Search results for " Race"
showing 10 items of 73 documents
Ant behaviour and brain gene expression of defending hosts depend on the ecological success of the intruding social parasite.
2019
The geographical mosaic theory of coevolution predicts that species interactions vary between locales. Depending on who leads the coevolutionary arms race, the effectivity of parasite attack or host defence strategies will explain parasite prevalence. Here, we compare behaviour and brain transcriptomes of Temnothorax longispinosus ant workers when defending their nest against an invading social parasite, the slavemaking ant Temnothorax americanus . A full-factorial design allowed us to test whether behaviour and gene expression are linked to parasite pressure on host populations or to the ecological success of parasite populations. Albeit host defences had been shown before to covary with …
Typification of eight names in Hieracium (Asteraceae)
2012
Eight names in Hieracium (H. atrovirens Froel., H. crinitum Sm., H. lucidum Guss., H. pallidum Biv., H. racemosum subsp. todaroanum Zahn, H. siculum Guss., H. siculum var. minus Guss., H. symphytifolium Froel.), the descriptions of which are based totally or in part on Sicilian material, are typified. Hieracium racemosum subsp. todaroanum is treated as a synonym of H. crinitum, and H. siculum and H. siculum var. minus are treated as synonyms of H. symphytifolium. Hieracium atrovirens is recognized as a subspecies of H. murorum L. (H. murorum subsp. atrovirens (Froel.) Raimondo & Di Grist.).
Adhesion enhancement of cribellate capture threads by epicuticular waxes of the insect prey sheds new light on spider web evolution
2017
To survive, web-building spiders rely on their capture threads to restrain prey. Many species use special adhesives for this task, and again the majority of those species cover their threads with viscoelastic glue droplets. Cribellate spiders, by contrast, use a wool of nanofibres as adhesive. Previous studies hypothesized that prey is restrained by van der Waals' forces and entrapment in the nanofibres. A large discrepancy when comparing the adhesive force on artificial surfaces versus prey implied that the real mechanism was still elusive. We observed that insect prey's epicuticular waxes infiltrate the wool of nanofibres, probably induced by capillary forces. The fibre-reinforced composi…
Multilocus sequence typing analysis of Italian Xanthomonas campestris pv. campestris strains suggests the evolution of local endemic populations of t…
2019
Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot in Brassicaceae. It is widespread in Italy and severe outbreaks occur under conditions that favour disease development. In this study a multilocus sequence typing approach (MLST) based on the partial sequence of seven loci was applied to a selection of strains representative of the main areas of cultivation and hosts. The aim was to investigate whether the long tradition of brassica crops in Italy has influenced the evolution of different Xcc populations. All loci were polymorphic; 14 allelic profiles were identified of which 13 were unique to Italian strains. Based on the seven loci, the most common genotype withi…
Kindness to the final host and vice versa: A trend for parasites providing easy prey?
2019
Traditionally the “extended phenotype” concept refers to parasites that manipulate host phenotype to increase parasite fitness. This includes parasites that render intermediate hosts more susceptible to predation by final hosts. We explore here the proposition that an evolutionary driver in such cases is the energetic benefit to the final host, in addition to increased parasite fitness. We will review some well-established host-manipulation models, where such a scenario seems likely. One example is provided by the protozoan Toxoplasma gondii, which conspicuously impairs predator avoidance in rodents. Pathologies in humans that acquire T. gondii are known, but infection in adult feline defin…
5' and 3' RACE Method to Obtain Full-Length 5' and 3' Ends of Ciona robusta Macrophage Migration Inhibitory Factors Mif1 and Mif2 cDNA
2019
The 5' and 3' RACE is a method to obtain full-length 5' and 3' ends of cDNA using known cDNA sequences from expressed sequence tags (ESTs), subtracted cDNA, differential display, or library screening. Here is described the identification of full-length 5' and 3' ends of Ciona robusta Mif1 and Mif2 cDNA by using 5' and 3' RACE method.
Changes in Serine Racemase-Dependent Modulation of NMDA Receptor: Impact on Physiological and Pathological Brain Aging
2018
International audience; The N-methyl-D-Aspartate glutamate receptors (NMDARs) are pivotal for the functional and morphological plasticity that are required in neuronal networks for efficient brain activities and notably for cognitive-related abilities. Because NMDARs are heterogeneous in subunit composition and associated with multiple functional regulatory sites, their efficacy is under the tonic influence of numerous allosteric modulations, whose dysfunction generally represents the first step generating pathological states. Among the enzymatic candidates, serine racemase (SR) has recently gathered an increasing interest considering that it tightly regulates the production of D-serine, an…
Anti-Semitism and Progressive Era Social Science. The case of John R. Commons
2016
This paper explores Common’s views toward Jews in order to assess whether his published writings contain assertion that today would be stigmatized as anti-Semitic. The evidence we provide shows that Commons’ racial characterization of Jews was framed within a broad and indiscriminate xenophobic framework. With other leading Progressive Era social scientists, in fact, Commons shared the idea that the new immigration from Eastern and southern Europe would increase competition in the labor market, drive down wages, and lead Anglo-Saxon men and women to have fewer children, since they would not want them to compete with those who survive on less. Within this general xenophobic context, Commons …
Economists and Eugenics: Progressive Era Racism and its (Jewish) Discontents
2017
This chapter analyzes the contribution to the debates on labor and immigration of a group of Jewish academicians and reformers who, during the second half of the Progressive Era, explicitly took a stance against the racialist and eugenic rhetoric of the period. This group includes first-rank economists like Edwin R. A. Seligman, Jacob H. Hollander, and Emanuel A. Goldenweiser; influential field specialists such as Isaac A. Hourwich and Isaac M. Rubinow; and relatively less known figures like Max J. Kohler and Samuel K. Joseph. By focusing on the voices of these dissenters, this chapter enriches the emerging picture of Progressive Era eugenic and racial thought.
Surviving learning races: An analysis of strategic alliance evolution capabilities
2014
This paper is aimed to identify and understand the main dimensions and processes that underlie the capacity of weaker firms in an initially unbalanced strategic alliance to purposefully channel the fruitful evolution of the alliance by creating, extending or modifying its scope in order to perceive and grasp new value creating opportunities which they would not be able to seize on their own. We call this capacity an alliance evolution capability and intend it as a particular type of dynamic capability of the firm (Teece, Pisano & Schuen, 1997; Helfat et al., 2007). The motivation for this paper is threefold: (1) to understand how weaker firms may survive learning race alliances (Hamel, 1991…