1,010 research outputs found
Natural groundwater quality and health
Natural groundwater composition and quality is of concern because it is used worldwide as a freshwater supply. Discarding artificial pollution, epidemiological studies have shown that many communities suffer important diseases linked to the groundwater ingested since several tens of years ago. As the available resources of freshwater decrease due to pollution and overexploitation, and the need of water increases, more efforts have to be devoted to guarantee water quality. Of course preventing pollution is the main task but studying and controlling the natural groundwater quality is also very important, mainly in developing countries. To study the relationship between natural groundwater composition and health implies working in many scientific disciplines such as hydrology, geology, geochemistry and toxicology. During its cycle, water acquires its natural composition depending on the hydrogeological scenario, which, in turn, depends on the climate, topography and rock properties (hydraulic properties, chemical composition). Nearly all natural waters contain traces of most chemical elements but often at extremely low concentrations. Major species invariably make up over 99% of the solute content. Major compounds as well as trace elements can be essential, toxic, potentially toxic and potentially beneficial. Special attention has to be paid to chemical elements present in many natural waters whose insufficient or excess intake produces critical illness and whose intake is mainly through the ingestion of water. A first approach to groundwater quality can be made using element concentrations in water but many efforts have to be devoted to perform epidemiological and risk assessment studies based on intake doses of chemical species
Hubble Ultraviolet Spectroscopy of Jupiter Trojans
We present the first ultraviolet spectra of Jupiter Trojans. These
observations were carried out using the Space Telescope Imaging Spectrograph on
the Hubble Space Telescope and cover the wavelength range 200-550 nm at low
resolution. The targets include objects from both of the Trojan color
subpopulations (less-red and red). We do not observe any discernible absorption
features in these spectra. Comparisons of the averaged UV spectra of less-red
and red targets show that the subpopulations are spectrally distinct in the UV.
Less-red objects display a steep UV slope and a rollover at around 450 nm to a
shallower visible slope, whereas red objects show the opposite trend.
Laboratory spectra of irradiated ices with and without HS exhibit
distinct UV absorption features; consequently, the featureless spectra observed
here suggest HS alone is not responsible for the observed color
bimodality of Trojans, as has been previously hypothesized. We propose some
possible explanations for the observed UV-visible spectra, including complex
organics, space weathering of iron-bearing silicates, and masked features due
to previous cometary activity.Comment: 7 pages, 4 figures, accepted by A
A new species of Entomobrya from Iraq (Collembola, Entomobryidae)
The systematic study of Entomobrya specimens from different museums in the Palaearctic region
and material obtained from other collections allowed some new species of the genus to be revealed.
Entomobrya iraqensis n. sp. is described from Mosul, Iraq. For the identification and description of the
species, the set of characters proposed by Jordana and Baquero (2005) was used
A proposal of characters for taxonomic identification of Entomobrya species (Collembola, Entomobryomorpha), with description of a new species
The species of the genus Entomobrya have bean traditionally identified using colouration. Only
some authors have considered a small number of morphological characters, in badly mounted or old
specimens, as well as chaetotaxical characters (but not used for species identification). The study of a
large series of slides from extensive collections of Entomobrya species with observation of the complete
chaetotaxy has demonstrated that specimens with the same colour pattern can have a very different
chaetotaxy, which is related with the geographical origin. On the other hand, specimens with similar
chaetotaxy but from distant geographical areas maintain the same colour pattern. The present paper
proposes a set of both morphological and chaetotaxical characters as a useful tool for the species
identification in the genus Entomobrya in connection with the observation of colour pattern. For the
selection of this set of characters more than 500 slides from the top-ranking European museums have
been studied. Two species of the genus with similar colour pattern but with a different chaetotaxy are
used as models for the methodology: E. nivalis (Linnaeus, 1758) and a new species from León (Spain)."By kind permission of Senckenberg Museum für Naturkunde Görlitz; copyright by Senckenberg Görlitz. See also: www.soil-organisms.org
A new species of Entomobrya (Collembola, Entomobryidae) from La Caldera de Taburiente National Park (La Palma Island, Canary Islands) and its associated collembolan fauna
Entomobrya palmensis n. sp. is described from the Canary Islands (Macaronesian Region). The new
species shares the colour pattern with E. multifasciata (Tullberg, 1871), but clearly differs in chaetotaxy.
A list of species and locations of the collembolan fauna of the area is given
New species of Pseudosinella Schäffer, 1897 (Collembola, Entomobryidae) from Spain
The revision of the specimens of Pseudosinella at the Bonet Collection (MNCN, Museo Nacional de Ciencias Naturales-
CSIC, Madrid) have allow us to describe four new species found among 175 slides with more than 420 specimens.
One of them belongs to the petterseni-group (unguiculus with a fully developed tooth and without eyes). The differential
characters of Pseudosinella species from Christiansen (2007), and four characters more, have been used for comparison
with the related species
The Genus Gonatocerus Nees (Hymenoptera Chalcidoidea Mymaridae) in Corn Fields of Navarra, North Spain
Eight species of Gonatocerus Nees, 1834 (Hymenoptera Chalcidoidea Mymaridae) are
added to the faunallist of Spain: G. li/oralis (Haliday, 1833 ), G. chrysis Debauche, 1848, G.
/hyrides Debauche, 1848, G. longior Soyka, 1946, G. sulphuripes (Forster, 1847), G. pic/us
(Haliday, 1833 ), G. minor Matthews, 1986 and G. Dvicena/us Leonard and Crosby, 1915.
Species descriptions and details about their distribution and biology are also included. The
name G. tremulae Bakkendorf, 1934 is synonymized under G. Dvicena/us. The specimens were
collected with a Malaise trap in Cadreita, and with a sweep net in sixty corn fields from 23 localities
around Navarra
A disjunct distribution for a new species of Orchesellides (Collembola, Entomobryidae, Orchesellinae)
A new species of Orchesellides is described from material collected in the Valsa n forest
(Segovia, Spain), and conserved in the collection of the National Museum of Natural Sciences
(MNCN), CSIC, Madrid. The genus was known only from the eastern Palaearctic, Oriental, and
Indo-Pacific (Hawaii) regions. This is the first reference for the genus from the western Palaearctic
region, creating an interesting disjunct distribution. The value of the morphological characteristics for
the identification of the species is discussed
Nota sobre la presencia de Sminthurus viridis (Linnaeus, 1758) como plaga de la alfalfa en la ribera del rio Arga (Navarra)
En este trabajo se describe una plagadeSminthurus viridis L. sobre la alfalfa de los
campos de la ribera del rio Arga en Navarra. La plaga apareció en el otoño de 1997. Junto
a S. viridis apareció, en grandes cantidades, Entomobrya schuetti Stach, 1922. Esta
última especie se encontraba alimentándose de los hongos que crecían en las heridas
producidas por S. viridis en las hojas de la alfalfa. Se contaron los individuos de ambas
especies en un 10% de la muestra. La proporción de ambas es del 26% (S. viridis) y
74% (E. schoetti) respectivamente. Se ha estimado la población en uno de los campos
estudiados en unos 2.000 ejemplares por planta de alfalfa
Two new species of Entomobrya (Collembola, Entomobryomorpha) from the cave collembolan collection of Bonet from Asturias and Cantabria (north of Spain)
Two new species of Entomobrya are described from two caves of Asturias and Cantabria (north of
Spain). The specimens were found in the Bonet collembolan collection at the “Museo Nacional de
Ciencias Naturales” of Madrid (Spain). Entomomobrya boneti n. sp. was found in three slides
containing 11, 4 and 1 specimens respectively, from the “Cueva del Castillo”, Puente el Viesgo
(Santander). Entomobrya luquei n. sp. was found in a slide with 11 specimens from “Cueva de
Cuetu-Lledías”, Llanes (Asturias). The species are described considering a set of 39 morphological
and chaetotaxy characters. Both species appear to be troglophiles by the pigment reduction,
although there are no other troglomorphic characters present. The gut content is composed of
organic matter and fungus spores
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