Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
304 result(s) for "De Luca, Paul"
Sort by:
A call for mixed-methods research on climate change, family systems and child mental health
[...]this viewpoint calls for mixed-methods research, using diverse and robust methodologies, to explore how climate threats affect child mental health through a family-centred lens. Extreme climate disruptions, such as natural disasters, can destabilise parent mental health, family dynamics (eg, parent–child/family conflict and connectedness) and child mental health.4 Climate change is also recognised as a threat multiplier for violence against children, amplifying risk through direct, indirect and interactive pathways across various social-ecological levels.5 For instance, extreme weather events and variations can increase the risk of armed conflicts, while climate-driven resource scarcity heightens the risk of forced displacement—both of which can affect child mental health through disruptions at individual, family and community levels (see5 for a discussion of relevant studies). [...]previous disaster literature applied the Family Stress Model7 to examine the systemic impact of Hurricane Katrina on children and families, revealing that financial strain was linked to maternal depression and reduced parenting efficacy, which, in turn, exacerbated child adjustment problems.8 By intersecting climate research and child and family psychology, we can explore key questions: (1) What climate-related stressors do parents face?; (2) How can insights from research on economic instability, disaster preparedness and recovery, and the COVID-19 pandemic inform mitigation strategies?; (3) How do gradual and chronic climate threats affect child and parent mental health in the short and long term?; (4) What mechanisms in parents (eg, biological, physiological and behavioural) link climate stressors to changes in family dynamics (eg, relationship quality, conflict and communication patterns) and child functioning?; (5) What are the bidirectional effects of parent and child mental health amid the climate crisis?; (6) How can longitudinal studies capture the long-term effects of climate change on the mental health of diverse families? and (7) What interventions are needed to mitigate the adverse effects of climate change on child, parent and family mental health?
Does body size predict the buzz‐pollination frequencies used by bees?
Body size is an important trait linking pollinators and plants. Morphological matching between pollinators and plants is thought to reinforce pollinator fidelity, as the correct fit ensures that both parties benefit from the interaction. We investigated the influence of body size in a specialized pollination system (buzz‐pollination) where bees vibrate flowers to release pollen concealed within poricidal stamens. Specifically, we explored how body size influences the frequency of buzz‐pollination vibrations. Body size is expected to affect frequency as a result of the physical constraints it places on the indirect flight muscles that control the production of floral vibrations. Larger insects beat their wings less rapidly than smaller‐bodied insects when flying, but whether similar scaling relationships exist with floral vibrations has not been widely explored. This is important because the amount of pollen ejected is determined by the frequency of the vibration and the displacement of a bee's thorax. We conducted a field study in three ecogeographic regions (alpine, desert, grassland) and recorded flight and floral vibrations from freely foraging bees from 27 species across four families. We found that floral vibration frequencies were significantly higher than flight frequencies, but never exceeded 400 Hz. Also, only flight frequencies were negatively correlated with body size. As a bee's size increased, its buzz ratio (floral frequency/flight frequency) increased such that only the largest bees were capable of generating floral vibration frequencies that exceeded double that of their flight vibrations. These results indicate size affects the capacity of bees to raise floral vibration frequencies substantially above flight frequencies. This may put smaller bees at a competitive disadvantage because even at the maximum floral vibration frequency of 400 Hz, their inability to achieve comparable thoracic displacements as larger bees would result in generating vibrations with lower amplitudes, and thus less total pollen ejected for the same foraging effort. We investigated the influence of body size on the frequencies of buzz pollination vibrations in bees across three different eco‐habitats. We found that body size was significantly negatively correlated with flight frequency but not with floral vibration frequency. Only larger bees produced floral vibrations that approached or exceeded twice that of their flight vibrations.
effects of age and relatedness on mating patterns in thornbug treehoppers: inbreeding avoidance or inbreeding tolerance
The social environment of many species includes synchronous maturation of siblings in family groups, followed by limited dispersal of adults from their natal site. Under these conditions, females may experience high encounter rates with same-age siblings during mate searching, increasing their risk of inbreeding. If inbreeding depression occurs, mating with a sibling is often considered maladaptive; however, in some contexts, the inclusive fitness benefits of inbreeding may outweigh the costs, favoring females that tolerate some level of inbreeding depression. We evaluated mating patterns in the treehopper Umbonia crassicornis, a semelparous species in which females encounter same-age siblings during mate searching. A female U. crassicornis that mates with a brother suffers from inbreeding depression. We used a free-choice mating design that offered females simultaneous mating opportunities with three groups of males: siblings, same-age nonsiblings, and older nonsiblings. These groups represent the types of males typically encountered by females during mate searching. Our goal was to assess whether mating patterns were influenced by inbreeding avoidance by evaluating two hypotheses: kin discrimination and age-based mating (older males cannot be siblings in this species). There was no difference in the proportions of females mating with siblings vs nonsiblings, suggesting an absence of kin discrimination. However, females mated with a greater proportion of older vs younger males. Given that females do not avoid siblings as mates despite a cost to inbreeding, our results provide a possible example of inbreeding tolerance. We also discuss some factors that may have contributed to the mating advantage of older males.
Erechthis Katydids (Tettigoniidae: Conocephalinae) in the Caribbean: New Species from the Bahamas and Hispaniola
Two new species of Caribbean conocephaline katydids (Agraeciini) are described for the previously monotypic genus Erechthis: one from the island of Eleuthera in the Bahamas, one from Hispaniola. The first-named species Erechthis gundlachi occurs on both Cuba and Hispaniola. A median projection (prong) of the subgenital plate is taken as a major generic diagnostic trait. This structure's morphology suggests a device for removal of rival sperm. The mate attraction song of males of the Eleutheran species is a steadily repeating series of chirps, each composed of 3 – 5 pulse trains. In the audio the frequency spectrum is broadband from 11 to beyond 20 kHz, with a coherent peak near 7 kHz. Inconsistency in some within-male song features may reflect this species' isolation from congenerics. The Eleutheran species bears a striking turquoise-colored face apparently absent in the other two species. We hypothesize that this coloration is a predatoravoidance adaptation. Possible Caribbean dispersal scenarios are discussed for these species.
Variability in bumblebee pollination buzzes affects the quantity of pollen released from flowers
Buzz-pollination is a plant strategy that promotes gamete transfer by requiring a pollinator, typically bees (Hymenoptera: Apoidea), to vibrate a flower's anthers in order to extract pollen. Although buzz-pollination is widespread in angiosperms with over 20,000 species using it, little is known about the functional connection between natural variation in buzzing vibrations and the amount of pollen that can be extracted from anthers. We characterized variability in the vibrations produced by Bombus terrestris bumblebees while collecting pollen from Solanum rostratum (Solanaceae), a buzz-pollinated plant. We found substantial variation in several buzzing properties both within and among workers from a single colony. As expected, some of this variation was predicted by the physical attributes of individual bumblebees: heavier workers produced buzzes of greater amplitude. We then constructed artificial \"pollination buzzes\" that varied in three parameters (peak frequency, peak amplitude, and duration), and stimulated S. rostratum flowers with these synthetic buzzes to quantify the relationship between buzz properties and pollen removal. We found that greater amplitude and longer duration buzzes ejected substantially more pollen, while frequency had no directional effect and only a weak quadratic effect on the amount of pollen removed. These findings suggest that foraging bumblebees may improve pollen collection by increasing the duration or amplitude of their buzzes. Moreover, given that amplitude is positively correlated with mass, preferential foraging by heavier workers is likely to result in the largest pollen yields per bee, and this could have significant consequences for the success of a colony foraging on buzz-pollinated flowers.
Age-Related Changes in an Insect Mating Signal Have No Effect on Female Choice
The structure of male mating signals is often influenced by age. The causes and consequences of agebased signal variation have been much studied in visual, acoustic, and chemical signaling modalities, but are less explored in species that use vibrational signals for mate attraction. However, the complex structure of many vibrational signals makes them ideal for investigating the relationships between age, signal variation, and patterns of female choice. In the thornbug treehopper, Umbonia crassicornis, females mate more often with older males, but the mechanism underlying older male mating success is unknown. Our goals in this study were to determine whether male vibrational mate advertisement signals vary with age, and, if so, whether females prefer the signals of older males. We recorded male signals over four consecutive weeks beginning at the onset of signaling (a period spanning most of the male reproductive lifespan), and measured ten temporal, spectral, and energy-related parameters from each signal. Several features of male signals changed markedly with age. However, females responded similarly to signals representing males of different ages, indicating that they do not favor older males on the basis of long distance mate advertisement signals. Nonetheless, the results reveal that even in short-lived, determinate growth species age can have surprisingly large effects on mating signals, and we discuss some factors that may contribute to age-related signal variability in U. crassicornis.
Courtship Communication in Meadow Katydids: Female Preference for Large Male Vibrations
Abstract Males of the katydid Conocephalus nigropleurum (Orthoptera: Tettigoniidae) shake their body to produce a substrate-borne vibratory signal in the context of courtship and mate attraction. We measured the physical parameters of this tremulation signal and then tested its effectiveness in eliciting taxis by virgin females. We also investigated the role of these vibrations in the choices made by females of larger males as mates. A search for correlations between male weight and vibratory signal parameters revealed a strong negative relationship to inter-pulse interval (ipi). In two-choice playback experiments females oriented towards tremulation vibration when it was the only vibration stimulus provided. In further playback experiments females also distinguished conspecific tremulation from a control vibration. When offered simultaneous presentations of tremulation signals that differed in ipi, females moved toward the stimulus with the shorter ipi indicative of a larger male. This is the first study to demonstrate that tremulation signalling by male katydids encodes critical information on body size, and that females discriminate among different vibratory signals in favour of those indicating a larger male.
Collaborative Registered Replication of Griskevicius et al. (2010): Can Pro-environmental Behavior Be Promoted by Priming Status Motivation?
The present study presents the results of a collaborative registered replication of Griskevicius et al. (2010, Experiment 1). As part of the Collaborative Replication and Education Project, 24 student groups from six countries (N = 3,774) investigated whether pro-environmental behavior can be promoted by priming status motives (desires for social status and prestige). This large, multi-site replication showed no evidence to support the hypothesis that hypothetical pro-environmental behavior can be stimulated by having participants read a story designed to prime status motives. We performed several exploratory analyses to investigate whether extension variables (i.e., equating “green” choices with prosocial behavior, political beliefs, sampling methods, location, duration of data collection, and gender) moderated the hypothesized effect of status motives on pro-environmental choices, but these analyses produced null results. One limitation of the study is that most data collection sites did not include a manipulation check, and the one site that did found a much weaker effect (d = 0.32) than the extremely large effect originally reported (d = 3.69). As a result, it remains unclear whether the null result reflects a failure of this specific priming method or a challenge to the underlying theory.
Vibratory signalling during courtship in the meadow katydid Conocephalus nigropleurum
When a male Conocephalus nigropleurum encounters a conspecific female he initiates the interaction with a behaviour known as tremulation. The male lifts his body up from the substrate and then brings it back down again a number of times in rapid succession. This behaviour always precedes copulation. Four components of this signal were measured in a population of lab reared males: pulse duration, peak positive amplitude, the number of oscillations per pulse, and pulse interval. Of these, peak positive amplitude and pulse interval displayed high repeatability. Correlations between male weight and the four parameters revealed a strong negative relationship only to pulse interval. In playback experiments females preferred to move onto a dowel transmitting tremulation over one that did not. Furthermore, when offered simultaneous presentations of tremulation signals that differed in pulse interval, females preferred to orient towards the signal with the shorter pulse interval reflecting a large male.