Search results for "Reproduction"
showing 10 items of 752 documents
Reproductive Biology Including Evidence for Superfetation in the European Badger Meles meles (Carnivora: Mustelidae)
2015
The reproductive biology of the European badger (Meles meles) is of wide interest because it is one of the few mammal species that show delayed implantation and one of only five which are suggested to show superfetation as a reproductive strategy. This study aimed to describe the reproductive biology of female Irish badgers with a view to increasing our understanding of the process of delayed implantation and superfetation. We carried out a detailed histological examination of the reproductive tract of 264 female badgers taken from sites across 20 of the 26 counties in the Republic of Ireland. The key results show evidence of multiple blastocysts at different stages of development present s…
Toxic Theisms? New Strategies for Prebunking Religious Belief-Behaviour Complexes
2020
This article offers a brief epidemiological analysis and description of some of the main cognitive (and coalitional) biases that can facilitate the emergence and enable the maintenance of a broad category of toxic traditions, which will be referred to here as “religious” belief-behaviour complexes (BBCs) or “theisms”. I argue that such BBCs played an “adaptive” role in the Upper Paleolithic and have continued to “work” throughout most of human history by enhancing the species’ capacity for material production and promoting its biological reproduction. However, today the theist credulity and conformity biases that surreptitiously shape these kinds of social assemblages have now becom…
Toxicological Impact of Rare Earth Elements (REEs) on the Reproduction and Development of Aquatic Organisms Using Sea Urchins as Biological Models
2022
The growing presence of lanthanides in the environment has drawn the attention of the scientific community on their safety and toxicity. The sources of lanthanides in the environment include diagnostic medicine, electronic devices, permanent magnets, etc. Their exponential use and the poor management of waste disposal raise serious concerns about the quality and safety of the ecosystems at a global level. This review focused on the impact of lanthanides in marine organisms on reproductive fitness, fertilization and embryonic development, using the sea urchin as a biological model system. Scientific evidence shows that exposure to lanthanides triggers a wide variety of toxic insults, includi…
Effects of tributyltin(IV) chloride on the gametes and fertilization ofAscidia malaca (Ascidiacea: Tunicata)
2003
Ascidia malaca gametes before fertilization incubated in 10-5 or 10-7 M solutions of tributyltin(IV) chloride, TBTCl, for 3 h appear highly damaged under transmission electron microscopy observation. Also, the fertilization process is affected by the compound: the damaged spermatozoa are present in the vitelline coat and the egg does not cleave. An increase of microbodies, structurally similar to peroxisomes, have been detected in the egg peripheral cytoplasm, probably in relation to their role in alleviating damage to some cellular components. The results have shown that the reproduction of ascidians under unfavourable environmental conditions is prevented. Copyright © 2003 John Wiley &…
Augmented Reality Gamification for Human Anatomy
2019
This paper focuses on the use of Augmented Reality technologies in relation to the introduction of game design elements to support university medical students in their learning activities during a human anatomy laboratory. In particular, the solution we propose will provide educational contents visually connected to the physical organ, giving also the opportunity to handle a 3D physical model that is a perfect reproduction of a real human organ.
Properties of food loads delivered to nestlings in the pied flycatcher: effects of clutch size manipulation, year, and sex.
1998
Experimental manipulation of the number of altricial offspring is supposed to modify parental expenditure in birds. In addition to the observed increase in parental feeding rate, it is also possible that the choice of prey or the size of load may change with the changing demand for food. Sexual differences in the provisioning response are also expected, on the basis of earlier studies. We examined the effect of brood size manipulation on choice of prey brought to nestlings and load size in the pied flycatcher. The composition and size of loads differed between years, possibly depending on varying availability of different prey types. Males responded to brood size enlargement by gathering he…
A Trade-Off Between Current Reproduction and Moult in the Pied Flycatcher- an Experiment
1994
1. Mechanisms causing costs of reproduction in birds are poorly understood. Here we focus on the renewing of feathers (= moult) which may be a possible physiological link between successive breeding attempts. 2. We performed clutch size manipulations to study whether the reproductive effort of the Pied Flycatcher (Ficedula hypoleuca) has any effect on the initiation and progress of the moult in the late nesting period. 3. The absolute timing of breeding did not affect the onset of parents' moult, i.e. latebreeding individuals did not start moulting before nestlings were fledged more frequently than early ones. This indicates that moult was closely related to the breeding schedule of each in…
Observed heterospecific clutch size can affect offspring investment decisions.
2011
Optimal investment in offspring is important in maximizing lifetime reproductive success. Yet, very little is known how animals gather and integrate information about environmental factors to fine tune investment. Observing the decisions and success of other individuals, particularly when those individuals initiate breeding earlier, may provide a way for animals to quickly arrive at better breeding investment decisions. Here we show, with a field experiment using artificial nests appearing similar to resident tit nests with completed clutches, that a migratory bird can use the observed high and low clutch size of a resident competing bird species to increase and decrease clutch size and egg…
Association between haematozoan infections and reproduction in the Pied Flycatcher
1997
1. Parasites may affect breeding success of their host since they compete for the same resources as their hosts. Reproduction may also increase the susceptibility of a host to parasite infections owing to lowered resistance to parasites during breeding. 2. We studied the association between breeding performance and haematozoan parasite infection in the Pied Flycatcher (Ficedula hypoleuca) by using both natural data on reproduction and data from clutch size manipulations. 3. The most frequent blood parasites of the Pied Flycatcher in central Finland were Haemoproteus pallidus, Haemoproteus balmorali and Trypanosoma avium complex. 4. We did not find evidence that these haematozoan parasites h…
Breeding success of a colony of Boat-billed Herons Cochlearius cochlearius (Ciconiiformes: Ardeidae) in pasturelands of Costa Rica
2014
The breeding success of a double-brooding colony of Boat-billed Herons Cochlearius cochlearius was studied in pasturelands of Costa Rica. Mean clutch size in the first clutches (2.9 eggs/nest) was higher than in second and repeat clutches (2.3 eggs/nest). Breeding success was similar in the first attempt and second attempts(20.7 % and 21.7 %, respectively). In both attempts earlier nests enjoyed a higher breeding success. Starvation of the youngest chicks within the nest and destruction of nests by bad weather conditions were the main factors related to nestling death. No effects of human activity on the reproduction of the breeding colony were observed. Rev. Biol. Trop. 54 (4): 1131-1134. …