Horizontal gene transfer contributes to plant evolution : the case of Agrobacterium T-DNAs

Horizontal gene transfer (HGT) can be defined as the acquisition of genetic material from another organism without being its offspring. HGT is common in the microbial world including archaea and bacteria, where HGT mechanisms are widely understood and recognized as an important force in evolution. In eukaryotes, HGT now appears to occur more frequently than originally thought. Many studies are currently detecting novel HGT events among distinct lineages using next-generation sequencing. Most examples to date include gene transfers from bacterial donors to recipient organisms including fungi, plants, and animals. In plants, one well-studied example of HGT is the transfer of the tumor-inducing genes (T-DNAs) from some Agrobacterium species into their host plant genomes. Evidence of T-DNAs from Agrobacterium spp. into plant genomes, and their subsequent maintenance in the germline, has been reported in Nicotiana, Linaria and, more recently, in Ipomoea species. The transferred genes do not produce the usual disease phenotype, and appear to have a role in evolution of these plants. In this paper, we review previous reported cases of HGT from Agrobacterium, including the transfer of T-DNA regions from Agrobacterium spp. to the sweetpotato [ Ipomoea batatas (L.) Lam.] genome which is, to date, the sole documented example of a naturally-occurring incidence of HGT from Agrobacterium to a domesticated crop plant. We also discuss the possible evolutionary impact of T-DNA acquisition on plants

La protección de los derechos humanos en el sistema interamericano: su evolución y una visión actual

El presente trabajo analiza desde un punto de vista histórico-jurídico el desarrollo del sistema interamericano de protección de los derechos humanos desde su origen en 1948 hasta la actualidad a través de sus órganos de protección, especialmente el de la Corte Interamericana de Derecho Humanos. Visibiliza los avances tanto en los aspectos sustantivos como procesales. Asimismo, identifica debilidades del sistema y posibles soluciones, para una mayor y mejor protección de las personas de esta región.This paper analyzes from a historical point of view-legal development of the inter-American system for the protection of human rights since its inception in 1948 to the present through their protection bodies, especially the Inter-American Court of Human Rights. Makes visible progress in both substantive and procedural aspects. It also establishes the possible weaknesses in the system and possible solutions for greater and better protection of the people of this region

The horizontal gene transfer of Agrobacterium T-DNAs into the series Batatas (genus Ipomoea) genome is not confined to hexaploid sweetpotato

The discovery of the insertion of IbT-DNA1 and IbT-DNA2 into the cultivated (hexaploid) sweetpotato [Ipomoea batatas (L.) Lam.] genome constitutes a clear example of an ancient event of Horizontal Gene Transfer (HGT). However, it remains unknown whether the acquisition of both IbT-DNAs by the cultivated sweetpotato occurred before or after its speciation. Therefore, this study aims to evaluate the presence of IbT-DNAs in the genomes of sweetpotato's wild relatives belonging to the taxonomic group series Batatas. Both IbT-DNA1 and IbT-DNA2 were found in tetraploid I. batatas (L.) Lam. and had highly similar sequences and at the same locus to those found in the cultivated sweetpotato. Moreover, IbT-DNA1 was also found in I. cordatotriloba and I. tenuissima while IbT-DNA2 was detected in I. trifida. This demonstrates that genome integrated IbT-DNAs are not restricted to the cultivated sweetpotato but are also present in tetraploid I. batatas and other related species

A neglected disease of humans: a new focus of visceral leishmaniasis in Bakool, Somalia.

Visceral leishmaniasis (VL) was observed in children in Bakool region, Somalia, an area where VL has not been reported before. We describe the extent of the problem in this war- and famine-stricken area. A retrospective analysis was done of all cases admitted to a VL treatment centre between July 2000 and August 2001. Patients with longstanding fever, splenomegaly and a positive direct agglutination test (DAT; titre > 1:3200) were treated as suspected VL cases. A rapid epidemiological and entomological assessment was performed in the area. Species identification was attempted from blood samples by polymerase chain reaction-restriction fragment length polymorphism analysis of cysteine proteinase B genes. In 1 year, 230 serologically-positive cases were diagnosed as VL, and response to therapy was good in 91.6% of the 225 treated with sodium stibogluconate. Parasitological confirmation was attempted and obtained in 2 cases. Parasites were found to be most similar to Sudanese and Ethiopian reference strains of the Leishmania donovani complex. In a serological survey of 161 healthy displaced persons, 15% were positive by the leishmanin skin test and 3 (2%) were positive by the DAT. The sandfly captures showed Phlebotomus martini and P. vansomerenae. VL seems to be a longstanding and serious health problem in Bakool region. Food insecurity might have contributed to the emergence and detection of VL in this area

Influence mutual of the deformation and chemical composition on induced precipitation in microalloyed steels

[ES] Mediante ensayos de torsión y usando el método hack extrapolation se ha determinado la cinética de recristalización estática de aceros microaleados con vanadio (V), niobio (Nb) y titanio (Ti) y, a partir de las mismas, ha sido posible dibujar los diagramas recristalizaciónprecipitación- tiempo'temperatura (RPTT), que muestran gráficamente la interacción recristalización-precipitación. Estos diagramas muestran que el efecto de la deformación en la cinética de precipitación depende del contenido de microaleante. En este sentido, se propone una nueva expresión para relacionar la influencia de la deformación y del contenido de microaleante sobre el periodo mínimo de incubación de la precipitación inducida.[EN] By means of torsion tests and applying the "back extrapolation" method, the static recrystallization kinetics in microalloyed steels with vanadium (V), niobium (Nb) and titanium (Ti) has been determined and, recrystallization-precipitation-time-temperature(RPTT) diagrams have been plotted also graphically, which show the Recrystallization-Precipitation interaction. These diagrams show that the effect of the deformation on the precipitation kinetics depends of the microalloy content. In this sense, a new expression is proposed to relate the influence of the deformation and the chemical composition on the minimum incubation of the precipitation kinetics.Peer reviewe

Evolution of Austenite Microstructure and Precipitation State during Hot Rolling of a Nb-Microalloyed Steel

Hot torsion tests were used to simulate hot rolling of a Nb-microalloyed steel. Subsequent graphic representation of Mean Flow Stress (MFS) versus the inverse of absolute temperature for each pass allowed to know the critical rolling temperatures (Tnr Ar3, Ar1,)) and residual stress accumulated in austenite just before austenite to ferrite phase transformation. It has been found that, as successive rolling passes are applied at temperatures below Tnr, mean precipitate size decreases as a result of deformation applied and hardening by incomplete recrystallization of austenite.Peer reviewe

Astrophysical foreground cleanup using non-local means

To create high-fidelity cosmic microwave background maps, current component separation methods rely on availability of information on different foreground components, usually through multi-band frequency coverage of the instrument. Internal linear combination (ILC) methods provide an unbiased estimators for CMB which are easy to implement, but component separation quality crucially depends on the signal to noise ratio of the input maps. In the present paper, we develop an efficient non-linear filter along the lines of non-local means used in digital imaging research which significantly improves signal to noise ratio for astrophysical foreground maps, while having minimal signal attenuation, and evaluate it performance in map and spectral domains. Noise reduction is achieved by averaging ``similar'' pixels in the map. We construct the rotationally-invariant feature vector space and compute the similarity metric on it for the case of non-Gaussian signal contaminated by an additive Gaussian noise. The proposed filter has two tuneable parameters, and with minimal tweaking achieves a factor of two improvement in signal to noise spectral density in Planck dust maps. A particularly desirable feature is that signal loss is extremely small at all scales.Comment: 10 pages, 6 figure

Vulnerability curves for masonry buildings affected by hyperconcentrated flows as natural disaster risk management tools for the quantification of material damage

The damage assessment caused by floods, earthquakes, hurricanes among others phenomenons in the world are analyzed with methodologies such as "Vulnerability curves". In Peru, disasters caused by hyperconcentrated flows are alarming due to a climatic variability such as the "El Nio Costero"phenomenon. Therefore, this research has developed vulnerability curves for 1 and 2-story confined masonry buildings in Urb. San Idelfonso, Ica - Peru; linking the variables: flow depth, associated with the event produced by heavy rains at the top of the "Quebrada Cansas"caused by the "El Nio Costero"phenomenon in 2017, and the percentage of the damage based on the methodology of the United States Army Corps of Engineers (USACE), whose formula is the repair value and total building value. The monetary amounts and items of the buildings are obtained from the RM 415-2017-VIVIENDA of the Ministry of Housing, Construction and Sanitation of Peru. The process consisted of hydrological modeling in HEC-HMS, hydraulic modeling in FLO-2D, damage percentage estimate and vulnerability curves production. Finally, the vulnerability curves for hyperconcentrated flows were contrasted with similar studies regarding curves for flooding and debris flow. The results of the investigation showed that the "El Nio Costero"phenomenon in 2017 had an economic impact of at least 1.3 million soles in Urb. San Idelfonso. In addition, at least 24 buildings had a complete damage and 21 buildings an extensive damage

Characterization by Electron Diffraction of Two Thermodynamical Phases of Precipitation in Nb-Microalloyed Steels

Excellent mechanical properties (high strength and toughness) of microalloyed steels are mainly caused by induced precipitation during thermomechanical treatment (TMT) and grain refinement. It has been recently found that TMT of Nb-microalloyed steels can give rise to two different kinds of precipitates, manifested by the double plateau in the statically recrystallised fraction (Xa) against time curves. This work presents an electron diffraction study performed in a transmission electron microscope, equipped with an EDS analytical system. Lattice parameters of a great deal of particles, smaller than 200 nm and with face cubic centred structure, have been measured. Frequency distribution of the values of lattice parameters shows that these are grouped in two sets whose mean values are close. Comparison of these values with those found in the literature for carbides, nitrides and carbonitrides usually present in microalloyed steels demonstrates that they are Nb carbonitrides with slight stoichiometric differences (NbCxNy).Peer reviewe

Las normas de ius cogens: ausencia de catálogo

En el presente trabajo se abordan las normas imperativas de derecho internacional general (ius cogens) desde sus orígenes y analiza su desarrollo, a lo largo de las más de cuatro décadas desde su positivización en la Convención de Viena sobre el Derecho de los Tratados, a través de la práctica de los Estados, la jurisprudencia internacional y la doctrina. Teniendo en cuenta la inexistencia de un catálogo de estas normas que nos permita identificar con claridad cuáles son, se pretende mostrar los rasgos que las caracterizan, los requisitos necesarios para su consideración como tal. Finalmente mencionar algunas normas cuya existencia y reconocimiento como normas de ius cogens hoy en día son indiscutibles