88,769 research outputs found
Famiglie senza matrimonio: informalità delle relazioni e continuità parentale in area senese
No full textCaratteristiche delle famiglie di fatto in relazione alle logiche parentali attivate in assenza di vincoli formali
La cultura organizzativa delle aziende sanitarie : aspetti teorici, evidenze e rilevanza per il governo clinico
No full textS. Grilli e F. Zanotelli (a cura di). Scelte di famiglia : tendenze della parentela nella società contemporanea
No full textRecensione del volume "Scelte di famiglia : tendenze della parentela nella società contemporanea", a cura di S. Grilli e F. Zanotelli
Incommensurate charge-density-wave instability in the extended three-band Hubbard model
No full textThe infinite-U three-band Hubbard model is considered in order to describe the CuO2 planes of the high-temperature superconducting cuprates. The charge instabilities are investigated when the model is extended with a nearest-neighbor repulsion between holes an copper d and oxygen p orbitals and in the presence of a long-range Coulombic repulsion. It is found that a first-order valence instability line ending with a critical point is present as in the previously investigated model without long-range forces. However, the dominant critical Instability is the formation of incommensurate charge-density waves, which always occur before the valence-instability critical point is reached, An effective singular attraction arises in the proximity of the charge-density wave instability, accounting for both a strong pairing mechanism and for the anomalous normal-state properties
EFFECTS OF PMSG INDUCED OESTRUS ON THE PERFORMANCES OF RABBIT DOES : A REVIEW +
No full text[EN] Although the rabbit is considered as a mammal
with an extreme high reproduction capacity, the irregular
alternation of oestrous and anoestrous periods 1s a
disadvantage in view of a regular, synchronized reproduction
rhythm. Especially with the increasing use of artificial
insemination in rabbit breeding, large groups of females in
the same reproductive and pllysiolog1cal stage are likely.
However, the receptivity of the tloe is largely aepending on
the hormonal antagonism between prolactin and
gonadotropin. In order to salve this problem, last years an
increasing use of a Pregnant Mare Serum Gonadotropin
(PMSG) treatment, 2 to 3 days before the insemination,
became widespread.
The authors reviewed the literature concerning the effects of
a PMSG treatment in arder to synchronize the oestrus. The
following beneflts generally determined were :
- an increase of the sexual receptivity to the male ; about
90 % accept the male 2-3 days after the treatment.
- especially in lactating non receptiva does, receptivity and
fertihty were significantly increased. - an increase of the prolificacy ; total litter size: + 5 to 1 O %
- positive results on does with reproductiva problems.
However, a number of dlsadvantages were found:
- the lack of improvement in non-lactating or receptiva does.
- because of antigenic properties, a decrease in fertility after
repeated treatments.
- an increase of the mortality rate at birth, probably related to
the dosage used.
- a changed distribution of litter size frequencies: larga litters
(> 12 young) and small litters (<5 young) are more numerous.
Based on these observations, the authors advise to consider
the application of PMSG induced oestrus only in relation to
the physiological status of the doe and at a low dosage.
Limited use on primiparous does and (or) on non-receptiva
does can help to synchronize the oestrus and to obtain more
favourable results in a well organized reproduction scheme.
However, further research efforts have to be done in order to
optimize feeding, zootechnical and environmental conditions
in view of oestrus synchronization and to avoid the
systematic use of PMSG.[FR] Bien que le lapin soit considéré comme un mammifere ayant
une tres grande capacité de reproduction, l'irrégularité dans
l'alternance des p'ériode d'oestrus et d'anoestrus est un
inconvénient lorsque que l'on veut régulariser, synchroniser
le rythme de reproduction. D'importanls groupes de feme/les
au meme stade physiologique de reproduction sont
particulierement concernées avec /'utilisation croissante de
l'insémination artificielle dans l'élevage du lapin. En outre la
réceptivité de la feme/le est largement dépendante de
l'équilibre hormona/e entre la prolactine et la gonadotrophine.
Afin de résoudre ce probleme, ces dernieres années ont vu
se développer rapidement l'usage de traitement par
"Prepnant Mare Serum Gonadotropm" ou PMSG, appliqué 2 a 3 JOUrS avant /'insémination artificie/le.
Les auteurs ont passé en revue la littérature concernant les
effets du traitement par PMSG destiné a synchroniser
l'oestrus. On peut en deduire les avantages suivants :
- un augmentation de la réceptivité au mate. Enviran 90 %
d'accepfation du mate 2 a 3 jours apres le traitement.
- La · réceptivité et la fertilité sont significativement
augmentées, plus particulierement chez les feme/les
allaitantes ou non réceptives
- une augmentation de la prolificité ; taille de la portée : + 5 a 10 %. - résultats positifs pour les feme/les ayant des probtemes de
reproduction
Cependant un certain nombre de désavantages ont été
relevés:
- /'absence d'amélioration pour les feme/les non allaitantes et
réceptives.
- une diminution de la fertilité apres des traitements répétés
causée par des propriétés antigenes.
- un augmentation du taux de mortalité a la naissance
probablement due aux doses utilisées.
- une répartition modifiée de la fréquence d'apparition des
tailles de portées : les tres grandes portées (> 12 lapereaux)
et les tres petites (<5 lapereaux) sont plus nombreuses.
En tenant compte de ces observations les auteurs
recommandent de n'utiliser le traitement par PMSG pour
induire l'oestrus qu'en fonction du statut physiologique de la
lapine et en dose faible. Une utilisation limitée aux tapines
primipares et/ou aux tapines non récepJives peut aider a
synchroniser l'oestrus et a obtenir de meilleurs résu/tats dans
un schéma de reproduction bien organisé.
D'autre part des recherches plus approfondies doivent etre
menées pour optimiser l'alimentation, les conditions
zootechniques et environnementales afin d'obtenir la
synchronisation de l'oestrus et d'éviter l'utilisation
systématique de PMSG.Maertens, L.; Luzi, F.; Grilli, G. (1995). EFFECTS OF PMSG INDUCED OESTRUS ON THE PERFORMANCES OF RABBIT DOES : A REVIEW +. World Rabbit Science. 3(4). https://doi.org/10.4995/wrs.1995.262SWORD3
An academic exchange between JCW Ahiakpor and F Gerits
No full textWe do not see very often one of our articles sparking a debate in the pages of our journal. However, we welcome this occurrence. In this case, Frank Gerits’ article in the latest issue of the Southern Journal for Contemporary History - which analyses the economic history of Ghana vis-à-vis the economic and political thought of important Ghanaian economists - has provoked a critical response from one of the intellectuals cited by Gerits himself: JCW Ahiakpor
A REVIEW OF POINT CLOUDS SEGMENTATION AND CLASSIFICATION ALGORITHMS
No full textToday 3D models and point clouds are very popular being currently used in several fields, shared through the internet and even accessed
on mobile phones. Despite their broad availability, there is still a relevant need of methods, preferably automatic, to provide 3D data
with meaningful attributes that characterize and provide significance to the objects represented in 3D. Segmentation is the process of
grouping point clouds into multiple homogeneous regions with similar properties whereas classification is the step that labels these
regions. The main goal of this paper is to analyse the most popular methodologies and algorithms to segment and classify 3D point
clouds. Strong and weak points of the different solutions presented in literature or implemented in commercial software will be listed
and shortly explained. For some algorithms, the results of the segmentation and classification is shown using real examples at different
scale in the Cultural Heritage field. Finally, open issues and research topics will be discussed
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