17 research outputs found
Polyphyly of the extinct family Oviparosiphidae and its implications forinferring aphid evolution (Hemiptera, Sternorrhyncha)
Aphidoidea, the so-called "true aphids" are one of the most challenging groups in terms of solving the phylogenetic relationships. Morphology-based analyses were strongly affected by widespread homoplasy, while the molecular-based attempts struggled with the lack of sufficient phylogenetic signal. Despite significant improvements, the higher classification still remains unresolved and rather controversial. However, the use of the fossil record, one of the most valuable sources of information, was mainly limited to calibration of a phylogenetic tree, without a direct inclusion into the analysis. The extinct family Oviparosiphidae has long been considered as the common ancestor of all recent Aphidoidea and it was used as a calibration point in several analyses, but it has been never analyzed in a phylogenetic context. The family has been treated as a monophyletic group purely based on the simultaneous presence of two abdominal structures, ovipositor and siphunculi. However, it has been shown recently that at least one more extinct lineage, present at the same time, was characterized by the same features. For these reasons, we performed a maximum parsimony analysis using morphological data for extinct aphid taxa to prove the monophyly of Oviparosiphidae. Our analysis shows that the presumed ancestor lineage of recent aphids is a polyphyletic group. Our results support the hypothesis of an early Mesozoic rapid radiation of aphids, which led to several different lineages characterized by both ovipositor and siphunculi. The results indicate the necessity of examining the other extinct families, and shows that the diversity of aphids before the Cretaceous Terrestrial Revolution (KTR) was higher than expected. Even though there is not enough data to perform a formal analysis, fossils seem to suggest a significant impact of the KTR on aphid diversification. Additionally, we have made a redescription of two genera and description of a new species, Vitimaphis subridens sp. nov
Revised concept of the fossil genus Oviparosiphum Shaposhnikov, 1979 with the description of a new genus (Hemiptera, Sternorrhyncha,Aphidomorpha)
This paper presents a revision of the aphid genus Oviparosiphum, which is known from the Cretaceous period. Redescriptions of two species: O. jakovlevi Shaposhnikov, 1979 and O. baissense Shaposhnikov & Wegierek, 1989 are made, and an updated diagnosis of this genus is provided. Oviparosiphum baissense is the type species of a newly described genus Archeoviparosiphum gen. n. Five other species of Oviparosiphum are also transferred to the new genus. The basis for their separation from Oviparosiphum is the structure of the siphunculi and ovipositor. A key is provided to the genera of Oviparosiphidae
Influencia de las compensaciones en el Clima Laboral de los trabajadores del Instituto Nicaragüense de Tecnología Agropecuaria (INTA) - Matagalpa, durante el año 2013
El presente documento tiene como objetivo el estudio del clima laboral de las
empresas productivas y de servicio en el municipio de Matagalpa, en el
periodo 2013, con el propósito de identificar, describir y analizar los tipos de
compensaciones los que le permitirán a la empresa conocer posibles
irregularidades presentadas respecto a la temática abordada y así tomar
medidas para mejorar las deficiencias.
La investigación contenida presenta información valiosa de forma analítica y
descriptiva enfocado en la influencia de las compensaciones en el clima
laboral de los trabajadores del Instituto Nicaragüense de Tecnología
Agropecuaria, lo que nos permitirá identificar los procesos utilizados para la
elaboración de la escala salarial, la valuación de puestos, los tipos de
compensaciones financieras y el sistema de compensaciones no financieras.
En el proceso de elaboración de este documento fue necesaria la recolección
de información a través de instrumentos como la entrevista dirigida al director,
administrador y responsable de recursos humanos y encuestas aplicadas al
personal que labora para esta institución con el fin de analizar y darle
repuestas a los objetivos planteados.
El estudio nos demuestra que a pesar que existe una gran fortaleza con
relación a los planes de compensaciones financiera indirecta (bonificaciones y
beneficios sociales) se observa que existe mucha inconformidad con relación
a los salarios, ya que los cargos no se les asignan el valor que realmente se
debería establece
On different types of instabilities in black hole accretion discs. Implications for X-ray binaries and AGN
We discuss two important instability mechanisms that may lead to the
limit-cycle oscillations of the luminosity of the accretion disks around
compact objects: ionization instability and radiation-pressure instability.
Ionization instability is well established as a mechanism of X-ray novae
eruptions in black hole binary systems but its applicability to AGN is still
problematic. Radiation pressure theory has still very weak observational
background in any of these sources. In the present paper we attempt to confront
the parameter space of these instabilities with the observational data. At the
basis of this simple survey of sources properties we argue that the radiation
pressure instability is likely to be present in several Galactic sources with
the Eddington ratios above 0.15, and in AGN with the Eddington ratio above
0.025. Our results favor the parameterization of the viscosity through the
geometrical mean of the radiation and gas pressure both in Galactic sources and
AGN. More examples of the quasi-regular outbursts in the timescales of 100
seconds in Galactic sources, and hundreds of years in AGN are needed to
formulate firm conclusions. We also show that the disk sizes in the X-ray novae
are consistent with the ionization instability. This instability may also
considerably influence the lifetime cycle and overall complexity in the
supermassive black hole environment.Comment: 9 pages, 3 figures, 1 table. Accepted to MNRA
Opieka, pomoc i aktywizacja: Caritas Archidiecezji Krakowskiej wobec potrzeb osób starszych i chorych
Help, care and stimulation: Caritas of the Archdiocese of Krakow for the elderly and sick,The article presents the work of the Caritas of the Archdiocese of Krakow, a catholic charity as well as non-profit organization, for the elderly, chronically ill and disabled. Wide range of these people needs has made help for them the most developed area of activity of Caritas in Krakow which is still seeking new solutions to acknowledged problems. The article describes centers of permanent, temporary and daily care as well as institutions for chronically ill patients, such as care centers and rehabilitation equipment rentals run by Caritas. It also outlines preventive programmes aimed at improving health condition in the elderly. Another issue is voluntary work in parishes for elderly and sick citizens, worth mentioning because of its profile and the fact that for majority of volunteers, who are in advanced age, such activity helps to find their place and function well in society
A new family of aphids (Hemiptera, Sternorrhyncha) from the Lower Cretaceous of Baissa, Transbaikalia
The family Rasnitsynaphididae fam. n. has a unique combination of characters: 9-segmented antennae; rhinaria arranged in many transverse rows, surrounding the antennal segments; segment IX narrower than other segments of flagellum, always without rhinaria; cubitus branches separated; ovipositor present; siphuncular pores absent. The new family comprises the genus Rasnitsynaphis gen. n. with three species, R. ennearticulata sp. n., R. coniuncta sp. n., and R. quadrata sp. n., all from the Lower Cretaceous of Transbaikalia
<i>Vitimaphis subridens</i> sp. nov., line drawings.
<p>A. 3064/5000, holotype, habitus (dorsal view); B. Holotype, secondary rhinaria on III antennal segment; C. Holotype, secondary rhinaria on IV antennal segment. Scale bars in mm.</p
<i>Vitimaphis subridens</i> sp. nov.
<p>A. 3064/5000, holotype, habitus (dorsal view); B. Holotype, head; C. Holotype, fragment of right antenna; D. Holotype, fragment of left antenna. Scale bars in mm.</p