726 research outputs found
Swap Operators and Electric Charges of Fermions
Electric Charges operator (ECO) in phase space formulation, proposed by
Zenczykowski, is expressed in terms of a swap operator, in some expressions for
possible physical interpretations. An expression of an ECO in terms of a swap
operator makes sense to the eigenvalues of the swap operator. An ECO including
all the fermions of the standard model (SM) is constructed.Comment: 10 pages, some minor changes and more precision in the conclusion. To
appear in International Journal of Theoretical and Applied Physics (IJTAP
Existence of conformal metrics with constant -curvature
Given a compact four dimensional manifold, we prove existence of conformal
metrics with constant -curvature under generic assumptions. The problem
amounts to solving a fourth-order nonlinear elliptic equation with variational
structure. Since the corresponding Euler functional is in general unbounded
from above and from below, we employ topological methods and minimax schemes,
jointly with a compactness result by the second author.Comment: 36 pages, revised version. To appear in Annals of Mathematic
Comparison between french and portuguese sensory evaluation applied on wool light fabrics
In the frame of bilateral collaboration, the same samples made of wool and dedicated to men suits (light fabrics) have been tested through sensory evaluation panel that has been developed in France (Mulhouse) and Portugal (Guimarães). In this paper, the obtained results have been analyzed, discussed, simulated and differences obtained have been statistically analyzed. It is appeared that for some samples the two panels have highlighted the same marking or the same trends and for others the evaluations have been really different. An analysis, attribute per attribute, have been carried out and it has been shown that some attributes have not been evaluated in the same manner depending on the nationality of the panelists.Fundação para a Ciência e a Tecnologia (FCT
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Ternary erbium chromium sulfides : structural relationships and magnetic properties
Single crystals of four erbium-chromium sulfides have been grown by chemical vapor transport using iodine as the transporting agent. Single-crystal X-ray diffraction reveals that in Er(3)CrS(6) octahedral sites are occupied exclusively by Cr(3+) cations, leading to one-dimensional CrS(4)(5-) chains of edge-sharing octahedra, while in Er(2)CrS(4), Er(3+), and Cr(2+) cations occupy the available octahedral sites in an ordered manner. By contrast, in Er(6)Cr(2)S(11) and Er(4)CrS(7), Er(3+) and Cr(2+) ions are disordered over the octahedral sites. In Er(2)CrS(4), Er(6)Cr(2)S(11), and Er(4)CrS(7), the network of octahedra generates an anionic framework constructed from M(2)S(5) slabs of varying thickness, linked by one-dimensional octahedral chains. This suggests that these three phases belong to a series in which the anionic framework may be described by the general formula [M(2n+1)S(4n+3)](x-), with charge balancing provided by Er(3+) cations located in sites of high-coordination number within one-dimensional channels defined by the framework. Er(4)CrS(7), Er(6)Cr(2)S(11), and Er(2)CrS(4) may thus be considered as the n = 1, 2, and infinity members of this series. While Er(4)CrS(7) is paramagnetic, successive magnetic transitions associated with ordering of the chromium and erbium sub-lattices are observed on cooling Er(3)CrS(6) (T(C)(Cr) = 30 K; T(C)(Er) = 11 K) and Er(2)CrS(4) (T(N)(Cr) = 42 K, T(N)(Er) = 10 K) whereas Er(6)Cr(2)S(11) exhibits ordering of the chromium sub-lattice only (T(N) = 11.4 K)
Direct amplification of nodD from community DNA reveals the genetic diversity of Rhizobium leguminosarum in soil
Sequences of nodD, a gene found only in rhizobia, were amplified from total community DNA isolated from a pasture soil. The polymerase chain reaction (PCR) primers used, Y5 and Y6, match nodD from Rhizobium leguminosarum biovar trifolii, R. leguminosarum biovar viciae and Sinorhizobium meliloti. The PCR product was cloned and yielded 68 clones that were identified by restriction pattern as derived from biovar trifolii [11 restriction fragment length polymorphism (RFLP) types] and 15 clones identified as viciae (seven RFLP types). These identifications were confirmed by sequencing. There were no clones related to S. meliloti nodD. For comparison, 122 strains were isolated from nodules of white clover (Trifolium repens) growing at the field site, and 134 from nodules on trap plants of T. repens inoculated with the soil. The nodule isolates were of four nodD RFLP types, with 77% being of a single type. All four of these patterns were also found among the clones from soil DNA, and the same type was the most abundant, although it made up only 34% of the trifolii-like clones. We conclude that clover selects specific genotypes from the available soil population, and that R. leguminosarum biovar trifolii was approximately five times more abundant than biovar viciae in this pasture soil, whereas S. meliloti was rare
Quiet Eye Duration and Gun Motion in Elite Shotgun Shooting
INTRODUCTION:
No literature exists to document skill-related differences in shotgun shooting and whether these may be a function of eye movements and control of gun motion. We therefore conducted an exploratory investigation of the visual search behaviors and gun barrel kinematics used by elite and subelite shooters across the three shotgun shooting subdisciplines.
METHODS:
Point of gaze and gun barrel kinematics were recorded in groups of elite (n = 24) and subelite (n = 24) shooters participating in skeet, trap, and double trap events. Point of gaze was calculated in relation to the scene, while motion of the gun was captured by two stationary external cameras. Quiet eye (final fixation or tracking gaze that is located on a specific location/object in the visual display for a minimum of 100 ms) duration and onset were analyzed as well as gun motion profiles in the horizontal and vertical planes.
RESULTS:
In skeet, trap, and double trap disciplines, elite shooters demonstrated both an earlier onset and a longer relative duration of quiet eye than their subelite counterparts did. Also, in all three disciplines, quiet eye duration was longer and onset earlier during successful compared with unsuccessful trials for elite and subelite shooters. Kinematic analyses indicated that a slower movement of the gun barrel was used by elite compared with subelite shooters.
CONCLUSIONS:
Overall, stable gun motion and a longer quiet eye duration seem critical to a successful performance in all three shotgun disciplines
A New Species of Extinct Oryzomyine Rodent From the Quaternary of Curaçao, Netherlands Antilles
An extinct new species of Oryzomyine rodent, known since 1936 from the cave of Grot van Hato on the island of Curaçao, is described from abundant new specimens collected from owl-pellet deposits at three localities on the island
Patched receptors sense, interpret and establish an epidermal Hedgehog signalling gradient
By employing the sensitivity of single molecule fluorescent in situ hybridisation (smFISH) we have precisely quantified the levels and defined the temporal and spatial distribution of Hedgehog signalling activity during embryonic skin development, and uncovered that there is a Hedgehog signalling gradient along the proximal-distal axis of developing hair follicles. In order to explore the contribution of Hedgehog receptors Ptch1 and Ptch2 in establishing the epidermal signalling gradient, we quantitated the level of pathway activity generated in Ptch1 and Ptch1;Ptch2-deficient skin and defined the contribution of each receptor to regulation of the levels of Hedgehog signalling identified in wild-type skin. Moreover, we show that both the cellular phenotype and level of pathway activity featured in Ptch1;Ptch2-deficient cells faithfully recapitulates the Peak level of endogenous Hedgehog signalling detected at the base of developing follicles, where the concentration of endogenous Shh is predicted to be highest. Taken together, these data demonstrate that both Ptch1 and Ptch2 play a crucial role in sensing the concentration of Hedgehog ligand and regulating the appropriate dose-dependent response
Crime and gambling disorders: A systematic review
It is generally believed that there is an instrumental relationship between problem gambling and crime such that some gamblers resort to illegal activity to recoup financial shortfalls resulting from their gambling. However, a clear understanding of the risk factors for the commission of crimes beyond financial stresses is absent in the literature. The aim of this review was to identify the nature of crimes perpetrated by problem gamblers and the factors that contribute to the commission of gambling-related crimes. A systematic review adhering to guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement searching eight databases – PsycINFO, Westlaw AU, Heinonline, Legal Source via Ebsco, Legaltrac via Gale, PubMed, Scopus, and Medline – was conducted. A total of 21 papers were included after screening and application of exclusion criteria. All studies examined reported crimes committed by problem gamblers, with a validated assessment tool measuring problem gambling. The review provided evidence that gambling-related crime typically consists of non-violent, income-generating offences. However, it also revealed that problem gamblers may commit violent crimes at a higher than expected rate, which may have been concealed by deliberate and unintentional under-reporting of gambling-related crimes. The causal relationship between problem gambling and violent crime, however, remains uncertain. Based on this review, suggestions are offered for the evaluation of perpetrators of gambling-related crime on a case-by-case basis, to better understand the relationship between gambling and crime and facilitate more frequent application of therapeutic jurisprudence in future.This work was supported by funding provided by the School of Psychology, Science Faculty, the University of Sydney. This work was supported by an Australian Research Council Discovery Early Career Research Award [DE1060100459] awarded to Dr. Sally Gainsbury
Evaluation of the Mixed Effects of Some Indigenous Strains of Arbuscular Mycorrhizal Fungi on the Growth of Maize Seedlings Under Greenhouse Conditions
The objective of the study was to evaluate the joint effects of three groups of native arbuscular mycorrhizal fungi (AMF) (Glomeraceae, Acaulosporaceae and Diversisporaceae) on the growth of Maize Seedlings. The mycorrhizal fungi were isolated by the wet sieving method through decreasing sieve (300 µm, 125 µm, 63 µm and 38 µm) followed by centrifugation on a sucrose gradient. The growth tests were evaluated in greenhouse conditions for 40 days. After opening a planting hole, two maize (2000 SYNEE-W) seeds, one coated with AMF and the other not coated (Control) were introduced into the planting hole for each treatment. Data on different parameters were evaluated. The results of this study revealed that the maximum heights, the largest noose diameters and the largest numbers of leaves were obtained with treatment "Acaulosporaceae + 50% NPK-Urea" having 20.55% and 17.04% respectively and 11.77% for that of the control. The produced biomass and the leaf area of the maize plants were improved by the treatment "Glomeraceae+ 50NPK-Urea" with a respective increase of 54.97% for fresh above biomass (FAB), 42.94% for fresh underground biomass (FUB) and 55.23% for the leaf area compared with the control. Also, very high frequency of mycorrhiza was recorded with treatment "Glomeraceae" while the largest numbers of mycorrhiza spores and intensity were recorded with treatment "Acaulosporaceae". These results augur the possibility of using these mixed AMF bio-products as organic fertilizers to improve maize productivity in Benin
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