1,007 research outputs found
Traditional Knowledge and Potential Use of Stingless Bees (Hymenoptera: Meliponinae) in the Manantlan Sierra, Jalisco, Mexico
Stingless bees (meliponines) play an important role in ecosystems; they pollinate different plant species, assist in the reproduction and conservation of floral biodiversity and their products can be obtained and sold, with the consequent economic benefit for stingless beekeepers. Surveys were conducted to find out how much knowledge inhabitants of two marginalized communities of the Manantlan Sierra in Jalisco, Mexico, have on the use and exploitation of stingless bees. In addition, several stingless bee species of this region were captured and identified, and wild nests of those bees were located and recorded in their natural habitats. Information about the knowledge and culture of stingless bees in the region was analyzed and based on that as well as on the most abundant species captured, those with more potential are suggested for management in a sustainable manner. Unlike other areas of Mexico where meliponiculture is practiced, in Jalisco there is no record of traditional culture of meliponines. However, a certain level of knowledge and a high degree of interest was found among the respondents for engaging in keeping and managing stingless bees, mainly because their management does not involve the risk of stinging incidents. Nine stingless bee species were identified in total. Of these, the most abundant were Scaptotrigona hellwegeri, Trigona fulviventris, Partomona bilineata, Friseomelita nigra and Nannotrigona perilampoides. It is recommended that studies are conducted to develop management practices for these bee species. The implementation of courses on how to keep these meliponines is also recommended, so that in the future, the inhabitants of these communities can benefit from the integral and sustainable use of stingless bees
7-(tert-Butyldiphenylsilyloxy)-2,2-dimethyl-1-benzofuran-3(2H)-one
The title compound, C26H28O3Si, is an allylic oxidation product of the tert-butyl(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)diphenylsilane with N-bromosuccinimide and 2,2′-azobis-isobutyronitrile. The nine-atom bicyclic system is almost planar, with an r.m.s deviation of 0.0123 (2) Å and a maximum deviation of 0.031 (2) Å for the O atom. In the crystal, the molecules pile up along the b axis but the strongest intermolecular contacts are the π–π stacking interactions between the benzene rings along the c axis [centroid–centroid distance = 3.655 (3) Å]
El Eucaliptal, una necrópolis romana de pescadores (Punta Umbría, Huelva)
En 1994 el Área de Arqueología de la Universidad de Huelva realizó una excavación de emergencia en la necrópolis de la factoría de salazones de El Eucaliptal (Punta Umbría, Huelva). En esta factoría ya se había intervenido anteriormente, pero sobre otras áreas funcionales del asentamiento (área de habitación, área industrial). La actuación de 1994 puso al descubierto el sector de necrópolis donde se documentó una amplia secuencia de enterramientos bajoimperiales, formada por tres fases claramente diferenciadas: una primera, correspondiente a inhumaciones e incineraciones en tumbas de tégulas a dos aguas; una segunda integrada por inhumaciones infantiles en ánforas; y finalmente, la más moderna caracterizada por inhumaciones en tumbas de ladrillo y pizarra sin ajuar.____________________________________In 1994 the Area of Archaeology of the University of Huelva carried out an emergency
excavation in the cemetery of the fish-sauce factory of El Eucaliptal (Punta Umbria,
Huelva). In this factory it had already been intervened previously, but on other functional
areas of the establishment (room area, industrial area). The performance of 1994 put to
the overdraft the cemetery sector where a wide sequence of the Late Empire burials was
documented, formed by three dearly differentiated phases: a first one, corresponding to
burials and incinerations in tiles tombs to two waters; a second integrated by infantile
burials in amphorae; and finally, the most modern characterized by burials in brick tombs
and slate without trousseau
Supersymmetric FRW model and the ground state of supergravity
In this work we construct the vacuum configuration of supergravity
interacting with homogeneous complex scalar matter fields. The corresponding
configuration is of the FRW model invariant under the local conformal
time supersymmetry, which is a subgroup of the four dimensional space-time
supersymmetry. We show, that the potential of the scalar matter fields is a
function of the K\"ahler potential and of the arbitrary parameter .
This parameter enumerates the vacuum states. The scalar matter potential
induces the spontaneous breaking of supersymmetry in supergravity. On the
quantum level our model is a specific supersymmetric quantum mechanics, which
admits quantum states in supergravity, and the states with zero energy are
described by the wave function of the FRW universe.Comment: 18 pages, Revtex, submitted to PR
Superevolution
Usually, in supersymmetric theories, it is assumed that the time-evolution of
states is determined by the Hamiltonian, through the Schr\"odinger equation.
Here we explore the superevolution of states in superspace, in which the
supercharges are the principal operators. The superevolution equation is
consistent with the Schr\"odinger equation, but it avoids the usual degeneracy
between bosonic and fermionic states. We discuss superevolution in
supersymmetric quantum mechanics and in a simple supersymmetric field theory.Comment: 23 page
NIKEL_AMC: Readout electronics for the NIKA2 experiment
The New Iram Kid Arrays-2 (NIKA2) instrument has recently been installed at
the IRAM 30 m telescope. NIKA2 is a state-of-art instrument dedicated to
mm-wave astronomy using microwave kinetic inductance detectors (KID) as
sensors. The three arrays installed in the camera, two at 1.25 mm and one at
2.05 mm, feature a total of 3300 KIDs. To instrument these large array of
detectors, a specifically designed electronics, composed of 20 readout boards
and hosted in three microTCA crates, has been developed. The implemented
solution and the achieved performances are presented in this paper. We find
that multiplexing factors of up to 400 detectors per board can be achieved with
homogeneous performance across boards in real observing conditions, and a
factor of more than 3 decrease in volume with respect to previous generations.Comment: 21 pages; 16 figure
La ciudad romana de Turobriga. Un modelo urbano en los Llanos de Aroche (Huelva)
The roman Turobriga, although known by scientists in the middle of 60's, until 1996 no archaeological excavations were conducted therein. As from said year several papers and reports have been issued of diverse field works carried out my members of Area de Arqueología de la Universidad de Huelva. In this paper a synthesis of new evidence is presented regarding historial implications of roman town in the Picos de Aroche territory context, its urban pattern, and special relevance of the evidence obtained in the forum area is giving.Aunque la ciudad romana de Turobriga es conocida en el mundo científico desde mediados de los años setenta, no se había realizado sobre ella ningún tipo de investigación hasta la presencia del Área de Arqueología de la Universidad de Huelva a partir de 1996. Desde entonces se han realizado varias campañas de investigación, de diferente carácter, que han generado varios artículos publicados en Congresos o revistas científicas, así como los preceptivos informes y memorias con los resultados de todas las intervenciones. En este trabajo presentamos una breve síntesis de los avances que se han producido, en especial en lo referente a la significación histórica de Turobriga en el contexto territorial de los Picos de Aroche y en las características de su trama urbana, resaltando especialmente los avances en el área del forum
Las industrias de salazones del litoral onubense : los casos de "El Eucaliptal" (Punta Umbría), y "El Cerro del Trigo" (Doñana, Almonte)
Una de las actividades que mejor definen la economía de época romana en el Golfo de Cádiz es la industria relacionada con la producción y comercialización de salsas de pescado (salazones). Según los testimonios arqueológicos, los orígenes de esta producción se remontan a momentos prerromanos en ámbitos geográficos relacionados con el comercio gaditano. Dado el escaso número de este tipo de instalaciones conocidas en la costa onubense durante el período romano, donde hasta la fecha sólo existían escasas referencias bibliográficas, se presentan en este trabajo los nuevos yacimientos dedicados a la producción de salazones descubiertos en prospecciones y excavaciones por el Área de Arqueología de la Universidad de Huelva, y se hace hincapié en una mayor abundancia de este tipo de instalaciones, que fenómenos geomorfológicos recientes, principalmente los donares, impiden valorar en su verdadera dispersión._____________________________One of the activities which better define the economy of Roman period in the Gulf of
Cadiz is the industry related to the production and marketing sauce of fish (fish-salting).
According to the archaeological testimonies, the origins of this production go back to preroman
moments, in areas related to the Cadiz trade.
In view of the scanty number of this type of facilities know in Huelva coast during
the Roman period, where up to the date only scanty bibliographical references existed,
there appear in this work the new deposits dedicated to the production of saltings discovered in explorations and excavations for the Area of Archaeology of the University of Huelva.
And it is emphisized a bigger abundance of this type of factories, which geomorphological
phenomenon, principally the littoral dunes system, prevent valuing at its real dispersion
Método novedoso para la deposición de óxidos metálicos en aerogeles de carbono con potencial uso en desionización capacitiva de agua salina
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