Evaluación de los efectos genotóxicos del herbicida 2,4-D en Piaractus mesopotamicus a través del test de micronúcleos

The herbicide 2,4-D is currently one of the most used agrochemicals in agriculture. The fish are target of contamination, these when being in contact with toxics develop later alterations that can be studied, reason why they are used as models in the evaluation of aquatic ecosystems. There is scarce information about the effects of these pesticides in fish. Because of this, the objective of this work was to evaluate the possible impact of a contamination with 2,4-D, in sub-lethal concentrations in Piaractus mesopotamicus, through the frequency of micronuclei (MN) and alterations in the shape of the nuclei (NMA) in peripheral blood erythrocytes in chronic conditions (70 days). Two trials were conducted, one with the herbicide 2,4-D pure (P) and another with a commercial formulation (2,4-D bitter amine) (FC). Each experience was composed of five aquariums with two specimens in each, where different concentrations of the pesticide were administered (1 ppm, 1.8 ppm, 3.2 ppm, 5.6 ppm and 10 ppm), and in another with well water (control). A total of 4000 cells per individual were analyzed. Through the test MN and NMA the presence of diverse nuclear alterations was evidenced. The mentioned test for P and dilutions 1 ppm, 1.8 ppm, 3.2 ppm, 5.6 ppm of FC did not show significant differences with the control, while the concentration of 10 ppm of FC differed statistically from its control, this could be due to additional components in FC.Los herbicidas están siendo abundantemente utilizados haciendo que los mismos no solo lleguen al organismo específico sino también contaminen el medio ambiente donde son empleados. El herbicida 2,4-D es en la actualidad uno de los agroquímicos más utilizado en la agricultura. Los peces son blanco de la contaminación, éstos al estar en contacto con tóxicos desarrollan posteriormente alteraciones que pueden ser estudiadas, por lo cual son utilizados como modelos en la evaluacion de ecosistemas acuáticos. Existe escasa información acerca de los efectos de estos pesticidas en peces, siendo el actual trabajo el primero en evaluar efectos crónicos. El objetivo de la presente investigación fue evaluar el posible impacto de una contaminación con 2,4-D en concentraciones subletales en Piaractus mesopotamicus, a través de la frecuencia de micronúcleos (MN) y de las alteraciones en la forma de los núcleos (NMA) en eritrocitos de sangre periférica en condiciones crónicas (70 días). Se realizaron dos ensayos, uno con el herbicida 2,4-D puro (P) y otro con una formulación comercial (2,4-D amina Sumargo) (FC). Cada experiencia estuvo compuesta por cinco acuarios con dos ejemplares en cada uno, donde se administraron difererentes concentraciones del plaguicida (1 ppm, 1,8 ppm, 3,2 ppm, 5,6 ppm y 10 ppm), y en otra con agua de pozo (control). Se analizó un total de 4000 células por individuo. A través del test MN y NMA se evidenció la presencia de diversas alteraciones nucleares. El mencionado test para P y las diluciones 1 ppm, 1,8 ppm, 3,2 ppm, 5,6 ppm de FC no mostraron diferencias significativas con el control, mientras que la concentración de 10 ppm de FC se diferenció estadísticamente de su control. El presente trabajo aporta luz de los potenciales efectos nocivos del 2,4-D en el medio ambiente y posibilita nuevos estudios prospectivos y retrospectivos

Probing QCD approach to thermal equilibrium with ultrahigh energy cosmic rays

The Pierre Auger Collaboration has reported an excess in the number of muons of a few tens of percent over expectations computed using extrapolation of hadronic interaction models tuned to accommodate LHC data. Very recently, we proposed an explanation for the muon excess assuming the formation of a deconfined quark matter (fireball) state in central collisions of ultrarelativistic cosmic rays with air nuclei. At the first stage of its evolution the fireball contains gluons as well as $u$ and $d$ quarks. The very high baryochemical potential inhibits gluons from fragmenting into $u \bar u$ and $d \bar d$, and so they fragment predominantly into $s \bar s$ pairs. In the hadronization which follows this leads to the strong suppression of pions and hence photons, but allows heavy hadrons to be emitted carrying away strangeness. In this manner, the extreme imbalance of hadron to photon content provides a way to enhance the muon content of the air shower. In this communication we study theoretical systematics from hadronic interaction models used to describe the cascades of secondary particles produced in the fireball explosion. We study the predictions of one of the leading LHC-tuned models QGSJET II-04 considered in the Auger analysis.Comment: 7 pages LaTeX, 6 .pdf figure

Indistinguishability right from the start in standard quantum mechanics

We discuss a reconstruction of standard quantum mechanics assuming indistinguishability right from the start, by appealing to quasi-set theory. After recalling the fundamental aspects of the construction and introducing some improvements in the original formulation, we extract some conclusions for the interpretation of quantum theory

Debris/ice/TPS assessment and integrated photographic analysis for Shuttle Mission STS-56

The Debris Team developed and implemented measures to control damage from debris in the Shuttle operational environment and to make the control measures a part of routine launch flows. These measures include engineering surveillance during vehicle processing and closeout operations, facility and flight hardware inspections before and after launch, and photographic analysis of mission events. Photographic analyses of mission imagery from launch, on-orbit, and landing provide significant data in verifying proper operation of systems and evaluating anomalies. In addition to the Kennedy Space Center (KSC) Photo/Video Analysis, reports from JSC, MSFC, and Rockwell International--Downey are also included in this document to provide an integrated assessment of the mission

Pressure dependence of Raman modes in double wall carbon nanotubes filled with α-Fe.

The preparation of highly anisotropic one-dimensional (1D) structures confined into carbon nanotubes (CNTs) in general is a key objective in CNTs research. In this work, the capillary effect was used to fill double wall carbon nanotubes with iron. The samples are characterized by Mössbauer and Raman spectroscopy, transmission electron microscopy, scanning area electron diffraction, and magnetization. In order to investigate their structural stability and compare it with that of single wall carbon nanotubes (SWNTs), elucidating the differences induced by the inner-outer tube interaction, unpolarized Raman spectra of tangential modes of double wall carbon nanotubes (DWNTs) filled with 1D nanocrystallin α-Fe excited with 514 nm were studied at room temperature and elevated pressure. Up to 16 GPa we find a pressure coefficient for the internal tube of 4.3 cm−1 GPa−1 and for the external tube of 5.5 cm−1 GPa−1. In addition, the tangential band of the external and internal tubes broadens and decreases in amplitude. All findings lead to the conclusion that the outer tube acts as a protection shield for the inner tubes (at least up 16 GPa). Structural phase transitions were not observed in this range of pressure

Surface functionalization of cuttlefish bone-derived biphasic calcium phosphate scaffolds with polymeric coatings

Cuttlefish bone (CB) has been explored as biomaterial in the bone tissue-engineering field due to its unique porous structure and capacity of the aragonite mineral to be hydrothermally converted into calcium phosphates (CaPs). In the present study, undoped and ion (Sr2+, Mg2+ and/or Zn2+) doped biphasic calcium phosphate (BCP) scaffolds were prepared by hydrothermal transformation (HT, 200 °C, 24 h) of CB. The obtained scaffolds were sintered and then coated with two commercial polymers, poly(ε-caprolactone) (PCL) or poly(DL-lactide) (PDLA), and with two synthesized ones, a poly(ester amide) (PEA) or a poly(ester urea) (PEU) in order to improve their compressive strength. The scaffolds were characterized by X-ray diffraction (XRD) coupled with structural Rietveld refinement, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The results demonstrate that CB could be entirely transformed into BCPs in the presence or absence of doping elements. The initial CB structure was preserved and the polymeric coatings did not jeopardize the interconnected porous structure. Furthermore, the polymeric coatings enhanced the compressive strength of the scaffolds. The in vitro bio-mineralization upon immersing the scaffolds into simulated body fluid (SBF) demonstrated the formation of bone-like apatite surface layers in both uncoated and coated scaffolds. Overall, the produced scaffolds exhibit promising properties for bone tissue engineering applications.publishe

Cymbeline

Quite high count of congestions between scenes, but most of them minimal or minimised

Geoarcheologicalprospection of megalithic structures using Ground Penetrating Radar (Almendralejo, Spain)

In 1980, in Almendralejo, Spain, it was discovered the Tomb of Huerta Montero, a megalithic funerary monument, the best preserved in the Iberian Peninsula, dating from the Chalcolithic (Copper Age, about 4650 BC). According to the opinion of archaeologists, it is quite probable that there are similar buried monuments in the vicinity of the known tomb. This suspicion led to the geophysical study, carried out with the aim of identifying new structures in the vicinity of the necropolis discovered. The choice of geophysical method it was the GPR, because it is a non-invasive technique, accurate and rapid in its implementation. The results obtained allow us to conclude that there may be a structure of circular shape, with a diameter of about 7 m which may to correspond to a funeral monument as there are a few meters, with a temporal thickness ranging between 13 and 21 ns deep. In the northern part of the structure there are two protrusions that may match an entry in the building or even the rest of the tunnel entrance