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

Specifying and Validating Probabilistic Inputs for Prescriptive Models of Decision Making over Time

Optimization models for making decisions over time in uncertain environments rely on probabilistic inputs, such as scenario trees for stochastic mathematical programs. The quality of model outputs, i.e., the solutions obtained, depends on the quality of these inputs. However, solution quality is rarely assessed in a rigorous way. The connection between validation of model inputs and quality of the resulting solution is not immediate. This chapter discusses some efforts to formulate realistic probabilistic inputs and subsequently validate them in terms of the quality of solutions they produce. These include formulating probabilistic models based on statistical descriptions understandable to decision makers; conducting statistical tests to assess the validity of stochastic process models and their discretization; and conducting re-enactments to assess the quality of the formulation in terms of solution performance against observational data. Studies of long-term capacity expansion in service industries, including electric power, and short-term scheduling of thermal electricity generating units provide motivation and illustrations. The chapter concludes with directions for future research

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

The Chemical Durability of Glass-ceramics Containing Industrial Waste

No rūpnieciskiem atkritumiem - tēraudliešanas nobirām, kodināšanas vannu atlikumiem. alumīniju saturošiem metālapstrādes atkritumiem, kā arī daudzsārmu stikla un Liepas atradnes māliem, izmantojot pulvertehnoloģijas metodi un termisko apstrādi, iegūti blīvi kompozītmetariāli (tilpummasa - 2.3 - 2.9 g/cm3 , ūdens uzsūce - 0.15 - 0.6 %), kas pēc raksturlielumiem atbilst Latvijas standarta LVS EN 176 B1 grupai. Lai raksturotu iegūto materiālu ķīmisko izturību, izmantojot trīs testēšnas ,metodes. Būtiskas paraugu masas izmaiņas konstatētas pēc to apstrādes HNO3 šķīdumā (pH≈2). Izmantojot ūdenī šķīstošo sāļu kristalizācijas testu (LVS EN12370), paraugu masas zudumi konstatēti pēc 10 cikla. Pēc iegūtajiem raksturlielumiem var secināt, ka kompozītmateriāli atbilst būvkeramikas prasībām

Development of a Strategy for Port Expansion: An Optimal Control Approach

Development of economically efficient expansion strategies for ports and transport infrastructure in general is highly relevant in view of the increasing need for justification of public funding for such projects. Optimisation of the investment and congestion costs, taking into account economies of scale and utilisation rate, and addressing the questions of when, with what size and with what relief interval capacity a port should be expanded, constitutes a generic problem in the planning of infrastructure. The derivation of such strategy, using optimal control theory and incorporating the balance between marginal investment costs and marginal benefits (here, reduction of congestion costs), is presented in this paper. The outcome is applied to a typical port planning problem, in which the optimal expansion strategy is determined for a container port that is confronted with steady demand growth. Recommendations comprise directions for further extension of the proposed modelling approach by the (1) use of non-linear demand patterns, (2) introduction of competition and (3) consideration of internal efficiency improvement alternatives. Major investments in Dutch ports, such as a second seaward expansion of Rotterdam port – a \[euro]2.9 billion project – and the presence of fierce competition between European seaports illustrate the relevance of this research effort. Maritime Economics & Logistics (2008) 10, 258–274. doi:10.1057/mel.2008.4

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