4,234 research outputs found
AFLPs: genetic markers for paternity studies in newts (Triturus vulgaris)
DNA-based genetic markers can reveal paternity whenever the direct assignment of fathers to offspring is precluded by multiple matings and internal fertilisation. Microsatellites are the current marker of choice in many behavioural studies, and have revealed important insights into genetic mating systems of European amphibians. However, the number of amphibian species for which the time-consuming designing of locus-specific microsatellite primers was successful is still limited, and the cross-utilisation of existing markers to closely related taxa seems to have a particularly low success rate. Allozymes can infer parentage without a species-specific protocol, but, due to their low degree of polymorphism, in mate choice experiments require the a priori screening of individuals. Dominant markers such as RAPDs successfully identified closely-related amphibian species and their hybrids, but might be less suited to distinguish between closely related individuals with a putatively high frequency of shared bands
Semi-analytical model for nonlinear light propagation in strongly interacting Rydberg gases
Rate equation models are extensively used to describe the many-body states of
laser driven atomic gases. We show that the properties of the rate equation
model used to describe nonlinear optical effects arising in interacting Rydberg
gases can be understood by considering the excitation of individual
super-atoms. From this we deduce a simple semi-analytic model that accurately
describes the Rydberg density and optical susceptibility for different
dimensionalities. We identify the previously reported universal dependence of
the susceptibility on the Rydberg excited fraction as an intrinsic property of
the rate equation model that is rooted in one-body properties. Benchmarking
against exact master equation calculations, we identify regimes in which the
semi-analytic model is particularly reliable. The performance of the model
improves in the presence of dephasing which destroys higher order atomic
coherences.Comment: 7 pages, 4 figure
Correlated Exciton Transport in Rydberg-Dressed-Atom Spin Chains
We investigate the transport of excitations through a chain of atoms with
non-local dissipation introduced through coupling to additional short-lived
states. The system is described by an effective spin-1/2 model where the ratio
of the exchange interaction strength to the reservoir coupling strength
determines the type of transport, including coherent exciton motion, incoherent
hopping and a regime in which an emergent length scale leads to a preferred
hopping distance far beyond nearest neighbors. For multiple impurities, the
dissipation gives rise to strong nearest-neighbor correlations and
entanglement. These results highlight the importance of non-trivial
dissipation, correlations and many-body effects in recent experiments on the
dipole-mediated transport of Rydberg excitations.Comment: 5 page
Molecular Analysis of Arabidopsis thaliana Genes Involved in Stress Response
Arabidopsis thaliana is an excellent model plant to study various plant processes, including plant’s response to environment, its interactions with other organisms, etc. In this study I characterized eight Arabidopsis genes that are likely to regulate plant’s responses to biotic and abiotic stresses. Microarray analysis was done previously in our lab to identify Arabidopsis genes that are differentially expressed in response to various biotic and abiotic stresses and several plant hormones. The biotic stresses include bacterial, fungal and viral pathogens (both virulent and avirulent strains), sucking and chewing insects. The abiotic stresses include chemicals that induce variety of oxidative stresses (paraquat, 3AT, mixture of glucose/glucose oxidase, and mixture of xanthine/xantine), wounding, heat, cold, freezing, senescence, drought, flooding and salt. The plant hormones include IAA (auxin), 2,4-D (synthetic auxin), BA (cytokinin), GA (gibberellic acid) ,ABA (abscisic acid) , ACC (ethylene precursor), JA (jasmonic acid), BR (brassinosteroid), and SA (salicylic acid). The results of these experiments were used to construct Arabidopsis Stress Microarray Database (ASMD). From this database, eight genes that were considerably up regulated in a number of different stress treatments were identified. To determine the role of these genes in regulating stresses, I constructed transgenic plants that over- or under-express the target genes
Alien Registration- Whitlock, Elsie M. (Milford, Penobscot County)
https://digitalmaine.com/alien_docs/8045/thumbnail.jp
Quantum simulation of energy transport with embedded Rydberg aggregates
We show that an array of ultracold Rydberg atoms embedded in a laser driven
background gas can serve as an aggregate for simulating exciton dynamics and
energy transport with a controlled environment. Spatial disorder and
decoherence introduced by the interaction with the background gas atoms can be
controlled by the laser parameters. This allows for an almost ideal realization
of a Haken-Reineker-Strobl type model for energy transport. Physics can be
monitored using the same mechanism that provides control over the environment.
The degree of decoherence is traced back to information gained on the
excitation location through the monitoring, turning the setup into an
experimentally accessible model system for studying the effects of quantum
measurements on the dynamics of a many-body quantum system.Comment: 5 pages, 4 figures, 3 pages supp. in
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