Search results for " asymmetry"
showing 10 items of 263 documents
Immunocompetence, developmental stability and wingspot size in the damselflyCalopteryx splendensL.
2000
Calopteryx splendens males exhibit a remarkable variation in wing pigmentation both within and between populations. In this study, we examined whether the wingspots of male C. splendens are related to male quality. We measured the nylon implant encapsulation rate for 85 males and found that males with larger wingspots had a faster encapsulation rate, indicating a better immunocompetence. We also found that the encapsulation rate was positively correlated with the density of haemocytes in the haemolymph. Another measurement of male quality, fluctuating asymmetry of wingspots, correlated negatively with the size of the wingspots. Males with asymmetrical wingspots also had lower encapsulation …
Tenectin is a novel alphaPS2betaPS integrin ligand required for wing morphogenesis and male genital looping in Drosophila.
2010
International audience; Morphogenesis of the adult structures of holometabolous insects is regulated by ecdysteroids and juvenile hormones and involves cell-cell interactions mediated in part by the cell surface integrin receptors and their extracellular matrix (ECM) ligands. These adhesion molecules and their regulation by hormones are not well characterized. We describe the gene structure of a newly described ECM molecule, tenectin, and demonstrate that it is a hormonally regulated ECM protein required for proper morphogenesis of the adult wing and male genitalia. Tenectin's function as a new ligand of the PS2 integrins is demonstrated by both genetic interactions in the fly and by cell s…
Lateral differences in the GABAergic system of the rat striatum.
1985
Asymmetric differences have been found in the pre- and postsynaptic activity of the GABAergic system of the left and right striata of the rat. 3H-GABA binding shows a higher dissociation constant (KD) and a higher number of sites (Bmax) in the left striatum than in the right. Moreover, 3H-diazepam binding seems to be more extensively activated by GABA in the right striatum suggesting a more sensitive postsynaptic GABAergic activity than on the left side. However, when the presynaptic marker (GAD activity) was measured, the asymmetry was in the opposite direction. The results provide further neurochemical evidence of the functional asymmetry of the rat brain.
PARASITIC INFECTION AND DEVELOPMENTAL STABILITY: FLUCTUATING ASYMMETRY IN GAMMARUS PULEX INFECTED WITH TWO ACANTHOCEPHALAN SPECIES
2002
Several studies have reported a negative association between developmental stability and parasitic infection. However, the host-parasite associations examined so far consist only of a limited number of parasite taxa, and developmental stability was appraised on definitive hosts. The present study examines the association between infection by 2 acanthocephalan parasites. Pomphorhynchus laevis and Polymorphus minutus, and the developmental stability of their common intermediate host Gammarus pulex. Developmental stability was estimated from the fluctuating asymmetry (FA) levels of 6 morphological traits. A positive association was found between FA and infection. Infected gammarids tended to b…
Gait asymmetry in patients with limb length discrepancy.
2004
Foot loading patterns and neuromuscular function of both limbs during walking were investigated on 25 patients with limb length discrepancy. Plantar pressures and 2-D ground reaction forces were recorded simultaneously with electromyographic activities at two different walking speeds. Bilateral comparison indicated that moderate limb length discrepancies resulted in asymmetrical gait patterns. The duration of the stance phase was reduced in the short limb in both walking speeds. The vertical ground reaction force (F) in the push-off phase was greater in the long limb both at normal (1.33 (SO, 0.05 BW) vs. 1.29 (SD, 0.09 BW)) (P=0.0027) and fast walking speed (1.55 (SD, 0.11) vs. 1.48 (SD, 0…
Infantile postural asymmetry and osteopathic treatment: a randomized therapeutic trial
2005
The aim of this study was to assess the therapeutic efficacy of osteopathic treatment in infants with postural asymmetry. A randomized clinical trial of efficacy with blinded videoscoring was performed. Sixty-one infants with postural asymmetry aged 6 to 12 weeks (mean 9wks) were recruited. Thirty-two infants (18 males, 14 females) with a gestational age of at least 36 weeks were found to be eligible and randomly assigned to the intervention groups, 16 receiving osteopathic treatment and 16 sham therapy. After a treatment period of 4 weeks the outcome was measured using a standardized scale (4-24 points). With sham therapy, five infants improved (at least 3 points), eight infants were uncha…
An empirical investigation into market risk disclosure: is there room to improve for Italian banks?
2020
PurposeThis paper aims to examine the market risk disclosure practices of large Italian banks. The contribution provides insights on the way banks should provide information about market risk. The problem related to the asymmetric information between banks from one side, and investors and stakeholders on the other, represents a crucial issue that requires further considerations by scholars and regulators.Design/methodology/approachThis contribution adopts a mixed methodological approach to analyse both qualitative and quantitative profiles of market risk disclosure in banking. This paper analyses the most important documents Italian banks are required to prepare for risk disclosure purposes…
Potential agency problems in European club football? The case of UEFA Financial Fair Play
2014
Purpose– With the licence season 2013/2014 onwards Union of European Football Associations (UEFA) Financial Fair Play (FFP) fully came into force. Among other things, FFP demands from the clubs to operate within their own revenues in order to counteract the increasing over indebtedness in European club football. The purpose of this paper is to cast further light on the relationship between UEFA and the clubs as the main actors of FFP and to derive implications to UEFA to improve the efficacy of this regulatory intervention.Design/methodology/approach– This paper explicitly examines the case of FFP from an agency theory perspective. A positivist agency approach is applied in order to describ…
Optimal vs satisfactory transparency : The impact of global macroeconomic fluctuations on corporate competitiveness
2019
Abstract Being able to separate temporary global macroeconomic influences – caused by fluctuations in exchange rates, interest rates and inflation – from intrinsic performance – related to a superior product, production process or management – is crucial to assessing the development of a firm’s competiveness. Against that background, this paper analyzes institutions’ role in making firms supply outside shareholders with relevant information corresponding to satisfactory transparency from the shareholder perspective. Based on a sample of the 100 largest public European firms, it is found that no firm provided information to a level deemed satisfactory by the outside shareholder. One explanat…
Standard and non-standard neutrino properties
2002
I review the interpretation of solar and atmospheric neutrino data in terms neutrino oscillations and describe some ways to account for the required neutrino masses and mixing angles from first principles, both within top-down and bottom-up approaches. I also discuss non-oscillation phenomena such as nu-less double beta which may probe the absolute scale of neutrino mass, and also reveal its Majorana nature. I note that leptonic CP violation induced by ``Majorana'' phases drop from oscillations but play a role in the leptogenesis scenario for the baryon asymmetry of the Universe. Direct tests of leptonic CP violation in oscillation experiments, such as neutrino factories, will be a tough ch…