Changes in the 5-HT2(A )receptor system in the pre-mammillary hypothalamus of the ewe are related to regulation of LH pulsatile secretion by an endogenous circannual rhythm

BACKGROUND: We wanted to determine if changes in the expression of serotonin 2A receptor (5HT2(A )receptor) gene in the premammillary hypothalamus are associated with changes in reproductive neuroendocrine status. Thus, we compared 2 groups of ovariectomized-estradiol-treated ewes that expressed high vs low LH pulsatility in two different paradigms (2 groups per paradigm): (a) refractoriness (low LH secretion) or not (high LH secretion) to short days in pineal-intact Ile-de-France ewes (RSD) and (b) endogenous circannual rhythm (ECR) in free-running pinealectomized Suffolk ewes in the active or inactive stage of their reproductive rhythm. RESULTS: In RSD ewes, density of 5HT2(A )receptor mRNA (by in situ hybridization) was significantly higher in the high LH group (25.3 ± 1.4 vs 21.4 ± 1.5 grains/neuron, P < 0.05) and (3)H-Ketanserin binding (a specific radioligand) of the median part of the premammillary hypothalamus tended to be higher in the high group (29.1 ± 4.0 vs 24.6 ± 4.2 fmol/mg tissu-equivalent; P < 0.10). In ECR ewes, density of 5HT2(A )receptor mRNA and (3)H-Ketanserin binding were both significantly higher in the high LH group (20.8 ± 1.6 vs 17.0 ± 1.5 grains/neuron, P < 0.01, and 19.7 ± 5.0 vs 7.4 ± 3.4 fmol/mg tissu-equivalent; P < 0.05, respectively). CONCLUSIONS: We conclude that these higher 5HT2(A )receptor gene expression and binding activity of 5HT2(A )receptor in the premammillary hypothalamus are associated with stimulation of LH pulsatility expressed before the development of refractoriness to short days and prior to the decline of reproductive neuroendocrine activity during expression of the endogenous circannual rhythm

Complementary network-based approaches for exploring genetic structure and functional connectivity in two vulnerable, endemic ground squirrels

The persistence of small populations is influenced by genetic structure and functional connectivity. We used two network-based approaches to understand the persistence of the northern Idaho ground squirrel (Urocitellus brunneus) and the southern Idaho ground squirrel (U. endemicus), two congeners of conservation concern. These graph theoretic approaches are conventionally applied to social or transportation networks, but here are used to study population persistence and connectivity. Population graph analyses revealed that local extinction rapidly reduced connectivity for the southern species, while connectivity for the northern species could be maintained following local extinction. Results from gravity models complemented those of population graph analyses, and indicated that potential vegetation productivity and topography drove connectivity in the northern species. For the southern species, development (roads) and small-scale topography reduced connectivity, while greater potential vegetation productivity increased connectivity. Taken together, the results of the two network-based methods (population graph analyses and gravity models) suggest the need for increased conservation action for the southern species, and that management efforts have been effective at maintaining habitat quality throughout the current range of the northern species. To prevent further declines, we encourage the continuation of management efforts for the northern species, whereas conservation of the southern species requires active management and additional measures to curtail habitat fragmentation. Our combination of population graph analyses and gravity models can inform conservation strategies of other species exhibiting patchy distributions

Mainshocks are aftershocks of conditional foreshocks: How do foreshock statistical properties emerge from aftershock laws

The inverse Omori law for foreshocks discovered in the 1970s states that the rate of earthquakes prior to a mainshock increases on average as a power law ~ 1/(t_c-t)^p' of the time to the mainshock occurring at t_c. Here, we show that this law results from the direct Omori law for aftershocks describing the power law decay ~ 1/(t-t_c)^p of seismicity after an earthquake, provided that any earthquake can trigger its suit of aftershocks. In this picture, the seismic activity at any time is the sum of the spontaneous tectonic loading and of the activity triggered by all preceding events weighted by their corresponding Omori law. The inverse Omori law then emerges as the expected (in a statistical sense) trajectory of seismicity, conditioned on the fact that it leads to the burst of seismic activity accompanying the mainshock. The often documented apparent decrease of the b-value of the GR law at the approach to the main shock results straightforwardly from the conditioning of the path of seismic activity culminating at the mainshock. In the space domain, we predict that the phenomenon of aftershock diffusion must have its mirror process reflected into an inward migration of foreshocks towards the mainshock. In this model, foreshock sequences are special aftershock sequences which are modified by the condition to end up in a burst of seismicity associated with the mainshock.Comment: Latex document of 35 pages, 10 figure

Le Forum, Vol. 46 #1 & #2

https://digitalcommons.library.umaine.edu/francoamericain_forum/1110/thumbnail.jp

Les hispani et l'hispania de Tite Live

Pelletier Agnès. Les hispani et l'hispania de Tite Live. In: Mélanges de la Casa de Velázquez, tome 22, 1986. pp. 5-25

Sagontins et Turdétans à la veille de la deuxième Guerre Punique

In 219 B.C., Hannibal would have besieged the Saguntines for their attack against the Turdetani. But the analysis of Livy's text proves that the Saguntines' neighbours were not Turdetani : actually, Turdetania is the politic and strategic concept of the part of Hispania belonging to the Carthaginians. Explaining its past in this way, Livy protects augustean Rome's greatness : Rome could help her allied against attacked Turdetani, but could not set herself against Carthage, only at the cost of an obvious breach of the right.En 219 avant Jésus-Christ, Hannibal aurait assiégé les Sagontins à cause de leur attaque contre les Turdétans. Or, la confrontation des sources antiques et, essentiellement, l'analyse du texte livien montrent que s'il y a eu conflit entre les Sagontins et leurs voisins, ceux-ci ne sauraient avoir été les Turdétans ; zone géographique bien délimitée, la Turdétanie équivaut, en fait, à un concept politique et stratégique : celui de l'Hispania carthaginoise. En expliquant ainsi son passé, Tite-Live préserve la grandeur de la Rome augustéenne : elle pouvait aider ses alliés sagontins contre les Turdétans qu'ils avaient attaqués — preuve de leur attachement à Rome — , mais elle n'aurait su s'opposer à Carthage qu'au prix d'une violation manifeste du droit.Pelletier Agnès. Sagontins et Turdétans à la veille de la deuxième Guerre Punique. In: Revue des Études Anciennes. Tome 88, 1986, n°1-4. Hommage à Robert Etienne. pp. 307-315

Sagonte, Iliturgi, Astapa: trois destins tragiques vus de Rome

Pelletier Agnès. Sagonte, Iliturgi, Astapa: trois destins tragiques vus de Rome. In: Mélanges de la Casa de Velázquez, tome 23, 1987. pp. 107-124

Communication des laboratoires pharmaceutiques auprès des patients (quels nouveaux enjeux?)

DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

Héparine de bas poids moléculaire aprés un remplacement valvulaire mécanique (évaluation clinique et pharmaco-économique)

PARIS-BIUP (751062107) / SudocSudocFranceF

Projection du film Mines d'or romaines en Espagne

Pelletier Agnès, Jacob Pierre, Domergue Claude, Hérail Gérard. Projection du film Mines d'or romaines en Espagne. In: Mélanges de la Casa de Velázquez, tome 21, 1985. pp. 473-476