11,401 research outputs found
Marriage record of Vina, Manuel F. and Bath, Lizzie M.
No full textMarriage license for Manuel F. Vina and Lizzie M. Bath. L.J. Tehuler was the officiant
The particulate methane monooxygenase from Methylococcus capsulatus (Bath)
No full textThe isolation procedure for the pMMO complex has been optimised to obtain a high
specific activity enzyme from Methylococcus capsulatus (Bath). The enzyme is
comprised of the pMMO hydroxylase (pMMOH) consisting of polypeptides 47,26 and
23kDa molecular mass. In addition to this, a putative pMMO reductase (pMMOR) was
also found to be necessary to maintain propylene oxidising activity. This component
was found to consist of two polypeptides of approximately 63 and 8kDa. Preliminary Nterminal
sequence data of the large subunit ofpMMOR indicates that the sequence bears
70% similarity to the methanol dehydrogenase (MDH) from Methylococcus capsulatus
(Bath). Therefore, we tentatively propose that the" MDH can act as a reductase
component to the pMMOH.
The significance of this result prompted investigations into the previous published
proposals that electrons derived from the methanol oxidation reaction can be channelled
back into the methane oxidation reaction by the methanol dehydrogenase, independent
of NADH. Any effect of methanol to act as a reductant to pMMO in membrane
preparations was lost upon isolation of the pMMO complex, indicating the necessity to
maintain a fully functional methanol dehydrogenase (MDH) upon isolation. In addition
to this, the in vitro electron donors of pMMO, NADH and duroquinol were found to act
via distinct pathways of electron transfer (electron transport inhibitor studies).
Electron paramagnetic resonance (EPR) spectroscopy data provided evidence that the
copper in the active site of pMMO existed as a mononuclear copper (II) centre not a
trinuclear copper centre suggested by Chan and coworkers (Chan et al., 1993; Nguyen et
al., 1994, 1996a, 1996b, 1998). In addition to this preliminary data also indicates the
presence of an iron centre which is only EPR visible after reduction of the complex
suggesting the majority of iron in the complex is EPR invisible. The exact nature of this
iron centre is still unclear.
A structural study of the pMMO complex has also been undertaken using electron
microscopy studies in conjunction with single particle analysis. This allowed low
resolution projection maps of different views of the pMMO complex to be generated.
The complex appears to exist in a polymeric state of at least a dimer, possibly a tetramer
if the molecular weight analysis calculated by sedimentation equilibrium analysis is
taken into account.
This study has provided some insight into basic characteristics and the structure of a
duroquinol-driven pMMO complex and its interaction with other electron transfer
proteins
Bath-applied PDF and sNPF induce cAMP increases in the IPCs.
No full textLive optical imaging in flies expressing a cAMP sensor in their IPCs (dilp2(p)>Epac1camps). Average inverse FRET traces (CFP/YFP) in IPCs reflecting intracellular changes in cAMP levels. Substances were bath-applied to freshly dissected fly brains at 100 s (indicated by black arrow). Application of 10−5 M adenylate cyclase activator NKH477 (NKH, dark gray) induced a robust increase in cAMP, indicating that the general procedure was working. As a negative control, hemolymph-like saline (HL3) was applied. (A) Bath-applied PDF (10−5 M) evokes cAMP increases in the IPCs (light blue), suggesting a possible functional connection between PDF+ cells and IPCs. Similar increase was observed when PDF was applied in the presence of 2μM sodium channel blocker tetrodotoxin (TTX; dark blue), indicating a direct connection. (B) Maximum inverse FRET changes quantified for each individual neuron and averaged for each pharmacological treatment between 100–1000 s. (C) A close-up of the immediate changes in cAMP levels occurring from the application point until 200 s. No significant changes can be observed when PDF or PDF+TTX were applied. (D) Maximum inverse FRET changes from 100–200 s. (E) Bath-applied sNPF (10−5 M) generates cAMP rises in the IPCs (yellow). Similar increase occurs in the presence of TTX (orange), thus suggesting a direct connection. (F) Maximum inverse FRET changes between 100–1000 s. (G) Magnification of the immediate changes between 100–200 s. (H) Maximum inverse FRET changes between 100–200 s. The legend shows the color code of the different treatments and the number of neurons in the dissected brains (in parentheses) considered in this analysis. Data are shown as mean ± SEM. Kruskal-Wallis test followed by Bonferroni-corrected Wilcoxon pairwise-comparisons. ***p<0.001, **p<0.01, *p<0.05, n.s. not significant.</p
Semiclassical Molecular Dynamics for Spectroscopic Calculations of Complex Systems
No full textI will present some novel semiclassical methods for spectroscopic calculations. These approaches can be employed for spectroscopic calculations of gas-phase molecular and supramolecular systems
up to hundreds of degrees of freedom, as well as to condensed phase systems. Some methods are based on a “divide-and-conquer” approach, where the full dimensional spectra are obtained as a
composition of several lower dimensional ones. Others exploit hierarchically the different levels of accuracy of different semiclassical propagators. For instance, in a system-bath problem lower
semiclassical accuracy is dedicated to the bath, while the system is treated with higher accuracy and the system spectrum is eventually singled out.
All methods are amenable for ab initio molecular dynamics simulations.
References
1. F. Gabas, G. Di Liberto, R. Conte, and M. Ceotto, Chemical Science 9 (41), 7885-8026 (2018);
2. X. Ma, G. Di Liberto, R. Conte, W. L. Hase, and M. Ceotto, JCP 149, 164113 (2018)
3. M. Micciarelli, R. Conte, J. Suarez, and M. Ceotto, JCP 149, 064115 (2018);
4. M. Buchholz, F. Grossmann, and M. Ceotto, JCP 148, 114107 (2018);
5. G. Di Liberto, R. Conte, and M. Ceotto, JCP 148, 104302 (2018);
6. G. Di Liberto, R. Conte, and M. Ceotto, JCP 148, 014307 (2018);
7. M. Buchholz, F. Grossmann, and M. Ceotto, JCP 147, 164110 (2017);
8. M. Ceotto, G. Di Liberto, and R. Conte, PRL 119, 010401 (2017);
9. F. Gabas, R. Conte, and M. Ceotto, JCTC 13, 2378-2388 (2017);
10. G. Di Liberto, M. Ceotto, JCP 145, 144107 (2016);
11. M. Buchholz, F. Grossmann, M. Ceotto, JCP 144, 094102 (2016)
Decoherence induced by a sparse bath of two-level fluctuators: peculiar features of noise in high-quality qubits
No full textProgress in fabrication of semiconductor and superconductor qubits has greatly diminished the number of decohering defects, thus decreasing the devastating low-frequency noise and extending the qubits\u27 coherence times (dephasing time and the echo decay time ). However, large qubit-to-qubit variation of the coherence properties remains a problem, making it difficult to produce a large-scale register where all qubits have a uniformly high quality. In this work we show that large variability is a characteristic feature of a qubit dephased by a sparse bath made of many () decohering defects, coupled to the qubit with similar strength. We model the defects as two-level fluctuators (TLFs) whose transition rates are sampled from a log-uniform distribution over an interval , which is a standard model for noise. We investigate decoherence by such a bath in the limit of high-quality qubit, i.e.\ when the TLF density is small (the limit of sparse bath, with , where is the number of TLFs and is the log-width of the distribution). We show that different realizations of the bath produce very similar noise power spectra , but lead to drastically different coherence times and . Thus, the spectral density does not determine coherence of a qubit coupled to a sparse TLF bath, as opposed to a dense bath; instead, decoherence is controlled by only a few exceptional fluctuators, determined by their value of . We show that removing only two of these TLFs greatly increases and times. Our findings help theoretical understanding and further improvements in the coherence properties of semiconductor and superconductor qubits, battling the noise in these platforms.20 pages, 12 figure
Local coherent-state approximation to system-bath quantum dynamics
No full textThe Local Coherent-State Approximation (LCSA)(Martinazzo et al., 2006) has been recently introduced to deal with typical system-bath
dynamical problems where the quantum nature of the system and/or the low temperature of the bath force one to correctly represent
the important system-bath quantum correlations. In the wavefunction description of the zero-temperature case LCSA
introduces a coherent-state description of the local bath states
obtained with the help of a Discrete Variable Representation of
the system state space. This allows one to enormously simplify
the bath dynamics while capturing at the same time an important
part of the system-bath correlations.
In this context, coupled, pseudo-classical equations of motion
for the bath and an effective Schr\ddot{\textrm{o}}dinger
equation for the system have been derived with the help of the
Dirac-Frenkel variational principle, and solved for a number of
model problems, ranging from tunneling to vibrational relaxation
and sticking dynamics. Comparison with exact,
Multi-Configuration-Time-Dependent-Hartree (MCDTH) results has
shown the merits and the limits of the approach(Martinazzo et al., 2006)
. On the one hand, optimal scaling with respect to the number of
bath degrees of freedom, as shown in practice with calculations
using tens of thousands of bath oscillators, is very appealing
for studying realistic problems with very large baths. On the
other hand, numerical stability problems have been preventing
straightforward applications of the method if no additional ad
hoc assumption is made on the bath dynamics.
In this contribution, we summarize the work done up to now on
LCSA, with some emphasis on its connections to the closely
related Gaussian-MCTDH(Burghardt et al., 1999; Worth and Burghardt, 2003)
and Coupled Coherent-State(Shalashilin and Child, 2000; Shalashilin and Child, 2004)
methods. We also present some results of our recent work on the
search of robust propagation schemes, which naturally leads one
to consider the geometrical properties of approximate
quantum-dynamical methods derived from a time-dependent
variational principle
Late Gothic architecture in South West England : four major centres of building activity at Wells, Bristol, Sherbourne and Bath
No full textBy 1360 the Perpendicular style was established as the successor to Decorated
architecture. During the subsequent one hundred and eighty years, until the Reformation,
major building work was carried out at four great churches in the south west of England.
The complete reconstructions of St Mary Redcliffe, Sherborne Abbey and Bath Abbey, and
considerable work to the precinct at Wells Cathedral during this period, form the basis for
this thesis. Through a study of each of these major centres, the issues of workshop identity
and stylistic trendsetters are considered.
It is shown how the interpretation of documentary evidence has impeded an
understanding of these buildings, which can be revealed by an analysis of the fabric. Based
primarily on a methodology of buildings archaeology and assessment of moulding profiles,
traditional assumptions concerning the chronology and patronage are challenged.
The new chronology for works at Sherborne Abbey, and the redating of the
commencement of Bath Abbey further our understanding of the nature of masons'
workshops, patronage and stylistic development within a regional context. Introspection in
masons' workshops during the 15th century, and retrospection in later design in the region,
demonstrates a reliance on the innovations of the 14th century, and the significance of the
parish church tradition in the region, respectively. The thesis concludes with a discussion on
the influence of major church workshops on domestic architecture, and the impact of the
dissemination of the lodges in the early 16th century
The Fordyce Bath House
No full textAn unused postcard of the Fordyce Bath House that is located in Hot Springs, Arkansas.Postcard of the Fordyce Bath House in Hot Springs, Arkansas. "The Fordyce bath house, is built over a group of Hot Springs including the famous Fordyce Spring, (the largest and hottest) from which it secures its water supply. This magnificent establishment is the MOST PRACTICAL, COMPLETE AND LUXURIOUS BATH HOUSE THE WORLD HAS KNOWN.
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