Space-exposed seed experiment developed for students

Author(s):  
Donna Leeper ◽  
Kelvin Bridgers ◽  
Ernest C. Hammond

The SEEDS project was flown in orbit aboard the Long Duration Exposure (LDEF) for nearly six years. During this time in space, the tomato seeds received an enormously abundant supply of cosmic radiation. Upon the return of the LDEF to earth, the SEEDS project was distributed throughout the United States and 30 foreign countries for analysis. The purpose of the experiment was to determine the long term effects of cosmic rays on living tissue. At Morgan, the analysis performed varied from germination and growth rates to electron microscopy and x ray analysis.In analyzing the seeds under the electron microscope, usual observations were performed on the nutritional and epidermic layers of the seed. These layers appeared to be more porous in the space-exposed seeds than in the Earth-based control seeds. This unusual characteristic may explain the increase in the space seeds’ growth pattern. (Several test results show that the space-exposed seeds germinate sooner than the Earth-based seeds. Also, the space exposed seeds are growing at a faster rate.) The porous nutritional region may allow the the seeds to receive necessary nutrients and liquids more readily. Thus, enabling the plant to grow at a much faster rate.

2011 ◽  
Vol 33 (6) ◽  
pp. 6-9
Author(s):  
Catherine Sheely ◽  
Samer Hattar

As the Earth rotates around its axis, the Sun illuminates different parts of the planet with varied strengths and amounts of light exposure. Primary producers, from unicellular cyanobacteria to redwood trees, harness the light energy and provide the basis for food chains in the Earth's ecosystems. Light, however, has other functions that are important for survival, which include phototaxis in unicellular organisms, measuring day length (photoperiodism) in plants and animals, and vision. Although the eye is a highly specialized organ that contains the photoreceptive machinery to mediate vision, organisms such as fish, birds and lizards rely on extraocular photoreceptors to co-ordinate long-term effects of light, including synchronization of daily rhythms to the solar day, photoperiodic measurements and hormonal regulation. Mammals, however, rely solely on the eyes and a specialized photoreceptive neuronal structure, the retina, to receive all light information for image and non-image forming visual functions.


2020 ◽  
Author(s):  
Joseph Matthews ◽  
Madhu Pandey

Propeller planes and small engine aircraft around the United States, legally utilize leaded aviation gasoline. The purpose of this experiment was to collect suspended particulate matter from a university campus, directly below an airport’s arriving flight path’s descent line, and to analyze lead content suspended in the air. Two collection sets of three separate samples were collected on six separate days, one set in July of 2018 and the second set in January 2019.


Author(s):  
Abraham L. Newman ◽  
Elliot Posner

Chapter 6 examines the long-term effects of international soft law on policy in the United States since 2008. The extent and type of post-crisis US cooperation with foreign jurisdictions have varied considerably with far-reaching ramifications for international financial markets. Focusing on the international interaction of reforms in banking and derivatives, the chapter uses the book’s approach to understand US regulation in the wake of the Great Recession. The authors attribute seemingly random variation in the US relationship to foreign regulation and markets to differences in pre-crisis international soft law. Here, the existence (or absence) of robust soft law and standard-creating institutions determines the resources available to policy entrepreneurs as well as their orientation and attitudes toward international cooperation. Soft law plays a central role in the evolution of US regulatory reform and its interface with the rest of the world.


2021 ◽  
pp. 048661342097642
Author(s):  
Juan E. Santarcángelo ◽  
Juan Manuel Padín

Argentina’s right-wing shift in the 2015 presidential election concluded twelve years of center-left rule. The elected president, Mauricio Macri, claimed that the economy would experience normalization of existing imbalances and recover its strength in a “new political era.” However, the new administration quickly restored the dominance of neoliberal economic policies through a comprehensive set of initiatives, which centrally included the return to international financial debt and equity markets and submission to the International Monetary Fund’s (IMF) rules. This article analyzes Argentina’s external-debt-growth process and discusses its objectives and long-term effects. This paper posits that the indebtedness process carried out by the Macri administration—and its modality—not only increased the relevance of financial capital in the Argentine economy but also structurally conditioned any future nonorthodox alternative path of development. This outcome cannot be understood without taking into account the deliberate role of the United States, the IMF, and the top companies that operate in Argentina, as well as the complicity of many political sectors. JEL Classification: H63, F34, F63


Author(s):  
Hao Yang ◽  
Zhiqiang Ma

While current research on the flipped classroom generally focuses on test results and (or) student/teacher perceptions as a measurement of its pedagogical efficacy, students' adaptation to it and the essential conditions for its application are rarely explored. This exploratory case study aims to rectify this by examining how university students adapted to flipped classrooms implemented in a public university in East China. The findings suggest that while the flipped model is impeded by entrenched polarity between students in terms of their learning dispositions and academic competence, students do develop a prototype of theories of learning, a sense of better self through learning from their peers and an awareness of the importance of intrinsic motivation. A gradualist approach is thus proposed for implementing flipped classrooms, which requires longitudinal studies accordingly to understand its long-term effects on learning behavior hitherto left unexplored.


2021 ◽  
pp. 65-80
Author(s):  
Sandro Galea

This chapter examines the foundational forces that shape health. Even without a pandemic, the United States is faced with public health threats that are shaped by foundational forces. From the political and economic roots of the obesity epidemic, to the social stigma that informs the opioid crisis, to the many structural drivers of climate change, the social, economic, political, and demographic foundations of health are central to the challenges that must be addressed, nationally and globally, in the years to come. Engaging with these forces helped inform the response to COVID-19; they can help in addressing these other challenges as well. And just as a virus can have long-term effects on the body, the pandemic reshaped the societal foundations, with lasting implications for the economy, culture, attitudes towards core issues like race, politics, and more. Whether the experience of the pandemic leads to significant long-term benefits will depend on whether Americans retain the hard lessons of that moment and apply them to foundational forces.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
F. G. M. Verspoor ◽  
M. J. L. Mastboom ◽  
G. Hannink ◽  
R. G. Maki ◽  
A. Wagner ◽  
...  

Abstract Tenosynovial giant cell tumors (TGCT), are rare colony stimulating factor-1(CSF-1)-driven proliferative disorders affecting joints. Diffuse-type TGCT often causes significant morbidity due to local recurrences necessitating multiple surgeries. Imatinib mesylate (IM) blocks the CSF-1 receptor. This study investigated the long term effects of IM in TGCT. We conducted an international multi-institutional retrospective study to assess the activity of IM: data was collected anonymously from individual patients with locally advanced, recurrent or metastatic TGCT. Sixty-two patients from 12 institutions across Europe, Australia and the United States were identified. Four patients with metastatic TGCT progressed rapidly on IM and were excluded for further analyses. Seventeen of 58 evaluable patients achieved complete response (CR) or partial response (PR). One- and five-year progression-free survival rates were 71% and 48%, respectively. Thirty-eight (66%) patients discontinued IM after a median of 7 (range 1–80) months. Reported adverse events in 45 (78%) patients were among other edema (48%) and fatigue (50%), mostly grade 1–2 (89%). Five patients experienced grade 3–4 toxicities. This study confirms, with additional follow-up, the efficacy of IM in TGCT. In responding cases we confirmed prolonged IM activity on TGCT symptoms even after discontinuation, but with high rates of treatment interruption and additional treatments.


2019 ◽  
Vol 85 (6) ◽  
pp. 631-637 ◽  
Author(s):  
Christina L. Kaufman ◽  
Neal Bhutiani ◽  
Allan Ramirez ◽  
Huey Y. Tien ◽  
Michelle D. Palazzo ◽  
...  

The field of vascularized composite allotransplantation (VCA) has moved from a highly experimental procedure to, at least for some patients, one of the best treatment alternatives for catastrophic tissue loss or dysfunction. Although the worldwide experience is still limited, progress has been made in translation to the clinic, and hand transplantation was recently designated standard of care and is now covered in full by the British Health System. This progress is tempered by the long-term challenges of systemic immunosuppression, and the rapidly evolving indications for VCA such as urogenital transplantation. This update will cover the state of and recent changes in the field, and an update of the Louisville VCA program as our initial recipient, the first person to receive a hand transplant in the United States celebrates the 20th anniversary of his transplant. The achievements and complications encountered over the last two decades will be reviewed. In addition, potential directions for research and collaboration as well as practical issues of how third party payers and funding are affecting growth of the field are presented.


Author(s):  
Taiki Hagiri ◽  
Takashi Kobayashi ◽  
Kengou Nishiura ◽  
Kazuaki Uchiyama

It is known that bolt forces reduce significantly after tightening bolted flanged connections in which expanded PTFE gaskets are used. Bolts are often post-tightened in practice after a while to compensate for the reduction of bolt forces. The viscoelastic characteristic of expanded PTFE gaskets is the main cause for the phenomenon. However, the long term effects of the post-tightening on the residual bolt forces and the sealing performance of flanged connections have not been clarified yet. In this study, two sets of flanged connections (2 inch in nominal size), in which PTFE gaskets were used, were prepared and tightened. One of the flanges was post-tightened after a designated time. The reduction of bolt forces and the change in the sealing performance were measured for about two months. The results were compared with those of flanges without post-tightening. Based on the test results, the effectiveness of post-tightening was discussed from the viewpoint of the residual bolt force and the sealing performance. It has been clarified that the effectiveness of post-tightening depends on gasket material and that post-tightening is effective for expanded PTFE gaskets.


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