673 research outputs found
Experimental rearing of Nile tilapia fry (Oreochromis niloticus) for saltwater culture
Represents a preliminary evaluation of the utility of various approaches of early salinity exposure for saltwater culture of tilapias. Studies the reproductive performance of Nile tilapia under laboratory conditions at various salinities; salinity tolerance of progeny; survivorship of fertilized eggs, spawned in freshwater but removed from the mouth of the parent female and artificially incubated at various salinities.Rearing, Experimental culture, Tilapia culture, Salinity tolerance, Salinity effects Oreochromis niloticus
Salinity tolerance of the tilapias Oreochromis aureus, O. niloticus and an O. mossambicus X O. niloticus hybrid
Studies ontogenetic changes in salinity tolerance in tilapias spawned and reared in freshwater using the indices of median lethal salinity, mean survival time and median survival time. Discusses implications of findings for brackish - and seawater culture of tilapias.Salinity tolerance, Hybrids, Tilapia Oreochromis aureus, Oreochromis niloticus, Oreochromis mossambicus
Understorey plant community and light availability in conifer plantations and natural hardwood forests in Taiwan
Questions: What are the effects of replacing mixed species natural forests with Cryptomeria japonica plantations on understorey plant functional and species diversity? What is the role of the understorey light environment in determining understorey diversity and community in the two types of forest?
Location: Subtropical northeast Taiwan.
Methods: We examined light environments using hemispherical photography, and diversity and composition of understorey plants of a 35âyr C. japonica plantation and an adjacent natural hardwood forest.
Results: Understorey plant species richness was similar in the two forests, but the communities were different; only 18 of the 91 recorded understorey plant species occurred in both forests. Relative abundance of plants among different functional groups differed between the two forests. Relative numbers of shadeâtolerant and shadeâintolerant seedling individuals were also different between the two forest types with only one shadeâintolerant seedling in the plantation compared to 23 seedlings belonging to two species in the natural forest. In the natural forest 11 species of tree seedling were found, while in the plantation only five were found, and the seedling density was only one third of that in the natural forest. Across plots in both forests, understorey plant richness and diversity were negatively correlated with direct sunlight but not indirect sunlight, possibly because direct light plays a more important role in understorey plant growth.
Conclusions: We report lower species and functional diversity and higher light availability in a natural hardwood forest than an adjacent 30âyr C. japonica plantation, possibly due to the increased dominance of shadeâintolerant species associated with higher light availability. To maintain plant diversity, management efforts must be made to prevent localized losses of shadeâadapted understorey plants
CP and T violation in neutrino oscillations
The conditions to induce appreciable CP-and T-odd effects in neutrino
oscillations are discussed. The propagation in matter leads to fake CP-and
CPT-odd asymmetries, besides a Bohm-Aharonov type modification of the
interference pattern. We study the separation of fake and genuine CP violation
by means of energy and distance dependence.Comment: To appear in the Proceedings of TAUP 99 Worksho
Conceitos Atuais No Tratamento Das Ataxias HereditĂĄrias
Hereditary ataxias (HA) represents an extensive group of clinically and genetically heterogeneous neurodegenerative diseases, characterized by progressive ataxia combined with extra-cerebellar and multi-systemic involvements, including peripheral neuropathy, pyramidal signs, movement disorders, seizures, and cognitive dysfunction. There is no effective treatment for HA, and management remains supportive and symptomatic. In this review, we will focus on the symptomatic treatment of the main autosomal recessive ataxias, autosomal dominant ataxias, X-linked cerebellar ataxias and mitochondrial ataxias. We describe management for different clinical symptoms, mechanismbased approaches, rehabilitation therapy, disease modifying therapy, future clinical trials and perspectives, genetic counseling and preimplantation genetic diagnosis. © 2016, Associacao Arquivos de Neuro-Psiquiatria. All rights reserved.74324425
Medium effects for terrestrial and atmospheric neutrino oscillations
Matter effects in neutrino propagation translate into effective parameters
for the oscillation and fake CP- and CPT-odd quantities, even in a scenario,
such as , where no genuine CP violation is present. This fact
seems to impose severe restrictions on the determination of intrinsic
parameters of the system from long-baseline experiments. We show, however, that
the resonance in the effective mixing can be observed for
a certain range of baselines. This provides a way to measure the vacuum mixing
angle and the sign of from atmospheric
neutrinos, using a detector with energy resolution and charge discrimination.Comment: 13 pages with 5 figure
The Oscillation Probability of GeV Solar Neutrinos of All Active Species
In this paper, I address the oscillation probability of O(GeV) neutrinos of
all active flavours produced inside the Sun and detected at the Earth. Flavours
other than electron-type neutrinos may be produced, for example, by the
annihilation of WIMPs which may be trapped inside the Sun. In the GeV energy
regime, matter effects are important both for the ``1-3'' system and the
``1-2'' system, and for different neutrino mass hierarchies. A numerical scan
of the multidimensional three-flavour parameter space is performed,
``inspired'' by the current experimental situation. One important result is
that, in the three-flavour oscillation case, P{alpha,beta} is different from
P{beta,alpha} for a significant portion of the parameter space, even if there
is no CP-violating phase in the MNS matrix. Furthermore, P{mu,mu} has a
significantly different behaviour from P{tau,tau}, which may affect
expectations for the number of events detected at large neutrino telescopes.Comment: 38 pages, 10 figure
Matter effects and CP violating neutrino oscillations with non-decoupling heavy neutrinos
The evolution equation for active and sterile neutrinos propagating in
general anisotropic or polarized background environment is found and solved for
a special case when heavy neutrinos do not decouple, resulting in non-unitary
mixing among light neutrino states. Then new CP violating neutrino oscillation
effects appear. In contrast to the standard unitary neutrino oscillations these
effects can be visible even for two flavour neutrino transitions and even if
one of the elements of the neutrino mixing matrix is equal to zero. They do not
necessarily vanish with and they are different for various
pairs of flavour neutrino transitions (), (), (). Neutrino oscillations in vacuum and Earth's
matter are calculated for some fixed baseline experiments and a comparison
between unitary and non-unitary oscillations are presented. It is shown, taking
into account the present experimental constraints, that heavy neutrino states
can affect CP and T asymmetries. This is especially true in the case of
oscillations.Comment: 18 pages, 6 fig
SN1987A and the Status of Oscillation Solutions to the Solar Neutrino Problem (including an appendix discussing the NC and day/night data from SNO)
We study neutrino oscillations and the level-crossing probability PLZ in
power-law potential profiles A(r)\propto r^n. We give local and global
adiabaticity conditions valid for all mixing angles theta and discuss different
representations for PLZ. For the 1/r^3 profile typical of supernova envelopes
we compare our analytical to numerical results and to earlier approximations
used in the literature. We then perform a combined likelihood analysis of the
observed SN1987A neutrino signal and of the latest solar neutrino data,
including the recent SNO CC measurement. We find that, unless all relevant
supernova parameters (released binding energy, \bar\nu_e and \bar\nu_{\mu,\tau}
temperatures) are near their lowest values found in simulations, the status of
large mixing type solutions deteriorates considerably compared to fits using
only solar data. This is sufficient to rule out the vacuum-type solutions for
most reasonable choices of astrophysics parameters. The LOW solution may still
be acceptable, but becomes worse than the SMA-MSW solution which may, in some
cases, be the best combined solution. On the other hand the LMA-MSW solution
can easily survive as the best overall solution, although its size is generally
reduced when compared to fits to the solar data only.Comment: 31 pages, 32 eps figures; 5 pages, 5 eps figures addendum in v2,
discussing the recent SNO NC data and changes in SN paramete
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