travel customers and airlines of Aeroworld. The RTL-46 is designed to serve the portion of the travel market which flies less than 10,000 feet per flight. The design cruise velocity for the aircraft is 35 ft/sec, which rapidly expedites travel through Aeroworld. The major focus of the endeavor was to design an aircraft which would serve the Aeroworld market better than the existing aircraft, the HB-40. This could have been done through targeting another portion of the Aeroworld market or through serving the current HB-40 market more effectively. Due to the fact that approximately 70 percent of the potential Aeroworld passengers desired flights of 10,000 ft or less, this range became the target market for the RTL-46
An Approach to the Design and the Interactions of a Fully Superconducting Synchronous Generator and Its Power Converter
Changes in colorectal cancer screening intention among people aged 18–49 in the United States
Background: To determine whether exposure to a peer-led intervention focused on colorectal cancer (CRC) screening, physical activity, and multi-vitamin intake can lead to increased intentions to be screened for CRC once age eligible among adults under the age of 50. Methods: Participants were residents of low-income housing sites, and CRC screening intentions were assessed at baseline and at follow-up (approximately 2 years later) to determine changes in screening intentions and factors associated with changes in intentions. Results: Participants (n = 692) were 78.4% female, 42.6% Hispanic and 50.8% black. At follow-up, 51% maintained their intention to be screened and 14.6% newly intended to get screened. Individuals newly intending to get screened were more likely to have participated in the intervention, be older, male, and born in Puerto Rico or the United States compared to those who maintained their intention not to get screened (p < 0.05). Conclusion: Exposure to CRC prevention messages before the age of 50 can increase screening intentions among individuals who did not initially intend to get screened. Peer-led interventions to promote CRC screening should include individual less than 50 years of age, as this may contribute to increased screening at the recommended age threshold
Social Support for Changing Multiple Behaviors: Factors Associated With Seeking Support and the Impact of Offered Support
Introduction. Social support is important for behavior change, and it may be particularly important for the complexities of changing multiple risk behaviors (MRB). Research is needed to determine if participants in an MRB intervention can be encouraged to activate their social network to aid their change efforts. Methods. Healthy Directions 2, a cluster-randomized controlled trial of an intervention conducted in two urban health centers, targeted five behaviors (physical activity, fruit and vegetable intake, red meat consumption, multivitamin use, and smoking). The self-guided intervention emphasized changing MRB simultaneously, focused on self-monitoring and action planning, and encouraged participants to seek support from social network members. An MRB score was calculated for each participant, with one point being assigned for each behavioral recommendation that was not met. Analyses were conducted to identify demographic and social contextual factors (e.g., interpersonal, neighborhood, and organizational resources) associated with seeking support and to determine if type and frequency of offered support were associated with changes in MRB score. Results. Half (49.6%) of participants identified a support person. Interpersonal resources were the only contextual factor that predicted engagement of a support person. Compared to individuals who did not seek support, those who identified one support person had 61% greater reduction in MRB score, and participants identifying multiple support persons had 100% greater reduction. Conclusion. Engagement of one’s social network leads to significantly greater change across multiple risk behaviors. Future research should explore strategies to address support need for individuals with limited interpersonal resources
An Approach to the Design and the Interactions of a Fully Superconducting Synchronous Generator and Its Power Converter
The design of a fully superconducting wind power generator is influenced by several factors. Among them, a low number of pole pairs is desirable to achieve low AC losses in the superconducting stator winding, which greatly influences the cooling system design and, consecutively, the efficiency of the entire wind power plant. However, it has been identified that a low number of pole pairs in a superconducting generator tends to greatly increase its output voltage, which in turn creates challenging conditions for the necessary power electronic converter. This study highlights the interdependencies between the design of a fully superconducting 10 MW wind power generator and the corresponding design of its power electronic converter. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
Gridless 3D Recovery of Image Sources from Room Impulse Responses
International audienceGiven a sound field generated by a sparse distribution of impulse image sources, can the continuous 3D positions and amplitudes of these sources be recovered from discrete, bandlimited measurements of the field at a finite set of locations, e.g., a multichannel room impulse response? Borrowing from recent advances in super-resolution imaging, it is shown that this nonlinear, non-convex inverse problem can be efficiently relaxed into a convex linear inverse problem over the space of Radon measures in R3. The linear operator introduced here stems from the fundamental solution of the free-field inhomogenous wave equation combined with the receivers' responses. An adaptation of the Sliding Frank-Wolfe algorithm is proposed to numerically solve the problem off-the-grid, i.e., in continuous 3D space. Simulated experiments show that the approach achieves near-exact recovery of hundreds of image sources using an arbitrarily placed compact 32-channel spherical microphone array in random rectangular rooms. The impact of noise, sampling rate and array diameter on these results is also examined
Male-female communication triggers calcium signatures during fertilization in Arabidopsis
Cell-cell communication and interaction is critical during fertilization and triggers free cytosolic calcium ([Ca2+](cyto)) as a key signal for egg activation and a polyspermy block in animal oocytes. Fertilization in flowering plants is more complex, involving interaction of a pollen tube with egg adjoining synergid cells, culminating in release of two sperm cells and their fusion with the egg and central cell, respectively. Here, we report the occurrence and role of [Ca2+](cyto) signals during the entire double fertilization process in Arabidopsis. [Ca2+](cyto) oscillations are initiated in synergid cells after physical contact with the pollen tube apex. In egg and central cells, a short [Ca2+](cyto) transient is associated with pollen tube burst and sperm cell arrival. A second extended [Ca2+](cyto) transient solely in the egg cell is correlated with successful fertilization. Thus, each female cell type involved in double fertilization displays a characteristic [Ca2+](cyto) signature differing by timing and behaviour from [Ca2+](cyto) waves reported in mammals
A randomized comparative effectiveness study of Healthy Directions 2—A multiple risk behavior intervention for primary care
Objective: To evaluate the effectiveness of the Healthy Directions 2 (HD2) intervention in the primary care setting.
Methods: HD2 was a cluster randomized trial (conducted 3/09–11/11). The primary sampling unit was provider (n = 33), with secondary sampling of patients within provider (n = 2440). Study arms included: 1) usual care (UC); 2) HD2—a patient self-guided intervention targeting 5 risk behaviors; and 3) HD2 plus 2 brief telephone coaching calls (HD2 + CC). The outcome measure was the proportion of participants with a lower multiple risk behavior (MRB) score by follow-up.
Results: At baseline, only 4% of the participants met all behavioral recommendations. Both HD2 and HD2 + CC led to improvements in MRB score, relative to UC, with no differences between the two HD2 conditions. Twenty-eight percent of the UC participants had improved MRB scores at 6 months, vs. 39% and 43% in HD2 and HD2 + CC, respectively (ps ≤ .001); results were similar at 18 months (p ≤ .05). The incremental cost of one risk factor reduction in MRB score was 450 for HD2 + CC.
Conclusions: Self-guided and coached intervention conditions had equivalent levels of effect in reducing multiple chronic disease risk factors, were relatively low cost, and thus are potentially useful for routine implementation in similar health settings
Differential expression patterns of Arabinogalactan Proteins in Arabidopsis thaliana reproductive tissues
36 p.-6 fig.Arabinogalactan proteins (AGPs) are heavily glycosylated proteins existing in all members of the plant kingdom and are differentially distributed through distinctive developmental stages. Here, we showed the individual distributions of specific Arabidopsis AGPs: AGP1, AGP9, AGP12, AGP15, and AGP23, throughout reproductive tissues and indicated their possible roles in several reproductive processes. AGP genes specifically expressed in female tissues were identified using available microarray data. This selection was confirmed by promoter analysis using multiple green fluorescent protein fusions to a nuclear localization signal, β-glucuronidase fusions, and in situ hybridization as approaches to confirm the expression patterns of the AGPs. Promoter analysis allowed the detection of a specific and differential presence of these proteins along the pathway followed by the pollen tube during its journey to reach the egg and the central cell inside the embryo sac. AGP1 was expressed in the stigma, style, transmitting tract, and the chalazal and funiculus tissues of the ovules. AGP9 was present along the vasculature of the reproductive tissues and AGP12 was expressed in the stigmatic cells, chalazal and funiculus cells of the ovules, and in the septum. AGP15 was expressed in all pistil tissues, except in the transmitting tract, while AGP23 was specific to the pollen grain and pollen tube. The expression pattern of these AGPs provides new evidence for the detection of a subset of specific AGPs
involved in plant reproductive processes, being of significance for this field of study. AGPs are prominent candidates
for male–female communication during reproduction.This work was financed by FEDER through the COMPETE programme, and by Portuguese National funds through FCT – Fundação para a Ciência e Tecnologia (Project PTDC/AGR-GPL/115358/2009) and from an FCT PhD grant SFRH/BD/60995/2009 awarded to AMP. This project also benefited from financial support from the COST Action FA0903: ‘Harnessing Plant Reproduction for Crop Improvement’.Peer reviewe
Male-female communication triggers calcium signatures during fertilization in Arabidopsis
Cell-cell communication and interaction is critical during fertilization and triggers free cytosolic calcium ([Ca2+](cyto)) as a key signal for egg activation and a polyspermy block in animal oocytes. Fertilization in flowering plants is more complex, involving interaction of a pollen tube with egg adjoining synergid cells, culminating in release of two sperm cells and their fusion with the egg and central cell, respectively. Here, we report the occurrence and role of [Ca2+](cyto) signals during the entire double fertilization process in Arabidopsis. [Ca2+](cyto) oscillations are initiated in synergid cells after physical contact with the pollen tube apex. In egg and central cells, a short [Ca2+](cyto) transient is associated with pollen tube burst and sperm cell arrival. A second extended [Ca2+](cyto) transient solely in the egg cell is correlated with successful fertilization. Thus, each female cell type involved in double fertilization displays a characteristic [Ca2+](cyto) signature differing by timing and behaviour from [Ca2+](cyto) waves reported in mammals
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