Manual de Direito do Trabalho
Xavier, Bernardo da Gama Lobo
2011-01-01
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C. acetobutylicum is an anaerobic bacterium that produces
acetic and butyric acids, hydrogen gas, and carbon dioxide
during the exponential phase of growth. When the culture
pH is allowed to remain near 4.5, the metabolism switches
to the production of the neutral compounds (solvents) -
acetone, n-butanol, and ethanol. The two metabolic phases
are known as the acidogenic and solventogenic phases. The
enzyme hydrogenase plays an important role in this
bacterium because it converts excess reducing power into
hydrogen gas to maintain a balance in the
oxidation-reduction state in the cell. During
solventogenesis, additional reducing power is used in the
production of n-butanol and ethanol, which leaves excess
reducing power to be vented as hydrogen gas. There are
conflicting reports about the level of hydrogenase in
acidogenic and solvento...
A new apparatus called Bypass Trapped Flow
Analysis System (ByT-FAS) is described. A properly
designed ByT-FAS gives an analyst the ability to use
analyte sample volumes of 10 to 200 μL [or more]
and reagent volumes of approximately the same size.
The sample and reagent are injected into their
respective carrier streams and attain physical steady
state concentrations in the detection cell within
approximately 15 to 45 seconds after injection. Upon
achievement of simultaneous sample and reagent
physical steady state concentrations, the system flow
is diverted around the detection cell and the reaction
mixture is trapped in the detection cell. The
concentration of the sample and reagent in the
detection cell can be readily computed from
knowledge of the original concentrations of the sample
and reagent and the flow rates of the streams
...
Cataract disease affects millions of people worldwide. It is characterized by the accumulation of light-scattering bodies within the lens that reduce visual acuity. Cataracts are effectively treated surgically, but at great expense, costing Medicare $3.4 billion in 1997. Development of an alternative therapy for this disease would provide medical and economic benefits.
We have investigated a novel antioxidant, the superoxide scavenger Mn(III)-salophen, as a therapeutic agent in the selenite cataract model. Mn(III)-salophen has been shown to protect E. coli colonies against oxidative stress but was untested in a eukaryotic system. A total dose of 300 mmol/kg, given IP in four equal 75 mmol/kg doses spaced four hours apart, protects 75% of neonatal rats from nuclear cataract development five days after selenite injection.
Selenite is tox...
Previous studies revealed that ß-95-Cys provides an
essential ligand to one of the Fe atoms on the P cluster
within the MoFe protein of nitrogenase, and a limited number
of substitutions at this position resulted in
inactive nitrogenase. It was also found that the
counterpart of ß-95-Cys, Alpha-88-Cys, which also
acts as
a cysteinyl ligand to the P cluster, is replaceable
without a complete loss of activity. In order to study
the structure-function relationship of the
protein environment in this region with respect to
the P-cluster, subtle changes were introduced at
ß-95-Cys
in Azotobacter vinelandiinitrogenase through
site-directed
mutagenesis and gene replacement method. Some
crude extracts from the mutants with substitutions at
ß-95-Cys contain typical FeMo cofactor EPR signal.
The ß-95Asp ...
This experiment attempts to measure the Michel parameter Rho in normal muon decay Mu to e nu_{e} nu_{mu} with a precision of 0.001. The Standard Model with pure V-A interaction gives 0.75 for this parameter. The world average value is 0.7518 +/- 0.0026. A deviation of the value of Rho from 0.75 will indicate new physics.
The experiment, RHO, was carried out at the Los Alamos Meson Physics Facility (LAMPF) of Los Alamos National Laboratory (LANL) in New Mexico, USA, in 1993. The existing experimental set-up that was built for the MEGA experiment was used for the RHO measurement. The experiment was a collaboration of about 50 physicists from Los Alamos National Laboratory, Stanford University, Fermi National Accelerator Laboratory, Virginia Tech, Texas A University, Indiana University, Valparaiso University, University of Houston, Univer...
Though modifications and improvements continue
on the Virginia Polytechnic Institute electrostatic
accelerator, the basic machine has been completed and
put into operation. The emphasis thus far has been on
experiments at energies below 750 kev and no attempt has
been made to determine the maximum operating potential.
This work describes the author's contributions to the overall project through the design and construction
of many of the electronic control and instrumentation circuits. Through a study of the inelastic collisions
of protons with fluorinet, a resolution of 9:1 key was
determined.
Aedes aegypti is an important vector of the viruses that cause dengue fever, dengue hemorrhagic fever, and yellow fever. In depth genetic studies of vector species have been made possible due to the availability of genome sequences and techniques for producing stably transformed mosquitoes. These resources have also contributed to the establishment of new genetics-based approaches to the control of vector borne disease.
Genetic studies of Ae. aegypti have benefited from the ability to drive targeted transgene expression, however a ubiquitous inducible promoter has not been identified in this mosquito. The Drosophila melanogaster heat shock 70 promoter has been shown to drive inducible expression in heterologous systems; however, DmHsp70 possesses significant basal activity in Aedes aegypti.
This study characterized the sequence and exp...
Cognitive Radio (CR) capitalizes advances in signal processing and radio technology and is capable of reconfiguring RF and switching to desired frequency bands. It is a frequency-agile data communication device that is vastly more powerful than existing multi-channel multi-radio (MC-MR) technology.
In this thesis, we investigate the important problem of multi-hop networking with CR nodes. In a CR network, each node has a set of frequency bands (not necessarily of equal size) that may not be the same as those at other nodes. The uneven size of frequency bands prompts the need of further division into sub-bands for optimal spectrum sharing. We characterize behaviors and constraints for such multi-hop CR network from multiple layers, including modeling of spectrum sharing and sub-band division, scheduling and interference constraints, and...
The proliferation of web based technologies has resulted in new forms of communities and organizations with enormous implications for design of learning and education. This thesis explores learning occurring within open source software (OSS) communities. OSS communities are a dominant form of organizing in software development with implications not only for innovative product development but also for the training of a large number of software developers. The central catalyst of learning within these communities is expert-novice interactions. These interactions between experts and novices or newcomers are critical for the growth and sustenance of a community and therefore it is imperative that experts are able to provide newcomers requisite advice and support as they traverse the community and develop software.
Although prior literature...
Closed-loop performance of an active noise reduction (ANR) headset is limited by phase lag. Speaker dynamics, control hardware, and acoustic wave propagation from the control speaker to the error microphone all contribute to this phase lag. Understanding these sources of phase lag and their relative effects on performance allows for better design of an analog or digital ANR headset.
This thesis demonstrates that the three most significant sources of phase lag in a digital ANR headset are the dynamics of the control speaker's diaphragm, the anti-aliasing filter, and the smoothing filter. Additionally, it is demonstrated that the acoustic wave propagation from the control speaker to the error microphone is not a major contributor of phase lag. Based on these results, it was determined that attention should be focused on the anti-alia...
