194 research outputs found
Letter From Charles G. Dawes and John McNulta to William McKinley, March 30, 1897
This document is a copy of a typed correspondence to President William McKinley from Charles Dawes and John McNulta endorsing Francis Mairs Huntington Wilson for a diplomatic appointment in London.https://digitalcommons.ursinus.edu/fmhw_early_career/1012/thumbnail.jp
Genes, psychological traits and civic engagement
Civic engagement is a classic example of a collective action problem: while civic participation improves life in the community as a whole, it is individually costly and thus there is an incentive to free ride on the actions of others. Yet, we observe significant inter-individual variation in the degree to which people are in fact civically engaged. Early accounts reconciling the theoretical prediction with empirical reality focused either on variation in individuals\u27 material resources or their attitudes, but recent work has turned to genetic differences between individuals. We show an underlying genetic contribution to an index of civic engagement (0.41), as well as for the individual acts of engagement of volunteering for community or public service activities (0.33), regularly contributing to charitable causes (0.28) and voting in elections (0.27). There are closer genetic relationships between donating and the other two activities; volunteering and voting are not genetically correlated. Further, we show that most of the correlation between civic engagement and both positive emotionality and verbal IQ can be attributed to genes that affect both traits. These results enrich our understanding of the way in which genetic variation may influence the wide range of collective action problems that individuals face in modern community life
The meandering instability of a viscous thread
A viscous thread falling from a nozzle onto a surface exhibits the famous
rope-coiling effect, in which the thread buckles to form loops. If the surface
is replaced by a belt moving with speed , the rotational symmetry of the
buckling instability is broken and a wealth of interesting states are observed
[See S. Chiu-Webster and J. R. Lister, J. Fluid Mech., {\bf 569}, 89 (2006)].
We experimentally studied this "fluid mechanical sewing machine" in a new, more
precise apparatus. As is reduced, the steady catenary thread bifurcates
into a meandering state in which the thread displacements are only transverse
to the motion of the belt. We measured the amplitude and frequency of
the meandering close to the bifurcation. For smaller , single-frequency
meandering bifurcates to a two-frequency "figure eight" state, which contains a
significant component and parallel as well as transverse
displacements. This eventually reverts to single-frequency coiling at still
smaller . More complex, highly hysteretic states with additional frequencies
are observed for larger nozzle heights. We propose to understand this zoology
in terms of the generic amplitude equations appropriate for resonant
interactions between two oscillatory modes with frequencies and
. The form of the amplitude equations captures both the axisymmetry of
the U=0 coiling state and the symmetry-breaking effects induced by the moving
belt.Comment: 12 pages, 9 figures, revised, resubmitted to Physical Review
Social Preferences and the Efficiency of Bilateral Exchange
Under what conditions do social preferences, such as altruism or a concern for fair outcomes, generate efficient trade? I analyze theoretically a simple bilateral exchange game: Each player sequentially takes an action that reduces his own material payoff but increases the other player’s. Each player’s preferences may depend on both his/her own material payoff and the other player’s. I identify necessary conditions and sufficient conditions on the players’ preferences for the outcome of their interaction to be Pareto efficient. The results have implications for interpreting the rotten kid theorem, gift exchange in the laboratory, and gift exchange in the field
Continuation for thin film hydrodynamics and related scalar problems
This chapter illustrates how to apply continuation techniques in the analysis
of a particular class of nonlinear kinetic equations that describe the time
evolution through transport equations for a single scalar field like a
densities or interface profiles of various types. We first systematically
introduce these equations as gradient dynamics combining mass-conserving and
nonmass-conserving fluxes followed by a discussion of nonvariational amendmends
and a brief introduction to their analysis by numerical continuation. The
approach is first applied to a number of common examples of variational
equations, namely, Allen-Cahn- and Cahn-Hilliard-type equations including
certain thin-film equations for partially wetting liquids on homogeneous and
heterogeneous substrates as well as Swift-Hohenberg and Phase-Field-Crystal
equations. Second we consider nonvariational examples as the
Kuramoto-Sivashinsky equation, convective Allen-Cahn and Cahn-Hilliard
equations and thin-film equations describing stationary sliding drops and a
transversal front instability in a dip-coating. Through the different examples
we illustrate how to employ the numerical tools provided by the packages
auto07p and pde2path to determine steady, stationary and time-periodic
solutions in one and two dimensions and the resulting bifurcation diagrams. The
incorporation of boundary conditions and integral side conditions is also
discussed as well as problem-specific implementation issues
GFS, a preparation of Tasmanian Undaria pinnatifida is associated with healing and inhibition of reactivation of Herpes
BACKGROUND: We sought to assess whether GFS, a proprietary preparation of Tasmanian Undaria pinnatifida, has effects on healing or re-emergence of Herpetic infections, and additionally, to assess effects of GFS in vitro. Undaria is the most commonly eaten seaweed in Japan, and contains sulphated polyanions and other components with potential anti-viral activity. Herpes simplex virus type 1 (HSV-1) infections have lower reactivation rates and Herpes type 2 (HSV-2) infections have lower incidence in Japan than in the west. METHODS: Patients with active (15 subjects) or latent (6 subjects) Herpetic infections (HSV-1, 2, EBV, Zoster) were monitored for response to ingestion of GFS. GFS extract was tested in vitro for human T cell mitogenicity and anti-Herpes activity. RESULTS: Ingestion of GFS was associated with increased healing rates in patients with active infections. In addition, patients with latent infection remained asymptomatic whilst ingesting GFS. GFS extract inhibited Herpes viruses in vitro and was mitogenic to human T cells in vitro. CONCLUSIONS: Ingestion of GFS has inhibitory effects on reactivation and is associated with increased rate of healing after Herpetic outbreaks. GFS extract potently inhibited Herpes virus in vitro, and had mitogenic effects on human T cells
Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility
Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes
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