Are tropical butterflies more colorful?

Adams, Jonathan M.,Kang, Changku,June‐,Wells, Mark Springer Japan 2014 Ecological research Vol.29 No.4

<P><B>Abstract</B></P><P>There is a common and long‐standing belief that tropical butterflies are more striking in their coloration than those of cooler climates. It has been suggested that this is due to more intense biotic selection or mate selection in the tropics. We tested whether there were differences in coloration by examining the dorsal surface color properties of male butterflies from three regions of the western hemisphere: the Jatun‐Satcha Reserve in lowland Ecuador (tropical), the state of Florida, USA (subtropical) and the state of Maine, USA (cool temperate). We digitally photographed the dorsal wing and body surface of male butterfly specimens from Maine, Florida, and Ecuador. For each photograph, we analyzed the mean and variation for the color‐parameters that are thought to be related to colorfulness; namely Hue, saturation and intensity. Overall, the Ecuadorian sample exhibited more varied intensity, saturation, and Hue compared to the other regions. These results suggest a more complex assemblage of colors and patterns regionally and on a butterfly‐by‐butterfly basis in the tropics. The greater complexity of colors within each butterfly in our Ecuadorian sample suggests that tropical butterflies are indeed more ‘colorful’, at least by some measures. Possible reasons for this include stronger predation pressure selecting for aposematism, greater species diversity selecting for camouflage or warning coloration against potential predators, and easier recognition of potential mates in a species rich environment.</P>

Outage Probability Analysis in RSMA Power Line Communications

Jonathan Obeng Agyapong,Abdul-Manan Zakari Adams,Roger K. Ahiadormey,Kyoung-Jae Lee 한국통신학회 2024 한국통신학회 학술대회논문집 Vol.2024 No.6

Diffuse large B-cell lymphoma (DLBCL) is infiltrated with activated CD8+ T-cells despite immune checkpoint signaling

Adam M. Greenbaum,Jonathan R. Fromm,Ajay K. Gopal,A. McGarry Houghton 대한혈액학회 2022 Blood Research Vol.57 No.2

Background B-cell non-Hodgkin lymphomas (NHL) are hematologic malignancies that arise in the lymph node. Despite this, the malignant cells are not cleared by the immune cells present. The failure of anti-tumor immunity may be due to immune checkpoints such as the PD-1/PDL-1 axis, which can cause T-cell exhaustion. Unfortunately, unlike Hodgkin lymphoma, checkpoint blockade in NHL has shown limited efficacy. Methods We performed an extensive functional analysis of malignant and non-malignant lymph nodes using high dimensional flow cytometry. We compared follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL), and lymph nodes harboring reactive hyperplasia (RH). Results We identified an expansion of CD8+PD1+ T-cells in the lymphomas relative to RH. Moreover, we demonstrate that these cells represent a mixture of activated and exhausted T-cells in FL. In contrast, these cells are nearly universally activated and functional in DLBCL. This is despite expression of counter-regulatory molecules such as PD-1, TIM-3, and CTLA-4, and the presence of regulatory T-cells. Conclusion These data may explain the failure of single-agent immune checkpoint inhibitors in the treatment of DLBCL. Accordingly, functional differences of CD8+ T-cells between FL and DLBCL may inform future therapeutic targeting strategies.

Lattice dynamics of the tin sulphides SnS ₂ , SnS and Sn ₂ S ₃ : vibrational spectra and thermal transport

Skelton, Jonathan M.,Burton, Lee A.,Jackson, Adam J.,Oba, Fumiyasu,Parker, Stephen C.,Walsh, Aron Royal Society of Chemistry 2017 Physical chemistry chemical physics Vol.19 No.19

<▼1><P>First-principles lattice-dynamics calculations are used to model and compare the vibrational spectra and thermal transport of four bulk tin-sulphide materials.</P></▼1><▼2><P>We present an in-depth first-principles study of the lattice dynamics of the tin sulphides SnS<SUB>2</SUB>, <I>Pnma</I> and π-cubic SnS and Sn<SUB>2</SUB>S<SUB>3</SUB>. An analysis of the harmonic phonon dispersion and vibrational density of states reveals phonon bandgaps between low- and high-frequency modes consisting of Sn and S motion, respectively, and evidences a bond-strength hierarchy in the low-dimensional SnS<SUB>2</SUB>, <I>Pnma</I> SnS and Sn<SUB>2</SUB>S<SUB>3</SUB> crystals. We model and perform a complete characterisation of the infrared and Raman spectra, including temperature-dependent anharmonic linewidths calculated using many-body perturbation theory. We illustrate how vibrational spectroscopy could be used to identify and characterise phase impurities in tin sulphide samples. The spectral linewidths are used to model the thermal transport, and the calculations indicate that the low-dimensional Sn<SUB>2</SUB>S<SUB>3</SUB> has a very low lattice thermal conductivity, potentially giving it superior performance to SnS as a candidate thermoelectric material.</P></▼2>

Excited-state intramolecular proton-transfer (ESIPT) based fluorescence sensors and imaging agents

Sedgwick, Adam C.,Wu, Luling,Han, Hai-Hao,Bull, Steven D.,He, Xiao-Peng,James, Tony D.,Sessler, Jonathan L.,Tang, Ben Zhong,Tian, He,Yoon, Juyoung The Royal Society of Chemistry 2018 Chemical Society reviews Vol.47 No.23

<P>In this review we will explore recent advances in the design and application of excited-state intramolecular proton-transfer (ESIPT) based fluorescent probes. Fluorescence based sensors and imaging agents (probes) are important in biology, physiology, pharmacology, and environmental science for the selective detection of biologically and/or environmentally important species. The development of ESIPT-based fluorescence probes is particularly attractive due to their unique properties, which include a large Stokes shift, environmental sensitivity and potential for ratiometric sensing.</P>

Strain solitons and topological defects in bilayer graphene

Alden, Jonathan S.,Tsen, Adam W.,Huang, Pinshane Y.,Hovden, Robert,Brown, Lola,Park, Jiwoong,Muller, David A.,McEuen, Paul L. National Academy of Sciences 2013 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.110 No.28

<P>Bilayer graphene has been a subject of intense study in recent years. The interlayer registry between the layers can have dramatic effects on the electronic properties: for example, in the presence of a perpendicular electric field, a band gap appears in the electronic spectrum of so-called Bernal-stacked graphene [Oostinga JB, et al. (2007) <I>Nature Materials</I> 7:151–157]. This band gap is intimately tied to a structural spontaneous symmetry breaking in bilayer graphene, where one of the graphene layers shifts by an atomic spacing with respect to the other. This shift can happen in multiple directions, resulting in multiple stacking domains with soliton-like structural boundaries between them. Theorists have recently proposed that novel electronic states exist at these boundaries [Vaezi A, et al. (2013) arXiv:1301.1690; Zhang F, et al. (2013) arXiv:1301.4205], but very little is known about their structural properties. Here we use electron microscopy to measure with nanoscale and atomic resolution the widths, motion, and topological structure of soliton boundaries and related topological defects in bilayer graphene. We find that each soliton consists of an atomic-scale registry shift between the two graphene layers occurring over 6–11 nm. We infer the minimal energy barrier to interlayer translation and observe soliton motion during in situ heating above 1,000 °C. The abundance of these structures across a variety of samples, as well as their unusual properties, suggests that they will have substantial effects on the electronic and mechanical properties of bilayer graphene.</P>

The Importance of Being Inconsistent

Wasserman, Adam,Nafziger, Jonathan,Jiang, Kaili,Kim, Min-Cheol,Sim, Eunji,Burke, Kieron Annual Reviews 2017 Annual review of physical chemistry Vol.68 No.-

<P>We review the role of self-consistency in density functional theory (DFT). Weapply a recent analysis to both Kohn-Sham and orbital-free DFT, as well as to partition DFT, which generalizes all aspects of standard DFT. In each case, the analysis distinguishes between errors in approximate functionals versus errors in the self-consistent density. This yields insights into the origins of many errors in DFT calculations, especially those often attributed to self-interaction or delocalization error. In many classes of problems, errors can be substantially reduced by using better densities. We review the history of these approaches, discuss many of their applications, and give simple pedagogical examples.</P>

Bacterial Diversity in the Mountains of South-West China: Climate Dominates Over Soil Parameters

Dharmesh Singh,Lingling Shi,Jonathan Miles Adams 한국미생물학회 2013 The journal of microbiology Vol.51 No.4

Certain patterns in soil bacterial diversity and community composition have become evident from metagenomics studies on a range of scales, from various parts of the world. For example, soil pH has generally been seen as dominating variation in bacterial diversity, above all other soil and climate parameters. It is important however to test the generality of these relationships by studying previously unsampled areas. We compared soil bacterial diversity and community composition under a wide range of climatic and edaphic conditions in mountainous Yunnan Province, SW China. Soil samples were taken from a range of primary forest types and altitudes, reflecting the great variation of forest environments in this region. From each soil sample, DNA was extracted and pyrosequenced for bacterial 16S rRNA gene identification. In contrast to other recent studies from other parts of the world, pH was a weaker predictor of bacterial community composition and diversity than exchangeable Ca2+ concentration, and also the more poorly defined environmental parameter of elevation. Samples from within each forest type clustered strongly, showing the distinctive pattern of their microbial communities on a regional scale. It is clear that on a regional scale in a very heterogeneous environment, additional factors beyond pH can emerge as more important in determining bacterial diversity.

Performance Analysis of Full-Duplex Massive MIMO Systems with RSMA

Abdul-Manan Zakari Adams,Jonathan Obeng Agyapong,Prince Anokye,Kyoung-Jae Lee 한국통신학회 2024 한국통신학회 학술대회논문집 Vol.2024 No.6

Identification of <i>Azadinium</i> species and a new azaspiracid from <i>Azadinium poporum</i> in Puget Sound, Washington State, USA

Kim, Joo-Hwan,Tillmann, Urban,Adams, Nicolaus G.,Krock, Bernd,Stutts, Whitney L.,Deeds, Jonathan R.,Han, Myung-Soo,Trainer, Vera L. Elsevier 2017 HARMFUL ALGAE Vol.68 No.-

<P><B>Abstract</B></P> <P>The identification of a new suite of toxins, called azaspiracids (AZA), as the cause of human illnesses after the consumption of shellfish from the Irish west coast in 1995, resulted in interest in understanding the global distribution of these toxins and of species of the small dinoflagellate genus <I>Azadinium</I>, known to produce them. Clonal isolates of four species of <I>Azadinium, A. poporum, A. cuneatum, A. obesum</I> and <I>A. dalianense</I> were obtained from incubated sediment samples collected from Puget Sound, Washington State in 2016. These <I>Azadinium</I> species were identified using morphological characteristics confirmed by molecular phylogeny. Whereas AZA could not be detected in any strains of <I>A. obesum, A. cuneatum</I> and <I>A. dalianense</I>, all four strains of <I>A. poporum</I> produced a new azaspiracid toxin, based on LC–MS analysis, named AZA-59. The presence of AZA-59 was confirmed at low levels <I>in situ</I> using a solid phase resin deployed at several stations along the coastlines of Puget Sound. Using a combination of molecular methods for species detection and solid phase resin deployment to target shellfish monitoring of toxin at high-risk sites, the risk of azaspiracid shellfish poisoning can be minimized.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Four <I>Azadinium</I> species were isolated from Puget Sound. </LI> <LI> <I>A. poporum</I> from Puget Sound produce a new azaspiracid, AZA-59. </LI> <LI> AZA-59 was detected at low levels in seawater from several stations in Puget Sound. </LI> </UL> </P>