710 research outputs found
Finite Element Simulation Methods for Dry Sliding Wear
The Holloman High Speed Test Track is a rocket sled track for testing at hypersonic velocities. However, there are customers that desire to test at even greater velocities. In order to achieve higher velocities there are several phenomena that must be overcome. One important phenomenon is wear of the shoe that holds the sled on the rail. This research is a look at the feasibility of using finite element analysis to predict the wear of the shoe during a test run down the track. Two methods are investigated, one is a macro-scale, incremental method utilizing traditional wear equations from Archard, the other is a micro-scale, material property method that using a failure criteria to determine the amount of wear. These methods are implemented at low velocities to allow for comparison to results from the literature. While the incremental method was found to provide accurate results, there are many numerical problems associated with it. The material property method was found to be feasible, but more research is needed to validate and calibrate the process
Antibacterial peptides of the moth Galleria mellonella
The work describes purification and biochemical characterization of two inducible antimicrobial peptides from the hemolymph of Galleria mellonella. The peptides were isolated by a sequence of reversed-phase chromatography steps from the hemolymph of larvae immunized with viable bacteria. The first peptide is a member of the cecropin family while the second one is rich in proline residues and has a unique sequence
Modular Biometric Monitoring System
A modular system for acquiring biometric data includes a plurality of data acquisition modules configured to sample biometric data from at least one respective input channel at a data acquisition rate. A representation of the sampled biometric data is stored in memory of each of the plurality of data acquisition modules. A central control system is in communication with each of the plurality of data acquisition modules through a bus. The central control system is configured to control communication of data, via the bus, with each of the plurality of data acquisition modules
PCN17 SYSTEMATIC REVIEW OF THE EFFICACY AND SAFETY OF IMIQUIMOD 5% CREAM FOR THE TREATMENT OF SUPERFICIAL BASAL CELL CARCINOMA
Post Activation Potentiation of Back Squat and Trap Bar Deadlift on Acute Sprint Performance
Please refer to the pdf version of the abstract located adjacent to the title
A homology model of restriction endonuclease SfiI in complex with DNA
BACKGROUND: Restriction enzymes (REases) are commercial reagents commonly used in recombinant DNA technologies. They are attractive models for studying protein-DNA interactions and valuable targets for protein engineering. They are, however, extremely divergent: the amino acid sequence of a typical REase usually shows no detectable similarities to any other proteins, with rare exceptions of other REases that recognize identical or very similar sequences. From structural analyses and bioinformatics studies it has been learned that some REases belong to at least four unrelated and structurally distinct superfamilies of nucleases, PD-DxK, PLD, HNH, and GIY-YIG. Hence, they are extremely hard targets for structure prediction and homology-based inference of sequence-function relationships and the great majority of REases remain structurally and evolutionarily unclassified. RESULTS: SfiI is a REase which recognizes the interrupted palindromic sequence 5'GGCCNNNN^NGGCC3' and generates 3 nt long 3' overhangs upon cleavage. SfiI is an archetypal Type IIF enzyme, which functions as a tetramer and cleaves two copies of the recognition site in a concerted manner. Its sequence shows no similarity to other proteins and nothing is known about the localization of its active site or residues important for oligomerization. Using the threading approach for protein fold-recognition, we identified a remote relationship between SfiI and BglI, a dimeric Type IIP restriction enzyme from the PD-DxK superfamily of nucleases, which recognizes the 5'GCCNNNN^NGGC3' sequence and whose structure in complex with the substrate DNA is available. We constructed a homology model of SfiI in complex with its target sequence and used it to predict residues important for dimerization, tetramerization, DNA binding and catalysis. CONCLUSIONS: The bioinformatics analysis suggest that SfiI, a Type IIF enzyme, is more closely related to BglI, an "orthodox" Type IIP restriction enzyme, than to any other REase, including other Type IIF REases with known structures, such as NgoMIV. NgoMIV and BglI belong to two different, very remotely related branches of the PD-DxK superfamily: the α-class (EcoRI-like), and the β-class (EcoRV-like), respectively. Thus, our analysis provides evidence that the ability to tetramerize and cut the two DNA sequences in a concerted manner was developed independently at least two times in the evolution of the PD-DxK superfamily of REases. The model of SfiI will also serve as a convenient platform for further experimental analyses
Ethical problems of palliative care in the period of its evolutionary transformation
Our long-time experience in palliative care
allowed us to notice changes in ethics of palliative
medicine. In the handbook of palliative medicine,
its authors R.G.Twycross and D.Frampton in 1995
did formulate the following ethical postulate:
respect for life, acceptance of death of a patient as
an unavoidable event, respect for a patient as a
person, beneficence, nonmaleficence, justice. In
addition, they stressed prohibition of euthanasia as
a rule. Nine years later, however, in the Oxford
handbook of palliative care, its authors:
M.S.Watson, C.T.Lukas, M.A.Hoy and J.N.Back
described their ethical basis, which were slightly
different but quite similar to those of
T.L.Beauchamp and J.F.Childers: autonomy of a
patient, beneficence, nonmaleficence, justice and
the trust. Their set of principles may induce
controversy because of unlimited patient's
autonomy and absence of physician's autonomy.
Further, it may permit euthanasia, which is
excluded by palliative medicine
Data Acquisition for Modular Biometric Monitoring System
A modular system for acquiring biometric data includes a plurality of data acquisition modules configured to sample biometric data from at least one respective input channel at a data acquisition rate. A representation of the sampled biometric data is stored in memory of each of the plurality of data acquisition modules. A central control system is in communication with each of the plurality of data acquisition modules through a bus. The central control system is configured to collect data asynchronously, via the bus, from the memory of the plurality of data acquisition modules according to a relative fullness of the memory of the plurality of data acquisition modules
Transfer Function Control for Biometric Monitoring System
A modular apparatus for acquiring biometric data may include circuitry operative to receive an input signal indicative of a biometric condition, the circuitry being configured to process the input signal according to a transfer function thereof and to provide a corresponding processed input signal. A controller is configured to provide at least one control signal to the circuitry to programmatically modify the transfer function of the modular system to facilitate acquisition of the biometric data
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