785 research outputs found
Visualizing solutions of the circular restricted three-body problem
No full textThe stability of a satellite near the Lagrange points is studied in a Circular Restricted Three-Body Problem (CR3BP). The Runge Kutta method is used to trace out the orbital path of the satellite over a period of time. Various initial positions near the Lagrange points and velocities are used to produce various paths the satellite can take. The primary paths focused are on horseshoe paths.
Horseshoe orbits are shown to be sometimes stable and sometimes chaotic.M.S.Includes bibliographical references (p. 40)by Nkosi Nathan Tri
Keywords Project for <i>Nathan the Wise</i>: Thoughts and Inspiration
No full textNathan the Wise was set in Jerusalem during the Crusades and describes the experience of Nathan, a Jewish merchant, with many people. Nathan is wise and has values of tolerance and understanding ahead of his time. This play advocates for understanding among different cultures and faiths, promoting the idea that wisdom and love can unite people despite their differences.While reading this play, certain words or characters inspired the author to think, and the author wishes to share these thoughts and understanding through this project. The author hopes this project and my writing can help readers to understand this book better or lead to some inspiration.</p
Pseudoproxies for the paper "A pseudoproxy assessment of data assimilation for reconstructing the atmosphere–ocean dynamics of hydroclimate extremes"
No full text<p>Pseudoproxies for the paper “A pseudoproxy assessment of data assimilation for reconstructing the atmosphere–ocean dynamics of hydroclimate extremes” by Steiger and Smerdon 2017.</p>
<p>If you have further questions, address them to the author Nathan J. Steiger.</p>
Nathan Perlmutter (1923-1987) papers, 1934-1989, 1949-1987.
No full textThis collection consists of the papers of Nathan Perlmutter, a lawyer, lecturer, author, political activist, and a long-time leader of the American Jewish community. It contains certificates, newspaper clippings, correspondence—including numerous condolence cards and letters sent to his family after his death—manuscripts and drafts of Perlmutter’s writings, obituaries, printed materials, programs, and subject files relating to topics he was interested in and that he wrote about.Published citations should take the following form: Identification of item, date (if known); Nathan Perlmutter (1923-1987) Papers; P-1012; box number; folder number; American Jewish Historical Society, New York, NY, and Boston, MA.Donated by Ruth Ann Perlmutter
Subsurface Structure And Impacts Of Marine Heatwaves In The Chesapeake Bay
No full textExtreme temperature events known as Marine Heatwaves (MHW), akin to atmospheric heatwaves, have only recently received attention by the estuarine scientific community. Thus far, studies have focused solely on surface events due to scarcity of long-term subsurface data. This study investigates, for the first time, the subsurface temperature and dissolved oxygen (DO) anomalies associated with surface MHW events in a large, temperate, partially mixed estuary: the Chesapeake Bay (CB). Using over three decades (1986-2021) of in-situ data from several long-term monitoring programs in the CB (including sub daily moored measurements and monthly/bimonthly cruises along the main stem) and a global atmospheric reanalysis product (ERA5), I were able to 1) characterize the spatiotemporal structure of subsurface temperature and DO anomalies during surface MHW events on seasonal time scales, 2) identify the vertical extent of warming before and after events, and 3) examine the relative role of atmospheric heat flux in driving temperature changes during the onset and decline of events. I found that subsurface temperature anomalies associated with surface MHWs had two distinct regimes: a thermally stratified spring-summer regime, when positive temperature anomalies were only present in the upper water column capped by the surface mixed layer; and a thermally homogenous fall-winter regime, when temperature anomalies extended throughout the water column. This seasonal variability in temperature anomalies was largely consistent with a simple 1-D response to heat, sourced primarily through the air-estuary interface, and with downward heat transport and diffusion controlled by seasonally variable stratification and mixing. Moreover, DO anomalies during MHW events presented a more complex spatiotemporal structure, with notable DO decreases (1-4 mg L-1) primarily occurring in the winter and spring. While negative DO anomalies were present across the main stem of the CB, the greatest DO decreases (~5 mg L-1) were observed in the upper region of CB below the mixed layer depth. During the hypoxic season (May to September), and in April and October, negative DO anomalies were often associated with an expansion of the hypoxic zone. Additionally, I observed that subsurface temperature anomalies were elevated 5-10 days before and up to 20 days after MHW events, while surface temperature anomalies were elevated for up to 2 months before and after events. This indicates that the timescales of elevated temperatures are typically much longer than the duration of individual MHW events, and therefore should be carefully taken into consideration when assessing the impact of these extreme events in the estuarine ecosystem. Using a simple 1D surface mixed layer heat budget, I identified air-estuary heat flux as the largest driver of the onset and decline of MHW events, with latent heat flux being the dominant constituent. In the CB, concurrent low DO during MHW events and persistent high temperatures before, during, and after events can compound the impacts of MHWs on habitat, which will be further exacerbated by climate change, severely impacting this valuable estuarine ecosystem.Virginia Institute of Marine ScienceMaster of Science (M.Sc.
Big Data, Big Libraries, Big Problems?: the 2014 LibTech Anti-talk?
No full textThe desire to create automatons is a familiar theme in human history, and during the age of the Enlightenment mechanical automatons became not only an “emblem of the cosmos”, but a symbol of man’s confidence that he would unlock nature’s greatest mysteries and fully harness her power. And yet only a century later, automatons had begun to represent human repression and servitude, a theme later picked up by writers of science fiction. Man’s confidence undeterred, the endgame of the modern scientific and technological mindset, or MSTM, seems to be increasingly coming into view with the rise of “information technology” in general and “Big data” in particular. Along with those who wield them, these can be seen as functioning together as a “mechanical muse” of sorts – surprisingly alluring – and, like a physical automaton can serve as a symbol – a microcosm – of what the MSTM sees (at the very least in practice) as the cosmic machine, our “final frontier”. And yet, individuals who unreflectively participate in these things – giving themselves over to them and seeking the powers afforded by the technology apart from technology’s rightful purposes – in fact yield to the same pragmatism and reductionism those wielding them are captive to. Thus, they ultimately nullify themselves philosophically, politically, and economically – their value increasingly being only the data concerning their persons, and its perceived usefulness. Likewise libraries, the time-honored place of, and symbol for, the intellectual flowering of the individual, will, insofar as they spurn the classical liberal arts (with the idea that things are intrinsically good, and in the case of humans, special as well) in favor of the alluring embrace of MSTM-driven “information technology” and Big data - unwittingly contribute to their irrelevance and demise as they find themselves increasingly less needed, valued, wanted. Likewise for the liberal arts as a whole, and in fact history itself, if the acid of a “science” untethered from what is, in fact, good (intrinsically), continues to gain strengt
Global extent of chloroquine-resistant Plasmodium vivax
No full textI wish to thank Ric Price and colleagues1 for highlighting the under-studied chloroquine resistance in Plasmodium vivax in their systematic review and meta-analysis. However, I would question their study inclusion criteria: the primary outcome was “the risk of recurrent P vivax parasitaemia at day 28” when table 1 lists four studies with follow-up periods of less than 27 days. I would also suggest that it seems a shame that two author-reviewers, independently, did not extract and analyse the studies and data for inclusion, as seems standard practice for good systematic reviews. 2 Lastly, although the paper underlines the extent and importance of chloroquine-resistant P vivax, I am none the wiser on what management I should offer in practice to patients from different areas given the prevalence of resistance.I declare no competing interests.<br/
Vitaleucopis nidolkah Gaimari 2020
No full textVitaleucopis nidolkah Gaimari, 2020: 72 Type locality: USA: New Mexico (HT ♂, CSCA). This species is known only from the southwestern United States in areas above 2100 m elevation. The first author reared numerous individuals from field-collected larvae attacking Cinara ponderosae infesting Pinus ponderosa.Published as part of Gaimari, Stephen D. & Havill, Nathan P., 2021, A new genus of Chamaemyiidae (Diptera: Lauxanioidea) predaceous on Adelgidae (Hemiptera), with a key to chamaemyiid species associated with Pinaceae-feeding Sternorrhyncha, pp. 1-39 in Zootaxa 5067 (1) on page 35, DOI: 10.11646/zootaxa.5067.1.1, http://zenodo.org/record/565643
\u3cem\u3eA Poetics of Handel’s Operas\u3c/em\u3e, by Nathan Link
No full textTextbooks and program notes summarize the relationship between story and music in opera seria with tidy bullet points: recitatives = action; arias = reflection; ensembles sometimes contribute to a story’s progression, while instrumental pieces typically do not. Nathan Link’s A Poetics of Handel’s Operas dismisses such generalizations as caricatures, going so far as to assert that opera seria is “easily among the most complex forms of storytelling yet devised” (p. 7). The author turns to narratological theory, with occasional forays into opera studies and cinema studies (including film music scholarship), to explain the “semantic decoding” (p. 2) that audiences must master to make sense of these drammi per musica
Influence of social factors on mothers in treatment for substance use disorders:
No full textConsideration of women-specific issues in addictions treatment requires attention be given to the subset of women who are also mothers. For these women, the repercussions of substance use are often profound and far-reaching. Impaired decisions and parenting skills may increase risk for child abuse and neglect. This dissertation sought to better understand how the quality of a mother’s social resources and her substance use behaviors are influenced by her primary drug of choice (heroin, cocaine/crack, marijuana, alcohol). Social network characteristics and substance use behaviors were characterized at treatment entry, treatment discharge, and six months post-treatment in a sample of 246 women, with minor children, who received addictions treatment based on involvement with the New Jersey Division of Youth and Family Services. Nearly half of these women had not achieved the equivalent of a high school degree and the majority was unemployed and unmarried. At treatment entry, primary heroin users reported more frequent primary drug use, more poly-drug use, and less abstinence in the past thirty days than women with other drug preferences. However, heroin using mothers improved most during treatment, reporting similar frequencies of substance use and use-related problems at both follow-up assessments as women with other drug preferences. At treatment entry, all participants reported extensive contact with family dense social networks that supported general well-being, abstinence and treatment seeking. Primary marijuana users, however, reported networks that were more neutral towards their continued substance use than women with other drug preferences. Over time, marijuana using women reported an increase in the frequency of substance use by their network members whereas women with heroin and cocaine preferences reported decreases. Importantly, frequency of substance use by network members was the social network characteristic most highly correlated with concurrent and subsequent substance use and use-related problems. The reason for these marijuana-specific social network differences is not immediately clear, but may reflect a broad societal belief that marijuana is less physiologically, psychologically, and socially harmful than other drugs. Nonetheless, these results suggest that treatment may not adequately address the importance of social factors in the maintenance of marijuana use disorders.Psy.DIncludes bibliographical references (p. 83-91)by Nathan V. Hilto
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