Prototypical Arthropod Gene Content and Genome Organisation in the Centipede Strigamia maritima

Myriapods (e.g., centipedes and millipedes) display a simple homonomous body plan relative to other arthropods. All members of the class are terrestrial, but they attained terrestriality independently of insects. Myriapoda is the only arthropod class not represented by a sequenced genome. We present an analysis of the genome of the centipede Strigamia maritima. It retains a compact genome that has undergone less gene loss and shuffling than previously sequenced arthropods, and many orthologues of genes conserved from the bilaterian ancestor that have been lost in insects. Our analysis locates many genes in conserved macro-synteny contexts, and many small-scale examples of gene clustering. We describe several examples where S. maritima shows different solutions from insects to similar problems. The insect olfactory receptor gene family is absent from S. maritima, and olfaction in air is likely effected by expansion of other receptor gene families. For some genes S. maritima has evolved paralogues to generate coding sequence diversity, where insects use alternate splicing. This is most striking for the Dscam gene, which in Drosophila generates more than 100,000 alternate splice forms, but in S. maritima is encoded by over 100 paralogues. We see an intriguing linkage between the absence of any known photosensory proteins in a blind organism and the additional absence of canonical circadian clock genes. The phylogenetic position of myriapods allows us to identify where in arthropod phylogeny several particular molecular mechanisms and traits emerged. For example, we conclude that juvenile hormone signalling evolved with the emergence of the exoskeleton in the arthropods and that RR-1 containing cuticle proteins evolved in the lineage leading to Mandibulata. We also identify when various gene expansions and losses occurred. The genome of S. maritima offers us a unique glimpse into the ancestral arthropod genome, while also displaying many adaptations to its specific life history.

Analysis of a Plant Complex Resistance Gene Locus Underlying Immune-Related Hybrid Incompatibility and Its Occurrence in Nature

Mechanisms underlying speciation in plants include detrimental (incompatible) genetic interactions between parental alleles that incur a fitness cost in hybrids. We reported on recessive hybrid incompatibility between an Arabidopsis thaliana strain from Poland, Landsberg erecta (Ler), and many Central Asian A. thaliana strains. The incompatible interaction is determined by a polymorphic cluster of Toll/interleukin-1 receptor-nucleotide binding-leucine rich repeat (TNL) RPP1 (Recognition of Peronospora parasitica1)-like genes in Ler and alleles of the receptor-like kinase Strubbelig Receptor Family 3 (SRF3) in Central Asian strains Kas-2 or Kond, causing temperature-dependent autoimmunity and loss of growth and reproductive fitness. Here, we genetically dissected the RPP1-like Ler locus to determine contributions of individual RPP1-like Ler (R1R8) genes to the incompatibility. In a neutral background, expression of most RPP1-like Ler genes, except R3, has no effect on growth or pathogen resistance. Incompatibility involves increased R3 expression and engineered R3 overexpression in a neutral background induces dwarfism and sterility. However, no individual RPP1-like Ler gene is sufficient for incompatibility between Ler and Kas-2 or Kond, suggesting that co-action of at least two RPP1-like members underlies this epistatic interaction. We find that the RPP1-like Ler haplotype is frequent and occurs with other Ler RPP1-like alleles in a local population in Gorzów Wielkopolski (Poland). Only Gorzów individuals carrying the RPP1-like Ler haplotype are incompatible with Kas-2 and Kond, whereas other RPP1-like alleles in the population are compatible. Therefore, the RPP1-like Ler haplotype has been maintained in genetically different individuals at a single site, allowing exploration of forces shaping the evolution of RPP1-like genes at local and regional population scales.

¿Qué significan los términos 'relaciones sexuales'? Definiciones y ejemplos proporcionados por jóvenes universitarios

Aims: The aim of this paper is to know what means for Spanish university students “sexual relations”, from a sexually transmitted infections prevention point of view. Method: Participants were seven hundred and fifty university students from 18 to 25 years (67.7% women; 65.5% between 18 and 21 years old) selected by multistage proportional sampling. They were asked to give a maximum of three free definitions or examples of “sexual relations”. They could use the language they feel more comfortable. An example of (vaginal sex) was provided and three blank spaces for answering were marked. Results: 23.5% of participants repeated the example provided (vaginal sex). The other answers were categorized in the following topics: euphemisms (42,3%), sex with penetration (40,3%), divagations (11,2%), sex without penetration (11,1%), anal sex (10,5%), oral sex (5,6%), masturbation (2,4%) and having an orgasm (1,5%). Conclusions: Young people’s meaning of “having sex” has become more diversified in the last years. These results must be useful in order to design future preventive campaigns

El agua: un medio de intervención para el psicomotricista

A partir de algunas de las ya clásicas definiciones de la psicomotricidad, la comunicación constata que lo que define la intervención psicomotriz no es su espacio físico de desarrollo sino su acción, su enfoque y su finalidad. Concretamente, la comunicación reflexiona sobre la función y actividad del psicomotricista proponiendo un nuevo espacio de intervención: el medio acuático. Se analizan sus propiedades en base a la definición de unas dimensiones física, evolutiva y simbólica para, en último, orientar las posibilidades de intervención psicomotriz en el medio acuático.

Modelo de comportamiento en sevicio para estructuras reticulares de hormigón. Parte I: Descripción del modelo y ejemplos de aplicación

A general method for instantaneous and time-dependent serviceability analysis of plane concrete frames is presented. The methodology is based in an extension of the classic matrix formulation for bars. The main aspects influencing the behaviour of the structural concrete are considered: cracking, creep, shrinkage or prestress losses. To simulate the effect of cracking a smeared model (developed in Part II) based on the modification of the tensile branch of the concrete stress-strain relationship is adopted. The general approach considered permits the application to different materials and constitutive laws. Sequential construction (sectional and structural), incorporation of reinforcement, consideration of the loads history; placing and removing shores, and restraining or releasing in boundary conditions are considered. Some examples are included to highlight the capabilities of the model

L'herència cultural de les orques àvies

Únicament hi ha tres espècies de mamífers en què les femelles passen, dins el seu cicle vital, per una fase de menopausa a la qual segueix una llarga etapa vital postmenopàusica. Des d'una perspectiva genètica i evolutiva estricta no és fàcil d'entendre el significat biològic d'aquesta etapa, en què els organismes consumeixen recursos del medi però no deixen cap descendent que perpetuï l'espècie. Darren P. Croft i els seus col·laboradors de la Universitat d'Exeter, al Regne Unit, han analitzat més de 750 hores de filmació sobre el comportament de les orques gravades en diferents anys i indrets, cosa que els ha permès proposar una explicació tan simple com sorprenent: els individus postmenopàusics serveixen d'acumuladors de coneixement ecològic.

Excés de salut

Menjar és una necessitat per a tots els éssers vius. Cada espècie presenta un tipus d'alimentació determinant, que és el resultat de la seva història evolutiva, la qual ha permès l'adaptació dels seus òrgans i la seva fisiologia als aliments disponibles en el seu entorn. Els humans som omnívors. El nostre cos està adaptat a una dieta variada, amb predomini del gra, la fruita i la verdura, i amb ingestes més escadusseres de productes d'origen animal [...].

Children's understanding of pretend emotions

This preliminary study aims to investigate children’s ability to understand that the emotional expressions that occur in pretend play do not necessarily coincide with the emotions people feel inside. Previous research has found that children aged 4 and 6 have difficulty to distinguish between the external and the internal emotion of a character who pretends an emotion. In the present work, thirteen 4-year-olds and eight 6-year-olds were administered stories in which a character simulated an emotion. Differently from previous research, the questions addressed to the children did not focus on the distinction external/internal emotion but on the distinction between real/pretend emotion. Furthermore, since previous research has suggested that children may understand better selfpretence than pretence of others, the participants in our study were engaged in a pretence situation where they had to pretend to be happy. The results obtained showed that, contrary to previous research, most 4- and 6-year-olds realize that pretend emotions may not be real, and this was true both for self-pretence and for the pretence of others

The usefulness of phonological information for the acquisition of grammatical structure in child language development

During the process of language development, one of the most important tasks that children must face is that of identifying the grammatical category to which words in their language belong. This is essential in order to be able to form grammatically correct utterances. How do children proceed in order to classify words in their language and assign them to their corresponding grammatical category? The present study investigates the usefulness of phonological information for the categorization of nouns in English, given the fact that it is phonology the first source of information that might be available to prelinguistic infants who lack access to semantic information or complex morphosyntactic information. We analyse four different corpora containing linguistic samples of English speaking mothers addressing their children in order to explore the reliability with which words are represented in mothers’ speech based on several phonological criteria. The results of the analysis confirm the prediction that most of the words to which English learning infants are exposed during the first two years of life can be accounted for in terms of their phonological resemblance

El cervell d'Estocolm

Un dels temes que darrerament m'ha fet meditar molt és el dels maltractaments. En concret, per què hi ha persones que senten l'impuls de maltractar els seus congèneres, i per què tot sovint les persones maltractades, tant en la violència de gènere com en qualsevol altre tipus d'assetjament, mantenen o desenvolupen vincles amb els seus maltractadors,culpant-se a si mateixes de la situació. La resposta és dins el cervell, en els nostres gens i en la nostra història evolutiva [...].