6,419 research outputs found
Power Series Solutions of Non-Linear q-Difference Equations and the Newton-Puiseux Polygon
Adapting the Newton-Puiseux Polygon process to nonlinear q-difference
equations of any order and degree, we compute their power series solutions,
study the properties of the set of exponents of the solutions and give a bound
for their Gevrey order in terms of the order of the original equation
Plusiotis ericsmithi (Coleoptera: Scarabaeidae) : a new metallic species from eastern Guatemala
Se describe Plusiotis ericsmithi sp. nov. de un bosque nuboso de baja altitud (1100 msnm) en la Sierra del Merend6n, Guatemala, cerca de la front era con Honduras. Ademas, se incluyen ilustraciones de los genitales masculinos y femeninos.Plusiotis ericsmithii n. sp. is described from a low altitude cloud forest (1100 m) in the Guatemalan
Merend6n mountain chain near the Honduran border. Male and female genitalia are illustrated
Colossendeis species (Pycnogonida: Colossendeidae) collected during the Italica XIX cruise to Victoria Land (Antarctica), with remarks on some taxonomic characters of the ovigers
The pycnogonid fauna of the genus Colossendeis collected during the Italica XIX cruise to Victoria Land (Ross Sea, Antarctica) was studied. A total of 19 specimens of six species were collected: Colossendeis australis (6), C. wilsoni (3), C. scotti (2), C. robusta (3), C. lilliei (2) and C. megalonyx (3). In the present contribution the observed variability of all collected Colossendeis species is described and illustrated. The previously synonymised C. lilliei is considered a different species from C. robusta. The observations made in this study lead us to discuss a controversy about the total number of oviger segments in this genus. Despite the currently established 10-segmented status, a short basal element is here considered to be a possible 11th segment. A detailed SEM study of the last oviger segment is carried out in all collected species, showing some intraspecific and the interspecific variability in the structures examined (shape and number of rows of compound spines, morphology of terminal claw, etc.). Finally, we discuss the taxonomic value of these characters of the last strigilis segment for distinguishing the Colossendeis species, and their possible utility in establishing internal phylogenetic relationships in future contributions
New findings and a new species of the genus Ammothea (Pycnogonida, Ammotheidae), with an updated identification key to all Antarctic and sub-Antarctic species
Specimens of the pycnogonid genus Ammothea
collected during the Polarstern cruise XXIII/8 (23
November 2006–30 January 2007) were studied. Nine
species were recognized in this collection: Ammothea
bentartica, A. bicorniculata, A. carolinensis, A. clausi, A.
longispina, A. minor, A. spinosa, A. striata and A. tibialis.
Three of them (A. bentartica, A. bicorniculata and A. tibialis) are reported for the second time, enlarging their
known geographical and bathymetric range. In the present
contribution, the observed morphological variability of all
collected Ammothea species is described and discussed.
For the identification and description of the material, different museum specimens were consulted. Among them,
we have consulted part of the Discovery collection housed
at the Natural History Museum in London. That material
was initially identified by Isabella Gordon, a reputed author
in the field of pycnogonid taxonomy. A new species, based
on a museum specimen previously highly confused in the
literature, is proposed in the present contribution as Ammothea isabellae n. sp. The new taxon is compared with its
closest congeners, especially with A. longispina and A.
stylirostris. Finally, we propose an updated dichotomous
key to species covering all currently known Antarctic and
sub-Antarctic Ammothea specie
Two new species of Ammothea (Pycnogonida, Ammotheidae) from Antarctic waters
Two new species of the genus Ammothea are
described from Elephant Island and the South Shetlands
Islands, Antarctica. The material was captured during the
Polarstern cruise XXIII/8 to the Antarctic Peninsula area.
The main features of Ammothea pseudospinosa n. sp. are a
proboscis distinctly trilobulated distally with a constriction
at 2/3 of its length and dimorphism between the propodi of
the anterior (first and second) and posterior (third and
fourth) legs, and a trunk: proboscis length ratio of about
1.5. The main features of Ammothea childi n. sp. are a
cylindrical proboscis, longer than trunk length, and adults
with functional chelifores. These species are compared
with their closest congeners from the Southern Ocean:
A. pseudospinosa n. sp. with Ammothea spinosa and
Ammothea allopodes;A. childi n. sp. withAmmothea gigantea,
Ammothea bicorniculata and Ammothea hesperidensis
Nuevo modo de desarrollo postembrionario en el género Ammothea (Pycnogonida: Ammotheidae) procedente de aguas Antárticas
In this paper the postembryonic development of Ammothea glacialis (family ammotheidae) is described. The
studied material was collected during the Italica XIX cruise to Victoria land, ross sea, antarctica. The external morphology
of three larval instars is described and illustrated. The development of A. glacialis has the following characteristics: (1)
protonymphon hatch from the eggs; (2) the larvae have yolk reserves and relatively large size (0.7 mm in length); (3) the
larvae remain on the ovigerous legs of males during several moults; (4) the larvae have reduced larval II-III appendages and
the spinning apparatus is absent; (5) the development of walking legs is sequential. This development is compared with those
previously known, especially with Propallene longiceps and Nymphon grossipes.Nuevo modo de desarrollo postembrionario en el género AmmotheA
(Pycnogonida: Ammotheidae)
procedente de aguas Antárticas. – En este trabajo se describe el desarrollo postembrionario de Ammothea glacialis
(familia ammotheidae). El material estudiado fue recolectado durante el crucero Itálica XIX a Tierra Victoria, en el mar de
ross, antártida. se describe e ilustra la morfología externa de tres estadios larvarios. El desarrollo de A. glacialis se caracteriza
por: (1) la larva eclosiona como protonymphon; (2) la larva es de tamaño relativo grande (0.7 mm de longitud) y con
reservas de vitelo; (3) la larva permanece en los ovígeros del macho durante varias mudas; (4) la larva presenta los apéndices
larvarios II y III reducidos y el “spinning apparatus” está ausente; (5) el desarrollo de las patas es secuencial. Este desarrollo
es comparado con otros desarrollos postembrionarios previamente conocidos, especialmente con los de Propallene longiceps
and Nymphon grossipes
Bioethics and health law: the living will. Proposal to create a living will record in Europe
In this piece of work, we present a proposal to create a living will record in Europe that will allow people to have the same rights wherever they are.
Therefore, this article will be studied from the bioethics and health law theory
- …