28,601 research outputs found
Non-abelian vector backgrounds with restored Lorentz invariance
The influence of vector backgrounds with restored Lorentz invariance on
non-abelian gauge field theories is studied. Lorentz invariance is ensured by
taking the average over a Lorentz invariant ensemble of background vectors.
Like in the abelian case [hep-ph/0506210], the propagation of fermions is
suppressed over long distances. Contrary to the fermionic sector, pure gauge
configurations of the background suppress the long-distance propagation of the
bosons only partially, i.e. not beyond the leading contribution for a large
number of colours.Comment: 6 pages, no figure
Odors: from chemical structures to gaseous plumes
We are immersed within an odorous sea of chemical currents that we parse into individual odors with complex structures. Odors have been posited as determined by the structural relation between the molecules that compose the chemical compounds and their interactions with the receptor site. But, naturally occurring smells are parsed from gaseous odor plumes. To give a comprehensive account of the nature of odors the chemosciences must account for these large distributed entities as well. We offer a focused review of what is known about the perception of odor plumes for olfactory navigation and tracking, which we then connect to what is known about the role odorants play as properties of the plume in determining odor identity with respect to odor quality. We end by motivating our central claim that more research needs to be conducted on the role that odorants play within the odor plume in determining odor identity
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Substrate-Specific Inhibition Constants for Phospholipase A2 Acting on Unique Phospholipid Substrates in Mixed Micelles and Membranes Using Lipidomics.
Assaying lipolytic enzymes is extremely challenging because they act on water-insoluble lipid substrates, which are normally components of micelles, vesicles, and cellular membranes. We extended a new lipidomics-based liquid chromatographic-mass spectrometric assay for phospholipases A2 to perform inhibition analysis using a variety of commercially available synthetic and natural phospholipids as substrates. Potent and selective inhibitors of three recombinant human enzymes, including cytosolic, calcium-independent, and secreted phospholipases A2 were used to establish and validate this assay. This is a novel use of dose-response curves with a mixture of phospholipid substrates, not previously feasible using traditional radioactive assays. The new application of lipidomics to developing assays for lipolytic enzymes revolutionizes in vitro testing for the discovery of potent and selective inhibitors using mixtures of membranelike substrates
Relationship Between Physical Conditioning and Plasma High Density Lipoprotein-Cholesterol Concentration
Five subjects (three females and two males) took part in an exercise regimen in order to determine if aerobic exercise results in an increase in high-density lipoprotein-cholesterol levels (HDL-C) in the plasma. The exercise regimen consisted of running three miles a day, five days per week for six months. Running speed was at such a pace that the subjects attained a minimum of 60% of their maximal heart rate reserve (MHRR). Before the training program began the following parameters were measured in all of the subjects: height, weight, percent body fat, maximal oxygen consumption (Vâ‚’â‚‚ max), vital capacity, resting heart rate, resting blood pressure, HDL-C, plasma triglycerides (TG), and plasma cholesterol (TC). These same measurements were retaken every two months and at the conclusion of the study. The exercise protocol produced significant changes in Vâ‚’â‚‚ max and resting heart rate. None of the other parameters were significantly changed. The results of this study have shown that aerobic exercise does not cause significant changes in HDL-C levels
Gamma-soft Analog of the Confined Beta-soft Rotor Model
A gamma-soft analog of the confined beta-soft (CBS) rotor model is developed,
by using a gamma-independent displaced infinite well beta-potential in the Bohr
Hamiltonian, for which exact separation of variables is possible. Level schemes
interpolating between the E(5) critical point symmetry (with R(4/2)=E(4)/E(2)=
2.20) and the O(5) gamma-soft rotor (with R(4/2)=2.50) are obtained, exhibiting
a crossover of excited 0+ bandheads which leads to agreement with the general
trends of first excited 0+ states in this region and is observed experimentally
in 128-Xe and 130-Xe.Comment: 10 pages, LaTeX, including 7 eps figure
The Effects of Ultraviolet Light on Anthocyanin Accumulation in the Adventitious Roots of Sedum wrightii (Crassulaceae)
Several studies have supported the idea that anthocyanin accumulation may be a possible protection mechanism in plants against DNA damage caused by ultraviolet radiation (UV). This study explored the accumulation of anthocyanins in the adventitious root tips of Sedum wrightii using the following treatments: UVA, UVA+low UVB, and UVA+high UVB. Following exposure to UV radiation, samples were analyzed for anthocyanin accumulation using an ethanol extraction procedure. Using ELISA, additional root samples were analyzed for indicators of DNA damage: cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone dimers (6-4 PPs). The anthocyanin concentrations were significantly higher in the UVA + high UVB treatment than the other groups. The ELISA resultsshowed that a difference occurred between the control and the treatments of UVA, UVA+low UVB and UVA+high UVB for CPDs and between the control and the UVB treatments for 6-4 PPs. Anthocyanins accumulated with increased UV exposure. However, additional research is needed to determine the significance of anthocyanins in the adventitious root tips of S. wrightii
Pengaruh Audit Operasional dan Sistem Pengendalian Manajemen terhadap Kinerja Karyawan (Survei pada PT Graha Pangan Lestari)
The good employee performance is generated thanks to competent of human resources and good corporate control. In the preparation of this thesis the authors do research in PT GrahaPangan Lestari. The purpose of this study is to know how much influence of operational audit and management control system to the employee performance.The method used in research is descriptive verification method, where the technique used in data collection is done by interview, questionnaire, and library research..From result of research indicate that operational audit influenced equal to 28,9% to the employee performance and management control system affecting 47.5% of the employee performance. Thus it can be concluded that operational audit within the company that has been applied properly can affect the employee performance
Dissipative Effects on Quantum Sticking
Using variational mean-field theory, many-body dissipative effects on the
threshold law for quantum sticking and reflection of neutral and charged
particles are examined. For the case of an ohmic bosonic bath, we study the
effects of the infrared divergence on the probability of sticking and obtain a
non-perturbative expression for the sticking rate. We find that for weak
dissipative coupling , the low energy threshold laws for quantum
sticking are modified by an infrared singularity in the bath. The sticking
probability for a neutral particle with incident energy behaves
asymptotically as ; for a charged
particle, we obtain . Thus, "quantum
mirrors" --surfaces that become perfectly reflective to particles with incident
energies asymptotically approaching zero-- can also exist for charged
particles.Comment: 10 pages, 0 fig
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