Biomedical subjects

Aaron A King

Publications and source records attributed to Aaron A King.

4 recordsLinked to original sources

PubMed2005

Maternal death after second-trimester genetic amniocentesis.

BACKGROUND: We report a maternal death after a second-trimester amniocentesis. CASE: An uncomplicated amniocentesis was performed using sterile technique and ultrasound guidance. A refrigerated amniotic fluid specimen demonstrated negative leukocyte esterase activity, negative Gram stain for bacteria and white blood cells, and normal glucose and interleukin-6. The patient died from Escherichia coli sepsis and disseminated intravascular coagulation 40 hours after the amniocentesis. The autopsy showed normal- appearing needle entries into the skin and uterus without evidence of bowel adhesion or a needle track through the bowel. CONCLUSION: Genetic counselors and obstetric care providers should be aware of potential serious maternal morbidity and mortality that may occur subsequent to uncomplicated amniocentesis.

Adult↗

PubMed2003

Anatomy of a chaotic attractor: subtle model-predicted patterns revealed in population data.

Mathematically, chaotic dynamics are not devoid of order but display episodes of near-cyclic temporal patterns. This is illustrated, in interesting ways, in the case of chaotic biological populations. Despite the individual nature of organisms and the noisy nature of biological time series, subtle temporal patterns have been detected. By using data drawn from chaotic insect populations, we show quantitatively that chaos manifests itself as a tapestry of identifiable and predictable patterns woven together by stochasticity. We show too that the mixture of patterns an experimentalist can expect to see depends on the scale of the system under study.

Animals↗

PubMed2003

Explaining and predicting patterns in stochastic population systems.

Lattice effects in ecological time-series are patterns that arise because of the inherent discreteness of animal numbers. In this paper, we suggest a systematic approach for predicting lattice effects. We also show that an explanation of all the patterns in a population time-series may require more than one deterministic model, especially when the dynamics are complex.

Animals↗

PubMed2003

Spatial mechanisms for coexistence of species sharing a common natural enemy.

We examine the conditions under which spatial structure can mediate coexistence of apparent competitors. We use a spatially explicit, host-parasitoid metapopulation model incorporating local dynamics of Nicholson-Bailey type and global dispersal. Depending on the model parameters, the resulting system displays a plethora of asynchronous dynamical behaviors for which permanent or transient coexistence is observed. We identify a number of spatially mediated tradeoffs which apparent competitors can utilize and demonstrate that the dynamics of spatial coexistence can typically be understood from consideration of two and three patch systems. The phase relationships of species abundances are different for our model than for some other mechanisms of spatial coexistence. We discuss the implications of our findings relative to issues of community organization and biological conservation.

Animals↗