24 research outputs found
Cutting Through the Discussion on Caesarean Delivery: Birth Practices as Social Practices
Women are finding appeal in (or, at minimum, a lower level of resistance to) caesarean delivery despite the health risks that it poses, and I investigate how this decision figures into a broader pattern of women\u27s gender socialisation within a culture that is deeply anxious about women\u27s bodies. I review scholarship on caesarean delivery, and use social practice theory to map possible contact points between theories of embodiment, a sociology of gender, and the specific practice of caesarean section. I consider caesarean delivery as a component of a social practice, and adopt a practice framework to analyze women\u27s motivation for selecting (or consenting to) caesarean delivery. I detail the materiality of the hospital, the medicalisation of women\u27s bodies, and women\u27s antagonistic body relationship to reveal some of the less immediately apparent reasons why caesarean delivery has been normalised and rendered invisible as part of the pattern of modern childbirth. Interventions to address the further escalation of caesarean delivery might consider how this decision aligns with other social practices. I conclude that activism addressing the social conditions that make caesarean delivery so attractive may radiate out to other aspects of women\u27s lives where the practices of normative femininity have proven equally restrictive
Exotic fish in exotic plantations: a multi-scale approach to understand amphibian occurrence in the mediterranean region
Globally, amphibian populations are threatened by a diverse range of factors including habitat
destruction and alteration. Forestry practices have been linked with low diversity and
abundance of amphibians. The effect of exotic Eucalyptus spp. plantations on amphibian
communities has been studied in a number of biodiversity hotspots, but little is known of its
impact in the Mediterranean region. Here, we identify the environmental factors influencing
the presence of six species of amphibians (the Caudata Pleurodeles waltl, Salamandra salamandra,
Lissotriton boscai, Triturus marmoratus and the anurans Pelobates cultripes and
Hyla arborea/meridionalis) occupying 88 ponds. The study was conducted in a Mediterranean
landscape dominated by eucalypt plantations alternated with traditional use (agricultural,
montados and native forest) at three different scales: local (pond), intermediate (400
metres radius buffer) and broad (1000 metres radius buffer). Using the Akaike Information
Criterion for small samples (AICc), we selected the top-ranked models for estimating the
probability of occurrence of each species at each spatial scale separately and across all
three spatial scales, using a combination of covariates from the different magnitudes. Models
with a combination of covariates at the different spatial scales had a stronger support
than those at individual scales. The presence of predatory fish in a pond had a strong effect
on Caudata presence. Permanent ponds were selected by Hyla arborea/meridionalis over
temporary ponds. Species occurrence was not increased by a higher density of streams,
but the density of ponds impacted negatively on Lissotriton boscai. The proximity of ponds
occupied by their conspecifics had a positive effect on the occurrence of Lissotriton boscai
and Pleurodeles waltl. Eucalypt plantations had a negative effect on the occurrence of the
newt Lissotriton boscai and anurans Hyla arborea/meridionalis, but had a positive effect on
the presence of Salamandra salamandra, while no effect on any of the other species was detected.
In conclusion, eucalypts had limited effects on the amphibian community at the intermediate
and broad scales, but predatory fish had a major impact when considering all the
scales combined. The over-riding importance of introduced fish as a negative impact suggests that forest managers should prevent new fish introductions and eradicate fish
from already-occupied ponds whenever possible
Microgeographic Divergence of Functional Responses among Salamanders under Antagonistic Selection from Apex Predators.
A predator\u27s functional response determines predator–prey interactions by describing the relationship between the number of prey available and the number eaten. Its shape and parameters fundamentally govern the dynamic equilibrium of predator–prey interactions and their joint abundances. Yet, estimates of these key parameters generally assume stasis in space and time and ignore the potential for local adaptation to alter feeding responses and the stability of trophic dynamics. Here, we evaluate if functional responses diverge among populations of spotted salamander (Ambystoma maculatum) larvae that face antagonistic selection on feeding strategies based on their own risk of predation. Common garden experiments revealed that spotted salamander from ponds with varying predation risks differed in their functional responses, suggesting an evolutionary response. Applying mechanistic equations, we discovered that the combined changes in attack rates, handling times and shape of the functional response enhanced feeding rate in environments with high densities of gape-limited predators. We suggest how these parameter changes could alter community equilibria and other emergent properties of food webs. Community ecologists might often need to consider how local evolution at fine scales alters key relationships in ways that alter local diversity patterns, food web dynamics, resource gradients and community responses to disturbance
Capacity Expansion for Random Exponential Demand Growth with Lead Times
The combination of demand uncertainty and a lead time for adding capacity creates the risk of capacity shortage during the lead time. We formulate a model of capacity expansion for uncertain exponential demand growth and deterministic expansion lead times when there is an obligation to provide a specified level of service. The service level, defined in terms of the ratio of expected lead-time shortage to installed capacity, is guaranteed by timing each expansion to begin when demand reaches a fixed proportion of the capacity position. Under this timing rule, the optimal facilities to install can be determined by solving an equivalent deterministic problem without lead times. Numerical results show the effects of the demand parameters and lead-time length on the expansion timing. The interaction of timing with expansion size is explored for the case when continuous facility sizes are available with economies of scale.geometric Brownian motion, infinite-horizon expected discounted cost, service-level constraint, proportional reserve policy