1 - 6 of 6
Number of results to display per page
Search Results
2. Jednodětnost v českých rodinách: kdo jsou ti, kdo mají nebo plánují pouze jedno dítě
- Creator:
- Rabušic, Ladislav and Chromková Manea, Beatrice-Elena
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- one-child family, fertility intentions, reproductive behaviour, fertility determinants, expected fertility, and Czech society
- Language:
- Czech
- Description:
- The article tackles the phenomenon of the one-child family in the Czech Republic. The authors try to answer the question of whether it is possible to expect that a significant proportion of Czech fertility intentions will be fulfilled when families conceive and give birth to an only child. Can it be assumed that one-child families will be a significant phenomenon in Czech society in the years to come? To answer the questions the authors used two different datasets in the analysis. The article includes a description of the socio-demographic characteristics of people who have or intend to have just one child. They then proceed to present some of the covariates that determine whether people have or intend to have one child in comparison with those who have other fertility intentions. Some of the findings indicate that it is likely that about 20-25% of women who finish their reproductive period within the next two decades will have only one child. The results indicate that being an only child increases the chances of intending to and having only one child. The opposite effect can be noticed when the place of residence is considered - living in small towns and rural areas may have a negative influence on the decision to have only one child.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Size- and context-dependent nest-staying behaviour of males of the Japanese dung beetle, Copris acutidens (Coleoptera: Scarabaeidae)
- Creator:
- Akamine, Mayumi
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, brouci, vrubounovití, beetles, Scarabaeidae, Coleoptera, Copris acutidens, reproductive behaviour, male dimorphism, subsocial Scarabaeinae, post-copulatory processes, paternal provisioning, 2, and 59
- Language:
- English
- Description:
- Male dimorphism in insects is often accompanied by alternative mating tactics, which may, together with morphological traits, determine fitness of the different male morphs. Fitness consequences of male head horn size, male-male competition and male nest-staying behaviour were experimentally assessed in Copris acutidens, in which major and minor males can co-occur in nests. Possible differences in their reproductive behaviour and breeding success were assayed in a breeding experiment, in which females were paired with one major male, one minor male, or a pair of major and minor males. The advantage of major males staying in a nest along with a rival male is that major males are reproductively more successful than minor males in this species. The weight of dung transported into nests was significantly less in rearing containers containing two males than in those with a single male of either morph, although it did not differ between major and minor males when kept alone. The results indicate that the presence of a rival male negatively affects male provisioning due to interference from rival males. In contrast, in the present study, an increased incidence of male nest-staying behaviour was recorded in the two- male and one minor male treatment than in the one major male treatment. These results indicate that because of the risk of sperm competition, major males stay longer in nests if a rival male is present. Furthermore, minor males (which are subject to a higher risk of sperm competition) stay longer than major males in nests without a rival male. In other words, the present study revealed an alternative behaviour during the post-copulatory stage associated with horn dimorphism and the presence or absence of a rival male., Mayumi Akamine., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. The biological characteristics and distribution of the greenbug, Schizaphis graminum, and Russian wheat aphid, Diuraphis noxia (Hemiptera: Aphididae), in Argentina and Chile
- Creator:
- Clua , Ariel, Castro , Ana M., Ramos, Silvia , Giimenez, Daniel O. , Vasicek , Araceli, Chidichimo , Hugo O., and Dixon, F. G.
- Type:
- article, model:article, and TEXT
- Subject:
- Greenbug, Schizaphis graminum, RWA, Diuraphis noxia, geographical distribution, reproductive behaviour, host-preference, and biotypes
- Language:
- English
- Description:
- The aphids Schizaphis graminum (Rondani) (greenbug) and Diuraphis noxia (Mordvilko) (Russian wheat aphid, RWA) were collected from several localities in Argentina and Southern Chile. Clones were established from aphids collected at each location. The host preferences were studied in free choice tests. Biotypes were characterized on the basis of aphid antibiosis and host plant tolerance. The production of sexuals was assessed under natural conditions, from March to November in 1997-2001, at La Plata (34°55' S, 57°57' W). The greenbug distribution ranged from 24°40' to 43°28' S, and was bounded between isothermals 18-20°C and 8-10°C, and isohyets 400-600 mm and greater than 1200 mm. The aphids at all localities were collected from a wide range of cultivated and wild hosts. The biotypes in ten out of thirty-four populations were identified. One population was obligatorily parthenogenetic, the remainder cyclically parthenogenetic. No correlation was found between the region they came from and the period required for the induction of sexuals. RWA was found between 26°50' and 43°28' S, bounded by the isothermals 20-22°C and 8-10°C, and isohyets 400-600 mm and 2000 mm. In Chile, this aphid was only found in Osorno County, which lies on isothermal 8-10°C and is bounded by the isohyets 1000 mm and 2000 mm. Only a few RWA genotypes (clones) produced sexuals irrespective of the host they were collected from, period of the year, region, current host, or the day length and average temperature of the rearing conditions. For the first time, RWA was found infesting cultivated as well as wild oats in South America. At low latitudes, populations of both aphid species were found only infesting wild Sorghum halepensis (L).
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5. The reproductive behaviour of an aphidophagous ladybeetle, Coccinella septempunctata (Coleoptera: Coccinellidae)
- Creator:
- OMKAR and Srivastava, Shefali
- Type:
- article, model:article, and TEXT
- Subject:
- Coccinellids, Coccinella septempunctata, reproductive behaviour, courtship and mating, mating duration, and mate recognition
- Language:
- English
- Description:
- The reproductive behaviour of a ladybeetle, Coccinella septempunctata was studied in detail. Males became sexually mature within 8.8 ± 0.3 days at 27°C, while females took 11.2 ± 0.4 days. Males exhibited courtship display in five steps: approach, watch, examine, mount and copulatory attempt. A prominent rejection display was shown by certain females who had not matured sexually, had recently mated or were about to oviposit. Males appeared to recognize females through chemical and some visual cues, such as size and body shape, with the chemical cues possibly playing a more significant role. Multiple matings took place within the same day. There was a gradual decrease with time in reproductive parametres, such as the duration of copulation, the number of copulatory bouts and the latent period from first to subsequent matings on the same day. The interval between mating bouts slightly increased from first to subsequent matings. The sexual status of males and females affected the duration of copulation, which was greatest in the case of unmated males and virgin females. Multiple matings increased the oviposition period, fecundity and percent hatching of eggs.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
6. Změny nastavení rodičovského příspěvku v Česku a jejich možný dopad na reprodukční chování
- Creator:
- Šťastná, Anna
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- family policy, parental benefit, reproductive behaviour, birth intervals, education, and Czech Republic
- Language:
- Czech
- Description:
- Childcare leave schemes are one of the key measures that affect the ability of women and men to balance their work and family lives. Both the length of the parental leave period and the amount of the benefit have the potential to shape the timing of a subsequent birth. Important changes have been introduced into the Czech parental benefit scheme over the last 10 years in terms of both the scheme’s flexibility and the monthly amount of the benefit, which has provided a unique opportunity for studying the links between the institutional conditions of parenthood and the behaviour of real stakeholders. Using data on births from the Czech Statistical Office and the parity-cohort analytical approach, we investigate changes in the spacing of second and third births among women who had their first or second child between 1986 and 2013. The results revealed an increase in the second- and third-birth rate during the second and third year following a delivery, together with a decrease in the second- and third-birth rate during the fourth year and later among mothers exposed to changes in the parental benefit scheme. These changes in reproductive behaviour noticeably coincided with the incentives that have been provided since 2008 by the increased flexibility of the parental leave scheme and the author argues that the option to increase the monthly amount of the parental benefit together with the flexibility of its use has contributed to the closer spacing of births, most notably among more educated women.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:private