Predation on recent marine ostracod populations of South Western Spain

This paper analyzes evidences of predation observed in ostracod populations collected in the southwestern Spanish shelf (0-70 m depth). Examination of seventy-two samples and almost 17,300 specimens allowed recovering more than 135 bored valves and carapaces. Percentages of bored specimens are very low (< 2%), with the highest values in isolated samples with low to very low ostracod densities. Two main types of boreholes can be distinguished: a) Oichnus paraboloides Bromley, accounting for over 70% of the total boreholes; and b) Oichnus simplex Bromley. Boreholes are concentrated mainly in the central and dorsal areas of the valves. Borehole diameter shows a positive but not significant correlation with the sizes of the predated valves. This diameter is usually higher in shallow marine areas. Predation affects the most abundant species of this shallow marine environment (mainly adults and the last juvenile instars). Ornamentation seems to be secondary in the predatory strategy

Impact of storms on Pliocene benthic foraminiferal assemblages of southwestern Spain

Lithostratigraphical and faunal analyses of five Pliocene sections located in the southwestern Guadalquivir Basin (S Spain) permit reveal three main faciès, which represent shallow marine fairweather conditions (FA-I), storm events (FA-2) and littoral/fluvial environments (FA-3). The vertical disposition of these facies indicates a regressive sequence. The statistical study of foraminiferal populations revealed five infralittoral and circalittoral assemblages. Vertical and horizontal variations among these assemblages, the P/B ratio and four diversity indices, together with the mollusc distributions, suggest the presence of a shallow marine palaeoenvironment in this area in the Lower Pliocene, with an increasing depth towards the southwestern. The main effects from storm events on the foraminiferal faunas are a slightly decrease of individuals and species, and a marked drop in the P/B ratio. The post-storm conditions are characterized by: a) a higher number of individuals; b) a progressive increase in the P/B ratio and c) small increases in the remaining indices. © Asociación Paleontológica Argentina

Implementation of an embedded system on a TS7800 board for robot control

Lithostratigraphical and faunal analyses of five Pliocene sections located in the southwestern Guadalquivir Basin (S Spain) permit reveal three main facies, which represent shallow marine fairweather conditions (FA-I), storm events (FA-2) and littoral/fluvial environments (FA-3). The vertical disposition of these facies indicates a regressive sequence. The statistical study of foraminiferal populations revealed five infralittoral and circalittoral assemblages. Vertical and horizontal variations among these assemblages, the P/B ratio and four diversity indices, together with the mollusc distributions, suggest the presence of a shallow marine palaeoenvironment in this area in the Lower Pliocene, with an increasing depth towards the southwestern. The main effects from storm events on the foraminiferal faunas are a slightly decrease of individuals and species, and a marked drop in the P/B ratio. The post-storm conditions are characterized by: a) a higher number of individuals; b) a progressive increase in the P/B ratio and c) small increases in the remaining indices. " Asociación Paleontológica Argentina.",,,,,,,,,"http://hdl.handle.net/20.500.12104/42096","http://www.scopus.com/inward/record.url?eid=2-s2.0-70349841373&partnerID=40&md5=7d994bc40883a13a98e79e1d1bdc4836",,,,,,"2",,"Ameghiniana",,"34

Braquiópodos neógenos del suroeste de la depresión del Guadalquivir (sur de España)

This paper analyzes the first brachiopod record of three Neogene formations of the southwestern Guadalquivir Basin (Huelva province, SW Spain) with a wide cartographical distribution. Samples obtained in five sections of these formations have allowed to recognize three species belonging to the genera Terebratula, Maltaia and Cryptopora, the latter being the first record of this genus in Spain. In addition, the biostratigraphical distribution and palaeoecological context of these species and others present in upper Neogene sediments (Tortonian-Lower Pliocene) of south Spain are discussed

Braqui�podos ne�genos del suroeste de la depresi�n del Guadalquivir (sur de Espa�a)

This paper analyzes the first brachiopod record of three Neogene formations of the southwestern Guadalquivir Basin (Huelva province, SW Spain) with a wide cartographical distribution. Samples obtained in five sections of these formations have allowed to recognize three species belonging to the genera Terebratula, Maltaia and Cryptopora, the latter being the first record of this genus in Spain. In addition, the biostratigraphical distribution and palaeoecological context of these species and others present in upper Neogene sediments (Tortonian-Lower Pliocene) of south Spain are discussed

The Functions of RNA-Dependent RNA Polymerases in Arabidopsis

One recently identified mechanism that regulates mRNA abundance is RNA silencing, and pioneering work in Arabidopsis thaliana and other genetic model organisms helped define this process. RNA silencing pathways are triggered by either self-complementary fold-back structures or the production of double-stranded RNA (dsRNA) that gives rise to small RNAs (smRNAs) known as microRNAs (miRNAs) or small-interfering RNAs (siRNAs). These smRNAs direct sequence-specific regulation of various gene transcripts, repetitive sequences, viruses, and mobile elements via RNA cleavage, translational inhibition, or transcriptional silencing through DNA methylation and heterochromatin formation. Early genetic screens in Arabidopsis were instrumental in uncovering numerous proteins required for these important regulatory pathways. Among the factors identified by these studies were RNA-dependent RNA polymerases (RDRs), which are proteins that synthesize siRNA-producing dsRNA molecules using a single-stranded RNA (ssRNA) molecule as a template. Recently, a growing body of evidence has implicated RDR-dependent RNA silencing in many different aspects of plant biology ranging from reproductive development to pathogen resistance. Here, we focus on the specific functions of the six Arabidopsis RDRs in RNA silencing, their ssRNA substrates and resulting RDR-dependent smRNAs, and the numerous biological functions of these proteins in plant development and stress responses