Chloride channels in stellate cells are essential for uniquely high secretion rates in neuropeptide-stimulated Drosophila diuresis

Epithelia frequently segregate transport processes to specific cell types, presumably for improved efficiency and control. The molecular players underlying this functional specialization are of particular interest. In Drosophila, the renal (Malpighian) tubule displays the highest per-cell transport rates known and has two main secretory cell types, principal and stellate. Electrogenic cation transport is known to reside in the principal cells, whereas stellate cells control the anion conductance, but by an as-yet-undefined route. Here, we resolve this issue by showing that a plasma membrane chloride channel, encoded by ClC-a, is exclusively expressed in the stellate cell and is required for Drosophila kinin-mediated induction of diuresis and chloride shunt conductance, evidenced by chloride ion movement through the stellate cells, leading to depolarization of the transepithelial potential. By contrast, ClC-a knockdown had no impact on resting secretion levels. Knockdown of a second CLC gene showing highly abundant expression in adult Malpighian tubules, ClC-c, did not impact depolarization of transepithelial potential after kinin stimulation. Therefore, the diuretic action of kinin in Drosophila can be explained by an increase in ClC-a–mediated chloride conductance, over and above a resting fluid transport level that relies on other (ClC-a–independent) mechanisms or routes. This key segregation of cation and anion transport could explain the extraordinary fluid transport rates displayed by some epithelia

Reconocimiento de los factores determinantes de la riqueza de especies: el caso de los Aphodiinae (Coleoptera, Scarabaeoidea, Aphodiidae) en la Península Ibérica

In the present article, variables that explain the Aphodiinae (Aphodiidae, Coleoptera) species richness at the Iberian Peninsula were explored, only considering previous faunistic studies and using the Generalized Linear Models statistic procedures. Data from 30 faunistic studies taken from the literature were analysed to examine the factors which have an influence on the species richness of this group. For each location, 22 variables were compiled, referred to topographic, geographic, environmental diversity, climatic, type of soils, and cattle customs factors. After eliminating area effects, several climatic, type of soils, cattle customs and geographic factors were able to explain the variation on Iberian Aphodiinae species richness. However, a function which made up the aridity index and the percentage of siliceous soils variable would gather all the variation on species richness distribution of Iberian Aphodiinae caused by environment. This fact showed the present correlation between these two variables with the other significant ones. Variance hierarchical partitioning techniques exhibited that climatic factors were the most influent on the species richness, followed by the type of soils, cattle customs and geographic ones. Nevertheless, space per se was able to explain more than all the environmental variables together, so some other variables which were not considered could better resume the variation on Aphodiinae richness. Distribution of Iberian Aphodiinae richness showed two areas with a higher number of species located southwards and in the north-western part of the peninsula. In our opinion, such variable would be of historic-geographic nature, and so: 1) Iberian Aphodiinae fauna would be constituted by two principal species groups of different origins and physic-climatic adaptations (a Palaearctic or cold-temperate group and a Mediterranean or Afrotropical group); and 2) the separated distribution of Aphodiinae richness centres would represent the most favourable areas at present, that give refuge to each one of these faunistic groups. Moreover, the fact of an accumulated species richness on the north-western part of the peninsula would be one of the evidences which reflect the Iberian Peninsula role both as a colonization route and as a refuge during glacial/interglacial cycles.En el presente artículo se procedió a explorar las variables que explican la riqueza de especies de Aphodiinae (Aphodiidae, Scarabaeoidea) a escala peninsular ibérica partiendo únicamente de previos estudios faunísticos y haciendo uso de las técnicas estadísticas conocidas como Modelos Lineales Generalizados. Para examinar los factores que influyen en la riqueza de este grupo, se analizaron los datos referidos a 30 estudios faunísticos procedentes de la literatura. Para cada localización, se recopilaron 22 variables, referidas a factores ambientales de tipo topográfico, geográfico, de diversidad ambiental, climático, litológico y de usos ganaderos. Tras eliminar el efecto del área, algunos de los factores ambientales climáticos, litológicos, de usos ganaderos y geográficos se mostraron capaces de explicar la variación en la riqueza de Aphodiinae ibéricos. No obstante, se observó que una función compuesta por el índice de aridez y la variable referida a la proporción de los suelos silíceos podría resumir toda la variación en la distribución de riqueza de Aphodiinae ibéricos propiciada por el ambiente, lo que ponía de manifiesto la correlación existente entre el resto de variables significativas con estas dos variables. Un análisis de jerarquización de la varianza expuso que los factores climáticos eran los más influyentes en la riqueza de especies, seguidos por los litológicos, los de usos ganaderos y los geográficos. Sin embargo, el espacio en sí mismo fue capaz de explicar mucho más que el resto de variables ambientales, por lo que otras variables no consideradas podrían expresar mejor la variación en la riqueza de Aphodiinae. La distribución de la riqueza de Aphodiinae ibéricos mostró dos áreas con un mayor número de especies, localizadas en la zona sur y la noroccidental de la península. A nuestro juicio, dicha variable no considerada tendría un carácter histórico-geográfico: la fauna ibérica de Aphodiinae estaría básicamente constituida por dos conjuntos de especies con diferentes orígenes y adaptaciones fisioclimáticas (un grupo paleártico o templado-frío y otro mediterráneo o afrotropical), y la distribución disyunta de los centros de riqueza de Aphodiinae coincidiría con las áreas, actualmente bajo condiciones más favorables, que alojan cada uno de estos conjuntos faunísticos. Además, la riqueza de especies que se acumula en el extremo noroccidental de la península sería una de las evidencias que reflejaría el papel ejercido por la Península Ibérica como corredor y refugio de faunas durante los ciclos glaciares/interglaciares

Los Scarabaeoidea Laparosticti (Coleoptera) del Archipiélago Canario depositados en el Museo Nacional de Ciencias Naturales de Madrid

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ParkDB: a Parkinson's disease gene expression database

Parkinson's disease (PD) is a common, adult-onset, neuro-degenerative disorder characterized by the degeneration of cardinal motor signs mainly due to the loss of dopaminergic neurons in the substantia nigra. To date, researchers still have limited understanding of the key molecular events that provoke neurodegeneration in this disease. Here, we present ParkDB, the first queryable database dedicated to gene expression in PD. ParkDB contains a complete set of re-analyzed, curated and annotated microarray datasets. This resource enables scientists to identify and compare expression signatures involved in PD and dopaminergic neuron differentiation under different biological conditions and across species. Database URL: http://www2.cancer.ucl.ac.uk/Parkinson_Db2

Promoting Entrepreneurship amid Youth in Windhoek’s Informal Settlements: A Namibian Case

Considering the high unemployment rate among Namibian youth and a lack of job opportunities, the promotion of entrepreneurship has gained wider attention in the country. A number of initiatives have been started such as entrepreneurship trainings and workshops, business idea competitions, etc. All these aim to inspire young people to think of alternative income sources. As part of a two-year funded community outreach research and development (R&D) project, we have investigated participatory approaches to engage marginalized youth into conceptualizing their own context, imparting skills, and deriving new career paths. This article reports and reflects on one of the interventions we have recently concluded with a group of youth in Havana, an informal settlement in the outskirts of Windhoek. We conducted what we entitled “The Havana Entrepreneur”, a series of interactions inspired upon the model of the American reality game show “The Apprentice”. Over a number of weeks two youth groups were given challenges to tackle by means of competing against one another. After completion of each challenge, groups were rated by a number of judges on skills demonstrated such as marketing, presentation, reflection and creativity among others. We observed an increase in, and improvement of skills revealed along tasks’ completion, besides an openly expressed self-realization and discovery of abilities by participants. Moreover, the youth are currently engaged in the continuation of activities beyond the initial entrepreneurial interactions. Thus we suggest replicating “The Havana Entrepreneur”, including the recording on camera of it by the youth themselves as a new mode to instigating a wider entrepreneurial spirit in informal settlements

Recensiones

RESEÑA 1 de : Tresmontant, C. Le Chríst hébreu. París : Albin Michel, 1992. RESEÑA 2 de : Fricke, W. El juicio contra Jesús. Barcelona : Martínez Roca, 1993. RESEÑA 3 de : Kramrisch, Stella. The Presence of Siva. Princeton University Press, 1992. RESEÑA 4 de : Tamayo-Acosta, Juan José. Para comprender la escatología cristiana. Estella : Verbo divino, 1993. RESEÑA 5 de : Marinatos, N.; Hägg, R. Greek Sanctuaries. New Approaches. Londres-Nueva York : Routledge, 1993. RESEÑA 6 de : Braccesi, L. Hesperia, 3. Studi sulla Grecitá di Occidente. Roma : «L'Erma» di Bretschneider, 1993. RESEÑA 7 de : Wells, B. Agriculture in Ancient Greece. Estocolmo : Svenska Institutet i Athen, 1992. RESEÑA 8 de : Fernández Uriel, Pilar. Introducción a la Historia Antigua-ll. El mundo griego, I. Madrid : 1993. RESEÑA 9 de : Mangas J.; Alvar, J. Homenaje a José M.Blázquez. I. Madrid : Ediciones Clásicas, 1993. RESEÑA 10 de : Fernández Uriel, P.; Vázquez Hoys, A.M. Diccionario del Mundo Antiguo. Próximo Oriente, Egipto, Grecia y Roma. Madrid : Alianza Editorial, 1994

Specialized stellate cells offer a privileged route for rapid water flux in Drosophila renal tubule

Insects are highly successful, in part through an excellent ability to osmoregulate. The renal (Malpighian) tubules can secrete fluid faster on a per-cell basis than any other epithelium, but the route for these remarkable water fluxes has not been established. In Drosophila melanogaster, we show that 4 genes of the major intrinsic protein family are expressed at a very high level in the fly renal tissue: the aquaporins (AQPs) Drip and Prip and the aquaglyceroporins Eglp2 and Eglp4. As predicted from their structure, and by their transport function by expressing these proteins in Xenopus oocytes, Drip, Prip, and Eglp2 show significant and specific water permeability, whereas Eglp2 and Eglp4 show very high permeability to glycerol and urea. Knockdowns of any of these genes result in impaired hormone-induced fluid secretion. The Drosophila tubule has 2 main secretory cell types: active cation-transporting principal cells, wherein the aquaglyceroporins localize to opposite plasma membranes, and small stellate cells, the site of the chloride shunt conductance, with these AQPs localizing to opposite plasma membranes. This suggests a model in which osmotically obliged water flows through the stellate cells. Consistent with this model, fluorescently labeled dextran, an in vivo marker of membrane water permeability, is trapped in the basal infoldings of the stellate cells after kinin diuretic peptide stimulation, confirming that these cells provide the major route for transepithelial water flux. The spatial segregation of these components of epithelial water transport may help to explain the unique success of the higher insects in regulating their internal environments

Hydrographic variability (1994-2020) in the Ría de Vigo and adjacent shelf (NW Iberia)

The Spanish Institute of Oceanography (IEO-CSIC) carries out monthly oceanographic samplings at across-shelf sections off the northern Spanish coast under the monitoring program RADIALES (https://www.seriestemporales-ieo.net/). This is a multidisciplinary marine research effort addressing long-term variability issues at the ecosystem level (Bode et al., 2015; Valdés et al., 2002). Currently, the monitoring program includes 5 perpendicular coastal transects in Northern Spain: Santander, Gijón, Cudillero, A Coruña and Vigo. Focusing on the section located in the Ría de Vigo and adjacent shelf, we have analysed a 27-year time series (1994 - 2020) of temperature and salinity obtained through CTD profiles in three stations, two inside the Ría (~30 and ~40 m depth) and one in the mid-shelf (~90 m depth). This study summarizes the hydrographic variability in the region through the construction of a local climatology. In addition, long-term trends and interannual changes in seasonality are examined. The results show a change in the salinity regime in medium depth waters in 2013, although not in temperature. Near the surface, the temperature undergoes a negative shift from 2016, in correspondence with the entry of the AMO into a new negative phase

Late differentiation syndrome in acute promyelocytic leukemia: a challenging diagnosis

Detailed knowledge about differentiation syndrome (DS) has remained limited. There are 2 large studies conducted by the Spanish workgroup PETHEMA (Programa Español de Tratamientos en Hematología; Spanish Program on Hematology Treatments) and the European group trial (LPA 96-99 and APL 93) in which the incidence, characteristics, prognostic factors and outcome of patients developing DS are evaluated. Both have described the median time of DS development between 10 and 12 days. The severity of the DS has been evaluated in the study conducted by PETHEMA, and severe DS usually occurs at the beginning of the treatment (median of 6 days), as compared with moderate DS (median of 15 days). We report here in two cases of late severe DS, with late diagnosis due to both time and form of presentation. We discuss the physiopathology, clinical presentation, prophylaxis and treatment of DS

The role of dynamical polarization of the ligand to metal charge transfer excitations in {\em ab initio} determination of effective exchange parameters

The role of the bridging ligand on the effective Heisenberg coupling parameters is analyzed in detail. This analysis strongly suggests that the ligand-to-metal charge transfer excitations are responsible for a large part of the final value of the magnetic coupling constant. This permits to suggest a new variant of the Difference Dedicated Configuration Interaction (DDCI) method, presently one of the most accurate and reliable for the evaluation of magnetic effective interactions. This new method treats the bridging ligand orbitals mediating the interaction at the same level than the magnetic orbitals and preserves the high quality of the DDCI results while being much less computationally demanding. The numerical accuracy of the new approach is illustrated on various systems with one or two magnetic electrons per magnetic center. The fact that accurate results can be obtained using a rather reduced configuration interaction space opens the possibility to study more complex systems with many magnetic centers and/or many electrons per center.Comment: 7 pages, 4 figure