DigitalUM :: Browsing by Subject "Distribution"

Browsing by Subject "Distribution"

Now showing 1 - 20 of 26

Open Access
Aproximación Empírica a la Distribución Estadística de los Ratios Contables
(2001) Andrés Suárez, Javier de
En este trabajo de investigación se determinan cuales son las formas funcionales más adecuadas para la caracterización de la distribución estadística de diversos ratios contables para un conjunto de empresas en un momento determinado del tiempo. Para ello se emplean diversas técnicas de transformación y contraste de normalidad. Los principales resultados indican que la función log-normal se ajusta a la distribución de activo circulante / cifra de negocios, activos líquidos / cifra de negocios, activo circulante / pasivo circulante, y activos líquidos / pasivo circulante. El ratio activos líquidos / total activo puede ser aproximado mediante la curva log-normal o la gamma, y para caracterizar a pasivo exigible / total activo es válida la distribución normal o la gamma, siendo activo circulante / total activo y capital circulante / total activo modelizables solamente a través de la curva normal.
Open Access
Concentration and distribution of macrominerals in tissues of Mediterranean mussel Mytilus galloprovincialis exposed to Cd and Cd-mixtures
(Universidad de Valparaiso (Chile), Facultad de Ciencias del Mar y Recursos Naturales, 2021-12-31) García-Navarro, José A.; Vera-Sánchez, Miguel A.; Romero, Diego; Ciencias Sociosanitarias
Marine ecosystems are under great pressure due to heavy metals pollution, and mussels remain an important knowledge source in this regard. In this study, Mediterranean mussels (Mytilus galloprovincialis) were exposed for 7 days to Cd and three Cd mixtures (Cd+Pb, Cd+Cu and Cd+Pb+Cu). The accumulation and tissue distribution of inorganic elements (Ca, K, Mg, Na, P and S, macrominerals) that are usually not taken into consideration in field studies on in bioassays were evaluated. Regarding concentration, the element which differed the most with respect to the control group was K, while Mg was the only one which showed no significant statistical difference with the control group. The group exposed to ternary mixture was the one in which there were more alterations in concentration and distribution of these macrominerals with respect to control, whereas in the group exposed to single Cd no significant differences in the concentration of these inorganic elements were found. The concentration and distribution of macrominerals in the compartments studied (digestive gland, gill and remaining soft tissues) is susceptible to the presence of Cd and heavy metal Cd-mixtures, with percentages of changes until 28.7%. Study results suggest that macrominerals composition in mussel tissues could be useful in studies of heavy metal contamination in marine ecosystems.
Open Access
Density assessment and reporting for Phlebotomus perniciosus and other sand fy species in periurban residential estates in Spain
(2021-09) Muñoz Hernández, Clara; Risueño Iranzo, José; Pérez Cutillas, Pedro; Bernal Gambín, Luis Jesús; Ortiz Sánchez, Juana; Ruiz de Ybáñez Carnero, María del Rocío; Sánchez-López, P.F.; Martínez Carrasco-Pleite, Carlos; Del Río Alonso, Laura; De la Rúa Tarín, Pilar; García Martínez, Juan Diego; Gonzálvez Juan, Moisés; Murcia, Laura; Collantes Alcaraz, Francisco; Goyena Salgado, María Elena; Spitzova, T.; Elshanat, S.; Berriatua Fernández de Larrea, Eduardo; Sanidad Animal
Green periurban residential areas in Mediterranean countries have flourished in the last decades and become foci for leishmaniasis. To remedy the absence of information on vector ecology in these environments, we examined phlebotomine sand fly distribution in 29 sites in Murcia City over a 3-year period, including the plots of 20 detached houses and nine non-urbanized sites nearby. We collected 5,066 specimens from five species using "sticky" interception and light attraction traps. The relative frequency of the main Leishmania infantum vector Phlebotomus perniciosus in these traps was 32% and 63%, respectively. Sand fly density was widely variable spatially and temporally and greatest in non-urbanized sites, particularly in caves and abandoned buildings close to domestic animal holdings. Phlebotomus perniciosus density in house plots was positively correlated with those in non-urbanized sites, greatest in larger properties with extensive vegetation and non-permanently lived, but not associated to dog presence or a history of canine leishmaniasis. Within house plots, sand fly density was highest in traps closest to walls. Furthermore, the study provides a guideline for insect density assessment and reporting and is envisioned as a building block towards the development of a pan-European database for robust investigation of environmental determinants of sand fly distribution.
Embargo
Differences in the accumulation and tissue distribution of Pb, Cd, and Cu in Mediterranean mussels (Mytilus galloprovincialis) exposed to single, binary, and ternary metal mixtures
(Springer, 2017-01-12) García-Navarro, José A.; Franco, Lorena; Romero, Diego; Ciencias Sociosanitarias
Heavy metals often accumulate in complex mixtures in the environment and are currently a source of concern in many marine ecosystems. Pb, Cd, and Cu are regarded as priority hazardous metals due to their great persistence, bioaccumulation, and toxicity. The aim of the present study was to investigate the tissue accumulation and distribution of these heavy metals in Mediterranean mussels (Mytilus galloprovincialis) exposed to binary and ternary mixtures of metals as opposed to only single exposures. Heavy metal concentrations in the digestive gland, gills, and the other soft tissues were determined by inductively coupled plasma optical emission spectrometry (ICP-OES), and the distribution of each metal was analyzed according to compartments. The concentrations of Pb, Cd, and Cu increased significantly in the group exposed to the ternary mixture; however, there was no common response pattern to exposure in single and binary mixtures. Above all, the metals concentrated in the digestive gland, although the percentages of each element varied between compartments and varied between tissues according to the treatment.
Open Access
Distribution and microstructure of intrarenal arteries in Bactrian camels (Camelus bactrianus)
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Li, Hui; Cui, Yan; Wang, Yali; Qiu, Haiyu; Afedo, Seth Yaw; Huang, Yufeng; Bai, Xuefeng
Studies and reports focusing on the Bactrian camels’ kidney structure from an anatomical perspective are scanty, therefore, this work aims to systemically investigate the anatomical structure of the kidney and examine the distribution and microstructure of intrarenal arteries. Ten pairs of healthy adult kidneys from male and female Bactrian camels were used in the study. The kidney of Bactrian camel appeared like a broad bean with a smooth surface. Using artery casting, we observed that the renal artery divided into dorsal and ventral branches; the dorsal branch continuously divided into a shorter anterior branch and a longer posterior branch, while the ventral branch directly divided into interlobar arteries. The number of interlobar arteries in the left and right kidneys were slightly different, 14 to 16 in left while 16 in the right kidney. No anastomosis was found between the dorsal and ventral branches or their sub- branches. To further study the microscopic structure, microanatomy and scanning microscope were used. Surprisingly, we observed two other ways afferent arteriole arose apart from the interlobular artery. They were the arcuate artery and conjoint afferent arteriole. Two afferent arterioles supplied one glomerulus and occasionally the absence of glomerulus was also observed, where the arteriole kept extending, and no typical glomerulus formed. Since branching of arteries and urologic function of kidneys are physiologically integrated, these features of Bactrian camel may help to further investigate their adaptations to desert climate.
Open Access
Epidemiological and genetic studies suggest a common Leishmania infantum transmission cycle in wildlife, dogs and humans associated to vector abundance in southeast Spain
(SAGE Publications, 2018-05-22) Risueño, J.; Ortuño, M.; Pérez Cutillas, Pedro; Goyena Salgado, María Elena; Maia, C.; Cortes, S.; Campino, L.; Bernal, L. J.; Muñoz, C.; Arcenillas, I.; Martínez-Rondán, F.J.; Gonzálvez, M.; Collantes, F.; Ortiz Sánchez, Juana; Martínez-Carrasco, C.; Berriatua, E.; Sanidad Animal
Leishmania infantum infection was investigated in 202 wild carnivores, rodents and lagomorphs in Southeast Spain using a real-time PCR (rtPCR) in skin and organ samples, mostly spleen. Lesions compatible with leishmaniosis were not observed in any of the animals. Prevalence defined as the percentage of rtPCR-positive animals was 32% overall, and 45% in foxes (n = 69), 30% in rabbits (n = 80) and stone martens (n = 10), 19% in wood mice (n = 16), 0% in black rats (n = 10) and ranged between 0% and 100% in other minoritarian species including badgers, wild cats, wolves, raccoons, genets and hares. Most infected rabbits were rtPCR-positive in skin and not in spleen samples and the opposite was the case for foxes (p < 0.05). L. infantum prevalence was lowest in spring following months of non-exposure to phlebotomine sand fly vectors, and spatially matched recently estimated Phlebotomus perniciosus vector abundance and the prevalence of subclinical infection in dogs and humans. Prevalence increased with altitude and was greater in drier and less windy South and West compared to the coastal Southeast of the study area (p < 0.05). Genetic diversity of L. infantum from foxes, investigated by PCR-restriction fragment length polymorphisms of kinetoplast DNA, revealed B genotype in all animals, which is frequent in people and dogs in the Iberian Peninsula and Morocco. The study provides further evidence that subclinical L. infantum infection is widespread in wildlife with prevalence depending on environmental factors and that parasite tissue tropism may vary according to host species. Moreover, it suggests that sylvatic and domestic transmission cycles are closely interconnected.
Open Access
High prevalence and intensity of Stephanurus dentatus in a population of wild boar (Sus scrofa) in south western Spain
(Elsevier, 2018) Moratal, Samantha; Ruiz de Ybáñez Carnero, María del Rocío; Barroso, Patricia; Granados, José Enrique; Höfle, Úrsula; Martínez Carrasco-Pleite, Carlos; Acevedo, Pelayo; Vicente, Joaquín; Sanidad Animal
In the period from October 2016 to February 2017, the urinary tracts of 390 wild boar (Sus scrofa) from four areas of south central Spain (102 from Doñana National Park; 150 from Sierra Morena and the Toledo Mountains; 84 from Sierra Nevada; 54 from Sierra de Cazorla, Segura y Las Villas Natural Park) were examined for the presence of adult specimens of Stephanurus dentatus (Nematoda: Strongyloidea). This parasite was only detected in the wild boar population of Doñana National Park, with high prevalence (76.5 ± 4.2%; 78/102), mean intensity (43.2 ± 4.4) and mean abundance (33.1 ± 3.8). Juvenile wild boar had significantly lower prevalence and abundance than subadult and adult wild boar. The intensity of infestation was significantly higher in male than in female wild boar. The detection of a focus of S. dentatus infestation in the wild boar population in Doñana National Park will provide further opportunities for understanding the epidemiology of this parasite.
Embargo
Hymenostylium chapadense M.J.Cano & J.A.Jiménez (Pottiaceae), a new species from Brazil and its phylogenetic position based on molecular data
(Taylor and Francis Group, 2022-03-18) Cano, María J.; Jiménez, Juan A.; Martínez, Mónica; Guerra, Juan; Biología Vegetal
In the context of a taxonomic revision of the tribe Pleuroweisieae in South America, we studied a specimen of Hymenostylium that did not match any previously known species of this genus in America. Here we present our arguments for recognising this moss as a new species.The morphology of the potential new species was compared with that of the species of Hymenostylium presently recognised. A phylogenetic analysis based on the nuclear ITS and plastid rps4 regions was performed to investigate relationships between the new species and closely related taxa. Based on morphological and molecular data, we describe this new species from Brazil, Hymenostylium chapadense M.J.Cano & J.A.Jiménez. The species is strikingly distinguished by a stem with central strand and hyalodermis, oblong-ligulate to oblong-elliptical leaves that are when dry slightly crisped in the upper part and usually constricted just above the base and recurved on one side in the lower third, with uni- to bistratose margins, obtuse apex, costa wide and ending below the apex or percurrent with ventral and dorsal surface cells of the costa differentiated as an epidermis, and middle laminal cells usually with a simple, coarse, central papilla. Our molecular study placed H. chapadense as sister to H. hildebrandtii (Müll.Hal.) R.H.Zander. Possible confusion with the latter species and other closely related taxa is discussed. A key to the South American species of Hymenostylium is provided.
Embargo
Investigations of Phlebotomus perniciosus sand flies in rural Spain reveal strongly aggregated and gender-specific spatial distributions and advocate use of light-attraction traps
(Wiley, Royal Entomological Society, 2017-11-07) Muñoz, C.; Risueño, J.; Yilmaz, A.; Pérez Cutillas, Pedro; Goyena Salgado, María Elena; Ortuño, M.; Bernal, L. J.; Ortiz Sánchez, Juana; Alten, B.; Berriatua, E.; Sanidad Animal
The spatial and temporal distribution of Phlebotomus perniciosus (Diptera: Psychodidae) (Newstead, 1911), the sand fly vector of pathogens of public and animal health importance, was investigated in a high sand fly density rural area in Spain using light-attraction and sticky-interception traps. Traps were placed inside animal buildings and outside at increasing distance from animals. A total of 8506 sand flies were collected, 87% with light traps. Species frequency differed between trap types. The abundance of P. perniciosus decreased exponentially with increasing distance to animals and, while females were most common in the animal enclosure, males predominated in adjoining storage places. Increasing CO2 concentration had an additional positive effect on female abundance only. Both male and female density increased with rising temperature, and there was some indication that females were more active than males at higher relative humidity. The study confirms that P. perniciosus aggregates around animal premises, although male and female distributions differ and should be analysed separately to account for biological and behavioural differences. This provides further evidence that light traps offer an accurate estimation of the relative spatial and temporal abundance of P. perniciosus, conferring an added value for the study of this species and the risk of pathogen transmission.
Open Access
New bryological data for the Balearic Islands. III.
(Universidad de Murcia. Servicio de Publicaciones, 2021) Sáez, Llorenç; Pinya, Samuel; Lara, Francisco
Se aportan datos corológicos para 27 briófitos de las Islas Baleares. La mayoría de las citas de esta contribución corresponden a especies relativamente raras de áreas montañosas de las Islas Baleares (principalmente de Mallorca), para las cuales, la información sobre su distribución en el archipiélago es escasa y poco actualizada. Se cita por primera vez la presencia en el archipiélago balear de Hypnum resupinatum, Lewinskya fastigiata y Ptychostomum kunzei. Por otro lado, Epipterygium tozeri constituye novedad para Mallorca. Son destacables las nuevas localidades en Mallorca de Plagiochasma appendiculatum, una especie amenazada en Europa.
Open Access
New chorological data on Hedwigia striata (Bruch & Schimp.) Bosw., (Hedwigiaceae, Musci) in Spain, and remarks on its morphological characters
(Servicios de Publicaciones Universidad de Murcia, 2014) Gallego Morales, María Teresa; Cano Bernabé, María Jesús; Guerra Montes, Juan
Hedwigia striata (Bruch & Schimp.) Bosw., a neglected species known in Spain only from a single and old collection of the early 20th century in Cáceres, is newly reported from Ávila, Burgos, Ciudad Real, La Coruña, León, Lugo, Orense, Salamanca, Teruel and Zamora. With these new localities, its distribution range in the Iberian Peninsula it expanded, since it was recorded mainly from Portugal. Diagnostic characters and differentiation from closely related European taxa are discussed. The species is illustrated.
Open Access
Novedades corológicas para la flora briofítica ibérica. X
(Universidad de Murcia. Servicio de publicaciones, 2024) Cano, María Jesús; Guerra, Juan; Mellado Díaz, Andrés; Jiménez, Juan Antonio
A partir del estudio de muestras recolectadas en los últimos años y revisión de especímenes de herbario, se aportan un total de 23 novedades corológicas provinciales para España. Hyophila involuta, una especie conocida únicamente de una localidad ibérica en el valle de Baztán en Navarra, se cita aquí de cinco nuevas localidades, siendo novedad para Cantabria y País Vasco. Destaca también el hallazgo de Didymodon desertorum que es novedad para Castilla y León, Cataluña y Galicia. Se aporta, además, una nueva localidad para Scopelophila cataractae especie catalogada como vulnerable en España.
Open Access
Nuevo registro de Thorectes valencianus Baraud, 1966 (Coleoptera: Geotrupidae) para el sudeste iberolevantino (España)
(Murcia: Servicio de Publicaciones de la Universidad de Murcia, 2014) Cortés, Elena; Verdú, José Ramón
En este trabajo se aporta una nueva cita para Thorectes valencianus (Coleoptera: Geotrupidae). Este coleóptero es un endemismo iberolevantino catalogado como Vulnerable en la lista roja de la UICN y localizado en la sierra de Escalona (Orihuela, Alicante).
Open Access
Nuevos datos sobre Aegopznella pura (Alder 1830) (Pulmonata: Stylommatophora: Zonztzdae) en la Península Ibérica
(Murcia: Universidad de Murcia, Servicio de Publicaciones, 1992) Altonaga, K.; Facultad de Biología
Bibliographical compilation and its critica1 revision have been canied out. Simultaneously, abundant biological material has been collected and anatomically examined. From these data, the distribution map of Ae.pura in the Iberian Peninsula has been obtained and the geonemy has been suggested: Ae.pura is relatively common in Central Pyrenees and it is found throughout Catalonia, although in few localities. It appears in Basque Mountains, Sierra Demanda, Picos de Urbión and Cantabric Cordillera; its findings are not frequeiit.
Open Access
Nuevos datos sobre cuatro especies de ascidias de la familia Polyclinidae en la Península Ibérica
(Murcia : Universidad de Murcia, Servicio de Publicaciones, 1993) Vázquez, Elsa; Urgorri, Victoriano; Facultad de Biología
Se aportan nuevos datos sobre la distribución de cuatro especies de ascidias en las costas de la Península Ibérica: Aplidium glabrum (Verril, 1871) y Synoicum pulmonaria (Ellis & Solander, 1786) son nuevas citas en la Península Ibérica, Aplidium punctum (Giard, 1873) lo es en las costas españolas y A. asperum (Drasche, 1883) en las costas atlánticas ibéricas. Se describe por primera vez la lawa de A. glabrum y se amplía su límite de distribución meridional hasta nuestras costas. Se discute la sinonimia entre A. asperum y A. coeruleum.
Open Access
Nuevos datos sobre Lygaeus Simulans Deckert, 1985 (Heteroptera Lygaeidae) en la Península Ibérica
(Murcia: Universidad de Murcia, Servicio de Publicaciones, 1991) Costas, M.; Vázquez, M.A.; Facultad de Biología
Se da a conocer la distribución de Lygaeus simulans Deckert,l985 en la Península Ibérica. Se adjuntan claves y figuras para la identificación de esta especie y su afín Lygaeus equestris (Linnaeus,l758).
Open Access
Orthopteroidea del sur de la provincia de Albacete (España).Enszfera. Mantodea. Phasmoptera. Blattoptera. Dermaptera
(Murcia : Universidad de Murcia, Servicio de Publicaciones, 1991) Gómez, R.; Presa Asensio, Juan José; García García, María Dolores; Facultad de Biología
Se han estudiado los Orthopteroidea (Ensifera. Mantodea. Phasrnoptera. Blattoptera. Derrnaptera) del sur de la provincia de Albacete, en base a los ejemplares recolectados en un total de 972 muestras, realizados a lo largo de los años 1988, 1989 y 1990, en 50 estaciones diferentes. Se recolectaron 1.303 individuos adultos pertenecientes a 52 especies. Se aportan datos sobre diferentes aspectos de su biología, tales como distribución espacial, altitudinal, fenología y preferencias en relación con la vegetación. Se aportan los primeros datos sobre la biología de Urornenus (Steropleurus) rnartorelli subsp. angulatus, Urornenus (Steropleurus) politus y Eugryllodes carrascoi
Open Access
Othopteroidea de los sistemas montañosos de Castilla-la Mancha (España). III. Celifera
(Murcia: Universidad de Murcia, Servicio de Publicaciones, 1995) Pardo, J. E.; Gómez, R.; Facultad de Biología
Se han estudiado los Orthopteroidea (Caelifera) de los principales sistemas montañosos de Castilla-La Mancha (España), en base a 10.784 ejemplares adultos y 446 ninfas, pertenecientes a 65 especies, capturados durante los años 1989, 1990 y 1991, en 179 estaciones de muestre0 repartidas por las Sierras de Alcaraz y del Segura, Sierra del Mugrón, Montes de Toledo, Serranía de Cuenca y Macizo de Ayllón. Se aportan datos sobre diferentes aspectos de su biología, tales como distribución superficial, altitudinal, fenología y preferencias en relación con la vegetación.
Embargo
Pseudocrossidium exiguum M.J.Cano & J.A.Jiménez (Pottiaceae), a new species from South America
(Taylor & Francis Group, 2015-03-26) Cano Bernabé, María Jesús; Jiménez, Juan Antonio; Alonso García, Marta; Guerra, Juan; Biología Vegetal
A new species of Pseudocrossidium R.S.Williams, P. exiguum M.J.Cano & J.A.Jiménez, is described from South America (Argentina, Brazil and Peru). The species is distinguished morphologically by its lingulate to oblong-ovate leaves, leaf marginal cells not or scarcely differentiated from inner, costa ending below apex or percurrent, and semicircular to elliptical in cross-section with two guide cells, scarcely differentiated perichaetial leaves and peristome of short and straight teeth. Drawings and light microscope photographs of the new species are provided. The principal distinctive characters that separate it from the nearest species of Pseudocrossidium and related genera are discussed.
Embargo
Pseudosymblepharis perlongifolia (Bryophyta, Pottiaceae), a neglected species from Malaysia new for América
(Magnolia Press, 2014-08-27) Alonso García, Marta; Cano Bernabé, María Jesús; Jiménez, Juan Antonio; Biología Vegetal
The Asian moss Pseudosymblepharis perlongifolia, previously known only from Malaysia, is reported for the first time for America on the basis of several collections from Maricao (Puerto Rico). The principal distinctive characters that separate it from the nearest species of Pseudosymblepharis and related genera are discussed. The species is described and illustrated.