Are rapid changes in gonadal testosterone release involved in the fast modulation of brain estrogen effects?
Cornil, Charlotte ; ;
in General and Comparative Endocrinology (2009)
Estradiol facilitates the expression of male sexual behavior in Japanese quail within a few minutes. These rapid behavioral effects of estradiol could result from rapid changes in its local production in ... [more ▼]
Estradiol facilitates the expression of male sexual behavior in Japanese quail within a few minutes. These rapid behavioral effects of estradiol could result from rapid changes in its local production in the preoptic area by aromatase, the enzyme converting testosterone into estradiol. Alternatively, aromatase activity may remain constant but fluctuations of local estradiol production could arise from rapid changes in the concentration of the enzymatic substrate, namely testosterone. Rapid increases of circulating testosterone levels have been observed in males of various species following social encounters. Surprisingly, in quail, the interaction with a female seems to result in a decrease in circulating testosterone levels. However, in that study conducted in quail, the samples were collected at intervals longer than the recently observed rapid effects of estradiol on sexual behavior. In the present study we investigated whether plasma testosterone concentrations fluctuate on a shorter time-frame. Eleven male were tested 5 min before and 5, 15 or 30 min after being allowed to have visual access to a female or to copulate with a female for 5 min. Both types of interactions resulted in a significant decline in circulating testosterone levels at latencies as short as 5 min. These data demonstrate that the decrease in testosterone levels is initiated shortly after sexual encounters. Because visual interactions with a female did not result in a rapid increase in testosterone concentrations, these findings rule out the possibility that a rapid rise in circulating testosterone levels participates in the rapid increase in brain estrogen synthesis and its facilitatory effects on copulatory behavior. [less ▲]Detailed reference viewed: 44 (12 ULg)
Are Similar Inflammatory Factors Involved in Strenuous Exercise and Sepsis?
; Deby, Ginette ; et al
in Intensive Care Medicine (1994), 20(8), 602-10
An increasing body of data suggest that strenuous exercise triggers an inflammatory response having some similarity with those occurring in sepsis. Indices of this inflammatory response to exercise (IRE ... [more ▼]
An increasing body of data suggest that strenuous exercise triggers an inflammatory response having some similarity with those occurring in sepsis. Indices of this inflammatory response to exercise (IRE) especially include leukocytosis, release of inflammatory mediators and acute phase reactants, tissue damage, priming of various white blood cell lines, production of free radicals; activation of complement, coagulation and fibrinolytic cascades. Inflammatory responses to strenuous exercise and sepsis could in part be due to the release of endotoxin in blood as common triggering factor, but it seems that tissue damage and/or contact system activation are more important triggering mechanisms in exercising subjects. While the magnitude and duration of cellular and humoral changes associated with IRE are quite different from those observed in sepsis, recent human studies suggested that chronic and/or excessive IRE could have adverse effects. Among the possible consequences of acute and chronic IRE are delayed onset muscular soreness and loss of force, cardiovascular complications, intravascular hemolysis, hypoferraemia and increased susceptibility to infection. [less ▲]Detailed reference viewed: 23 (0 ULg)
Are Simple Calculation Models always on the Safe Side?
in Schaumann, Peter (Ed.) Festschrift Peter Schaumann (2014)
This paper examines the question whether simple calculation models are always on the safe side compared to advanced calculation models. This question is examined for the shadow effect, for the contact ... [more ▼]
This paper examines the question whether simple calculation models are always on the safe side compared to advanced calculation models. This question is examined for the shadow effect, for the contact between steel and concrete in composite steel-concrete floors, for the buckling curves of steel sections and, finally, for the factors κ1 and κ2 applied to the bending resistance of steel beams. [less ▲]Detailed reference viewed: 17 (1 ULg)
Are Skinner's warnings still relevant to current psychology ? Commentary on B.F.Skinner, Methods and theories in the experimental analysis of behavior
in Behavioral and Brain Sciences (1984), 7Detailed reference viewed: 3 (0 ULg)
Are spatial memories strengthened in the human hippocampus during slow wave sleep?
Peigneux, Philippe ; Laureys, Steven ; et al
in Neuron (2004), 44(3), 535-545
In rats, the firing sequences observed in hippocampal ensembles during spatial learning are replayed during subsequent sleep, suggesting a role for posttraining sleep periods in the offline processing of ... [more ▼]
In rats, the firing sequences observed in hippocampal ensembles during spatial learning are replayed during subsequent sleep, suggesting a role for posttraining sleep periods in the offline processing of spatial memories. Here, using regional cerebral blood flow measurements, we show that, in humans, hippocampal areas that are activated during route learning in a virtual town are likewise activated during subsequent slow wave sleep. Most importantly, we found that the amount of hippocampal activity expressed during slow wave sleep positively correlates with the improvement of performance in route retrieval on the next day. These findings suggest that learning-dependent modulation in hippocampal activity during human sleep reflects the offline processing of recent episodic and spatial memory traces, which eventually leads to the plastic changes underlying the subsequent improvement in performance. [less ▲]Detailed reference viewed: 37 (2 ULg)
Are Tangs Morphological Adaptations in View of Hafting? Macro- and microscopic wear analysis on a selection of tanged burins from Maisières-Canal
in Notae Praehistoricae (2002), 114Detailed reference viewed: 9 (4 ULg)
are target dioxin levels in animal feedingstuffs achievable for laboratories in terms of analytical requirements? Results of an interlaboratory study
Eppe, Gauthier ; De Pauw, Edwin
in Organohalogen Compounds (2002)Detailed reference viewed: 8 (0 ULg)
Are the 1999 and 2000 urban floods in Senegal due to exceptional rainfall events?
; Ozer, Pierre
in Demarée, Gaston; De Dapper, Morgan; Alexandre, Jean (Eds.) Tropical Climatology, Meteorology and Hydrology: Climate-related risk analysis and sustainable development in tropical areas. (2004)Detailed reference viewed: 24 (2 ULg)
Are the back educational interventions effective for preventing low back pain
Demoulin, Christophe ; ; et al
in Abstract book of the 8th Interdisciplinary World Congress on Low Back and Pelvic Pain (2013, October)Detailed reference viewed: 8 (0 ULg)
Are the CMIP5 GCMs able to simulate atmospheric blocking situations over Europe ?
Belleflamme, Alexandre ; Fettweis, Xavier ; Erpicum, Michel
Poster (2012, April 26)
Some studies show that most General Circulation Models (GCMs) have difficulties to simulate the main observed circulation patterns and their frequencies. However, this does not only impact the GCM based ... [more ▼]
Some studies show that most General Circulation Models (GCMs) have difficulties to simulate the main observed circulation patterns and their frequencies. However, this does not only impact the GCM based projections for future climate, but also the results of downscaling methods using the circulation simulated by GCMs as forcing. Indeed, the downscaling methods are not able to correct the biases introduced by the GCM simulations in the free atmosphere. Here, we focus on the anticyclonic blocking situations over western Europe for summer (June, July and August). Indeed, these blocking situations, which are often related to droughts and heat waves, could become more frequent due to global warming. Moreover, their frequency and persistence depend on the variability of the circulation, which is known to be difficult to reproduce by the GCMs. In order to evaluate the ability of the GCMs to reproduce the observed frequency and persistence of blocking situations, we compare them with two reanalysis datasets (NCEP-NCAR 1 and ECMWF ERA-40) by using an automatic circulation type classification. The daily geopotential height at 500 hPa over the last 30 years of the current climate simulation (Historical experiment, 1976-2005) of all available CMIP5 GCMs prepared for the upcoming IPCC report AR5 is used here. The circulation type classification groups similar daily circulation situations together on basis of a leader-algorithm to obtain a few homogeneous circulation types describing the general circulation of the region. Thus, the frequency and the persistence of each circulation type can be analysed on a daily timescale. We show that the ability of the GCMs to reproduce the observed frequency and persistence of blocking situations is influenced by the anomalies in their circulation type frequency repartition. So, the GCMs which underestimate the frequency of the anticyclonic types tend to simulate less and shorter blocking situations. The contrary is observed for GCMs that overestimate the frequency of these circulation types. This rises questions about the reliability of the future projections for events related to blocking situations. Indeed, when applying the same approach as for the current climate to the future projections (experiments RCP4.5 and RCP8.5), it seems that the blocking situations become more frequent and persistent. However, when considering only the circulation patterns by removing the mean geopotential height increase due to global warming, there is no significant circulation change till 2100. This means that the GCMs conserve their circulation biases in spite of climate change and so, the frequency and the persistence of the blocking situations are projected to remain almost the same as those simulated for the current climate. [less ▲]Detailed reference viewed: 34 (1 ULg)
Are the complications of arteriovenous fistulas associated with an abnormal Ankle-Brachial Index in hemodialysis patients?
Xhignesse, Patricia ; Saint-Remy, Annie ; Dubois, Bernard et al
in Acta Clinica Belgica (2010), 65(1), 65
The peripheral artery disease is frequent among patients undergoing hemodialysis much more than in the general population. The ankle-brachial index (AB!) is a potent tool to screen this pathology. We ... [more ▼]
The peripheral artery disease is frequent among patients undergoing hemodialysis much more than in the general population. The ankle-brachial index (AB!) is a potent tool to screen this pathology. We analysed the relationship between ABI abnormal values and arteriovenous fistulas (AVF) complications such as stenosis and thrombosis among chronically hemodialysis pat ients (HD). [less ▲]Detailed reference viewed: 44 (10 ULg)
Are the creatinine-based equations accurate to estimate glomerular filtration rate in african american populations ?
DELANAYE, Pierre ; ; et al
in Clinical Journal of the American Society of Nephrology (2011), 6
Regarding the high prevalence of African American patients with ESRD, it is important to estimate the prevalence of early stages of chronic kidney disease in this specific population. Because serum ... [more ▼]
Regarding the high prevalence of African American patients with ESRD, it is important to estimate the prevalence of early stages of chronic kidney disease in this specific population. Because serum creatinine concentration is dependent on muscular mass, an ethnic factor has to be applied to creatinine-based equations. Such ethnic factors have been proposed in the Modification of Diet in Renal Disease (MDRD) study equation and in the more recent Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. This review analyzes how these correction factors have been developed and how they have, or have not, been validated in external populations. It will be demonstrated that the African American factor in the MDRD study equation is accurate in African American chronic kidney disease (CKD) patients. However, it will be shown that this factor is probably too high for subjects with a GFR of >60 ml/min per 1.73 m2, leading to an underestimation of the prevalence of CKD in the global African American population. It will also be confirmed that this ethnic factor is not accurate in African (non-American) subjects. Lastly, the lack of true external validation of the new CKD-EPI equations will be discussed. Additional trials seem necessary in American African and African populations to better estimate GFR and apprehend the true prevalence of CKD in this population with a high renal risk. [less ▲]Detailed reference viewed: 55 (5 ULg)
Are The Fusion Processes Involved In Birth, Life And Death Of The Cell Depending On Tilted Insertion Of Peptides Into Membranes?
; ; Lins, Laurence et al
in Journal of Theoretical Biology (1999), 198(2), 173-81
Various peptide segments have been modeled as asymmetric amphipathic alpha-helices. Theoretical calculations have shown that they insert obliquely into model membranes. They have been named "tilted ... [more ▼]
Various peptide segments have been modeled as asymmetric amphipathic alpha-helices. Theoretical calculations have shown that they insert obliquely into model membranes. They have been named "tilted peptides". Molecular modeling results reported here also evidence the presence of tilted peptides in ADM-1 protein of Caenorhabditis elegans that may be involved in fusion events, in meltrin alpha, a protein implicated in myoblast fusion, in hemagglutinin of influenza virus, in the E2 glycoprotein of rubella virus, in the S protein of hepatitis B virus, in a subdomain of Ebola virus and in the malaria CS protein. Experimental results have indicated that tilted peptide fragments may be involved in cellular life events like sperm-egg fecondation, muscle development, protein translocation through signal sequences and cellular death caused by viral infection or parasite infestation. We speculate that membrane destabilization by these tilted peptides may be an important common step in life processes involving fusion phenomena. [less ▲]Detailed reference viewed: 6 (0 ULg)
Are the IKKs and IKK-related kinases TBK1 and IKK-ε similarly activated ?
Chau, Tieu-Lan ; Gioia, Romain ; GATOT, Jean-Stéphane et al
in Trends in Biochemical Sciences - Regular Edition (2008), 33
The IKKs, IKKa and IKKb, and the IKK-related kinases TBK1 and IKKe, play essential roles in innate immunity through signal-induced activation of NF-κB and IRF3/7, respectively. Although the signaling ... [more ▼]
The IKKs, IKKa and IKKb, and the IKK-related kinases TBK1 and IKKe, play essential roles in innate immunity through signal-induced activation of NF-κB and IRF3/7, respectively. Although the signaling events within these pathways have been extensively studied, the mechanisms of IKK and IKK-related complex assembly and activation remain poorly defined. Recent data provide insight into the requirement for scaffold proteins in complex assembly; NEMO coordinates some IKK complexes, whereas TANK, NAP1 or SINTBAD assemble TBK1 and IKKe complexes. The different scaffold proteins undergo similar post-translational modifications, including phosphorylation and non-degradative polyubiquitylation. Moreover, increasing evidence suggests that distinct scaffold proteins assemble IKK and potentially TBK1 and IKKε sub-complexes in a stimulus-specific manner, which might be a mechanism to achieve specificity. [less ▲]Detailed reference viewed: 131 (11 ULg)
Are the interactions between neurodegenerative proteins and polymeric surfaces related to the hydrophilic and hydrophobic balance ?
; ; et al
in Macromolecular Bioscience (2012), In press
In pressDetailed reference viewed: 5 (0 ULg)
Are the interactions between recombinant prion protein and polymeric surfaces related to the hydrophilic and hydrophobic balance ?
; ; et al
in Macromolecular Bioscience (2012), In press
In pressDetailed reference viewed: 14 (1 ULg)
Are the stars of a new class of variability detected in NGC 3766 fast rotating SPB stars?
Salmon, Sébastien ; ; et al
in Meynet, Georges; Georgy, Cyril; Groh, Jose (Eds.) et al Proceedings of the International Astronomical Union S307 (2015, January 01)
A recent photometric survey in the NGC 3766 cluster led to the detection of stars presenting an unexpected variability. They lie in a region of the Hertzsprung-Russell (HR) diagram where no pulsation are ... [more ▼]
A recent photometric survey in the NGC 3766 cluster led to the detection of stars presenting an unexpected variability. They lie in a region of the Hertzsprung-Russell (HR) diagram where no pulsation are theoretically expected, in between the δ Scuti and slowly pulsating B (SPB) star instability domains. Their variability periods, between ~0.1-0.7 d, are outside the expected domains of these well-known pulsators. The NCG 3766 cluster is known to host fast rotating stars. Rotation can significantly affect the pulsation properties of stars and alter their apparent luminosity through gravity darkening. Therefore we inspect if the new variable stars could correspond to fast rotating SPB stars. We carry out instability and visibility analysis of SPB pulsation modes within the frame of the traditional approximation. The effects of gravity darkening on typical SPB models are next studied. We find that at the red border of the SPB instability strip, prograde sectoral (PS) modes are preferentially excited, with periods shifted in the 0.2-0.5 d range due to the Coriolis effect. These modes are best seen when the star is seen equator-on. For such inclinations, low-mass SPB models can appear fainter due to gravity darkening and as if they were located between the δ Scuti and SPB instability strips. [less ▲]Detailed reference viewed: 1 (0 ULg)
Are there any specific neural substrates for short-term storage? Further data from functional magnetic resonance imaging.
Conference (2008, March 18)Detailed reference viewed: 6 (0 ULg)
Are there arguments allowing to propose that polyamines are preventive agents of food allergy
Dandrifosse, Guy ; Peulen, Olivier ; et al
Conference (1998, November)Detailed reference viewed: 8 (2 ULg)
Are there arguments suggesting that polyamines are preventive agents of food allergy ?
Dandrifosse, Guy ; Peulen, Olivier ; et al
in Proceeding of the COST 917 Meeting in Malaga (2000)Detailed reference viewed: 5 (1 ULg)