3,487 research outputs found
Phylogenetic analysis reveals an ancient gene duplication as the origin of the MdtABC efflux pump.
The efflux pumps from the Resistance-Nodulation-Division family, RND, are main contributors to intrinsic antibiotic resistance in Gram-negative bacteria. Among this family, the MdtABC pump is unusual by having two inner membrane components. The two components, MdtB and MdtC are homologs, therefore it is evident that the two components arose by gene duplication. In this paper, we describe the results obtained from a phylogenetic analysis of the MdtBC pumps in the context of other RNDs. We show that the individual inner membrane components (MdtB and MdtC) are conserved throughout the Proteobacterial species and that their existence is a result of a single gene duplication. We argue that this gene duplication was an ancient event which occurred before the split of Proteobacteria into Alpha-, Beta- and Gamma- classes. Moreover, we find that the MdtABC pumps and the MexMN pump from Pseudomonas aeruginosa share a close common ancestor, suggesting the MexMN pump arose by another gene duplication event of the original Mdt ancestor. Taken together, these results shed light on the evolution of the RND efflux pumps and demonstrate the ancient origin of the Mdt pumps and suggest that the core bacterial efflux pump repertoires have been generally stable throughout the course of evolution
The Relationship of CSR and Financial Performance: New Evidence From Indonesian Companies
The research objectives of the study are to investigate whether there are any positive
relationships between CFP and CSR under the slack resource theory and to investigate
whether there are any positive relationships between CSR and CFP under good
management theory by integrating concept of strategic management into the definition
of CSR as sustainable corporate performance including economy, social, and
environment. To answer the research questions of this study, questionnaire-based
survey research design was used. The questionnaires that include items representing
variables in this study (corporate social performance, corporate financial performance,
business environment, strategy, organization structure, and control system) were sent to
the respondents who are managers of state-owned companies (BUMN) and private-
owned companies using post and e-mail services. There is a positive relationship
between CFP and CSP under the slack resource theory and under good management
theory.
Keywords: corporate social performance, corporate financial performance, business
environment, strategy, organization structure, and control system, slack resource theory,
good management theor
A new species of the genus Gomphomastax Brunner von Wattenwyl (Orthoptera: Eumastacidae: Gomphomastacinae) from Indian Kashmir
A new species, Gomphomastax nigrovittata Usmani, from Kashmir is described and illustrated. In addition to conventional morphological characters, genitalic structures are also studied. A key to known species of Gomphomastax from Indian Kashmir is given
Trade-off coding for universal qudit cloners motivated by the Unruh effect
A "triple trade-off" capacity region of a noisy quantum channel provides a
more complete description of its capabilities than does a single capacity
formula. However, few full descriptions of a channel's ability have been given
due to the difficult nature of the calculation of such regions---it may demand
an optimization of information-theoretic quantities over an infinite number of
channel uses. This work analyzes the d-dimensional Unruh channel, a noisy
quantum channel which emerges in relativistic quantum information theory. We
show that this channel belongs to the class of quantum channels whose capacity
region requires an optimization over a single channel use, and as such is
tractable. We determine two triple-trade off regions, the quantum dynamic
capacity region and the private dynamic capacity region, of the d-dimensional
Unruh channel. Our results show that the set of achievable rate triples using
this coding strategy is larger than the set achieved using a time-sharing
strategy. Furthermore, we prove that the Unruh channel has a distinct structure
made up of universal qudit cloning channels, thus providing a clear
relationship between this relativistic channel and the process of stimulated
emission present in quantum optical amplifiers.Comment: 26 pages, 4 figures; v2 has minor corrections to Definition 2.
Definition 4 and Remark 5 have been adde
On the probability of finding marked connected components using quantum walks
Finding a marked vertex in a graph can be a complicated task when using
quantum walks. Recent results show that for two or more adjacent marked
vertices search by quantum walk with Grover's coin may have no speed-up over
classical exhaustive search. In this paper, we analyze the probability of
finding a marked vertex for a set of connected components of marked vertices.
We prove two upper bounds on the probability of finding a marked vertex and
sketch further research directions.Comment: 13 pages. To appear at Lobachevskii Journal of Mathematic
Trade-off capacities of the quantum Hadamard channels
Coding theorems in quantum Shannon theory express the ultimate rates at which
a sender can transmit information over a noisy quantum channel. More often than
not, the known formulas expressing these transmission rates are intractable,
requiring an optimization over an infinite number of uses of the channel.
Researchers have rarely found quantum channels with a tractable classical or
quantum capacity, but when such a finding occurs, it demonstrates a complete
understanding of that channel's capabilities for transmitting classical or
quantum information. Here, we show that the three-dimensional capacity region
for entanglement-assisted transmission of classical and quantum information is
tractable for the Hadamard class of channels. Examples of Hadamard channels
include generalized dephasing channels, cloning channels, and the Unruh
channel. The generalized dephasing channels and the cloning channels are
natural processes that occur in quantum systems through the loss of quantum
coherence or stimulated emission, respectively. The Unruh channel is a noisy
process that occurs in relativistic quantum information theory as a result of
the Unruh effect and bears a strong relationship to the cloning channels. We
give exact formulas for the entanglement-assisted classical and quantum
communication capacity regions of these channels. The coding strategy for each
of these examples is superior to a naive time-sharing strategy, and we
introduce a measure to determine this improvement.Comment: 27 pages, 6 figures, some slight refinements and submitted to
Physical Review
Identifying the quantum correlations in light-harvesting complexes
One of the major efforts in the quantum biological program is to subject
biological systems to standard tests or measures of quantumness. These tests
and measures should elucidate if non-trivial quantum effects may be present in
biological systems. Two such measures of quantum correlations are the quantum
discord and the relative entropy of entanglement. Here, we show that the
relative entropy of entanglement admits a simple analytic form when dynamics
and accessible degrees of freedom are restricted to a zero- and
single-excitation subspace. We also simulate and calculate the amount of
quantum discord that is present in the Fenna-Matthews-Olson protein complex
during the transfer of an excitation from a chlorosome antenna to a reaction
center. We find that the single-excitation quantum discord and relative entropy
of entanglement are equal for all of our numerical simulations, but a proof of
their general equality for this setting evades us for now. Also, some of our
simulations demonstrate that the relative entropy of entanglement without the
single-excitation restriction is much lower than the quantum discord. The first
picosecond of dynamics is the relevant timescale for the transfer of the
excitation, according to some sources in the literature. Our simulation results
indicate that quantum correlations contribute a significant fraction of the
total correlation during this first picosecond in many cases, at both cryogenic
and physiological temperature.Comment: 15 pages, 7 figures, significant improvements including (1) an
analytical formula for the single-excitation relative entropy of entanglement
(REE), (2) simulations indicating that the single-excitation REE is equal to
the single-excitation discord, and (3) simulations indicating that the full
REE can be much lower than the single-excitation RE
Perencanaan Syariah
Any individual or any organization definitely requires planning in a variety of activities. Good planning is not based on sharia, or Islamic-based (conventional) basically has a lot in common, in addition to also have many differences. In this article the author intends to explain the concept - the basic concept of sharia perenaaan well as its association with the concept of conventional planning. Thing - the most important thing in this article is a discussion about the basic concepts, principles, vision, mission, the laws, the feasibility and planning stages in sharia Planning sharia is essentially the same as planning in general, the difference principle is the \u27value - value\u27 that surrounded him. Because it takes a lot of socialization and continuing on the planning concept of sharia.DOI: 10.15408/ess.v4i3.243
THEORY OF CULTURAL AND SOCIAL REVOLUTION AS VIEWED BY WALTER GARRISON RUNCIMAN
Ostatnia praca Waltera Garrisona Runcimana The Theory of Cultural and Social Selection stanowi nową próbę zbudowania socjologicznej teorii ewolucji na podstawie neodarwinizmu oraz znacznie wychodzi poza dotychczasowe propozycje: torii podwójnego dziedziczenia oraz memetyki. Jednakże selekcjonizm ¬– paradygmat, który w niej rozwija, ze względu na zastosowanie uproszczonej biologii ewolucyjnej wymaga zredukowania społeczeństwa do prostej populacji jednostek dziedzicznego doboru i podobnej redukcji kultury. Runciman nie połączył przekonująco neodarwinowskiego populacyjnego podejścia ze swoim własnym systemem socjologicznym. Jednym z głównych powodów jego niepowodzenia jest, moim zdaniem, radykalne zerwanie z klasyczną tradycją socjologii.Walter Garrison Runciman’s recent work The Theory of Cultural and Social Selection is a new attempt to create a sociological theory of evolution based on neodarwinism. It is also an important step extending beyond the previous propositions of dual inheritance theory as well as memetics. However, selectionism, a paradigm developed in it by the use of simplified evolutionary biology, requires a reduction of a society to simple population of heritable units of selection and a similar reduction of culture. Runciman has failed to convincingly integrate the neodarwinian populational approach with his own sociological system. One of the main reason for his failure is, in my opinion, his radical break with the classical tradition of sociology
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