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Helen Carnaghan Catherine P. James Paul B. Charlesworth Marco Ghionzoli Susana Pereira Mohamed Elkhouli David Baud Paolo De Coppi Greg Ryan Prakesh S. Shah Mark Davenport Anna L. David Agostino Pierro Simon Eaton Gastroschisis Study Group 《黑龙江环境通报》2020,40(8):991-997
Objective
In gastroschisis, there is evidence to suggest that gut dysfunction develops secondary to bowel inflammation; we aimed to evaluate the effect of maternal antenatal corticosteroids administered for obstetric reasons on time to full enteral feeds in a multicenter cohort study of gastroschisis infants.Methods
A three center, retrospective cohort study (1992-2013) with linked fetal/neonatal gastroschisis data was conducted. The primary outcome measure was time to full enteral feeds (a surrogate measure for bowel function) and secondary outcome measure was length of hospital stay. Analysis included Mann-Whitney and Cox regression.Results
Of 500 patients included in the study, 69 (GA at birth 34 [25-38] weeks) received antenatal corticosteroids and 431 (GA at birth 37 [31-41] weeks) did not. Antenatal corticosteroids had no effect on the rate of reaching full feeds (Hazard ratio HR 1.0 [95% CI: 0.8-1.4]). However, complex gastroschisis (HR 0.3 [95% CI: 0.2-0.4]) was associated with an increased time to reach full feeds and later GA at birth (HR 1.1 per week increase in GA [95% CI: 1.1-1.2]) was associated with a decreased time to reach full feeds.Conclusion
Maternal antenatal corticosteroids use, under current antenatal steroid protocols, in gastroschisis is not associated with an improvement in neonatal outcomes such as time to full enteral feeds or length of hospital stay. 相似文献534.
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537.
Life history and reproductive strategies influence population dynamics at the inter- and intra-specific level. Environmental
conditions suitable for gonad development and spawning, the reproductive range, may be a smaller portion of the broader species
distribution. The only known breeding population of veined rapa whelks (Rapana venosa) in North America is in Chesapeake Bay, USA. There is considerable interest in the potential reproductive range of this non-indigenous
species given the rapa whelk’s negative impacts on commercial shellfish species in both its native and introduced ranges.
Weight-specific reproductive output is described for wild caught Chesapeake Bay rapa whelks maintained in flow-through mesocosms
for 2 years. Measured reproductive output within and between egg capsule deposition seasons (years) in relation to water temperature,
salinity, daylength, and female size is used to describe the rapa whelk’s reproductive range. Egg capsule production is influenced
by seasonal and absolute water temperatures as well as seasonal daylength cycles. Egg capsule deposition by Chesapeake Bay
rapa whelks begins at water temperatures of approximately 18°C and continues for 11–15 weeks. Forty to 70% of female whelks
deposited egg capsules in most weeks during this season, producing 150–200 egg capsules female−1 week−1. Water temperatures >28°C caused reduced egg capsule production relative to temperatures of 20–25°C. Egg capsule production
was positively related to seasonal changes in daylength, and two peaks of egg capsule deposition were observed in the 2001
and 2002 deposition seasons. The combination of declining daylength and higher water temperatures in late summer was associated
with the cessation of egg capsule deposition. A lower average weight specific reproductive output in 130–145 mm SL rapa whelks
(average 12 ± 1%) than in 90–106 mm SL rapa whelks (average 22 ± 1% of body weight) may reflect a life history that balances
the physiological costs of maintaining a large body mass with the production of many planktonic larvae from multiple clutches
of egg capsules per breeding season over a 10–15-year lifespan. Estimates of the cumulative day-degree requirements corresponding
to the annual initiation of egg capsule deposition were 238 and 236 for 2001 and 2002, respectively. Reproductive output and
day-degree requirements for Chesapeake Bay rapa whelks were similar to values calculated from previous studies of native muricids
(Eupleura caudata and Urosalpinx cinerea). A latitudinal range of 30–41° (N and S) is predicted as the realized reproductive range for rapa whelk populations on the
basis of the day-degree requirements for native whelks and reproductively active invasive rapa whelk populations.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
538.
Jeremy?FieldEmail author Robert?Paxton Antonella?Soro Paul?Craze Catherine?Bridge 《Behavioral ecology and sociobiology》2012,66(5):743-756
Phenotypic plasticity may evolve when conditions vary temporally or spatially on a small enough scale. Plasticity is thought
to play a central role in the early stages of evolutionary transitions, including major transitions such as those between
non-sociality and sociality. The sweat bee Halictus rubicundus is of special interest in this respect, because it is socially plastic in the British Isles: Nests are social or non-social
depending on the environment. However, sociality comprises a complex suite of inter-related traits. To further investigate
social plasticity in H. rubicundus, we measured traits that are potentially integral to social phenotype at a northern site, where nests are non-social, and
a southern site where nests can be social. We found that foundresses at non-social sites were smaller, produced offspring
of a size more similar to themselves, initiated nesting later, and took longer to produce their first female offspring. They
began provisioning earlier in the day, finished earlier, and collected more pollen loads. Common garden experiments suggested
that these differences represent mainly plasticity, as expected for traits involved in the overall plastic social phenotype,
with only limited evidence for fixed genetic differences in foraging. Conditions during overwintering did not have major effects
on a foundress' subsequent behaviour. 相似文献
539.
Plants are expected to differentially allocate resources to reproduction, growth, and survival in order to maximize overall fitness. Life history theory predicts that the allocation of resources to reproduction should occur at the expense of vegetative growth. Although it is known that both organism size and resource availability can influence life history traits, few studies have addressed how size dependencies of growth and reproduction and variation in resource supply jointly affect the coupling between growth and reproduction. In order to understand the relationship between growth and reproduction in the context of resource variability, we utilize a long-term observational data set consisting of 670 individual trees over a 10-year period within a local population of Bursera simaruba (L.) Sarg. We (1) quantify the functional form and variability in the growth-reproduction relationship at the population and individual-tree level and (2) develop a theoretical framework to understand the allometric dependence of growth and reproduction. Our findings suggest that the differential responses of allometric growth and reproduction to resource availability, both between years and between microsites, underlie the apparent relationship between growth and reproduction. Finally, we offer an alternative approach for quantifying the relationship between growth and reproduction that accounts for variation in allometries. 相似文献
540.
Selecting pseudo-absence data for presence-only distribution modeling: How far should you stray from what you know? 总被引:1,自引:0,他引:1
An important decision in presence-only species distribution modeling is how to select background (or pseudo-absence) localities for model parameterization. The selection of such localities may influence model parameterization and thus, can influence the appropriateness and accuracy of the model prediction when extrapolating the species distribution across time and space. We used 12 species from the Australian Wet Tropics (AWT) to evaluate the relationship between the geographic extent from which pseudo-absences are taken and model performance, and shape and importance of predictor variables using the MAXENT modeling method. Model performance is lower when pseudo-absence points are taken from either a restricted or broad region with respect to species occurrence data than from an intermediate region. Furthermore, variable importance (i.e., contribution to the model) changed such that, models became increasingly simplified, dominated by just two variables, as the area from which pseudo-absence points were drawn increased. Our results suggest that it is important to consider the spatial extent from which pseudo-absence data are taken. We suggest species distribution modeling exercises should begin with exploratory analyses evaluating what extent might provide both the most accurate results and biologically meaningful fit between species occurrence and predictor variables. This is especially important when modeling across space or time—a growing application for species distributional modeling. 相似文献