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multiple trace theory

Nan Zhao, Jonathan C Papa, Kyle Fuerschbach, Yanfeng Qiao, Kevin P Thompson, Jannick P Rolland
Nodal aberration theory (NAT) describes the aberration properties of optical systems without symmetry. NAT was fully described mathematically and investigated through real-ray tracing software, but an experimental investigation is yet to be realized. In this study, a two-mirror Ritchey-Chrétien telescope was designed and built, including testing of the mirrors in null configurations, for experimental investigation of NAT. A feature of this custom telescope is a high-precision hexapod that controls the secondary mirror of the telescope to purposely introduce system misalignments and quantify the introduced aberrations interferometrically...
April 2, 2018: Optics Express
Simon D W Frost, Brittany Rife Magalis, Sergei L Kosakovsky Pond
The evolution of viral pathogens is shaped by strong selective forces that are exerted during jumps to new hosts, confrontations with host immune responses and antiviral drugs, and numerous other processes. However, while undeniably strong and frequent, adaptive evolution is largely confined to small parts of information-packed viral genomes, and the majority of observed variation is effectively neutral. The predictions and implications of the neutral theory have proven immensely useful in this context, with applications spanning understanding within-host population structure, tracing the origins and spread of viral pathogens, predicting evolutionary dynamics, and modeling the emergence of drug resistance...
June 1, 2018: Molecular Biology and Evolution
Jeongmin Kim, Yuan Wang, Xiang Zhang
A vectorial diffraction theory that considers light polarization is essential to predict the performance of optical systems that have a high numerical aperture or use engineered polarization or phase. Vectorial diffraction integrals to describe light diffraction typically require boundary fields on aperture surfaces. Estimating such boundary fields can be challenging in complex systems that induce multiple depolarizations, unless vectorial ray tracing using 3×3 Jones matrices is employed. The tracing method, however, has not been sufficiently detailed to cover complex systems and, more importantly, seems influenced by system geometry (transmission versus reflection)...
April 1, 2018: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Nima Ghaderi
The analytic solutions, that is, populations, are derived for the K-adiabatic and K-active bimolecular master equations, separately, for a single and multiple potential wells and reaction channels, where K is the component of the total angular momentum J along the axis of least moment of inertia of the recombination products at a given energy E. The analytic approach provides the functional dependence of the population of molecules on its K-active or K-adiabatic dissociation, association rate constants and the intermolecular energy transfer, where the approach may complement the usual numerical approaches for reactions of interest...
April 12, 2018: Journal of Physical Chemistry. A
Si He, Xia Wang, Runqiu Xia, Weiqi Jin, Jian'an Liang
A novel method to simulate the polarimetric infrared imaging of a synthetic sea surface with atmospheric Mie scattering effects is presented. The infrared emission, multiple reflections, and infrared polarization of the sea surface and the Mie scattering of aerosols are all included for the first time. At first, a new approach to retrieving the radiative characteristics of a wind-roughened sea surface is introduced. A two-scale method of sea surface realization and the inverse ray tracing of light transfer calculation are combined and executed simultaneously, decreasing the consumption of time and memory dramatically...
March 1, 2018: Applied Optics
A J M Sabadel, A D Stumbo, C D MacLeod
Parasites are often overlooked in the construction of food webs, despite their ubiquitous presence in almost every type of ecosystem. Researchers who do recognize their importance often struggle to include parasites using classical food-web theory, mainly due to the parasites' multiple hosts and life stages. A novel approach using compound-specific stable-isotope analysis promises to provide considerable insight into the energetic exchanges of parasite and host, which may solve some of the issues inherent in incorporating parasites using a classical approach...
February 28, 2018: Journal of Helminthology
Pietro Ghezzi, Kevin Davies, Aidan Delaney, Luciano Floridi
Biomarkers are widely used not only as prognostic or diagnostic indicators, or as surrogate markers of disease in clinical trials, but also to formulate theories of pathogenesis. We identify two problems in the use of biomarkers in mechanistic studies. The first problem arises in the case of multifactorial diseases, where different combinations of multiple causes result in patient heterogeneity. The second problem arises when a pathogenic mediator is difficult to measure. This is the case of the oxidative stress (OS) theory of disease, where the causal components are reactive oxygen species (ROS) that have very short half-lives...
March 6, 2018: Proceedings of the National Academy of Sciences of the United States of America
Xu Tang, Yun Wang, Juan Han, Liang Ni, Huiqin Zhang, Cheng Li, Jing Li, Yue Qiu
At present, the design of multi ion sensing receptors is a new area of research due to their potential application in the recognition of analytes. Herein, a novel fluorescent probe for the detection of multi metal ions was designed and synthesized based on the fluorophores of biphenyl and rhodamine. Probe 1 exhibits multiple fluorescence responses to various metal ions (Zn2+ , Al3+ , Cr3+ and Fe3+ ) and is accompanied by different optical signal outputs. Moreover, the interference between the target ions can also be effectively solved by the introduction of probe 2 and the addition of the corresponding anions...
March 6, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Jukka Törrönen, Christoffer Tigerstedt
The article applies actor network theory (ANT) to autobiographical data on alcohol dependence to explore what ANT can offer to the analysis of 'addiction stories'. By defining 'addiction' as a relational achievement, as the effect of elements acting together as a configuration of human and non-human actors, the article demonstrates how the moving and changing attachments of addiction can be dynamically analyzed with concepts of 'assemblage', 'mediator', 'tendency', 'translation', 'trajectory', 'immutable mobile', 'fluid' and 'bush fire'...
April 2018: International Journal on Drug Policy
Céline Pisapia, Frédéric Jamme, Ludovic Duponchel, Bénédicte Ménez
Finding traces of life or organic components of prebiotic interest in the rock record is an appealing goal for numerous fields in Earth and space sciences. However, this is often hampered by the scarceness and highly heterogeneous distribution of organic compounds within rocks. We assess here an innovative analytical strategy combining Synchrotron radiation-based Fourier-Transform Infrared microspectroscopy (S-FTIR) and multivariate analysis techniques to track and characterize organic compounds at the pore level in complex oceanic rocks...
February 5, 2018: Scientific Reports
Zimbul Albo, Johannes Gräff
Long-lasting memories form the basis of our identity as individuals and lie central in shaping future behaviours that guide survival. Surprisingly, however, our current knowledge of how such memories are stored in the brain and retrieved, as well as the dynamics of the circuits involved, remains scarce despite seminal technical and experimental breakthroughs in recent years. Traditionally, it has been proposed that, over time, information initially learnt in the hippocampus is stored in distributed cortical networks...
March 19, 2018: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
Anne-Marie Turcotte-Tremblay, Idriss Ali Gali-Gali, Manuela De Allegri, Valéry Ridde
Performance-based financing (PBF) is being widely implemented to improve healthcare services in Africa. An essential component of PBF involves conducting community verifications, wherein investigators from local associations attempt to trace samples of patients. Community surveys are administered to patients to verify whether healthcare workers reported fictitious services to increase their revenue. At the same time, client satisfaction surveys are administered to assess whether patients are satisfied with the services received...
September 8, 2017: Social Science & Medicine
Aurèle Vuillemin, Fabian Horn, Mashal Alawi, Cynthia Henny, Dirk Wagner, Sean A Crowe, Jens Kallmeyer
Extracellular DNA is ubiquitous in soil and sediment and constitutes a dominant fraction of environmental DNA in aquatic systems. In theory, extracellular DNA is composed of genomic elements persisting at different degrees of preservation produced by processes occurring on land, in the water column and sediment. Extracellular DNA can be taken up as a nutrient source, excreted or degraded by microorganisms, or adsorbed onto mineral matrices, thus potentially preserving information from past environments. To test whether extracellular DNA records lacustrine conditions, we sequentially extracted extracellular and intracellular DNA from anoxic sediments of ferruginous Lake Towuti, Indonesia...
2017: Frontiers in Microbiology
Hartmut Fitz, Franklin Chang
Nativist theories have argued that language involves syntactic principles which are unlearnable from the input children receive. A paradigm case of these innate principles is the structure dependence of auxiliary inversion in complex polar questions (Chomsky, 1968, 1975, 1980). Computational approaches have focused on the properties of the input in explaining how children acquire these questions. In contrast, we argue that messages are structured in a way that supports structure dependence in syntax. We demonstrate this approach within a connectionist model of sentence production (Chang, 2009) which learned to generate a range of complex polar questions from a structured message without positive exemplars in the input...
September 2017: Cognition
Bridget N Queenan, Tomás J Ryan, Michael S Gazzaniga, Charles R Gallistel
The search for memory is one of the oldest quests in written human history. For at least two millennia, we have tried to understand how we learn and remember. We have gradually converged on the brain and looked inside it to find the basis of knowledge, the trace of memory. The search for memory has been conducted on multiple levels, from the organ to the cell to the synapse, and has been distributed across disciplines with less chronological or intellectual overlap than one might hope. Frequently, the study of the mind and its memories has been severely restricted by technological or philosophical limitations...
May 2017: Annals of the New York Academy of Sciences
Jacobus J Boomsma, Richard Gawne
More than a century ago, William Morton Wheeler proposed that social insect colonies can be regarded as superorganisms when they have morphologically differentiated reproductive and nursing castes that are analogous to the metazoan germ-line and soma. Following the rise of sociobiology in the 1970s, Wheeler's insights were largely neglected, and we were left with multiple new superorganism concepts that are mutually inconsistent and uninformative on how superorganismality originated. These difficulties can be traced to the broadened sociobiological concept of eusociality, which denies that physical queen-worker caste differentiation is a universal hallmark of superorganismal colonies...
February 2018: Biological Reviews of the Cambridge Philosophical Society
Francesca Merlin, Livio Riboli-Sasco
The current debate over extending inheritance and its evolutionary impact has focused on adding new categories of non-genetic factors to the classical transmission of DNA, and on trying to redefine inheritance. Transmitted factors have been mainly characterized by their directions of transmission (vertical, horizontal, or both) and the way they store variations. In this paper, we leave aside the issue of defining inheritance. We rather try to build an evolutionary conceptual framework that allows for tracing most, if not all forms of transmission and makes sense of their different tempos and modes...
June 2017: Acta Biotheoretica
Kevin C Rose, Rose A Graves, Winslow D Hansen, Brian J Harvey, Jiangxiao Qiu, Stephen A Wood, Carly Ziter, Monica G Turner
Macrosystems ecology is an effort to understand ecological processes and interactions at the broadest spatial scales and has potential to help solve globally important social and ecological challenges. It is important to understand the intellectual legacies underpinning macrosystems ecology: How the subdiscipline fits within, builds upon, differs from and extends previous theories. We trace the rise of macrosystems ecology with respect to preceding theories and present a new hypothesis that integrates the multiple components of macrosystems theory...
February 2017: Ecology Letters
Roberto Mazzoli, Enrica Pessione
Gut microbiota provides the host with multiple functions (e.g., by contributing to food digestion, vitamin supplementation, and defense against pathogenic strains) and interacts with the host organism through both direct contact (e.g., through surface antigens) and soluble molecules, which are produced by the microbial metabolism. The existence of the so-called gut-brain axis of bi-directional communication between the gastrointestinal tract and the central nervous system (CNS) also supports a communication pathway between the gut microbiota and neural circuits of the host, including the CNS...
2016: Frontiers in Microbiology
Edward Matthews, Caroline E H Dessent
Even in relatively simple molecules, the sites of protonation or deprotonation formed upon electrospray ionization can be controversial. This situation means that it is important to develop new approaches for identifying "protomers" and "deprotomers". In this study, we demonstrate that routine, low-resolution UV laser photodissociation spectroscopy can be applied to identify the gaseous protomers of nicotinamide formed upon electrospray. Nicotinamide is an important biological molecule that possesses multiple protonation sites associated with its pyridine and amide groups...
November 23, 2016: Journal of Physical Chemistry. A
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