8,236 research outputs found
The Production Rate and Employment of Ph.D. Astronomers
In an effort to encourage self-regulation of the astronomy job market, I
examine the supply of, and demand for, astronomers over time. On the supply
side, I document the production rate of Ph.D. astronomers from 1970 to 2006
using the UMI Dissertation Abstracts database, along with data from other
independent sources. I compare the long-term trends in Ph.D. production with
federal astronomy research funding over the same time period, and I demonstrate
that additional funding is correlated with higher subsequent Ph.D. production.
On the demand side, I monitor the changing patterns of employment using
statistics about the number and types of jobs advertised in the AAS Job
Register from 1984 to 2006. Finally, I assess the sustainability of the job
market by normalizing this demand by the annual Ph.D. production. The most
recent data suggest that there are now annual advertisements for about one
postdoctoral job, half a faculty job, and half a research/support position for
every new domestic Ph.D. recipient in astronomy and astrophysics. The average
new astronomer might expect to hold up to 3 jobs before finding a steady
position.Comment: 5 pages, 4 figures, 2 tables, PASP accepte
Function and dysfunction of fatty acid mobilization: a review
Western populations have a growing obesity epidemic due in part to excessive nutrient intake from high-fat diets, which are increasingly common. Overindulgence of nutrients is associated with a greater incidence of metabolic dysfunction and a greater risk for obesity, diabetes, hypertension, and other metabolic disorders that lower quality of life. Research in humans and animal models has improved our understanding of how excess circulating free fatty acids negatively impact the ability of muscle and other tissues to regulate nutrient uptake and utilization. It is generally accepted by the scientific community that excess circulating fatty acids lead to insulin resistance, but there is little clarity regarding the underlying mechanisms. In the present review, we will outline the current understanding of the characteristics associated with fatty acid mobilization and fatty acid utilization within specific tissues. We will also discuss the potential mechanistic role of hyperlipidemia on metabolic dysfunction associated with type 2 diabetes
Experimental demonstration of stimulated polarization wave in a chain of nuclear spins
A stimulated wave of polarization, which implements a simple mechanism of
quantum amplification, is experimentally demonstrated in a chain of four
J-coupled nuclear spins, irradiated by a weak radio-frequency transverse field.
The "quantum domino" dynamics, a wave of flipped spins triggered by a flip of
the first spin, has been observed in fully C-labeled sodium butyrate.Comment: 8 pages including 3 figure
New parametrization method for dissipative particle dynamics
We introduce an improved method of parameterizing the Groot-Warren version of Dissipative Particle Dynamics (DPD) by exploiting a correspondence between DPD and
Scatchard-Hildebrand regular solution theory. The new parameterization scheme widens the realm of applicability of DPD by first removing the restriction of equal repulsive
interactions between like beads, and second, by relating all conservative interactions between beads directly to cohesive energy densities.
We establish the correspondence by deriving an expression for the Helmoltz free energy of mixing obtaining a heat of mixing which is exactly the same form as that for a
regular mixture (quadratic in the volume fraction) and an entropy of mixing which reduces to the ideal entropy of mixing for equal molar volumes. We equate the conservative interaction parameters in the DPD force law to the cohesive energy densities of the pure fluids providing an alternative method of calculating the self-interaction
parameters as well as a route to the cross-interaction parameter.
We validate the new parameterization by modelling the binary system: SnI4/SiCl4, which displays liquid-liquid coexistence below an upper critical solution temperature
around 140°C. A series of DPD simulations were conducted at a set of temperatures ranging from 0°C to above the experimental upper critical solution temperature using
conservative parameters based on extrapolated experimental data. These simulations can be regarded as being equivalent to a quench from a high temperature to a lower one at constant volume.
Our simulations recover the expected phase behaviour ranging from solid-liquid coexistence to liquid-liquid co-existence and eventually leading to a homogeneous single
phase system. The results yield a binodal curve in close agreement with one predicted using regular solution theory, but, significantly, in closer agreement with actual solubility
measurements
A Fait Accompli: The Prague Spring, Warsaw Pact Invasion, and the United States’ Reaction, 1968
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"Of order and liberty" : Catholic intellectuals in Argentina and Brazil
textThis project challenges the historical binary of a revolutionary versus a reactionary Church through a comparative case study of right-wing Christian Democrats in Brazil and Integralist/Nationalist intellectuals in Argentina. Intellectually, the project centers on Jacques Maritain and notable Latin American figures. Such figures include Brazilians Alceu Amoroso Lima and Dom Hélder Câmara, and Argentine leaders Julio Meinvielle and Leonardo Castellani. The study will argue that these figures' intellectual stands represented diverging paths for each country's conservative majority, but also shaped their respective hierarchies' reactions to key events in the Catholic and secular world: the Spanish Civil War, World War II, the Second Vatican Council. While anti-Modernists, Brazilian intellectuals came to favor pluralist and democratic solutions of Social Democracy over and above the organic (and encompassing) visions espoused by Franco's Spain, and subsequently, the Argentine hierarchy. This study will analyze major Catholic newspapers and journals, including Criterio, Jauja , A Ordem, and O Diario de Belo Horioznte. These sources will give the reader a glimpse into the intellectual societies and forums in which these thinkers moved, and will more clearly display the distinction mentioned above. Surprisingly, conservative Brazilian papers maintained a vigorous anti-Communist stance, but came to see the government as an oppressing force prohibiting the legitimate social actions of the Catholic faithful. Argentine intellectuals took a much more ambivalent attitude toward democracy at best, and a more hostile one at worst. Julio Meinvielle and Leonardo Castellani from their journal Jauja directly challenged the Second Vatican Council, the liberal state, and the rights of left-wing dissidents. More generally, Argentine ties to Franco's Spain through the 1970s, as well as to conservative varieties of Peronism, as well as the loss of the unifying Gustavo Franceschi (editor of Criterio) in 1957, put the sizable democratic and reformist minority firmly outside the good graces of the hierarchy, paving the way for the Catholic purges in Argentina of the 1970s.Latin American Studie
Baptism by Fire: Ireland, The Easter Rising of 1916 and Its Experiment with Radical Republicanism
The Easter Uprising of 1916 represents one of the most tumultuous moments in modern Irish history. A relatively small group of revolutionaries sought to throw off the shackles of British rule in favor of Irish independence and self-determination. The uprising, lasting a mere six days, transformed the very nature of relations between Great Britain and the Irish populace. The Rising resulted in wholesale changes in legislation including women gaining the right to vote and run for office. Ireland following the uprising was completely transformed as its populace reeled with its effects.
This paper examines the immediate build-up to the uprising all the way through to its conclusion including the ramifications. The paper utilizes numerous sources from contemporary studies as well as two books penned by people who experienced the chaos that was Dublin firsthand
Cloning, Purification, and Biochemical Characterization of Human Prolyl Endopeptidase
Eurygaster integriceps Puton, common name sunn Pest, is one of the primary sources of wheat crop wastes in North Africa, Middle East, and Eastern Europe. It feeds by injecting the wheat grain with an enzyme characterized as prolyl endoprotease (spPEP) that breaks down Gluten, the wheat’s main constitutive protein necessary for bread production (Darkoh et al., 2010). Previously, it has been shown that peptides isolated from Lactobacillus hydrolysates of caseins in bovine milk are able to inhibit mammalian PEP in colon cells, as well as bacterial PEP (Juillerat-Jeanneret et al., 2010). While recombinant versions of these peptides are also potential inhibitors of the spPEP, their specificity must be tested also against hPEP. The primary objective of this study was to clone hPEP into the same expression vector as spPEP in order to compare hPEP to spPEP with regards to substrate binding, recognition, and inhibition. Initially, hPEP was PCR amplified in order to incorporate the 5’ and 3’ ends necessary for ligation independent cloning (LIC) into the expression vector. This was then expressed in BL21(DE3)/pTFs and purified on a nickel column. Future studies will include comparing inhibition between hPEP and spPEP using 16 PCR amplified fragments of varying length that contain the non-allergenic (as demonstrated by Ruiter, 2005) inhibitory sequence LNENLLRFFVAPFPEVFG, isolated from bovine αS1 casein
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The Violence of Nostalgia: Conspiracy Theorism, White Nationalism, and Restoring American Exceptionalism
This dissertation serves three interconnected ends: (1) highlight the connections between nationalism, nostalgia, mythology, and conspiracy, (2) research and articulate the deeper story behind the resurgence of conspiracy fueled white nationalism, and (3) analyze increasing popular support for racialized hatred across the United States as coalesced through the nostalgic desire to restore “our lost great America.” I adapt John Dewey’s pragmatism to interpret how publics take political action in response to evolving technologies and cultural shifts, and accordingly develop a typology of groups on the right wing of American politics. The Proud Boys are chauvinist white nationalists, Patriot Prayer are Christian freedom fighters, and QAnon adherents are revolutionary conspiracy theorists. Each of these groups describe lost American values which they want to recover in the face of mortal enemies, and they claim to emulate those lost traditional values through their language and actions. Group affiliates have also been known to engage in street brawling and violence as part of their perceived struggle to restore America. In tandem, these publics among others form an umbrella coalition of right-wing groups, religious groups, free speech activists, men’s right’s activists, white nationalists, and white supremacists, all fighting to “Make America Great Again” in their respective ways. Importantly, the reach of each group has served to radicalize individuals and shift the parameters for when violence is morally justified. Their nostalgic and conspiratorial language describe and justify a mythologized “lost great America” to recover in the face of evil enemies, sometimes through violent means. Nationalist nostalgia – a prosthetically constructed memory which inspires longing for a lost mythological past – and conspiracy theorism – a systematized set of beliefs which inspires real political action in the face of evil – have worked in tandem through political rhetoric to embolden white nationalist sentiment. It is this confluence of political language and action which ultimately erupted into the January 6th Capitol Insurrection
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