76,539 research outputs found
Shifting metabolic priorities among key protistan taxa within and below the euphotic zone
No full textDataset for submitted publication: Sarah K. Hu, Zhenfeng Liu, Harriet Alexander, Victoria Campbell, Paige Connell, Karla B. Heidelberg, Sonya Dyhrman, & David A. Caron. Shifting metabolic priorities among key protistan taxonomic groups within and below the euphotic zone. In press. Environmental Microbiology. https://doi.org/10.1111/1462-2920.14259
See associated GitHub repository: https://github.com/shu251/SPOT_metatranscriptome
Abstract
A metatranscriptome study targeting the protistan community was conducted off the coast of Southern California, at the San Pedro Ocean Time-series station at the surface, 150 m (oxycline), and 890 m to link putative metabolic patterns to distinct protistan lineages. Comparison of relative transcript abundances revealed depth-related shifts in the nutritional modes of key taxonomic groups. Eukaryotic gene expression in the sunlit surface environment was dominated by phototrophs, such as diatoms and chlorophytes, and high abundances of transcripts associated with synthesis pathways (e.g. photosynthesis, carbon fixation, fatty acid synthesis). Sub-euphotic depths (150 m and 890 m) exhibited strong contributions from dinoflagellates and ciliates, and were characterized by transcripts relating to digestion or intracellular nutrient recycling (e.g. breakdown of fatty acids and V-type ATPases). These transcriptional patterns underlie the distinct nutritional modes of ecologically important protistan lineages that drive marine food webs, and provide a framework to investigate trophic dynamics across diverse protistan communities.
Most recent version - March 16, 2018</p
Performance Evaluation of Distributed-Antenna Communications Systems Using Beam-Hopping
No full textDigital beamforming (DBF) techniques are capable of improving the performance of communications systems significantly. However, if the transmitted signals are conflicted with strong interference, especially, in the direction of the transmitted beams , these directional jamming signals will severely degrade the system performance. In order to efficiently mitigate the interference of the directional jammers, in this contribution a beam-hopping (BH) communications scheme is proposed. In the proposed BH communications scheme, only one pair of the beams is used for transmission and it hops from one to the next according to an assigned BH pattern. In this contribution a range of expressions in terms of the average SINR performance have been derived, when both the uplink and downlink are considered. The average SINR performance of the proposed BH scheme and that of the conventional single-beam (SB) as well as multiple-beam (MB) assisted beam-processing schemes have been investigated. Our analysis and results show that the proposed BH scheme is capable of efficiently combating the directional jamming, with the aid of utilizing the directional gain of the beams generated by both the transmitter and the receiver. Furthermore, the BH scheme is capable of reducing the intercept probability of the communications. Therefore, the proposed BH scheme is suitable for communications, when several distributed antenna arrays are available around a mobile
Variations of the Morse-Hedlund Theorem for k-Abelian Equivalence
No full textIn this paper we investigate local-to-global phenomena for a new family of complexity functions of infinite words indexed by k >= 0. Two finite words u and v are said to be k-abelian equivalent if for all words x of length less than or equal to k, the number of occurrences of x in u is equal to the number of occurrences of x in v. This defines a family of equivalence relations, bridging the gap between the usual notion of abelian equivalence (when k = 1) and equality (when k = infinity). Given an infinite word w, we consider the associated complexity function which counts the number of k-abelian equivalence classes of factors of w of length n. As a whole, these complexity functions have a number of common features: Each gives a characterization of periodicity in the context of bi-infinite words, and each can be used to characterize Sturmian words in the framework of aperiodic one-sided infinite words. Nevertheless, they also exhibit a number of striking differences, the study of which is one of the main topics of our paper
k-delivery traveling salesman problem on tree networks
No full textIn this paper we study the k-delivery traveling salesman problem (TSP)on trees, a variant of the non-preemptive capacitated vehicle routing problem with pickups and deliveries. We are given n pickup locations and n delivery locations on trees, with exactly one item at each pickup location. The k-delivery TSP is to find a minimum length tour by a vehicle of finite capacity k to pick up and deliver exactly one item to each delivery location. We show that an optimal solution for the k-delivery TSP on paths can be found that allows succinct representations of the routes. By exploring the symmetry inherent in the k-delivery TSP, we design a 5/3-approximation algorithm for the k-delivery TSP on trees of arbitrary heights. The ratio can be improved to (3/2 - 1/2k) for the problem on trees of height 2. The developed algorithms are based on the following observation: under certain conditions, it makes sense for a non-empty vehicle to turn around and pick up additional loads
Tun hu: (du mu ju ji).
No full text復工之前 -- 母女們 -- 囤戶.吳天著.Drama.Wu Tian zhu.Fu gong zhi qian -- Mu nü men -- Tun hu
O Projeto ético-político na produção de conhecimentos do serviço social: uma análise no hospital universitário - HU
No full textTCC (graduação) - Universidade Federal de Santa Catarina, Centro Sócio Econômico, Curso de Serviço Social.O presente Trabalho de Conclusão de Curso tem como objeto de estudo investigar se as produções dos TCCs do Serviço Social do HU estão em conformidade com o projeto éticopolítico profissional e os fundamentos do SUS. Para a realização do trabalho utilizou-se a pesquisa bibliográfica, com o objetivo de coletar dados e analisar o conteúdo, visando conhecer o que a produção dos acadêmicos/pesquisadores reflete em relação ao projeto éticopolítico profissional e ao SUS. Foi feito um levantamento de todos os TCCs em Serviço Social realizados no HU, posteriormente estes trabalhos foram sistematizados por período, setor de atuação do Serviço Social no HU e por temas. Definiu-se como amostra de pesquisa os TCCs elaborados na Maternidade do HU. Estes abordavam os temas: Auxílio Natalidade, gravidez de alto risco, aborto por anencefalia, planejamento familiar, projeto de extensão # organizações da sociedade civil e prematuridade, descritos no presente trabalho. Por fim, fezse uma análise destes temas em relação a quais elementos do projeto ético-político estavam presentes nos TCC
Feimer László hadihíd-építő és a "K"-híd
No full textThis study focuses on the histroy of the “K” bridge and László Feimer military bridge designer\u27s activity. The author outlines László Feimer’s biography and the using of the “K” bridge in the World War II.This study focuses on the histroy of the “K” bridge and László Feimer military bridge designer\u27s activity. The author outlines László Feimer’s biography and the using of the “K” bridge in the World War II
Flow dynamics on a U shaped channel flow: a numerical study
No full textThe paper deals with the numerical simulation of river channel flows at laboratory scale. The adopted geometry
consists of a U shaped trapezoidal smooth open channel with fixed slope. The branches, 3m of length each, are linked with a joint, 0.40m long, realizing two 90 degrees bends. The system is fed upstream with a water discharge under critical conditions while a Cipolletti weir is set downstream to control flow profiles.
Steady flow movements are obtained by means of two different softwares: a pure Lagrangian developed by the author, based on the Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) technique and Flow3D®, a commercial CFD software based on a Finite Volume formulation of the Navier Stokes equations in the Eulerian framework. Depending on the assumed boundary conditions, velocity profiles and water interfaces at certain cross sections are deducted by using the codes. Results are discussed and compared, showing a satisfactory agreement
HU Protein Induces Incoherent DNA Persistence Length
No full textHU is a highly conserved protein that is believed to play an important role in the architecture and dynamic compaction of bacterial DNA. Its ability to control DNA bending is crucial for functions such as transcription and replication. The effects of HU on the DNA structure have been studied so far mainly by single molecule methods that require us to apply stretching forces on the DNA and therefore may perturb the DNA-protein interaction. To overcome this hurdle, we study the effect of HU on the DNA structure without applying external forces by using an improved tethered particle motion method. By combining the results with DNA curvature analysis from atomic force microscopy measurements we find that the DNA consists of two different curvature distributions and the measured persistence length is determined by their interplay. As a result, the effective persistence length adopts a bimodal property that depends primarily on the HU concentration. The results can be explained according to a recently suggested model that distinguishes single protein binding from cooperative protein binding.Imaging Science and TechnologyApplied Science
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