1,671 research outputs found
Case study the poultry industry in Colombia
"As developing countries open their economies further to trade, their food industries are striving to raise safety and quality standards in order to compete in new markets. Such is the case with the Colombian poultry industry... Critical questions face the Colombian poultry industry: Is it ready to compete with foreign poultry producers on price, quality, and safety? Can industry efforts to produce better quality products assure an increased share of domestic and regional markets? This brief reviews the private initiatives undertaken by the Colombian poultry industry to assure food safety in light of these questions." from TextFood safety ,food security ,Public health ,
Leptonic Charged Higgs Decays in the Zee Model
We consider the version of the Zee model where both Higgs doublets couple to
leptons. Within this framework we study charged Higgs decays. We focus on a
model with minimal number of parameters consistent with experimental neutrino
data. Using constraints from neutrino physics we (i) discuss the reconstruction
of the parameter space of the model using the leptonic decay patterns of both
of the two charged Higgses, , and the decay
of the heavier charged Higgs, ; (ii) show that the
decay rate in general is enhanced in
comparision to the standard two Higgs doublet model while in some regions of
parameter space even dominates over
.Comment: 25 pages, 9 figure
Experimental tests for the Babu-Zee two-loop model of Majorana neutrino masses
The smallness of the observed neutrino masses might have a radiative origin.
Here we revisit a specific two-loop model of neutrino mass, independently
proposed by Babu and Zee. We point out that current constraints from neutrino
data can be used to derive strict lower limits on the branching ratio of
flavour changing charged lepton decays, such as .
Non-observation of Br() at the level of would rule
out singly charged scalar masses smaller than 590 GeV (5.04 TeV) in case of
normal (inverse) neutrino mass hierarchy. Conversely, decay branching ratios of
the non-standard scalars of the model can be fixed by the measured neutrino
angles (and mass scale). Thus, if the scalars of the model are light enough to
be produced at the LHC or ILC, measuring their decay properties would serve as
a direct test of the model as the origin of neutrino masses.Comment: 14 pages, 16 figure
Neutrino masses in with adjoint flavons
We present a supersymmetric model for neutrino masses
and mixings that implements the seesaw mechanism by means of the heavy SU(2)
singlets and triplets states contained in three adjoints of SU(5). We discuss
how Abelian symmetries can naturally yield non-hierarchical light
neutrinos even when the heavy states are strongly hierarchical, and how it can
also ensure that --parity arises as an exact accidental symmetry. By
assigning two flavons that break to the adjoint representation of
SU(5) and assuming universality for all the fundamental couplings, the
coefficients of the effective Yukawa and Majorana mass operators become
calculable in terms of group theoretical quantities. There is a single free
parameter in the model, however, at leading order the structure of the light
neutrinos mass matrix is determined in a parameter independent way.Comment: 16 pages, 9 figures. Included contributions to neutrino masses from
the triplet states contained in the three adjoints of SU(5
6. Green chemistry: Ecotoxicity and biodegradability of ionic liquids
Abstract. Green chemistry plays a very important role in the sustainable development, seeking to reduce and prevent pollution at its source, minimizing the hazard and maximizing the efficiency of the chemical processes. Ionic liquids (ILs) are a new generation of chemicals that have a great potential for contributing to the greenness of chemical processes and developing new applications, both being of interest for the pharmaceutical industry. This work deals with the development of ILs as greener alternatives for some of the processes within the frame of green chemistry. It focuses on the environmental impact of the ILs, their ecotoxicity and potential biodegradability, compiling results of different ecotoxicological studies. ILs have the reputation of being "green" chemicals, but not all of them can pass favourably the tests evaluating their environmental effects
Edad y provenincia de las rocas volcánico sedimentarias de la formación combia en el suroccidente antioqueño colombia
Los estudios petrográficos y de paleocorrientes realizados en la Formación Combia (Mioceno), departamentos de Antioquia y Caldas en Colombia sugieren que ésta se formó a partir flujos volcánicos y volcanicoclásticos que se originaron hacia el oeste y este del actual Valle del RÃo Cauca.Los estudios de trazas de fisión en circones colectados de diferentes horizontes de la Formación Combia arrojan edades Cretácicas, Paleoceno TardÃo EocenoTemprano y Mioceno TardÃo, las cuales han sido interpretadas como el resultadode eventos sintectónicos generados a lo largo del Sistema de Fallas Romeral, en los que se dio el retrabajamiento del basamento cretácico y del Miembro inferior de la Formación Amagá, coetáneamente con los eventos volcánicos, entre 10 y 6 Ma, que dieron origen a la Formación Combia.Dentro de las edades obtenidas se destaca la de 53,4 ± 1,4 Ma en una muestra de ceniza de caÃda que no presenta retrabajamiento alguno. Este resultado sugiere que los sedimentos subyacentes serÃan aún más antiguos y en consecuencia, que el volcanismo tipo Combia pudo haber comenzado en el Paleoceno y no en el Mioceno como ha sido hasta el momento aceptado
Discovery of Phytophthora infestans Genes Expressed in Planta through Mining of cDNA Libraries
BACKGROUND: Phytophthora infestans (Mont.) de Bary causes late blight of potato and tomato, and has a broad host range within the Solanaceae family. Most studies of the Phytophthora--Solanum pathosystem have focused on gene expression in the host and have not analyzed pathogen gene expression in planta. METHODOLOGY/PRINCIPAL FINDINGS: We describe in detail an in silico approach to mine ESTs from inoculated host plants deposited in a database in order to identify particular pathogen sequences associated with disease. We identified candidate effector genes through mining of 22,795 ESTs corresponding to P. infestans cDNA libraries in compatible and incompatible interactions with hosts from the Solanaceae family. CONCLUSIONS/SIGNIFICANCE: We annotated genes of P. infestans expressed in planta associated with late blight using different approaches and assigned putative functions to 373 out of the 501 sequences found in the P. infestans genome draft, including putative secreted proteins, domains associated with pathogenicity and poorly characterized proteins ideal for further experimental studies. Our study provides a methodology for analyzing cDNA libraries and provides an understanding of the plant--oomycete pathosystems that is independent of the host, condition, or type of sample by identifying genes of the pathogen expressed in planta
Latest Cretaceous palaeogeographic evolution of northeast Iberia: Insights from the Campanian continental Montalbán subbasin (Spain)
This work characterizes for the first time the 500–700 m-thick uppermost Cretaceous continental sedimentary succession of the Allueva Fm recorded in the northeastern margin of the Iberian basin, in the Montalbán subbasin (Maestrazgo domain, Spain). The middle-upper Campanian age of this unit constrained here by new paleomagnetic and biostratigraphic data involves major revision of previous stratigraphic and palaeogeographic interpretations. The uplift of the northern marginal areas of the Montalbán subbasin onwards from the middle Campanian supplied the coarse terrigenous-clastic sediments common in the alluvial Allueva Fm. Moreover, a sharp increase of the sedimentation rates (from 4 to 19 cm/ky) from the lower to the middle-upper part of the Allueva Fm has been related to further increase of the tectonic activity during the middle part of the late Campanian. Also relevant are the new discovered vertebrate sites mostly found in the marginal areas of a large lacustrine-palustrine carbonate system developed during the latest Campanian. Vertebrate sites include a fossil assemblage with abundance of titanosaur sauropod dinosaurs as well as the presence of ornithopod dinosaurs and crocodylomorphs. A review of the dinosaur fossil sites recorded in other Iberian subbasins shows a similar fossil assembage occurrence during the late Campanian–earliest Maastrichtian timespan, previous to the faunal turnover that took place in the Ibero-Armorican landmass around the onset of the late Maastrichtian. The stratigraphic, sedimentological and paleontological characterization of the successions recorded during the initial stages of development of the Montalbán subbasin have major implication to understand the latest Cretaceous palaeogeographic evolution of northeast Iberia. Comparative review to other latest Cretaceous continental successions deposited in other domains of the Iberian basin indicates a south to north migration of newly developed subsident subbasins: during the Campanian (South Iberian domain), during the middle-late Campanian (northern Maestrazgo domain), and during the Maastrichtian (central Castillian domain)
Characterization of amino acid substitution W20S in MgrB involved in polymyxin resistance in Klebsiella pneumoniae
In the major human pathogen Klebsiella pneumoniae, MgrB inactivation by disruptive insertion sequence (IS) elements and mutations leading to early termination are known to play an important role in polymyxin resistance. In this study, we examined a collection of invasive blaKPC-2-producing K. pneumoniae isolates belonging to the high-risk clone sequence type 258 (ST258) displaying high rates of resistance to many antimicrobials, including polymyxins. We identified a deleterious substitution (W20S) in MgrB and confirmed by genetic complementation analysis that this variant was inactive, leading to increased polymyxin B and colistin MICs
Implications of Flavor Dynamics for Fermion Triplet Leptogenesis
We analyze the importance of flavor effects in models in which leptogenesis
proceeds via the decay of Majorana electroweak triplets. We find that depending
on the relative strengths of gauge and Yukawa reactions the asymmetry can
be sizably enhanced, exceeding in some cases an order of magnitude level. We
also discuss the impact that such effects can have for TeV-scale triplets
showing that as long as the asymmetry is produced by the dynamics of the
lightest such triplet they are negligible, but open the possibility for
scenarios in which the asymmetry is generated above the TeV scale by heavier
states, possibly surviving the TeV triplet related washouts. We investigate
these cases and show how they can be disentangled at the LHC by using Majorana
triplet collider observables and, in the case of minimal type III see-saw
models even through lepton flavor violation observables.Comment: 22 pages, 9 figures, extended discussion on collider phenomenology,
references added. Version matches publication in JHE
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