Search results for "PET"
showing 10 items of 12749 documents
Trade is not necessary for agglomeration to arise
2003
We develop a spatial general equilibrium model in which the absence of trade is an endogenous outcome and we show that trade is not a necessarycondition for agglomeration to arise. More precisely, extending the modeldeveloped by Ottaviano et al. [13], we show that equilibria without tradediffer significantly from those obtained in the presence of trade. Somewhatsurprisingly, equilibrium structures without trade are richer than those withtrade, since partial agglomeration becomes a feasible outcome. Equilibrianow depend on the ratio of mobile to immobile factors and an increase in thatratio triggers a process of spatial agglomeration.
Differential Response of Ant Colonies to Intruders: Attack Strategies Correlate With Potential Threat
2011
Animals are often threatened by predators, parasites, or competitors, and attacks against these enemies are a common response, which can help to remove the danger. The costs of defense are complex and involve the risk of injury, the loss of energy ⁄time, and the erroneous identification of a friend as a foe. Our goal was to study the specificity of defense strategies. We analyzed the aggressive responses of ant colonies by confronting them with workers of an unfamiliar congeneric species, a non-nestmate conspecific, a co-occurring congeneric competitor species, and a social parasite—a slave-making ant. As expected, the latter species, which can inflict dramatic fitness losses to the colony,…
Aggressivität, Assertivität und sexuelle Devianz: Eine empirisch-quantitative Prüfung der Stoller’schen Perversionstheorie
2022
Aggressiveness, assertiveness, and sexual deviance: An empirical-quantitative examination of Stoller's perversion theoryObjectives: The main aim of the present study was to empirically examinate the psychodynamic-founded perversion theory of Robert D. Stoller (1979), particularly his assumption of a transformation of aggressive impulses into sexual deviant fantasies due to traumatic experiences. Methods: In the present study different aspects of the theory were examined by using a sample (N = 954) of individuals convicted of sexually motivated offenses who had been clinically and forensically assessed between 2002 and 2018 at the Federal Evaluation Centre for Violent and Sexual Offenders (F…
Influence of gene action across different time scales on behavior.
2002
Genes can affect natural behavioral variation in different ways. Allelic variation causes alternative behavioral phenotypes, whereas changes in gene expression can influence the initiation of behavior at different ages. We show that the age-related transition by honey bees from hive work to foraging is associated with an increase in the expression of the foraging ( for ) gene, which encodes a guanosine 3′,5′-monophosphate (cGMP)–dependent protein kinase (PKG). cGMP treatment elevated PKG activity and caused foraging behavior. Previous research showed that allelic differences in PKG expression result in two Drosophila foraging variants. The same gene can thus exert different types of influe…
Progerin expression induces a significant downregulation of transcription from human repetitive sequences in iPSC-derived dopaminergic neurons.
2019
Repetitive DNA sequences represent about half of the human genome. They have a central role in human biology, especially neurobiology, but are notoriously difficult to study. The purpose of this study was to quantify the transcription from repetitive sequences in a progerin-expressing cellular model of neuronal aging. Progerin is a nuclear protein causative of the Hutchinson–Gilford progeria syndrome that is also incrementally expressed during the normal aging process. A dedicated pipeline of analysis allowed to quantify transcripts containing repetitive sequences from RNAseq datasets oblivious of their genomic localization, tolerating a sufficient degree of mutational noise, all with low c…
European undergraduate curriculum in geriatric medicine developed using an international modified Delphi technique.
2014
Introduction: the rise in the number of older, frail adults necessitates that future doctors are adequately trained in the skills of geriatric medicine. Few countries have dedicated curricula in geriatric medicine at the undergraduate level. The aim of this project was to develop a consensus among geriatricians on a curriculum with the minimal requirements that a medical student should achieve by the end of medical school. Methods: a modified Delphi process was used. First, educational experts and geriatricians proposed a set of learning objectives based on a literature review. Second, three Delphi rounds involving a panel with 49 experts representing 29 countries affiliated to the European…
Extracellular Domains of the Bradykinin B2 Receptor Involved in Ligand Binding and Agonist Sensing Defined by Anti-peptide Antibodies
1996
Many of the physiological functions of bradykinin are mediated via the B2 receptor. Little is known about binding sites for bradykinin on the receptor. Therefore, antisera against peptides derived from the putative extracellular domains of the B2 receptor were raised. The antibodies strongly reacted with their corresponding antigens and cross-reacted both with the denatured and the native B2 receptor. Affinity-purified antibodies to the various extracellular domains were used to probe the contact sites between the receptor and its agonist, bradykinin or its antagonist HOE140. Antibodies to extracellular domain 3 (second loop) efficiently interfered, in a concentration-dependent manner, with…
Shared midgut binding sites for Cry1A.105, Cry1Aa, Cry1Ab, Cry1Ac and Cry1Fa proteins from Bacillus thuringiensis in two important corn pests, Ostrin…
2013
First generation of insect-protected transgenic corn (Bt-corn) was based on the expression of Cry1Ab or Cry1Fa proteins. Currently, the trend is the combination of two or more genes expressing proteins that bind to different targets. In addition to broadening the spectrum of action, this strategy helps to delay the evolution of resistance in exposed insect populations. One of such examples is the combination of Cry1A.105 with Cry1Fa and Cry2Ab to control O. nubilalis and S. frugiperda. Cry1A.105 is a chimeric protein with domains I and II and the C-terminal half of the protein from Cry1Ac, and domain III almost identical to Cry1Fa. The aim of the present study was to determine whether the c…
STRATEGY TO INCREASE THE FARM COMPETITIVENESS
2014
Italy’s wine-growing production structure is highly pulverized. So, for many wine-growing farms loweri ng the production cost represents the only way of gain ing a competitive advantage. Production at average unit costs lower than competitors allows to improve prof itability. Among farming operations, winter pruning and tying of productive vine-branches require a high hu man labor. For this reason the paper presents the r esults of research conducted on a sample of Sicilian wine- producing farms in order to study the cost-effectiv eness to make the pruning and the subsequent ligation of productive branches with tools that facilitate the work. The economic analysis, after the determination o…