71 research outputs found
Archival data on wild food plants used in Poland in 1948
<p>Abstract</p> <p>Background</p> <p>In 1948, Professor JĂłzef Gajek initiated a detailed census of the wild edible plants used in Poland. The questionnaires were collected by correspondents of the Polish Folklore Society in 95 localities throughout Poland. A major part of these archival materials, including a substantial collection of herbarium specimens, had not undergone thorough analysis prior to this study, which presents a quantitative analysis of this archival set of data.</p> <p>Methods</p> <p>Herbarium specimens were identified and a database was created.</p> <p>Results</p> <p>Ninety-eight taxa identified to genus or species level, including 71 botanical species, identified using herbarium specimens, were found. On average only 11 edible plant species per locality were listed, the longest list included 39 species. No correlation between latitude and the number of edible species was found, whereas there was small but significant correlation with the longitude. Fruits were the most frequently collected part of plants. Most plants were primarily collected by women and children. Children both helped parents to collect wild fruits and also ate many species raw, which were not consumed by adults, but had often been eaten in the past. Eighteen of the taxa had not been reported in a recent comprehensive review of edible plants of Poland. <it>Stratiotes aloides</it>, used as a famine vegetable in the ĆĂłdĆș region, has never been reported as edible in any ethnobotanical literature.</p> <p>Conclusion</p> <p>The results undermine the conclusions of a recent comprehensive review of edible plants of Poland, which stated that many more wild edible plants have been collected in the Carpathians than in lowland Poland. However such results were shown to be caused by the substantially larger number of ethnographic studies undertaken in the Carpathians. In fact, large numbers of edible plant species were collected in the mid-20<sup>th </sup>century in a few regions, particularly along the eastern border, in the Carpathians and in communities originating from the expanded Soviet Union, which had been resettled to the north-west of Poland in 1945.</p
How Grandparents Matter: Support for the Cooperative Breeding Hypothesis in a Contemporary Dutch Population
Low birth rates in developed societies reflect womenâs difficulties in combining work and motherhood. While demographic research has focused on the role of formal childcare in easing this dilemma, evolutionary theory points to the importance of kin. The cooperative breeding hypothesis states that the wider kin group has facilitated womenâs reproduction during our evolutionary history. This mechanism has been demonstrated in pre-industrial societies, but there is no direct evidence of beneficial effects of kinâs support on parentsâ reproduction in modern societies. Using three-generation longitudinal data anchored in a sample of grandparents aged 55 and over in 1992 in the Netherlands, we show that childcare support from grandparents increases the probability that parents have additional children in the next 8 to 10Â years. Grandparental childcare provided to a nephew or niece of childless children did not significantly increase the probability that those children started a family. These results suggest that childcare support by grandparents can enhance their childrenâs reproductive success in modern societies and is an important factor in peopleâs fertility decisions, along with the availability of formal childcare
Developing "personality" taxonomies: Metatheoretical and methodological rationales underlying selection approaches, methods of data generation and reduction principles
Taxonomic "personality" models are widely used in research and applied fields. This article applies the Transdisciplinary Philosophy-of-Science Paradigm for Research on Individuals (TPS-Paradigm) to scrutinise the three methodological steps that are required for developing comprehensive âpersonalityâ taxonomies: 1) the approaches used to select the phenomena and events to be studied, 2) the methods used to generate data about the selected phenomena and events and 3) the reduction principles used to extract the âmost importantâ individual-specific variations for constructing âpersonalityâ taxonomies. Analyses of some currently popular taxonomies reveal frequent mismatches between the researchersâ explicit and implicit metatheories about âpersonalityâ and the abilities of previous methodologies to capture the particular kinds of phenomena toward which they are targeted. Serious deficiencies that preclude scientific quantifications are identified in standardised questionnaires, psychologyâs established standard method of investigation. These mismatches and deficiencies derive from the lack of an explicit formulation and critical reflection on the philosophical and metatheoretical assumptions being made by scientists and from the established practice of radically matching the methodological tools to researchersâ preconceived ideas and to pre-existing statistical theories rather than to the particular phenomena and individuals under study. These findings raise serious doubts about the ability of previous taxonomies to appropriately and comprehensively reflect the phenomena towards which they are targeted and the structures of individual-specificity occurring in them. The article elaborates and illustrates with empirical examples methodological principles that allow researchers to appropriately meet the metatheoretical requirements and that are suitable for comprehensively exploring individualsâ âpersonalityâ
Are elder siblings helpers or competitors? Antagonistic fitness effects of sibling interactions in humans
Determining the fitness consequences of sibling interactions is pivotal for understanding the evolution of family living, but studies investigating them across lifetime are lacking. We used a large demographic dataset on preindustrial humans from Finland to study the effect of elder siblings on key life-history traits. The presence of elder siblings improved the chances of younger siblings surviving to sexual maturity, suggesting that despite a competition for parental resources, they may help rearing their younger siblings. After reaching sexual maturity however, same-sex elder siblings' presence was associated with reduced reproductive success in the focal individual, indicating the existence of competition among same-sex siblings. Overall, lifetime fitness was reduced by same-sex elder siblings' presence and increased by opposite-sex elder siblings' presence. Our study shows opposite effects of sibling interactions depending on the life-history stage, and highlights the need for using long-term fitness measures to understand the selection pressures acting on sibling interactions
Recommended from our members
Origin, migration and fate of newly generated neurons in the adult rodent piriform cortex.
Newly generated neurons are continuously added to the olfactory epithelium and olfactory bulbs of adult mammals. Studies also report newly generated neurons in the piriform cortex, the primary cortical projection site of the olfactory bulbs. The current study used BrdU-injection paradigms, and in vivo and in vitro DiI tracing methods to address three fundamental issues of these cells: their origin, migratory route and fate. The results show that 1 day after a BrdU-injection, BrdU/DCX double-labeled cells appear deep to the ventricular subependyma, within the white matter. Such cells appear further ventral and caudal in the ensuing days, first appearing in the rostral piriform cortex of mice at 2 days after the BrdU-injection, and at 4 days in the rat. In the caudal piriform cortex, BrdU/DCX labeled cells first appear at 4 days after the injection in mice and 7 days in rats. The time it takes for these cells to appear in the piriform cortex and the temporal distribution pattern suggest that they migrate from outside this region. DiI tracing methods confirmed a migratory route to the piriform cortex from the ventricular subependyma. The presence of BrdU/NeuN labeled cells as early as 7 days after a BrdU injection in mice and 10 days in the rat and lasting as long as 41 days indicates that some of these cells have extended survival durations in the adult piriform cortex
- âŠ