552 research outputs found
Bounded Arithmetic in Free Logic
One of the central open questions in bounded arithmetic is whether Buss'
hierarchy of theories of bounded arithmetic collapses or not. In this paper, we
reformulate Buss' theories using free logic and conjecture that such theories
are easier to handle. To show this, we first prove that Buss' theories prove
consistencies of induction-free fragments of our theories whose formulae have
bounded complexity. Next, we prove that although our theories are based on an
apparently weaker logic, we can interpret theories in Buss' hierarchy by our
theories using a simple translation. Finally, we investigate finitistic G\"odel
sentences in our systems in the hope of proving that a theory in a lower level
of Buss' hierarchy cannot prove consistency of induction-free fragments of our
theories whose formulae have higher complexity
Maladie vésiculeuse du Porc
Guerche J., Delagneau J. F., Adamowicz Ph., Durand Maurice P., Prunet Patrick. Maladie vésiculeuse du porc. In: Bulletin de l'Académie Vétérinaire de France tome 126 n°9, 1973. pp. 385-388
Measuring price elasticities of demand and supply of water entitlements based on stated and revealed preference data
Estimates of price elasticities of water entitlements, known as permanent water or water rights in the United States, are complicated by data limitations and problems of endogeneity. To overcome these issues, we develop an approach to generate stated preference data and combine them with revealed preference data to estimate price elasticities from various types of water entitlement sales in the southern Murray-Darling Basin, Australia. Our results suggest that price elasticities of demand and supply of high security water entitlements are inelastic in the relevant market price range between AUD 2,100 per mega-liter, and that supply is relatively more inelastic than demand. For lower reliability water entitlements, the price elasticity of demand is estimated to be even more inelastic than high security water entitlements. The price elasticity of supply for general security water entitlements is similar to high security water entitlements, while the supply of low reliability water entitlements is extremely inelastic for our data set. The comparison between the stated and revealed preference data provides strong evidence of support for a data fusion approach, nevertheless, some differences in water sale preferences were found for irrigators choosing not to sell all of their water. The consistency of our results signals support for the use of this methodology in other water basins around the world.Alec Zuo, Sarah Ann Wheeler, W.L. (Vic) Adamowicz, Peter C. Boxall and Darla Hatton-MacDonal
Quantum Monte Carlo calculations of the one-body density matrix and excitation energies of silicon
Quantum Monte Carlo (QMC) techniques are used to calculate the one-body
density matrix and excitation energies for the valence electrons of bulk
silicon. The one-body density matrix and energies are obtained from a
Slater-Jastrow wave function with a determinant of local density approximation
(LDA) orbitals. The QMC density matrix evaluated in a basis of LDA orbitals is
strongly diagonally dominant. The natural orbitals obtained by diagonalizing
the QMC density matrix resemble the LDA orbitals very closely. Replacing the
determinant of LDA orbitals in the wave function by a determinant of natural
orbitals makes no significant difference to the quality of the wave function's
nodal surface, leaving the diffusion Monte Carlo energy unchanged. The Extended
Koopmans' Theorem for correlated wave functions is used to calculate excitation
energies for silicon, which are in reasonable agreement with the available
experimental data. A diagonal approximation to the theorem, evaluated in the
basis of LDA orbitals, works quite well for both the quasihole and
quasielectron states. We have found that this approximation has an advantageous
scaling with system size, allowing more efficient studies of larger systems.Comment: 13 pages, 4 figures. To appear in Phys. Rev.
Two novel C-terminal frameshift mutations in the β-globin gene lead to rapid mRNA decay
BACKGROUND:
The thalassemia syndromes are classified according to the globin chain or chains whose production is affected. β-thalassemias are caused by point mutations or, more rarely, deletions or insertions of a few nucleotides in the β-globin gene or its immediate flanking sequences. These mutations interfere with the gene function either at the transcriptional, translational or posttranslational level.
METHODS:
Two cases of Polish patients with hereditary hemolytic anemia suspected of thalassemia were studied. DNA sequencing and mRNA quantification were performed. Stable human cell lines which express wild-type HBB and mutated versions were used to verify that detected mutation are responsible for mRNA degradation.
RESULTS:
We identified two different frameshift mutations positioned in the third exon of HBB. Both patients harboring these mutations present the clinical phenotype of thalassemia intermedia and showed dominant pattern of inheritance. In both cases the mutations do not generate premature stop codon. Instead, slightly longer protein with unnatural C-terminus could be produced. Interestingly, although detected mutations are not expected to induce NMD, the mutant version of mRNA is not detectable. Restoring of the open reading frame brought back the RNA to that of the wild-type level.
CONCLUSION:
Our results show that a lack of natural stop codon due to the frameshift in exon 3 of β-globin gene causes rapid degradation of its mRNA and indicate existence of novel surveillance pathway
Preferences and skills of Indian public sector teachers
With a sample of 700 future public sector primary teachers in India, a Discrete Choice Experiment is used to measure job preferences, particularly regarding location. General skills are also tested. Urban origin teachers and women are more averse to remote locations than rural origin teachers and men respectively. Women would require a 26-73 percent increase in salary for moving to a remote location. The results suggest that existing caste and gender quotas can be detrimental for hiring skilled teachers willing to work in remote locations. The most preferred location is home, which supports decentralised hiring, although this could compromise skills
Sustainable Forest Management Preferences of Interest Groups in Three Regions with Different Levels of Industrial Forestry: An Exploratory Attribute-Based Choice Experiment
The challenge of sustainable forest management is to integrate diverse and sometimes conflicting management objectives. In order to achieve this goal, we need a better understanding of the aspects influencing the preferences of diverse groups and how these groups make trade-offs between different attributes of SFM. We compare the SFM preferences of interest groups in regions with different forest use histories based on the reasoning that the condition of the forest reflects the forest use history of the area. The condition of the forest also shapes an individual’s forest values and attitudes. These held values and attitudes are thought to influence SFM preferences. We tested whether the SFM preferences vary amongst the different interest groups within and across regions. We collected data from 252 persons using a choice experiment approach, where participants chose multiple times among different options described by a combination of attributes that are assigned different levels. The novelty of our approach was the use of choice experiments in the assessment of regional preference differences. Given the complexity of interregional comparison and the small sample size, this was an exploratory study based on a purposive rather than random sample. Nevertheless, our results suggest that the aggregation of preferences of all individuals within a region does not reveal all information necessary for forest management planning since opposing viewpoints could cancel each other out and lead to an interpretation that does not reflect possibly polarised views. Although based on a small\ud
sample size, the preferences of interest groups within a region are generally statistically significantly different from each other; however preferences of interest groups across regions are also significantly different. This illustrates the potential importance of assessing heterogeneity by region and by group
Non-Born-Oppenheimer calculations of the lowest vibrational energy of HD including relativistic corrections
In this work we report variational calculations of the two lowest vibrational states of the HD molecule within
the framework that does not assume the Born-Oppenheimer BO approximation. The nonrelativistic energies
of the states were corrected for the relativistic effects of the order of 2 where = 1
c , calculated as expectation
values of the operators representing these effects with the nonrelativistic non-BO wave functions. The non-BO
wave functions were expanded in terms of the one-center explicitly correlated Gaussian functions multiplied by
even powers of the internuclear distance. The v=0→1 transition energy obtained in the calculations is compared
with the previous calculations, as well as with the transition frequency obtained from the experimental
spectra. The comparison shows the need to include corrections higher than second order in to further
improve the agreement between the theory and the experimen
Activity profiles of elite wheelchair rugby players during competition
To quantify the activity profiles of elite wheelchair rugby and establish classification-specific arbitrary speed zones. Additionally, indicators of fatigue during full matches were explored. Methods: Seventy-five elite wheelchair rugby players from eleven national teams were monitored using a radio-frequency based, indoor tracking system across two international tournaments. Players who participated in complete quarters (n = 75) and full matches (n = 25) were included and grouped by their International Wheelchair Rugby Federation functional classification: group I (0-0.5), II (1.0-1.5), III (2.0-2.5) and IV (3.0-3.5). Results: During a typical quarter, significant increases in total distance (m), relative distance (m·minˉ¹), and mean speed (m·sˉ¹) were associated with an increase in classification group (P < 0.001), with the exception of group III and IV. However, group IV players achieved significantly higher peak speeds (3.82 ± 0.31 m·sˉ¹) than groups I (2.99 ± 0.28 m·sˉ¹), II (3.44 ± 0.26 m·sˉ¹) and III (3.67 ± 0.32 m·sˉ¹). Groups I and II differed significantly in match intensity during very low/low speed zones and the number of high-intensity activities in comparison with groups III and IV (P < 0.001). Full match analysis revealed that activity profiles did not differ significantly between quarters. Conclusions: Notable differences in the volume of activity were displayed across the functional classification groups. However, the specific on-court requirements of defensive (I and II) and offensive (III and IV) match roles appeared to influence the intensity of match activities and consequently training prescription should be structured accordingly
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