829 research outputs found
Ancient DNA from coral-hosted Symbiodinium reveal a static mutualism over the last 172 years.
Ancient DNA (aDNA) provides powerful evidence for detecting the genetic basis for adaptation to environmental change in many taxa. Among the greatest of changes in our biosphere within the last century is rapid anthropogenic ocean warming. This phenomenon threatens corals with extinction, evidenced by the increasing observation of widespread mortality following mass bleaching events. There is some evidence and conjecture that coral-dinoflagellate symbioses change partnerships in response to changing external conditions over ecological and evolutionary timescales. Until now, we have been unable to ascertain the genetic identity of Symbiodinium hosted by corals prior to the rapid global change of the last century. Here, we show that Symbiodinium cells recovered from dry, century old specimens of 6 host species of octocorals contain sufficient DNA for amplification of the ITS2 subregion of the nuclear ribosomal DNA, commonly used for genotyping within this genus. Through comparisons with modern specimens sampled from similar locales we show that symbiotic associations among several species have been static over the last century, thereby suggesting that adaptive shifts to novel symbiont types is not common among these gorgonians, and perhaps, symbiotic corals in general
Noninnatist alternatives to the negative evidence hypothesis
Journal ArticleIn this commentary we consider three issues. First, we suggest that Crain's definition of innateness is not biologically plausible. Second, we show how the criteria he uses as hallmarks of innateness can have alternative explanations. Finally, we reinterpret his research findings on grounds that do not involve innatist explanations
Effect of Tyrosine on the Productivity of PC12 Cells by Measuring Extracellular ATP release
Given the challenge to “reverse-engineer the brain”, our group tried to address the problems of a lack of long term focus and attention span. Tyrosine was determined to aid in mental focus and brain productivity as it is a precursor to the neurotransmitter Dopamine. Given that Tyrosine is naturally occurring in the body, it is preferable to add to the body, whereas a substance like Adderall has negative effects, including increased heart rate that, over time, can cause cardiovascular damage. Drawing connections between in increase ATP and an increased ability to focus and perform under stress, extracellular ATP secretion of PC12 cells is measured using a luminometer. This research is novel and important as it attempts to find a way to increase the human brain’s ability to focus. Based on results, higher levels of tyrosine in the brain would lead to increase overall human cognitive function and productivit
HIV-1 Evolutionary Patterns Associated with Metastatic Kaposi's Sarcoma during AIDS.
Kaposi's sarcoma (KS) in HIV-infected individuals can have a wide range of clinical outcomes, from indolent skin tumors to a life-threatening visceral cancer. KS tumors contain endothelial-related cells and inflammatory cells that may be HIV-infected. In this study we tested if HIV evolutionary patterns distinguish KS tumor relatedness and progression. Multisite autopsies from participants who died from HIV-AIDS with KS prior to the availability of antiretroviral therapy were identified at the AIDS and Cancer Specimen Resource (ACSR). Two patients (KS1 and KS2) died predominantly from non-KS-associated disease and KS3 died due to aggressive and metastatic KS within one month of diagnosis. Skin and visceral tumor and nontumor autopsy tissues were obtained (n = 12). Single genome sequencing was used to amplify HIV RNA and DNA, which was present in all tumors. Independent HIV tumor clades in phylogenies differentiated KS1 and KS2 from KS3, whose sequences were interrelated by both phylogeny and selection. HIV compartmentalization was confirmed in KS1 and KS2 tumors; however, in KS3, no compartmentalization was observed among sampled tissues. While the sample size is small, the HIV evolutionary patterns observed in all patients suggest an interplay between tumor cells and HIV-infected cells which provides a selective advantage and could promote KS progression
Direct Wigner tomography of a superconducting anharmonic oscillator
The analysis of wave-packet dynamics may be greatly simplified when viewed in
phase-space. While harmonic oscillators are often used as a convenient platform
to study wave-packets, arbitrary state preparation in these systems is more
challenging. Here, we demonstrate a direct measurement of the Wigner
distribution of complex photon states in an anharmonic oscillator - a
superconducting phase circuit, biased in the small anharmonicity regime. We
test our method on both non-classical states composed of two energy eigenstates
and on the dynamics of a phase-locked wavepacket. This method requires a simple
calibration, and is easily applicable in our system out to the fifth level.Comment: 5 figures, 1 table and supplementary materia
LABA/LAMA combinations versus LAMA monotherapy or LABA/ICS in COPD : a systematic review and meta-analysis
Acknowledgments The meta-analysis work was performed by Guruprasad Rao KS and Sharanbasappa Durg of Molecular Connections (P) Ltd, Bangalore, India, under the guidance of the manuscript authors and Novartis Pharma AG (Basel, Switzerland). Medical writing assistance was provided by Colette O’Sullivan, PhD, of Scriva Medical Communications Ltd, a professional medical writer funded by Novartis. Development of the manuscript was supported by Novartis Pharma AG (Basel, Switzerland). The authors received no compensation related to the development of the manuscript.Peer reviewedPublisher PD
Are planetary nebulae derived from multiple evolutionary scenarios?
Our understanding of planetary nebulae has been significantly enhanced as a
result of several recent large surveys (Parker et al., these proceedings).
These new discoveries suggest that the `PN phenomenon' is in fact more
heterogeneous than previously envisaged. Even after the careful elimination of
mimics from Galactic PN catalogues, there remains a surprising diversity in the
population of PNe and especially their central stars. Indeed, several
evolutionary scenarios are implicated in the formation of objects presently
catalogued as PNe. We provide a summary of these evolutionary pathways and give
examples of each. Eventually, a full census of local PNe can be used to
confront both stellar evolution theory and population synthesis models.Comment: 4 pages, 1 figure. To be published in Planetary Nebulae: an Eye to
the Future, Proceedings of IAU Symposium 283, held in Puerto de la Cruz,
Tenerife, Spain, July 25-29 201
Quantitative Structure-Activity Relationships by Evolved Neural Networks for the Inhibition of Dihydrofolate Reductase by Pyrimidines
Abstract Evolutionary computation provides a useful method for training neural networks in the face of multiple local optima. This paper begins with a description of methods for quantitative structure activity relationships (QSAR). An overview of artificial neural networks for pattern recognition problems such as QSAR is presented and extended with the description of how evolutionary computation can be used to evolve neural networks. Experiments are conducted to examine QSAR for the inhibition of dihydrofolate reductase by pyrimidines using evolved neural networks. Results indicate the utility of evolutionary algorithms and neural networks for the predictive task at hand. Furthermore, results that are comparable or perhaps better than those published previously were obtained using only a small fraction of the previously required degrees of freedom
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