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The endings of Spanish nouns reflect gender with varying degrees of frequency and regularity. The most common and regular endings are -o for masculine nouns and -a for feminine nouns, -o being more frequent and less closely associated with a specific gender category (masculine) than -a. Pairs of words occurring with both gender categories differ in the frequencies with which they are used as masculine or feminine forms: médic-o/médic-a ‘doctor’ (m.)/‘doctor’ (f.) is a clear example of a masculine-dominant pair, whereas enfermer-o/enfermer-a ‘nurse’ (m.)/ ‘nurse’ (f.) is a feminine-dominant pair. Adult readers of Spanish are faster in recognizing feminine forms of feminine-dominant pairs, and masculine forms of masculine-dominant pairs (Dominguez, Alberto, Fernando Cuetos & Juan Segui. 1999. The processing of grammatical gender and number in Spanish. Journal of Psycholinguistic Research 28(5). 485–498). This study aims to test the dominant frequency effect in third and sixth grade children, as well as in adults. Children were faster in recognizing masculine forms in masculine-dominant pairs, but not feminine forms in feminine-dominant pairs. Adults, by contrast, tended to respond faster to higher frequency words, irrespective of gender, indicating that they have independent representations for both genders. The dominance of masculine forms in children could be a consequence of the statistical distribution of gender dominance and regularity in Spanish. The experience of skilled adult readers seems to make them less dependent on this statistical pattern.

This article examines the relationship between individual differences in speech perception and sublexical/phonological processing in reading. We used an auditory phoneme identification task in which a /ba/-/pa/ syllable continuum measured sensitivity to classify participants into three performance groups: poor, medium, and good categorizers. A lexical decision task manipulated syllable and word frequency. We found that the two tasks were associated. Poor categorizers did not present the typical syllable frequency effect; however, the other groups were sensitive to phonological information to differing degrees and showed the inhibitory syllable frequency effect only for low-frequency words. These results suggest that auditory phoneme identification efficiency may be related to the sublexical processes involved in reading words. (Contains 2 figures and 1 table.)

In the present article, we report 3 experiments using the odd-man-out variant of the implicit priming paradigm, aimed at determining the role played by phonological information during the handwriting process. Participants were asked to write a small set of words learned in response to prompts. Within each block, response words could share initial segments (constant homogeneous) or not (heterogeneous). Also, 2 variable homogeneous blocks were created by including a response word that did not share orthographic onset with the other response (odd-man-out). This odd-man-out could be phonologically related to the targets or not. Experiment 1 showed a preparation effect in the constant homogeneous condition, which disappeared (spoil effect) in the variable condition not phonologically related. However, no spoil effect was found when the odd-man-out shared the phonological initial segment with the targets. In Experiment 2, we obtained a spoil effect in the variable phonologically related condition, but it was significantly smaller than in the variable not phonologically related condition. The effects observed in Experiment 2 vanished in Experiment 3 under articulatory suppression, suggesting that they originated at a sublexical level. These findings suggest that phonological sublexical information is used during handwriting and provide evidence that the implicit priming paradigm (and the odd-man-out version of this) is a suitable tool for handwriting production research. (Contains 6 tables.)

Two experiments examined the role of syllables in writing Spanish words. In Experiment 1, participants had to write single words that were aurally presented. The interletter intervals (ILIs) between critical letters were measured. Longer ILIs were found in the intersyllabic than the intrasyllabic condition. In Experiment 2, the inputs were pictures to remove any potential phonological bias stemming from the input stimulus. Results suggested that the linguistic nature of the input is not determining the output. Post hoc analyses revealed that other characteristics of the stimuli cannot explain the results. These results indicate that syllables are essential units of processing in writing Spanish and that central processes related to spelling and the graphemic buffer affect peripheral processes at movement execution.

This research focused on the syllable as a processing unit in handwriting. Participants wrote, in uppercase letters, words that had been visually presented. The interletter intervals provide information on the timing of motor production. In Experiment 1, French participants wrote words that shared the initial letters but had different syllable boundaries. In Experiment 2, French- and Spanish-speaking participants wrote cognates and pseudowords with a letter sequence that was always intrasyllabic in French and intersyllabic in Spanish. In Experiment 3, French-Spanish bilinguals wrote the cognates and pseudowords with the same type of sequences. In the 3 experiments, the critical interletter intervals were longer between syllables than within syllables, indicating that word syllable structure constrains motor production both in French and Spanish.

A study involving 26 Spanish students (ages 14 through 18) and teachers found that, although some Braille reading processes were similar to those of reading printed text, Braille readers did not show any sensitivity to sublexical variables or to most of the variables that were assumed to be related to integration processes. (Author/CR)

The presence of BaCl2 nanocrystals and the crystallographic phase that they adopt controls the optical behavior of fluorochlorozirconate glass-ceramics. We have used in situ X-ray diffraction heating experiments and ex situ transmission electron microscopy to follow the BaCl2 nanocrystal nucleation and growth processes as a function of heating rate and isothermal hold temperature. The BaCl2 nanocrystals nucleate with the hexagonal crystal structure and grow as spherical particles to a size of ~10 to 20 nm. They then undergo a structural transformation to the orthorhombic phase and their shape changes to rounded disks, with diameters ranging from 150 to 250 nm, and thicknesses ranging from 80 to 120 nm. The change in size results from Ostwald ripening of the hexagonal BaCl2 nanocrystals to form the orthorhombic BaCl2 nanocrystals. [ABSTRACT FROM AUTHOR]

In this work, we study growth and migration of atomic defects in MoSe 2 on graphene using multiple advanced transmission electron microscopy techniques to explore defect behavior in vdW heterostructures. A MoSe 2 /graphene vdW heterostructure is prepared by a direct growth of both monolayers, thereby attaining an ideal vdW interface between the monolayers. We investigate the intrinsic defects (inversion domains and grain boundaries) in synthesized MoSe 2 , their evolution amid growth processing steps, and their influence on the formation and movement of extrinsic defects. Electron diffraction identifies a preferential interlayer orientation of 2° between MoSe 2 and graphene, which is caused by the presence of intrinsic IBD defects. Extrinsic defects (point and line defects) are generated by in situ electron irradiation in the MoSe 2 layer. Our results shed light on how to independently modify the MoSe 2 atomic structure in vdW heterostructures for potential utilization in device processing.

The influence of sublexical and lexico-syntactic factors during the grammatical gender assignment process in Spanish was studied in two experiments using the gender decision task. In Experiment 1, the regularity of the ending of gender-marked nouns (masculine nouns ended in -o and feminine nouns ended in -a) and of nouns with gender-correlated but unmarked word-endings (e.g., -ad) was manipulated. The results showed that regularity affected reaction times and error rates only in the case of gender-marked nouns, suggesting that the mere statistical distribution of a word-ending across genders is not responsible for the regularity effect. In Experiment 2, gender-marked nouns and gender-unmarked nouns were preceded by a masked prime which could be a definite article (which provides information about the gender of the noun) or a possessive pronoun (which does not contain gender information). The presentation of the definite article led to shorter reaction times and less errors only when the word-ending was different from -o or -a. Taken together, these results indicate that gender assignment in Spanish is carried out through different processes depending on the noun ending: gender decisions for gender-marked nouns are based on the gender-to-ending distribution. Meanwhile, gender decisions for unmarked nouns seem to require the retrieval of the corresponding definite grammatical article, regardless of the statistical distribution of the noun ending across genders.

The goal of this paper is to study possible differences between the processing of inflectional vs. derivational morphology in Spanish word recognition using electrophysiological measures. A lexical decision task to target words preceded by morphological-related (or unrelated) primes was used. The orthographic and phonological overlap and the grammatical class for the two experimental conditions were exactly the same. Examples of the related conditions were, for inflection, NIÑO-NIÑA ("girl"-"boy"), and for derivation, RAMO-RAMA ("bunch"-"branch"). These conditions were compared with unrelated pairs without orthographic, phonological or semantic relationships. An attenuation of the N-400 component was found for both related conditions from 300 ms until 450 ms (until 500 ms for inflections only). In addition, different locations were suggested by the source analysis. These findings are consistent with accounts that argue for differences between the processing of inflections and derivations., (© 2010 Elsevier Ireland Ltd. All rights reserved.)

The study of the interaction of ghrelin (1), the endogenous ligand for the GH secretagogues receptor (GHS-R1a), and des-acyl ghrelin (2) with the GHS-R1a by NMR using living cells is presented, using GHS-R1a stably transfected cell lines (CHO and HEK 293) and wild type cells. Therefore, the interaction of 1 and 2 with the GHS-R1a receptor has been performed using quasi-physiological conditions. Ghrelin (1), showed a higher number of residues affected by chemical shift perturbation (CSP) or chemical shift exchange (CSE) effects: Ser3, Phe4, Leu5, Val12, Gln13/Gln14, Lys16/Lys19, Glu17 and Lys24 were much more affected in 1 than in des-acyl ghrelin (2). The chemical shift index CSI values indicated the presence of a possible alpha-helical region between Glu8 and Lys20 for ghrelin (1). After analysing the NMR data, two possible structures have arisen, which present different proline rotamers: the EEZE and the EZEZ conformers, at positions Pro7, Pro21, Pro22 and Pro27, respectively, keeping a left-handed alpha-helix from Glu8 to Lys20. These experimental evidences might imply that the GHS-R1a receptor is acting as a prolyl-cis/trans isomerase., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Obestatin, the ghrelin-associated peptide, showed to activate MAPK signaling with no effect on Akt nor cell proliferating activity in rat tumor somatotroph cells (growth cells, GC). A sequential analysis of the obestatin transmembrane signaling pathway indicated a route involving the consecutive activation of G(i), PI3k, novel PKCepsilon, and Src for ERK1/2 activation. Furthermore, obestatin treatment triggers growth hormone (GH) release in the first 30min, being more acute at 15min. At 1h, obestatin treated cells showed the same levels in GH secretion than controls. Added to this functionality, obestatin was secreted by GC cells. Based on the capacity to stimulate GH release from somatotroph cells, obestatin may act directly in the pituitary through an autocrine/paracrine mechanism.

Obestatin was identified as a gut peptide encoded by the ghrelin gene that interacts with the G protein-coupled receptor, GPR39. In this work, a sequential analysis of its transmembrane signalling pathway has been undertaken to characterize the intracellular mechanisms responsible for Akt activation. The results show that Akt activation requires the phosphorylation of T308 in the A-loop by the phosphoinositide-dependent kinase 1 (PDK1) and S473 within the HM by the mammalian target of rapamycin (mTOR) kinase complex 2 (mTORC2: Rictor, mLST8, mSin1, mTOR kinase) with participation neither of G(i)(/o)-protein nor Gbetagamma dimers. Obestatin induces the association of GPR39/beta-arrestin 1/Src signalling complex resulting in the transactivation of the epidermal growth factor receptor (EGFR) and downstream Akt signalling. Upon administration of obestatin, phosphorylation of mTOR (S2448) and p70S6K1 (T389) rise with a time course that parallels that of Akt activation. Based on the experimental data obtained, a signalling pathway involving a beta-arrestin 1 scaffolding complex and EGFR to activate Akt signalling is proposed.

Two reaction time experiments were carried out to examine the morphological gender processing of Spanish words that were either transparent -that is, ending in o/a (e.g., banco - bank)-or opaque-that is, without superficial gender marking (e.g., virtud - virtue). In Experiment 1, participants categorized the gender of a transparent gender target preceded by a derived word of the same gender (e.g., banquillo-dock, masculine) or of different gender (e.g., banqueta-stool, feminine). A negative priming gender effect indicates the use of strategic-attentional mechanisms to decide the gender of the target, but also automatic computation of the prime gender. Experiment 2 used a lexical decision task with the stimuli of Experiment 1 in addition to opaque gender words. The results show longer reaction times for transparent gender words with regard to opaque items. This effect was possibly due to the lexical requirements of the task: lexical decision, and also because transparent words are morphologically more complex than opaque words. Finally, in both experiments, there was negative priming: when prime and target were of the same gender, reaction times were longer. This effect indicates that participants cannot ignore the gender of the prime when they respond to the target.

In order to test the frequent assumption that lexical access in visual word recognition would proceed independent of central attention, the overlapping task paradigm has recently been employed with somewhat contradictory results. Here we combined overlapping tasks with the recording of event-related brain potentials to assess task load dependent modulations of lexical access in more detail. The study was carried out in Spanish with native Spanish speaking participants. They performed a high-priority pitch discrimination task followed by a visual lexical decision task, in which the difficulty of lexical access was manipulated by means of word frequency. Increasing task load by reducing the stimulus onset asynchrony between both tasks from 700 to 100 ms resulted in considerable slowing of lexical decisions. Word frequency effects were underadditive with the slowing induced by task overlap, indicating lexical access to take place although central attention was dedicated to the high-priority task. The effect of word frequency on the event-related potentials, used as electrophysiological indicator of lexical access, was much less delayed than the lexical decision responses in conditions of high task overlap, providing converging evidence for the independence of lexical access from central attention. On the other hand, this slight delay and an amplitude reduction of the effect with high task load show that lexical access may not be completely autonomous, but subject to some additional early source of interference.

Ghrelin, the endogenous ligand for the growth hormone secretagogue receptor type 1a (GHS-R1a), is a 28 amino acid residue with a post-translational octanoyl modification on Ser3. Despite the biomedical interest in this hormone, the fine details of its regulation and the mechanisms controlling its secretion are largely unknown. The present study analyzes the molecular steps involved in the full lysophosphatidic acid (LPA) receptor-mediated activation of the mitogenic extracellular signal-regulated kinase (ERK) pathway and its consequent role as an inhibitor of ghrelin secretion in the gastric adenocarcinoma cell line AGS. ERK1/2 phosphorylation mediated by LPA proceeds via activation of the type 2 LPA receptor, activation of the nonreceptor tyrosine kinase c-Src, and subsequent transactivation of the epidermal growth factor receptor. Furthermore, LPA-induced ERK activation was found to be independent of matrix metalloproteinases; thus, c-Src acted as the scaffold-transactivating epidermal growth factor receptor. Finally, a correlation was observed between the mitogenic effects of LPA and ghrelin secretion in the human gastric adenocarcinoma cell line AGS. These data suggest a possible physiological role of LPA in ghrelin secretion. The relationship found between LPA and ghrelin secretion might explain the low circulating levels of ghrelin observed in obese patients, as a bona fide reflex of the energetic stores.