1,305 research outputs found
Reassessing the Greek National Schism of World War I: The Ideological Parameters
The National Schism that erupted in Greece during World War I has already been thoroughly analysed in the bibliography as a crisis of national unification, defined by geographical, political and socio economic criteria. The aim of this article is to move a step forward, to support that the National Schism might also be considered as an act in the broader and much older Greek ideological drama, that of the tantalising and incomplete “return” to the East via the European West. It is argued that the Schism, far from being a bipolar confrontation between supporters and opponents of Europe, did select from the East–West debate whatever arguments were necessary to invest military and political choices with a “deeper” meaning. Our approach focuses mostly on the rhetoric produced by the two opposing camps, the Venizelists and the anti-Venizelist block, from 1914 to 1922. It is, however, complemented by a retrospective presentation of the nineteenth-century debateover the Enlightenment and liberalism, on the one hand, and German idealism, on the other
Reassessing the Greek National Schism of World War I: The Ideological Parameters
The National Schism that erupted in Greece during World War I has already been thoroughly analysed in the bibliography as a crisis of national unification, defined by geographical, political and socio economic criteria. The aim of this article is to move a step forward, to support that the National Schism might also be considered as an act in the broader and much older Greek ideological drama, that of the tantalising and incomplete “return” to the East via the European West. It is argued that the Schism, far from being a bipolar confrontation between supporters and opponents of Europe, did select from the East–West debate whatever arguments were necessary to invest military and political choices with a “deeper” meaning. Our approach focuses mostly on the rhetoric produced by the two opposing camps, the Venizelists and the anti-Venizelist block, from 1914 to 1922. It is, however, complemented by a retrospective presentation of the nineteenth-century debateover the Enlightenment and liberalism, on the one hand, and German idealism, on the other
A cutoff phenomenon in accelerated stochastic simulations of chemical kinetics via flow averaging (FLAVOR-SSA)
We present a simple algorithm for the simulation of stiff, discrete-space, continuous-time Markov processes. The algorithm is based on the concept of flow averaging for the integration of stiff ordinary and stochastic differential equations and ultimately leads to a straightforward variation of the the well-known stochastic simulation algorithm (SSA). The speedup that can be achieved by the present algorithm [flow averaging integrator SSA (FLAVOR-SSA)] over the classical SSA comes naturally at the expense of its accuracy. The error of the proposed method exhibits a cutoff phenomenon as a function of its speed-up, allowing for optimal tuning. Two numerical examples from chemical
kinetics are provided to illustrate the efficiency of the method
How Structural Complexity of Vegetation Facilitates Invasion: Integrating LiDAR and FIA Invasive Species Plot Data in the Appalachian Mountains of the USA
This study examines how the vertical structure of forests and the variation in forest canopy tree composition relates to where forest plant invasions occur at a regional scale. We used LiDAR data on vertical structure of forests collected across 16 counties of western North Carolina, and Forest Inventory and Analysis (FIA) abundance data of invasive plant species and canopy tree species from 575 plots. We found that nearly one third of these plots were invaded by at least one invasive plant species (range = 1 to 8 species). We derived canopy gaps/clear-cut areas of the study site using LiDAR data matrix (RH100) and 2006 NLCD image to compare invasive species richness at the vegetation gap and closed canopy areas. The most frequently occurring invasive species of the 22 recorded invasive species in the vegetation gap and closed canopy areas were Lonicera japonica (Japanese honeysuckle; 67% & 49%), Rosa spp. (non-native rose; 58% & 51%) and Ligustrum sinense (Chinese privet; 36% & 25%) respectively. Majority of invasive species in both vegetation gap and closed canopy areas are dispersed by birds/ small mammals. Preliminary results suggest that plots in areas having greater forest structural complexity have less invasive plant species present. A variety of mechanisms can explain how forest structural complexity may impact invasivability. We conclude by summarizing these possible mechanisms and the role that LiDAR can play in studying and managing forested landscapes threatened by invasive species
Indoor collections of the Anopheles funestus group (Diptera: Culicidae) in sprayed houses in northern KwaZulu-Natal, South Africa
BACKGROUND: Insecticide resistance in malaria vector mosquitoes presents a serious problem for those involved in control of this disease. South Africa experienced a severe malaria epidemic during 1999/2000 due to pyrethroid resistance in the major vector Anopheles funestus. Subsequent monitoring and surveillance of mosquito populations were conducted as part of the malaria vector control programme. METHODS: A sample of 269 Anopheles funestus s.l. was collected in Mamfene, northern KwaZulu-Natal, using exit window traps in pyrethroid sprayed houses between May and June 2005. Mosquitoes were identified to species level, assayed for insecticide susceptibility, analysed for Plasmodium falciparum infectivity and blood meal source. RESULTS: Of the 220 mosquitoes identified using the rDNA PCR method, two (0.9%) were An. funestus s.s. and 218 (99.1%) Anopheles parensis. Standard WHO insecticide susceptibility tests were performed on F1 progeny from wild caught An. parensis females and a significant survival 24 h post exposure was detected in 40% of families exposed to 0.05% deltamethrin. Biochemical analysis of F1 An. parensis showed no elevation in levels/activity of the detoxifying enzyme systems when compared with an insecticide susceptible An. funestus laboratory strain. Among the 149 female An. parensis tested for P. falciparum circumsporozoite infections, 13.4% were positive. All ELISA positive specimens (n = 20) were re-examined for P. falciparum infections using a PCR assay and none were found to be positive. Direct ELISA analysis of 169 blood meal positive specimens showed > 75% of blood meals were taken from animals. All blood fed, false positive mosquito samples for the detection of sporozoites of P. falciparum were zoophilic. CONCLUSION: The combination of pyrethroid resistance and P. falciparum false-positivity in An. parensis poses a problem for vector control. If accurate species identification had not been carried out, scarce resources would have been wasted in the unnecessary changing of control strategies to combat a non-vector species
Phylogenetic and experimental characterization of an acyl-ACP thioesterase family reveals significant diversity in enzymatic specificity and activity
<p>Abstract</p> <p>Background</p> <p>Acyl-acyl carrier protein thioesterases (acyl-ACP TEs) catalyze the hydrolysis of the thioester bond that links the acyl chain to the sulfhydryl group of the phosphopantetheine prosthetic group of ACP. This reaction terminates acyl chain elongation of fatty acid biosynthesis, and in plant seeds it is the biochemical determinant of the fatty acid compositions of storage lipids.</p> <p>Results</p> <p>To explore acyl-ACP TE diversity and to identify novel acyl ACP-TEs, 31 acyl-ACP TEs from wide-ranging phylogenetic sources were characterized to ascertain their <it>in vivo </it>activities and substrate specificities. These acyl-ACP TEs were chosen by two different approaches: 1) 24 TEs were selected from public databases on the basis of phylogenetic analysis and fatty acid profile knowledge of their source organisms; and 2) seven TEs were molecularly cloned from oil palm (<it>Elaeis guineensis</it>), coconut (<it>Cocos nucifera</it>) and <it>Cuphea viscosissima</it>, organisms that produce medium-chain and short-chain fatty acids in their seeds. The <it>in vivo </it>substrate specificities of the acyl-ACP TEs were determined in <it>E. coli</it>. Based on their specificities, these enzymes were clustered into three classes: 1) Class I acyl-ACP TEs act primarily on 14- and 16-carbon acyl-ACP substrates; 2) Class II acyl-ACP TEs have broad substrate specificities, with major activities toward 8- and 14-carbon acyl-ACP substrates; and 3) Class III acyl-ACP TEs act predominantly on 8-carbon acyl-ACPs. Several novel acyl-ACP TEs act on short-chain and unsaturated acyl-ACP or 3-ketoacyl-ACP substrates, indicating the diversity of enzymatic specificity in this enzyme family.</p> <p>Conclusion</p> <p>These acyl-ACP TEs can potentially be used to diversify the fatty acid biosynthesis pathway to produce novel fatty acids.</p
Explorations in anatomy: the remains from Royal London Hospital
This paper considers the faunal remains from recent excavations at the Royal London Hospital. The remains date to the beginning of the 19th century and offer an insight into the life of the hospital's patients and practices of the attached medical school. Many of the animal remains consist of partially dissected skeletons, including the unique finds of Hermann's tortoise (Testudo hermanni) and Cercopithecus monkey. The hospital diet and developments in comparative anatomy are discussed by integrating the results with documentary research. They show that zooarchaeological study of later post-medieval material can significantly enhance our understanding of the exploitation of animals in this perio
Modeling tumor cell migration: from microscopic to macroscopic
It has been shown experimentally that contact interactions may influence the
migration of cancer cells. Previous works have modelized this thanks to
stochastic, discrete models (cellular automata) at the cell level. However, for
the study of the growth of real-size tumors with several millions of cells, it
is best to use a macroscopic model having the form of a partial differential
equation (PDE) for the density of cells. The difficulty is to predict the
effect, at the macroscopic scale, of contact interactions that take place at
the microscopic scale. To address this we use a multiscale approach: starting
from a very simple, yet experimentally validated, microscopic model of
migration with contact interactions, we derive a macroscopic model. We show
that a diffusion equation arises, as is often postulated in the field of glioma
modeling, but it is nonlinear because of the interactions. We give the explicit
dependence of diffusivity on the cell density and on a parameter governing
cell-cell interactions. We discuss in details the conditions of validity of the
approximations used in the derivation and we compare analytic results from our
PDE to numerical simulations and to some in vitro experiments. We notice that
the family of microscopic models we started from includes as special cases some
kinetically constrained models that were introduced for the study of the
physics of glasses, supercooled liquids and jamming systems.Comment: Final published version; 14 pages, 7 figure
Supervillin Binding to Myosin II and Synergism with Anillin Are Required for Cytokinesis
Cytokinesis, the process in which cytoplasm is apportioned between dividing daughter cells, requires coordination of myosin II function, membrane trafficking and central spindle organization. Most known regulators act during late cytokinesis; a few, including the myosin II-binding proteins anillin and supervillin, act earlier. Anillin\u27s role in scaffolding the membrane cortex with the central spindle is well established, but the mechanism of supervillin action is relatively uncharacterized. We show here that two regions within supervillin affect cell division: residues 831-1281, which bind central spindle proteins, and residues 1-170, which bind the myosin II heavy chain (MHC) and the long form of myosin light chain kinase (l-MLCK). MHC binding is required to rescue supervillin deficiency, and mutagenesis of this site creates a dominant-negative phenotype. Supervillin concentrates activated and total myosin II at the furrow, and simultaneous knockdown of supervillin and anillin additively increase cell division failure. Knockdown of either protein causes mislocalization of the other, and endogenous anillin increases upon supervillin knockdown. Proteomic identification of interaction partners recovered using a high-affinity GFP nanobody suggest that supervillin and anillin regulate the myosin II- and actin cortical cytoskeletons through separate pathways. We conclude that supervillin and anillin play complementary roles during vertebrate cytokinesis
Imprints of the Quantum World in Classical Mechanics
The imprints left by quantum mechanics in classical (Hamiltonian) mechanics
are much more numerous than is usually believed. We show Using no physical
hypotheses) that the Schroedinger equation for a nonrelativistic system of
spinless particles is a classical equation which is equivalent to Hamilton's
equations.Comment: Paper submitted to Foundations of Physic
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