87 research outputs found
Developing documents for practical sessions in Zoology
La implantación del sistema unificado de créditos (E.C.T.S.) implica
nuevos planteamientos por parte del profesorado al elaborar la programación
teórico-práctica de las diferentes asignaturas. Con la elaboración de los
protocolos prácticos de zoología pretendemos alcanzar los objetivos siguientes:
1. Proveer a los alumnos de material didáctico básico y complementario a la
información impartida en las sesiones prácticas. 2. Proporcionar una perspectiva
amplia de diferentes aspectos prácticos de la zoología. 3. Familiarizar a los
alumnos con las fuentes (complementarias) de información y los procedimientos
de acceso a diferentes tipos de material biológico. 4. Favorecer el trabajo
personal y de grupo, enfatizando diferentes aspectos biológicos necesarios para
la asimilación de los contenidos prácticos de la asignatura. 5. Facilitar la
preparación de las pruebas prácticas que los alumnos han de realizar. En el curso
académico 2003/2004 nos fue concedido un primer proyecto docente que nos
permitió preparar contenidos correspondientes a la práctica “Introducción a las
técnicas de campo y de laboratorio en Zoología”. A partir de esta primera
experiencia hemos desarrollado varios proyectos docentes que nos han permitido
preparar materiales y contenidos prácticos de los principales taxones de animales
invertebrados: Poríferos y Cnidarios. Platelmintos, Nematodos y Anélidos.
Artrópodos. Moluscos. Equinodermos. La preparación de estos contenidos nos
ha obligado a realizar desplazamientos así como a solicitar colaboraciones de
diversas instituciones, por ejemplo, al Museo Nacional de Ciencias Naturales de
Madrid. Los protocolos están diseñados de forma que fomentan la labor
individual y auto-formativa del alumnado, así como el estudio en grupo. Todo
está encaminado hacia una completa preparación y correcta adecuación al nuevo
sistema educativo. Las presentaciones multimedia están a disposición del
alumnado gracias a las posibilidades que ofrece la web de la Universidad de
Córdoba.The implementation of the unified credit system (ECTS) involves new
approaches by teachers in the development of both theoretical and practical
curricula of different subjects. With the development of practical zoology
documents we aim to achieve the following objectives: 1. To provide the
students with basic educational materials, and complementary information to the
practical sessions. 2. To provide a broad overview of different practical aspects
of zoology. 3. To familiarize students with additional sources of information and
procedures for access to different types of biological material. 4. To encourage
personal and group work, emphasizing different biological aspects, which are
necessary for the understanding of the practical contents of the subjects. 5. To
assist in the preparation of exams that students must perform. In the academic
course 2003/2004 we were awarded with a first educational project that allowed
us to prepare content for the practice "Introduction to field and lab techniques in
Zoology". From this first experience we have developed several educational
projects that have allowed us to prepare materials and practical content of the
main taxa of invertebrates: Sponges and Cnidarians. Flatworms, Nematodes and
Annelids. Arthropods. Molluscs. Echinoderms. The preparation of these
materials has lead us to make trips and to request contributions from various
institutions, for example, the Museo Nacional de Ciencias Naturales in Madrid.
The protocols are designed in ways that encourage individual work and selftraining
of students, and study groups. Everything is aimed to the complete
preparation and fair adaptation to the new educational system. Multimedia
presentations are available to students thanks to the possibilities offered by the
website of the University of Cordoba
n-Hexadecane hydrocracking Single-Event MicroKinetics on Pt/H-beta
[EN] The Single-Event MicroKinetic (SEMK) model constructed for gas-phase hydroconversion of light n-alkanes on large-pore USY zeolites was applied, for the first time, to the hydrocracking of n-hexadecane on a Pt/H-Beta catalyst. Despite the 12-ringed pore channels, shape selectivity was observed in the formation of ethyl side chains. Additionally, heavy feed molecules such as n-hexadecane lead to physisorption saturation of the catalyst pores by strong Van der Waals interactions of the long alkyl chains with the zeolite framework. Intermolecular interactions and packing efficiencies in the pores induce deviations from typical Henry-regime physisorption characteristics as the physisorption selectivity, which is expected to increase with increasing carbon number, appeared to be independent of the latter. Micropore saturation effects were described by the 'size entropy' which quantifies the difference in standard entropy loss between physisorption in the Henry regime and hindered physisorption on a saturated surface. The size entropy is proportional to the catalyst loading with physisorbed species and the adsorbate carbon number. The addition of a size entropy term in the SEMK model, amounting to 102J mol(-1) K-1 for a hexadecane molecule at full saturation, allowed accurately reproducing the contribution of secondary isomerization and cracking reactions, as quantified by means of a contribution analysis. (C) 2012 Elsevier B.V. All rights reserved.This work was funded by the European Research Institute of
Catalysis and the European Community’s Sixth Framework Programme. This work was also supported by the Research Board
of Ghent University (BOF), the Interuniversity Attraction Poles
Programme–Belgian State–Belgian Science Policy and the Long
Term Structural Methusalem Funding by the Flemish Government.
Financial support by the Comisión Interministerial de Ciencia y Tecnología (CICYT) of Spain through the Project CTQ2010-17988/PPQ
is also gratefully acknowledged.Vandegehuchte, BD.; Thybaut, JW.; Martinez Feliu, A.; Arribas Viana, MDLD.; Marin, GB. (2012). n-Hexadecane hydrocracking Single-Event MicroKinetics on Pt/H-beta. Applied Catalysis A General. 441:10-20. doi:10.1016/j.apcata.2012.06.054S102044
Phosphorylation of SOS1 on tyrosine 1196 promotes its RAC GEF activity and contributes to BCR-ABL leukemogenesis
Son of Sevenless 1 (SOS1) is a dual guanine nucleotide exchange factor (GEF) that activates the small GTPases RAC and RAS. Although the molecular mechanisms of RAS GEF catalysis have been unveiled, how SOS1 acquires RAC GEF activity and what is the physio-pathological relevance of this activity is much less understood. Here we show that SOS1 is tyrosine phosphorylated on Y1196 by ABL. Phosphorylation of Y1196 controls SOS1 inter-molecular interaction, is required to promote the exchange of nucleotides on RAC in vitro and for platelet-derived growth factor (PDGF) activation of RAC- and RAC-dependent actin remodeling and cell migration. SOS1 is also phosphorylated on Y1196 by BCR-ABL in chronic myelogenous leukemic cells. Importantly, in these cells, SOS1 is required for BCR-ABL-mediated activation of RAC, cell proliferation and transformation in vitro and in a xenograft mouse model. Finally, genetic removal of Sos1 in the bone marrow-derived cells (BMDCs) from Sos1fl/flmice and infected with BCR-ABL causes a significant delay in the onset of leukemogenesis once BMDCs are injected into recipient, lethally irradiated mice. Thus, SOS1 is required for full transformation and critically contribute to the leukemogenic potential of BCR-ABL
RICORS2040 : The need for collaborative research in chronic kidney disease
Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true
Reproductive modes and taxonomy
Nomenclature, taxonomy and species concepts of clonal (asexual) lineages have for a long time
been hotly debated subjects. We argue that separating the 'asexuals' into different types, facilitates
the discussion. In ancient asexuals, separate lineages have low intraspecific genetic and morphological
variability and clear interspecific genetic and morphological gaps. Their taxonomy is thus
(relatively) straightforward, species are conform to morphological, genetic and evolutionary species
concepts. No special species concept for these taxa is necessary. In species with mixed reproduction,
bisexual and asexual populations cluster amongst each other and form an inclusive species,
with large intraspecific genetic and morphological variability. Accepting an inclusive approach,
such species with mixed reproduction are again conform to morphological, genetic and evolutionary
species concepts. Many problems remain, however,with the asexual spin-offs from species with
sexual roots, be they advanced mutational lineages or interspecific hybrids. Congeneric lineages are
often difficult to identifY unambiguously and, for several reasons, most of these clusters must be
regarded as evolutionary species complexes for which a separate (theoretical) species concept (e.g.
the agamospecies) must be invoked.
Subspecies in clonal taxonomy should be avoided in all categories of asexuals, and this for different
reasons. Possible exceptions are identifiable sib clones with special ecological preference
Tradeoff between foraging and antipredator behaviour in a macrophyte dwelling ostracod
The ostracod Cypridopsis vidua is a highly mobile crustacean which frequently occurs in beds of submerged macrophytes in lakes or ponds. A laboratory experiment consisting of eight different treatments was performed to test if this species responds to fluctuations in predation risk, food abundance, hunger, and plant structure by trading off conflicting demands such as searching for food in the sheltered lower zone of a macrophyte or shifting to nutritionally more rewarding patches in the exposed upper zone of this plant. Stems of the macrophyte Chara fragilis covered with a variable amount of periphyton were used as plant structures. To signal predation risk, chemical stimuli derived from tanks containing cyprinid fish were used. The ostracods responded to predator signals by spending significantly more time in the lower zone of the aquaria and by increasing swimming activity especially during the initial phase of encountering the signals. Both with increased hunger level and high food abundance the time spent on Chara increased. When only a single stem of Cham was offered, time spent swimming in the lower zone of the aquarium increased markedly compared to the presence of three stems. In response to different predation risk and food abundance, C. vidua ostracods performed shifts in their vertical microhabitat use as a result of a tradeoff between foraging and antipredator demands. In three experimental treatments the ostracods showed considerable temporal variations in microhabitat choice indicating additional behavioural fine-tuning after a quick preliminary adjustment. In agreement with earlier experimental studies our data support the conclusion that these phytophilous crustaceans are characterized by a well developed capability for exploring their surroundings and by responding to external and internal factors in a flexible and behaviourally dynamic manner
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