Search results for "Reproduction"
showing 10 items of 752 documents
PARASITES AND SEXUAL REPRODUCTION IN PSYCHID MOTHS
2004
Persistence of sexual reproduction among coexisting asexual competitors has been a major paradox in evolutionary biology. The number of empirical studies is still very limited, as few systems with coexisting sexual and strictly asexual lineages have been found. We studied the ecological mechanisms behind the simultaneous coexistence of a sexually and an asexually reproducing closely related species of psychid moth in Central Finland between 1999 and 2001. The two species compete for the same resources and are often infected by the same hymenopteran parasitoids. They are extremely morphologically and behaviorally similar and can be separated only by their reproductive strategy (sexual vs. as…
Acute stress may induce ovulation in women
2010
Abstract Background This study aims to gather information either supporting or rejecting the hypothesis that acute stress may induce ovulation in women. The formulation of this hypothesis is based on 2 facts: 1) estrogen-primed postmenopausal or ovariectomized women display an adrenal-progesterone-induced ovulatory-like luteinizing hormone (LH) surge in response to exogenous adrenocorticotropic hormone (ACTH) administration; and 2) women display multiple follicular waves during an interovulatory interval, and likely during pregnancy and lactation. Thus, acute stress may induce ovulation in women displaying appropriate serum levels of estradiol and one or more follicles large enough to respo…
Derecho de los hijos nacidos por reproducción asistida a conocer la identidad de sus padres biológicos: Breves reflexiones y propuestas
2018
The present communication intends to analyze and reflect on the existing problem and the conflict of rights produced regarding the need of information of a son to know the identity of his biological parents, possible discrimination by birth. Comparative law. Analysis of the right to personal and family privacy, and right to Identity. Consideration of public information as an essential element of the practice of techniques
Laboratorio Pandemia. Genere, riproduzione, spazio domestico
2021
Mettendo al lavoro il metodo di una critica femminista che parte da Marx per andare oltre, Claudia Borgia e Gabriella Palermo guardano alle trasformazioni della sfera riproduttiva accelerate dalla pandemia. Richiamano un processo complessivo di ristrutturazione della riproduzione che investe lo spazio domestico e il suo esterno, il lavoro salariato e quello non retribuito. Nella complessità delle trasformazioni in atto, scelgono di indagare due aspetti specifici: «le implicazioni politiche e sociali di una pandemia del tutto scaricata sui cosiddetti lavori essenziali» e «le conseguenze del doppio carico di lavoro sulle spalle delle donne, divenuto estenuante». A partire da qui individuano a…
Parent of origin effects in attention/deficit hyperactivity disorder (ADHD): analysis of data from the international multicenter ADHD genetics (IMAGE…
2008
Contains fulltext : 71540.pdf (Publisher’s version ) (Closed access) There are conflicting reports suggesting that the parental origin of transmitted risk alleles may play a role in the etiology of attention deficit/hyperactivity disorder (ADHD). A recent report by Hawi and colleagues observed a generalized paternal over-transmission of alleles associated with ADHD. This was not replicated in more recent studies. Using data from a large multicenter study we examined the overall and gene-specific parent of origin effect in 554 independent SNPs across 47 genes. Transmission disequilibrium and explicit parent of origin test were performed using PLINK. Overall parent of origin effect was tested…
Geographical variation in egg size of the Great Tit Parus major: a new perspective
2002
A recent study on geographical variation in egg size of Great Tits Parus major concluded that: (1) mean egg size tended to increase with increasing latitude; and (2) mean egg size was positively correlated with mean clutch size. Including new data on both egg and clutch size, we reanalysed the relationships between egg size, clutch size and latitude, and investigated the possible effects of habitat type, female body size and egg shape on these relationships. We found that (1) egg volume showed minimum values around 51 ° N, increasing both north and southwards; (2) female body size increased linearly with increasing latitude; (3) female body size was positively correlated with egg breadth, b…
Clutch size and egg volume in great tits (Parus major) increase under low intensity electromagnetic fields: a long-term field study.
2012
Exposure to electromagnetic fields (EMFs) can affect a wide range of biological processes, including reproduction, growth and development. Experiments aimed at investigating the biological effects of EMFs, focused on potential harmful effects on humans, have been mostly carried out in vitro or with animal models in laboratory conditions. By contrast, studies performed on wild animals are scarce. The effects of EMFs created by an electric power line on reproductive traits of a wild great tit (Parus major) population were explored by analysing data gathered during nine breeding seasons. EMF exposure significantly increased clutch size (7%) and egg volume (3%), implying a 10% increase in clutc…
Exposure to trihalomethanes through different water uses and birth weight, small for gestational age, and preterm delivery in Spain
2011
Background: Evidence associating exposure to water disinfection by-products with reduced birth weight and altered duration of gestation remains inconclusive. Objective: We assessed exposure to trihalomethanes (THMs) during pregnancy through different water uses and evaluated the association with birth weight, small for gestational age (SGA), low birth weight (LBW), and preterm delivery. Methods: Mother–child cohorts set up in five Spanish areas during the years 2000–2008 contributed data on water ingestion, showering, bathing, and swimming in pools. We ascertained residential THM levels during pregnancy periods through ad hoc sampling campaigns (828 measurements) and regulatory data (264 me…
Pentachlorophenol accumulation in the freshwater mussels Anodonta anatina and Pseudanodonta complanata, and some physiological consequences of labora…
1995
Freshwater mussels Anodanta anatina and Pseudanodonta complanata were exposed to (14C)-pentachlorophenol. The wet weight based bioconcentration factor (BCF = activity in animal per activity in water) at steady state varied from 80 to 120 for A. anatina and from 61 to 85 for P. complanata. The species did not differ significantly in their wet weight or lipid based BCFs but dry weight based values were significantly higher (40-50%) for A. anatina. The soft tissue dry weight and dry weight based condition index of A. anatina (Cl4 = soft tissue dry weight per shell length) differed significantly between natural mussel populations. In animals kept from 4 to 8 months in laboratory conditions, the…
Acid stress in respect to calcium and magnesium concentrations in the plasma of perch during maturation and spawning
1988
Plasma calcium and magnesium concentrations in perch,Perca fluviatilis, were monitored in an acid lake, Lake Iso Tenhetty (pH ∼5, Al concentrations 0.3–0.5 mg l-1) compared with a nearby reference lake, Lake Paijanne, in Southern Finland. The effect of acid stress could be noticed as 1/3 lower fecundity of perch in the acid lake. Plasma Ca concentrations were temporarily lower in the middle of the winter in the fish of the acid lake, and in April–May samples the situation was opposite. Plasma Mg concentration was also lower in the perch from the acid lake in midwinter months, when compared with the double as high values (∼3 mmol l-1) from the reference lake. Elevated level of plasma Mg have…