Autonomous and Robust Orbit-Keeping for Small-Body Missions

2022 ◽  
pp. 1-12
Author(s):  
Rodolfo Batista Negri ◽  
Antônio F. B. A. Prado
Keyword(s):  
Methodology ◽  
2015 ◽  
Vol 11 (3) ◽  
pp. 89-99 ◽  
Author(s):  
Leslie Rutkowski ◽  
Yan Zhou

Abstract. Given a consistent interest in comparing achievement across sub-populations in international assessments such as TIMSS, PIRLS, and PISA, it is critical that sub-population achievement is estimated reliably and with sufficient precision. As such, we systematically examine the limitations to current estimation methods used by these programs. Using a simulation study along with empirical results from the 2007 cycle of TIMSS, we show that a combination of missing and misclassified data in the conditioning model induces biases in sub-population achievement estimates, the magnitude and degree to which can be readily explained by data quality. Importantly, estimated biases in sub-population achievement are limited to the conditioning variable with poor-quality data while other sub-population achievement estimates are unaffected. Findings are generally in line with theory on missing and error-prone covariates. The current research adds to a small body of literature that has noted some of the limitations to sub-population estimation.


1996 ◽  
Vol 76 (05) ◽  
pp. 682-688 ◽  
Author(s):  
Jos P J Wester ◽  
Harold W de Valk ◽  
Karel H Nieuwenhuis ◽  
Catherine B Brouwer ◽  
Yolanda van der Graaf ◽  
...  

Summary Objective: Identification of risk factors for bleeding and prospective evaluation of two bleeding risk scores in the treatment of acute venous thromboembolism. Design: Secondary analysis of a prospective, randomized, assessor-blind, multicenter clinical trial. Setting: One university and 2 regional teaching hospitals. Patients: 188 patients treated with heparin or danaparoid for acute venous thromboembolism. Measurements: The presenting clinical features, the doses of the drugs, and the anticoagulant responses were analyzed using univariate and multivariate logistic regression analysis in order to evaluate prognostic factors for bleeding. In addition, the recently developed Utrecht bleeding risk score and Landefeld bleeding risk index were evaluated prospectively. Results: Major bleeding occurred in 4 patients (2.1%) and minor bleeding in 101 patients (53.7%). For all (major and minor combined) bleeding, body surface area ≤2 m2 (odds ratio 2.3, 95% Cl 1.2-4.4; p = 0.01), and malignancy (odds ratio 2.4, 95% Cl 1.1-4.9; p = 0.02) were confirmed to be independent risk factors. An increased treatment-related risk of bleeding was observed in patients treated with high doses of heparin, independent of the concomitant activated partial thromboplastin time ratios. Both bleeding risk scores had low diagnostic value for bleeding in this sample of mainly minor bleeders. Conclusions: A small body surface area and malignancy were associated with a higher frequency of bleeding. The bleeding risk scores merely offer the clinician a general estimation of the risk of bleeding. In patients with a small body surface area or in patients with malignancy, it may be of interest to study whether limited dose reduction of the anticoagulant drug may cause less bleeding without affecting efficacy.


2010 ◽  
Vol 3 (2) ◽  
pp. 119-133 ◽  
Author(s):  
Michelle Superle

In the past two decades, the previously silent voices of diasporic Indian writers for young people have emerged, and a small body of texts has begun to develop in the United States and the United Kingdom. One of the major preoccupations of these texts is cultural identity development, especially in the novels published for a young adult audience, which often feature protagonists in the throes of an identity crisis. For example, the novels The Roller Birds of Rampur (1991) by Indi Rana, Born Confused (2002) by Tanuja Desai Hidier, and The Not-So-Star-Spangled Life of Sunita Sen (2005) by Mitali Perkins all focus on an adolescent girl coping with her bicultural identity with angst and confusion, and delineate the ways her self-concept and relationships are affected. The texts are empowering in their suggestion that young people have the agency to explore and create their own balanced bicultural identities, but like other young adult fiction, they ultimately situate adolescents within insurmountable institutional forces that are much more powerful than any individual.


2020 ◽  
Vol 6 (2) ◽  
pp. 145-173 ◽  
Author(s):  
Heidi E. Rademacher

Promoting the ratification of the Convention on the Elimination of All Forms of Discrimination against Women (CEDAW) was a key objective of the transnational women's movement of the 1980s and 1990s. Yet, few studies examine what factors contribute to ratification. The small body of literature on this topic comes from a world-society perspective, which suggests that CEDAW represented a global shift toward women's rights and that ratification increased as international NGOs proliferated. However, this framing fails to consider whether diffusion varies in a stratified world-system. I combine world-society and world-systems approaches, adding to the literature by examining the impact of women's and human rights transnational social movement organizations on CEDAW ratification at varied world-system positions. The findings illustrate the complex strengths and limitations of a global movement, with such organizations having a negative effect on ratification among core nations, a positive effect in the semiperiphery, and no effect among periphery nations. This suggests that the impact of mobilization was neither a universal application of global scripts nor simply representative of the broad domination of core nations, but a complex and diverse result of civil society actors embedded in a politically stratified world.


2011 ◽  
Vol 14 (1) ◽  
pp. 28 ◽  
Author(s):  
George Vretzakis ◽  
Athina Kleitsaki ◽  
Diamanto Aretha ◽  
Menelaos Karanikolas

Blood transfusions are associated with adverse physiologic effects and increased cost, and therefore reduction of blood product use during surgery is a desirable goal for all patients. Cardiac surgery is a major consumer of donor blood products, especially when cardiopulmonary bypass (CPB) is used, because hematocrit drops precipitously during CPB due to blood loss and blood cell dilution. Advanced age, low preoperative red blood cell volume (preoperative anemia or small body size), preoperative antiplatelet or antithrombotic drugs, complex or re-operative procedures or emergency operations, and patient comorbidities were identified as important transfusion risk indicators in a report recently published by the Society of Cardiovascular Anesthesiologists. This report also identified several pre- and intraoperative interventions that may help reduce blood transfusions, including off-pump procedures, preoperative autologous blood donation, normovolemic hemodilution, and routine cell saver use.A multimodal approach to blood conservation, with highrisk patients receiving all available interventions, may help preserve vital organ perfusion and reduce blood product utilization. In addition, because positive intravenous fluid balance is a significant factor affecting hemodilution during cardiac surgery, especially when CPB is used, strategies aimed at limiting intraoperative fluid balance positiveness may also lead to reduced blood product utilization.This review discusses currently available techniques that can be used intraoperatively in an attempt to avoid or minimize fluid balance positiveness, to preserve the patient's own red blood cells, and to decrease blood product utilization during cardiac surgery.


2005 ◽  
Author(s):  
Colin R McInnes ◽  
Gareth W Hughes ◽  
Malcolm Macdonald
Keyword(s):  

Author(s):  
Kirk Moss ◽  
Stephen Benham ◽  
Kristen Pellegrino

After reviewing a small body of literature on the assessment practices of American orchestra directors, this chapter quickly shifts attention to conducting original research. It describes a descriptive survey study with American String Teachers Association (ASTA) members (N = 416) that found performance-based assessments were the most frequently used form of formal assessment to evaluate technique, musicianship skills, creative musicianship, and ensemble skills. Music literacy was nearly equally split between performance-based and written assessments, while evaluation of music and musical performances and historical and cultural elements tended toward written assessments and verbal feedback. Creative musicianship and historical/cultural elements were the top two nonassessed areas, but were still assessed by the vast majority of teachers. Interviews with five string teachers demonstrate that the research participants emphasized performing/playing assessments, focused on student learning/improvement, acknowledged the role of the school district/administration and benefited from its support, and recognized the value in aligning assessment to standards/curriculum.


Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2053
Author(s):  
Junsong Shi ◽  
Baohua Tan ◽  
Lvhua Luo ◽  
Zicong Li ◽  
Linjun Hong ◽  
...  

How to maximize the use of the genetic merits of the high-ranking boars (also called superior ones) is a considerable question in the pig breeding industry, considering the money and time spent on selection. Somatic cell nuclear transfer (SCNT) is one of the potential ways to answer the question, which can be applied to produce clones with genetic resources of superior boar for the production of commercial pigs. For practical application, it is essential to investigate whether the clones and their progeny keep behaving better than the “normal boars”, considering that in vitro culture and transfer manipulation would cause a series of harmful effects to the development of clones. In this study, 59,061 cloned embryos were transferred into 250 recipient sows to produce the clones of superior Pietrain boars. The growth performance of 12 clones and 36 non-clones and the semen quality of 19 clones and 28 non-clones were compared. The reproductive performance of 21 clones and 25 non-clones were also tested. Furthermore, we made a comparison in the growth performance between 466 progeny of the clones and 822 progeny of the non-clones. Our results showed that no significant difference in semen quality and reproductive performance was observed between the clones and the non-clones, although the clones grew slower and exhibited smaller body size than the non-clones. The F1 progeny of the clones showed a greater growth rate than the non-clones. Our results demonstrated through the large animal population showed that SCNT manipulation resulted in a low growth rate and small body size, but the clones could normally produce F1 progeny with excellent growth traits to bring more economic benefits. Therefore, SCNT could be effective in enlarging the merit genetics of the superior boars and increasing the economic benefits in pig reproduction and breeding.


BMC Biology ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Amrita Srivathsan ◽  
Emily Hartop ◽  
Jayanthi Puniamoorthy ◽  
Wan Ting Lee ◽  
Sujatha Narayanan Kutty ◽  
...  

Abstract Background More than 80% of all animal species remain unknown to science. Most of these species live in the tropics and belong to animal taxa that combine small body size with high specimen abundance and large species richness. For such clades, using morphology for species discovery is slow because large numbers of specimens must be sorted based on detailed microscopic investigations. Fortunately, species discovery could be greatly accelerated if DNA sequences could be used for sorting specimens to species. Morphological verification of such “molecular operational taxonomic units” (mOTUs) could then be based on dissection of a small subset of specimens. However, this approach requires cost-effective and low-tech DNA barcoding techniques because well-equipped, well-funded molecular laboratories are not readily available in many biodiverse countries. Results We here document how MinION sequencing can be used for large-scale species discovery in a specimen- and species-rich taxon like the hyperdiverse fly family Phoridae (Diptera). We sequenced 7059 specimens collected in a single Malaise trap in Kibale National Park, Uganda, over the short period of 8 weeks. We discovered > 650 species which exceeds the number of phorid species currently described for the entire Afrotropical region. The barcodes were obtained using an improved low-cost MinION pipeline that increased the barcoding capacity sevenfold from 500 to 3500 barcodes per flowcell. This was achieved by adopting 1D sequencing, resequencing weak amplicons on a used flowcell, and improving demultiplexing. Comparison with Illumina data revealed that the MinION barcodes were very accurate (99.99% accuracy, 0.46% Ns) and thus yielded very similar species units (match ratio 0.991). Morphological examination of 100 mOTUs also confirmed good congruence with morphology (93% of mOTUs; > 99% of specimens) and revealed that 90% of the putative species belong to the neglected, megadiverse genus Megaselia. We demonstrate for one Megaselia species how the molecular data can guide the description of a new species (Megaselia sepsioides sp. nov.). Conclusions We document that one field site in Africa can be home to an estimated 1000 species of phorids and speculate that the Afrotropical diversity could exceed 200,000 species. We furthermore conclude that low-cost MinION sequencers are very suitable for reliable, rapid, and large-scale species discovery in hyperdiverse taxa. MinION sequencing could quickly reveal the extent of the unknown diversity and is especially suitable for biodiverse countries with limited access to capital-intensive sequencing facilities.


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