3,187 research outputs found
Electromagnetic multipole moments of elementary spin-1/2, 1, and 3/2 particles
We study multipole decompositions of the electromagnetic currents of
spin-1/2, 1, and 3/2 particles described in terms of Lagrangians designed to
reproduce representation specific wave equations which are second order in the
momenta and which emerge within the recently elaborated Poincar\'e covariant
projector method. We calculate the electric multipoles of the above spins for
the spinor, the four-vector, and the four-vector--spinor representations,
attend to the most general non-Lagrangian spin-3/2 currents which are allowed
by Lorentz invariance to be of third order in the momenta and construct the
linear current equivalent of identical multipole moments of one of them. We
conclude that such non-Lagrangian currents are not necessarily more general
than the two-term currents emerging within the covariant projector method. We
compare our results with those of the conventional Proca-, and Rarita-Schwinger
frameworks. Finally, we test the representation dependence of the multipoles by
placing spin-1 and spin-3/2 in the respective (1,0)(0,1), and
(3/2,0)(0,3/2) single-spin representations. We observe representation
independence of the charge monopoles and the magnetic dipoles, in contrast to
the higher multipoles, which turn out to be representation dependent. In
particular, we find the bi-vector to be characterized by an
electric quadrupole moment of opposite sign to the one found in ,
and consequently, to the boson. Our finding points toward the possibility
that the meson could transform as part of an antisymmetric tensor with
an meson-like state as its representation companion.Comment: 27 pages, 2 figure
Exploring the natural history of intrinsic capacity impairments: longitudinal patterns in the 10/66 study
Backgroundintrinsic capacity (IC) is a construct encompassing people’s physical and mental abilities. There is an implicit link amongst IC domains: cognition, locomotion, nutrition, sensory and psychological. However, little is known about the integration of the domains.Objectivesto investigate patterns in the presentation and evolution of IC domain impairments in low-and-middle-income countries and if such patterns were associated with adverse outcomes.Methodssecondary analyses of the first two waves of the 10/66 study (population-based surveys conducted in eight urban and four rural catchment areas in Cuba, Dominican Republic, Puerto Rico, Venezuela, Peru, Mexico and China). We applied latent transition analysis on IC to find latent statuses (latent clusters) of IC domain impairments. We evaluated the longitudinal association of the latent statuses with the risk of frailty, disability and mortality, and tested concurrent and predictive validity.Resultsamongst 14,923 participants included, the four latent statuses were: high IC (43%), low deterioration with impaired locomotion (17%), high deterioration without cognitive impairment (22%), and high deterioration with cognitive impairment (18%). A total of 61% of the participants worsened over time, 35% were stable, and 3% improved to a healthier status.Participants with deteriorated IC had a significantly higher risk of frailty, disability and dementia than people with high IC. There was strong concurrent and predictive validity. (Mortality Hazard Ratio = 4.60, 95%CI 4.16; 5.09; Harrel’s C = 0.73 (95%CI 0.72;0.74)).Conclusionshalf of the study population had high IC at baseline, and most participants followed a worsening trend. Four qualitatively different IC statuses or statuses were characterised by low and high levels of deterioration associated with their risk of disability and frailty. Locomotion and cognition impairments showed other trends than psychological and nutrition domains across the latent statuses
Effect of type of food and culture density on growth and lipid composition of Seriola dumerili juveniles
The aim of this study was to determine the effect of three different types of food and two stocking densities on growth, survival and lipid composition of muscle and liver of Seriola dumerili juveniles. Juvenile of S. dumerili were randomly distributed in groups of 15 fish/tank (low stocking density, LD) and groups of 25 fish/tank (high stocking density, HD) and fed with three different types of food: commercial pellets for Sparidae (SP), commercial pellets for S. dumerili (SE) and frozen Mackerel (MA). Samples of muscle and liver were taken for lipid analysis at the end of trial (86 days).
Fish fed with SP showed growth significantly lower than the groups fed with SE and MA for both stocking densities. Higher survival rates was observed in fish fed diet SE and MA held at LD.
Lipid composition analyses revealed important differences between fish fed with different diets but no difference between groups with different stocking density were detected. Total lipid content in muscle and liver from fish fed with SE was very much higher than in fish fed with SP and MA, which was reflected in higher tryglicerides and lower cholesterol contents.
The fatty acid composition of tissues clearly reflected the composition of the diet supplied. The groups fed with MA presented the highest proportion of docosahexaenoic acid (DHA), arachidonic acid (ARA) and the lower amounts of eicosapentaenoic acid (EPA). In contrast, fish fed with SE presented the lower amounts of ARA and DHA and higher content in 18:2n-6 specifically in the liver. In consequence, fish fed with MA presented a higher DHA/EPA ratio and a lower EPA/AA ratio in both tissues while the opposite was observed in group SE.
These preliminary results indicate that SE diet allows get better performance than SP diet obtaining growth and survival rates comparable to fish fed with MA, although with a higher lipid deposition in tissues
COMBINED EFFECT OF LC-PUFA-RICH LIPIDS AND CAROTENOIDS IN ROTIFERS ENRICHMENT PRODUCTS FOR GREATER AMBERJACK LARVAE
Expression of Novel Opsins and Intrinsic Light Responses in the Mammalian Retinal Ganglion Cell Line RGC-5. Presence of OPN5 in the Rat Retina
The vertebrate retina is known to contain three classes of photoreceptor cells: cones and rods responsible for vision, and intrinsically photoresponsive retinal ganglion cells (RGCs) involved in diverse non-visual functions such as photic entrainment of daily rhythms and pupillary light responses. In this paper we investigated the potential intrinsic photoresponsiveness of the rat RGC line, RGC-5, by testing for the presence of visual and non-visual opsins and assessing expression of the immediate-early gene protein c-Fos and changes in intracellular Ca2+mobilization in response to brief light pulses. Cultured RGC-5 cells express a number of photopigment mRNAs such as retinal G protein coupled receptor (RGR), encephalopsin/panopsin (Opn3), neuropsin (Opn5) and cone opsin (Opn1mw) but not melanopsin (Opn4) or rhodopsin. Opn5 immunoreactivity was observed in RGC-5 cells and in the inner retina of rat, mainly localized in the ganglion cell layer (GCL). Furthermore, white light pulses of different intensities and durations elicited changes both in intracellular Ca2+ levels and in the induction of c-Fos protein in RGC-5 cell cultures. The results demonstrate that RGC-5 cells expressing diverse putative functional photopigments display intrinsic photosensitivity which accounts for the photic induction of c-Fos protein and changes in intracellular Ca2+ mobilization. The presence of Opn5 in the GCL of the rat retina suggests the existence of a novel type of photoreceptor cell
Resultados y perspectivas de la conservación in vitro de recursos fitogenéticos en la región oriental de Cuba
Estimation of Individual Micro Data from Aggregated Open Data
In this paper, we propose a method of estimating individual micro data from
aggregated open data based on semi-supervised learning and conditional
probability. Firstly, the proposed method collects aggregated open data and
support data, which are related to the individual micro data to be estimated.
Then, we perform the locality sensitive hashing (LSH) algorithm to find a
subset of the support data that is similar to the aggregated open data and then
classify them by using the Ensemble classification model, which is learned by
semi-supervised learning. Finally, we use conditional probability to estimate
the individual micro data by finding the most suitable record for the
probability distribution of the individual micro data among the classification
results. To evaluate the performance of the proposed method, we estimated the
individual building data where the fire occurred using the aggregated fire open
data. According to the experimental results, the micro data estimation
performance of the proposed method is 59.41% on average in terms of accuracy.Comment: 7 page
Electromagnetic couplings of elementary vector particles
On the basis of the three fundamental principles of (i) Poincar\'{e} symmetry
of space time, (ii) electromagnetic gauge symmetry, and (iii) unitarity, we
construct an universal Lagrangian for the electromagnetic interactions of
elementary vector particles, i.e., massive spin-1 particles transforming in the
/1/2,1/2) representation space of the Homogeneous Lorentz Group (HLG). We make
the point that the first two symmetries alone do not fix the electromagnetic
couplings uniquely but solely prescribe a general Lagrangian depending on two
free parameters, here denoted by \xi and g. The first one defines the
electric-dipole and the magnetic-quadrupole moments of the vector particle,
while the second determines its magnetic-dipole and electric-quadrupole
moments. In order to fix the parameters one needs an additional physical input
suited for the implementation of the third principle. As such, one chooses
Compton scattering off a vector target and requires the cross section to
respect the unitarity bounds in the high energy limit. In result, we obtain the
universal g=2, and \xi=0 values which completely characterize the
electromagnetic couplings of the considered elementary vector field at tree
level. The nature of this vector particle, Abelian versus non-Abelian, does not
affect this structure. Merely, a partition of the g=2 value into non-Abelian,
g_{na}, and Abelian, g_{a}=2-g_{na}, contributions occurs for non-Abelian
fields with the size of g_{na} being determined by the specific non-Abelian
group appearing in the theory of interest, be it the Standard Model or any
other theory.Comment: 10 pages, 2 figures, contributed to the XI Mexican Workshop on
Particles and Fields. Accepted in Phys. Rev.
FATTY ACID PROFILE OF WILD GREATER AMBERJACK FEMALE GONADS FROM MEDITERRANEAN AND ATLANTIC AREAS
- …