Revealing ensemble state transition patterns in multi-electrode neuronal recordings using hidden Markov models

In order to harness the computational capacity of dissociated cultured neuronal networks, it is necessary to understand neuronal dynamics and connectivity on a mesoscopic scale. To this end, this paper uncovers dynamic spatiotemporal patterns emerging from electrically stimulated neuronal cultures using hidden Markov models (HMMs) to characterize multi-channel spike trains as a progression of patterns of underlying states of neuronal activity. However, experimentation aimed at optimal choice of parameters for such models is essential and results are reported in detail. Results derived from ensemble neuronal data revealed highly repeatable patterns of state transitions in the order of milliseconds in response to probing stimuli

Shoot yield drives phosphorus use efficiency in Brassica oleracea and correlates with root architecture traits

The environmental and financial costs of using inorganic phosphate fertilizers to maintain crop yield and quality are high. Breeding crops that acquire and use phosphorus (P) more efficiently could reduce these costs. The variation in shoot P concentration (shoot-P) and various measures of P use efficiency (PUE) were quantified among 355 Brassica oleracea L. accessions, 74 current commercial cultivars, and 90 doubled haploid (DH) mapping lines from a reference genetic mapping population. Accessions were grown at two or more external P concentrations in glasshouse experiments; commercial and DH accessions were also grown in replicated field experiments. Within the substantial species-wide diversity observed for shoot-P and various measures of PUE in B. oleracea, current commercial cultivars have greater PUE than would be expected by chance. This may be a consequence of breeding for increased yield, which is a significant component of most measures of PUE, or early establishment. Root development and architecture correlate with PUE; in particular, lateral root number, length, and growth rate. Significant quantitative trait loci associated with shoot-P and PUE occur on chromosomes C3 and C7. These data provide information to initiate breeding programmes to improve PUE in B. oleracea

Formation mechanisms of carbonate concretions of the Monterey Formation: Analyses of clumped isotopes, iron, sulfur and carbon

Carbonate concretions can form as a result of organic matter degradation within sediments. However, the ability to determine specific processes and formation temperatures of particular concretions has remained elusive. Here, we employ concentrations of carbonate-associated sulfate (CAS), δ^(34)S_(CAS) and clumped isotopes (along with more traditional approaches) to characterize the nature of concretion authigenesis within the Miocene Monterey Formation

Biological methods to assess unaccompanied asylum-seeking children's age

Report by the interim Age Estimation Science Advisory Committee (AESAC) on scientific methodologies for assessing the age of unaccompanied asylum-seeking children

It's a dry heat: Quantifying effects of increasing atmospheric moisture demand on native Oklahoma trees

Anthropogenic climate change is predicted to alter precipitation frequency and intensity across Oklahoma in the coming decades, leading to an increase in the frequency, intensity, and duration of extreme events such as soil drought. Concurrently, temperature is predicted to continue rising, causing an ever-increasing atmospheric demand from plants. While the effect of soil droughts has been extensively studied in recent years, the impact of ever-increasing atmospheric droughts on trees is less characterized. Trees regulate photosynthesis though the interactive effects of availability of soil water (supply) and atmospheric demand for water (Vapor Pressure Deficit, VPD). Using recent innovations, and a novel experimental design, we set out to test gas exchange response for three native Oklahoma tree species to varying levels of VPD, with the hypothesis that drought adapted species would be less sensitive to increasing VPD. Two of the species, Quercus stellata and Quercus marilandica, often occur on unfavorable dry sites, while Cercis canadensis is found in riparian areas and wet forest interiors. We exposed six trees of each species to a range of VPDs, between 1kPa and 3kPa, at a constant temperature under well-watered conditions. We measured rates of carbon assimilation and stomatal conductance at five intervals across our VPD measurement range using a LI-COR LI-6800 infrared gas analyzer. Relative rates of carbon assimilation and stomatal conductance decreased as VPD increased across taxa. However, C. canadensis decreased carbon assimilation much quicker than the Quercus species as VPD increased in support of our hypothesis. Our results provide a preliminary understanding of photosynthetic response across a range of VPDs for deciduous forest trees in Oklahoma. Additionally, our methods provide a clear and repeatable way forward, as we aim to disentangle the effects of soil and atmospheric drought on photosynthetic rates in future experiments.Lew Wentz FoundationPlant Biology, Ecology and Evolutio

Biological methods to assess unaccompanied asylum-seeking children’s age:Interim Age Estimation Science Advisory Committee

Report by the interim Age Estimation Science Advisory Committee (AESAC) on scientific methodologies for assessing the age of unaccompanied asylum-seeking children.<br/

Biological methods to assess unaccompanied asylum-seeking children’s age:Interim Age Estimation Science Advisory Committee

Report by the interim Age Estimation Science Advisory Committee (AESAC) on scientific methodologies for assessing the age of unaccompanied asylum-seeking children.<br/