7 research outputs found

    A biphasic curve for modeling, classifying, and predicting egg production in single cycle and molted flocks

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    Egg production on a flock level can be summarized into several phases determined by biology of individual birds: rapid increase in production reflecting achieving sexual maturity, peak production related to maximum laying potential, followed by gradual decrease in the rate of lay as the birds age. In 1989 Yang et al. proposed a mathematical model (modified compartmental model) to describe this process. In this study a biphasic modified compartmental model was proposed for modeling, classifying, and predicting egg production in single cycle and molted flocks. Goodness-of-fit was high for both single cycle (average R2 = 0.99) and molted flocks (average R2 = 0.97), suggesting that the model could be used for benchmarking molted flocks. The difference in R2 between the biphasic model and the model used by Yang et al in 1989 can be used to differentiate between single cycle and molted flocks. The biphasic model was shown to predict future records well up to 8 wk in advance, but as with any regression model, caution is recommended when predicting records outside of the observed age range

    Phylogeny and Biogeography of Hawkmoths (Lepidoptera: Sphingidae): Evidence from Five Nuclear Genes

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    The 1400 species of hawkmoths (Lepidoptera: Sphingidae) comprise one of most conspicuous and well-studied groups of insects, and provide model systems for diverse biological disciplines. However, a robust phylogenetic framework for the family is currently lacking. Morphology is unable to confidently determine relationships among most groups. As a major step toward understanding relationships of this model group, we have undertaken the first large-scale molecular phylogenetic analysis of hawkmoths representing all subfamilies, tribes and subtribes.The data set consisted of 131 sphingid species and 6793 bp of sequence from five protein-coding nuclear genes. Maximum likelihood and parsimony analyses provided strong support for more than two-thirds of all nodes, including strong signal for or against nearly all of the fifteen current subfamily, tribal and sub-tribal groupings. Monophyly was strongly supported for some of these, including Macroglossinae, Sphinginae, Acherontiini, Ambulycini, Philampelini, Choerocampina, and Hemarina. Other groupings proved para- or polyphyletic, and will need significant redefinition; these include Smerinthinae, Smerinthini, Sphingini, Sphingulini, Dilophonotini, Dilophonotina, Macroglossini, and Macroglossina. The basal divergence, strongly supported, is between Macroglossinae and Smerinthinae+Sphinginae. All genes contribute significantly to the signal from the combined data set, and there is little conflict between genes. Ancestral state reconstruction reveals multiple separate origins of New World and Old World radiations.Our study provides the first comprehensive phylogeny of one of the most conspicuous and well-studied insects. The molecular phylogeny challenges current concepts of Sphingidae based on morphology, and provides a foundation for a new classification. While there are multiple independent origins of New World and Old World radiations, we conclude that broad-scale geographic distribution in hawkmoths is more phylogenetically conserved than previously postulated

    A biphasic curve for modeling, classifying, and predicting egg production in single cycle and molted flocks

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    Egg production on a flock level can be summarized into several phases determined by biology of individual birds: rapid increase in production reflecting achieving sexual maturity, peak production related to maximum laying potential, followed by gradual decrease in the rate of lay as the birds age. In 1989 Yang et al. proposed a mathematical model (modified compartmental model) to describe this process. In this study a biphasic modified compartmental model was proposed for modeling, classifying, and predicting egg production in single cycle and molted flocks. Goodness-of-fit was high for both single cycle (average R2 = 0.99) and molted flocks (average R2 = 0.97), suggesting that the model could be used for benchmarking molted flocks. The difference in R2 between the biphasic model and the model used by Yang et al in 1989 can be used to differentiate between single cycle and molted flocks. The biphasic model was shown to predict future records well up to 8 wk in advance, but as with any regression model, caution is recommended when predicting records outside of the observed age range.This article is published as Wolc, Anna, Jesus Arango, Ian Rubinoff, and Jack CM Dekkers. "A biphasic curve for modeling, classifying, and predicting egg production in single cycle and molted flocks." Poultry Science 99 (2020): 2007-2010. doi: 10.1016/j.psj.2019.11.037.</p

    Data from: Evolution of Manduca sexta hornworms and relatives: biogeographical analysis reveals an ancestral diversification in Central America

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    The hawkmoth genus Manduca is a diverse group of very large, conspicuous moths that has served as an important model across many biological disciplines. Two species in particular, the tobacco hornworm (Manduca sexta) and the tomato hornworm (Manduca quinquemaculatus) have been researched extensively. Studies across biological fields have referred to these two species as being closely related or even sister species, but the extent to which these two model organisms are related remains largely unknown. We conducted a comprehensive multi-gene phylogenetic analysis of Manduca, based on both an ML and Bayesian framework, which resulted in a monophyletic Manduca but only when two other genera, Dolba and Euryglottis are included. We tentatively conclude that the sister group to Manduca sexta comprises the Caribbean M. afflicta and M. johanni, and the sister lineage to this clade includes M. quinquemaculatus and the Hawaiian M. blackburni. Thus, M. sexta and M. quinquemaculatus are closely related, but are not sister species. Biogeographical analyses reveal an ancestral center of diversification in Central America, and Manduca appears to have subsequently colonized North and South America. Our phylogeny provides an important foundation for comparative studies of two model organisms and their relatives

    Adaptive spectroscopic visible-light optical coherence tomography for clinical retinal oximetry

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    Abstract Background Retinal oxygen saturation (sO2) provides essential information about the eye’s response to pathological changes that can result in vision loss. Visible-light optical coherence tomography (vis-OCT) is a noninvasive tool that has the potential to measure retinal sO2 in a clinical setting. However, its reliability is currently limited by unwanted signals referred to as spectral contaminants (SCs), and a comprehensive strategy to isolate true oxygen-dependent signals from SCs in vis-OCT is lacking. Methods We develop an adaptive spectroscopic vis-OCT (ADS-vis-OCT) technique that can adaptively remove SCs and accurately measure sO2 under the unique conditions of each vessel. We also validate the accuracy of ADS-vis-OCT using ex vivo blood phantoms and assess its repeatability in the retina of healthy volunteers. Results In ex vivo blood phantoms, ADS-vis-OCT agrees with a blood gas machine with only a 1% bias in samples with sO2 ranging from 0% to 100%. In the human retina, the root mean squared error between sO2 values in major arteries measured by ADS-vis-OCT and a pulse oximeter is 2.1% across 18 research participants. Additionally, the standard deviations of repeated ADS-vis-OCT measurements of sO2 values in smaller arteries and veins are 2.5% and 2.3%, respectively. Non-adaptive methods do not achieve comparable repeatabilities from healthy volunteers. Conclusions ADS-vis-OCT effectively removes SCs from human images, yielding accurate and repeatable sO2 measurements in retinal arteries and veins with varying diameters. This work could have important implications for the clinical use of vis-OCT to manage eye diseases
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