2,314 research outputs found
La guerre contre les drogues illicites : Est-ce qu’elle est perdue ?
Il sistema legale messicano versa in uno stato disastroso a causa dei cartelli della droga sostenuti e sovvenzionati dagli Stati Uniti d’America. Infatti, gli USA rappresentano il principale mercato della marijuana, della cocaina e delle droghe sintetiche (queste ultime in misura minore) provenienti dal Messico. L’articolo mette in evidenza che le regioni frontaliere del Messico sono prese in ostaggio, da una parte, dai principali produttori modiali di cocaina e, dall’altra, dai principali consumatori (che si trovano nell’America del Nord ed in Europa). Pertanto, secondo l’autrice ed il suo collaboratore, il Messico non può risolvere da solo i suoi problemi derivanti dal narco-traffico
First Results from Viper: Detection of Small-Scale Anisotropy at 40 GHZ
Results of a search for small-scale anisotropy in the cosmic microwave
background (CMB) are presented. Observations were made at the South Pole using
the Viper telescope, with a .26 degree (FWHM) beam and a passband centered at
40 GHz. Anisotropy band-power measurements in bands centered at l = 108, 173,
237, 263, 422 and 589 are reported. Statistically significant anisotropy is
detected in all bands.Comment: 5 pages, 4 figures, uses emulateapj.sty, submitted to ApJ Letter
The bane of juvenile fish catches
Juvenile fishes are defined as immature fishes
that have not yet had the opportunity to
replenish the fish population by spawning.
The length at which 50% of the fishes of any
particular species mature varies among species
and is called its Length at First Maturity (Lm).
When juveniles are caught in large numbers
there is an economic loss as fishermen get
very low prices for the small sized young fish as
compared to the larger adults
Anisotropy in the Cosmic Microwave Background at Degree Angular Scales: Python V Results
Observations of the microwave sky using the Python telescope in its fifth
season of operation at the Amundsen-Scott South Pole Station in Antarctica are
presented. The system consists of a 0.75 m off-axis telescope instrumented with
a HEMT amplifier-based radiometer having continuum sensitivity from 37-45 GHz
in two frequency bands. With a 0.91 deg x 1.02 deg beam the instrument fully
sampled 598 deg^2 of sky, including fields measured during the previous four
seasons of Python observations. Interpreting the observed fluctuations as
anisotropy in the cosmic microwave background, we place constraints on the
angular power spectrum of fluctuations in eight multipole bands up to l ~ 260.
The observed spectrum is consistent with both the COBE experiment and previous
Python results. There is no significant contamination from known foregrounds.
The results show a discernible rise in the angular power spectrum from large (l
~ 40) to small (l ~ 200) angular scales. The shape of the observed power
spectrum is not a simple linear rise but has a sharply increasing slope
starting at l ~ 150.Comment: 5 page
किशोर मछली पकड़ का अभिशाप (The bane of juvenile fish catches)
Juvenile fishes are defined as immature fishes
that have not yet had the opportunity to
replenish the fish population by spawning.
The length at which 50% of the fishes of any
particular species mature varies among species
and is called its Length at First Maturity (Lm).
When juveniles are caught in large numbers
there is an economic loss as fishermen get
very low prices for the small sized young fish as
compared to the larger adults
Ring seine fishery of Kerala: An overview
Among the various fishing gears employed for
pelagic schooling fishes along the Kerala coast,
seines are the most efficient. Contribution of ring
seine to total marine fish landings of Kerala has
steadily increased since its introduction during the
early eighties. It was 21.4 % in the nineties rising to
36.7 % during the period 2000-2004 and contributing
more than 50 % since then. In recent years, about
90 % of the oil sardine and about 60 % of the
mackerel landed in Kerala were caught in ring
seines. Ring seines were introduced during the early
eighties by traditional fishers of Alappuzha District
which became highly successful
Population dynamics of cobia Rachycentron canadum (Linnaeus, 1766) off Cochin coast, south-eastern Arabian Sea
Estimated landings of cobia from the Indian EEZ by the commercial fishing vessels are mostly as bycatch in hooks and line
cum gillnet and trawl nets. However, the catches are substantial compared to that reported in several other countries of Asia.
The species is also gaining considerable importance as a favoured candidate species for sea farming using cages. Very little
is known about the fishery and biological characters such as maturation, fecundity and feeding preferences of cobia in Indian
seas. Study indicated a fast growth rate with estimates of L∞ = 184 cm (FL) and K = 2.6 (yr-1) in cobia. The total mortality rate
(Z) was estimated as 5.18, natural mortality (M) was 2.01 and fishing mortality (F) was 3.17 with an exploitation rate (E) of
0.61. The length at first capture (Lc50) estimated from the catch curve was 72 cm. Fecundity was found to be high and
variable, with mean fecundity estimated as 12,37,545 eggs with a coefficient of variation (CV) of 16.7. As inferred from the
oocyte development pattern, spawning activity is brief and fish is classified as synchronous ovulatory type. The growth
parameters and condition factor estimated in this study indicate that relatively high growth rates are also possible in wild
stocks considering that food is abundant and the environmental temperature is in the optimum range. Feeding
preferences indicated balistid fish and shrimps with a wide variety of food items including finfishes, crustaceans and molluscs
present
Foregrounds in the BOOMERANG-LDB data: a preliminary rms analysis
We present a preliminary analysis of the BOOMERanG LDB maps, focused on
foregrounds. BOOMERanG detects dust emission at moderately low galactic
latitudes () in bands centered at 90, 150, 240, 410 GHz. At higher
Galactic latitudes, we use the BOOMERanG data to set conservative upper limits
on the level of contamination at 90 and 150 GHz. We find that the mean square
signal correlated with the IRAS/DIRBE dust template is less than 3% of the mean
square signal due to CMB anisotropy
Recovering the Inflationary Potential
A procedure is developed for the recovery of the inflationary potential over
the interval that affects astrophysical scales (\approx 1\Mpc - 10^4\Mpc).
The amplitudes of the scalar and tensor metric perturbations and their
power-spectrum indices, which can in principle be inferred from large-angle CBR
anisotropy experiments and other cosmological data, determine the value of the
inflationary potential and its first two derivatives. From these, the
inflationary potential can be reconstructed in a Taylor series and the
consistency of the inflationary hypothesis tested. A number of examples are
presented, and the effect of observational uncertainties is discussed.Comment: 13 pages LaTeX, 6 Figs. available on request, FNAL-Pub-93/182-
Fate of Zinc Oxide Nanoparticles Coated onto Macronutrient Fertilizers in an Alkaline Calcareous Soil
Citation: Milani, N., Hettiarachchi, G. M., Kirby, J. K., Beak, D. G., Stacey, S. P., & McLaughlin, M. J. (2015). Fate of Zinc Oxide Nanoparticles Coated onto Macronutrient Fertilizers in an Alkaline Calcareous Soil. Plos One, 10(5), 16. doi:10.1371/journal.pone.0126275Zinc oxide (ZnO) nanoparticles may provide a more soluble and plant available source of Zn in Zn fertilizers due to their greater reactivity compared to equivalent micron-or millimetresized (bulk) particles. However, the effect of soil on solubility, spatial distribution and speciation of ZnO nanoparticles has not yet been investigated. In this study, we examined the diffusion and solid phase speciation of Zn in an alkaline calcareous soil following application of nanoparticulate and bulk ZnO coated fertilizer products (monoammonium phosphate (MAP) and urea) using laboratory-based x-ray techniques and synchrotron-based mu-x-ray fluorescence (mu-XRF) mapping and absorption fine structure spectroscopy (mu-XAFS). Mapping of the soil-fertilizer reaction zones revealed that most of the applied Zn for all treatments remained on the coated fertilizer granule or close to the point of application after five weeks of incubation in soil. Zinc precipitated mainly as scholzite (CaZn2(PO4)(2)center dot 2H(2)O) and zinc ammonium phosphate (Zn(NH4)PO4) species at the surface of MAP granules. These reactions reduced dissolution and diffusion of Zn from the MAP granules. Although Zn remained as zincite (ZnO) at the surface of urea granules, limited diffusion of Zn from ZnO-coated urea granules was also observed for both bulk and nanoparticulate ZnO treatments. This might be due to either the high pH of urea granules, which reduced solubility of Zn, or aggregation (due to high ionic strength) of released ZnO nanoparticles around the granule/point of application. The relative proportion of Zn(OH)(2) and ZnCO3 species increased for all Zn treatments with increasing distance from coated MAP and urea granules in the calcareous soil. When coated on macronutrient fertilizers, Zn from ZnO nanoparticles (without surface modifiers) was not more mobile or diffusible compared to bulk forms of ZnO. The results also suggest that risk associated with the presence of ZnO NPs in calcareous soils would be the same as bulk sources of ZnO
- …
