The word frequency effect in picture naming: Contrasting two hypotheses using homonym pictures

Fonologische representatie

Identification and characterization of a novel zebrafish (Danio rerio) pentraxin–carbonic anhydrase

Background Carbonic anhydrases (CAs) are ubiquitous, essential enzymes which catalyze the conversion of carbon dioxide and water to bicarbonate and H+ ions. Vertebrate genomes generally contain gene loci for 15–21 different CA isoforms, three of which are enzymatically inactive. CA VI is the only secretory protein of the enzymatically active isoforms. We discovered that non-mammalian CA VI contains a C-terminal pentraxin (PTX) domain, a novel combination for both CAs and PTXs. Methods We isolated and sequenced zebrafish (Danio rerio) CA VI cDNA, complete with the sequence coding for the PTX domain, and produced the recombinant CA VI–PTX protein. Enzymatic activity and kinetic parameters were measured with a stopped-flow instrument. Mass spectrometry, analytical gel filtration and dynamic light scattering were used for biophysical characterization. Sequence analyses and Bayesian phylogenetics were used in generating hypotheses of protein structure and CA VI gene evolution. A CA VI–PTX antiserum was produced, and the expression of CA VI protein was studied by immunohistochemistry. A knock-down zebrafish model was constructed, and larvae were observed up to five days post-fertilization (dpf). The expression of ca6 mRNA was quantitated by qRT-PCR in different developmental times in morphant and wild-type larvae and in different adult fish tissues. Finally, the swimming behavior of the morphant fish was compared to that of wild-type fish. Results The recombinant enzyme has a very high carbonate dehydratase activity. Sequencing confirms a 530-residue protein identical to one of the predicted proteins in the Ensembl database (ensembl.org). The protein is pentameric in solution, as studied by gel filtration and light scattering, presumably joined by the PTX domains. Mass spectrometry confirms the predicted signal peptide cleavage and disulfides, and N-glycosylation in two of the four observed glycosylation motifs. Molecular modeling of the pentamer is consistent with the modifications observed in mass spectrometry. Phylogenetics and sequence analyses provide a consistent hypothesis of the evolutionary history of domains associated with CA VI in mammals and non-mammals. Briefly, the evidence suggests that ancestral CA VI was a transmembrane protein, the exon coding for the cytoplasmic domain was replaced by one coding for PTX domain, and finally, in the therian lineage, the PTX-coding exon was lost. We knocked down CA VI expression in zebrafish embryos with antisense morpholino oligonucleotides, resulting in phenotype features of decreased buoyancy and swim bladder deflation in 4 dpf larvae. Discussion These findings provide novel insights into the evolution, structure, and function of this unique CA form

Buccal alterations in diabetes mellitus

Long standing hyperglycaemia besides damaging the kidneys, eyes, nerves, blood vessels, heart, can also impair the function of the salivary glands leading to a reduction in the salivary flow. When salivary flow decreases, as a consequence of an acute hyperglycaemia, many buccal or oral alterations can occur such as: a) increased concentration of mucin and glucose; b) impaired production and/or action of many antimicrobial factors; c) absence of a metalloprotein called gustin, that contains zinc and is responsible for the constant maturation of taste papillae; d) bad taste; e) oral candidiasis f) increased cells exfoliation after contact, because of poor lubrication; g) increased proliferation of pathogenic microorganisms; h) coated tongue; i) halitosis; and many others may occur as a consequence of chronic hyperglycaemia: a) tongue alterations, generally a burning mouth; b) periodontal disease; c) white spots due to demineralization in the teeth; d) caries; e) delayed healing of wounds; f) greater tendency to infections; g) lichen planus; h) mucosa ulcerations. Buccal alterations found in diabetic patients, although not specific of this disease, have its incidence and progression increased when an inadequate glycaemic control is present

Statistical learning and memory

Learners often need to identify and remember recurring units in continuous sequences, but the underlying mechanisms are debated. A particularly prominent candidate mechanism relies on distributional statistics such as Transitional Probabilities (TPs). However, it is unclear what the outputs of statistical segmentation mechanisms are, and if learners store these outputs as discrete chunks in memory. We critically review the evidence for the possibility that statistically coherent items are stored in memory and outline difficulties in interpreting past research. We use Slone and Johnson's (2018) experiments as a case study to show that it is difficult to delineate the different mechanisms learners might use to solve a learning problem. Slone and Johnson (2018) reported that 8-month-old infants learned coherent chunks of shapes in visual sequences. Here, we describe an alternate interpretation of their findings based on a multiple-cue integration perspective. First, when multiple cues to statistical structure were available, infants' looking behavior seemed to track with the strength of the strongest one | backward TPs, suggesting that infants process multiple cues simultaneously and select the strongest one. Second, like adults, infants are exquisitely sensitive to chunks, but may require multiple cues to extract them. In Slone and Johnson's (2018) experiments, these cues were provided by immediate chunk repetitions during familiarization. Accordingly, infants showed strongest evidence of chunking following familiarization sequences in which immediate repetitions were more frequent. These interpretations provide a strong argument for infants' processing of multiple cues and the potential importance of multiple cues for chunk recognition in infancy

Comparison of salivary proteome of children with different sensitivities for bitter and sweet tastes: association with body mass index

Background/objectives: Oral sensorial perception is a key aspect in food choices and knowing the mechanisms modulating such perception is of major importance in the context of child obesity, which is reaching high rates in Mediterranean countries. Salivary proteome has been linked to taste sensitivity in adults. The aim of this study was to search for differences in salivary proteomes of children with different bitter or sweet taste sensitivities and to assess if these potential differences are associated with their body mass index percentile (BMI percentile). Subjects/methods: 387 children aged 8-9 years old were assessed for BMI percentile and classified according to their sensitivity to bitter and sweet tastes, according to their caffeine and sucrose detection thresholds, respectively. Saliva protein composition was compared among taste sensitivity groups, taking into account BMI percentile and gender, using gel-based proteomics approaches, coupled to mass spectrometry for protein identification. Results: Among the salivary proteins related to bitter taste sensitivity, higher levels of cystatins were observed in bitter-sensitive children, in the case of those of normal weight, and in bitter low-sensitive, in the case of overweight children. For sweetness, the relationship between saliva and taste perception was also dependent on BMI percentile, with several proteins (including salivary cystatins) differing between taste sensitivity groups, with disparities arising between normal-weight and overweight children. Cystatin isoforms A, B and SA were observed to be considerably increased in saliva from obese children. Conclusions: Salivary proteome is related with sensitivities to bitter and sweet tastes in children, but the association is dependent on BMI percentile and gender

Liao Archaeology: Tombs and Ideology along the Northern Frontier of China

The death and burial practices of the semi-nomadic Liao empire (A.D. 947-1125) of China and Inner Mongolia are explored to determine whether, once the northeast Asian group known as the Qidan established their dynasty in Chinese territory, they came to follow the customs of the Chinese afterlife as they had done in their transformations from nomadism to city dwelling and from native practices to Buddhist worship; or, if in the privacy of death they retained their native rites and customs. Evidence pertaining to this issue comes both from Chinese texts and from excavations of Liao-period tombs. Chinese texts about Qidan burial practice are cited, showing that from the Chinese point of view, the burial customs of the Qidan classified them as barbarians. Evidence from Qidan tombs, however, seems to contradict the Chinese textual accounts. The tombs of the Liao emperors, it will be shown, employed Chinese architecture in dramatic fashion even in the early tenth century. Excavated evidence from nonroyal Liao tombs also shows the use of Chinese building traditions. Beneath or behind the architectural facades, however, native Qidan practices often persisted. In addition, it is argued that burial practices suggest that the Qidan not only deviated at times from Chinese funerary practices, but also were influenced by practices of other peoples of north and northeast Asia, including the first-millenium B.C. Scythians. KEYWORDS: Chinese archaeology, north Asia, northeast Asia, mortuary practices, ethnicity

An Electronically Reconfigurable Three Band Low-Noise Amplifier in 0.5 μm GaAs pHEMT Technology

State-of-the-art RF front-end circuits are typically designed to operate at a single frequency. With an increasing number of available wireless standards, personal mobile communication devices require an increasing number of individually designed RF circuits. To save space and cost, one alternative possibility is to reuse much of the circuitry by utilizing electronically reconfigurable topologies. The ubiquitous low-noise amplifier is one of the many circuits that can be redesigned with the reconfigurable aspect in mind. In this thesis, previous work in reconfigurable LNAs is reviewed as well as a brief comparison of CMOS and GaAs processes used for RF amplifiers. Three new reconfigurable LNA topologies are also presented. The first two topologies, based on the common-gate stage and synchronous filters, are investigated but not manufactured. The third design, based on the cascode topology, was manufactured in a 0.5 µm GaAs process with enhancement-mode and depletion-mode pHEMTs. The LNA features 12.7 dB, 13.6 dB, and 13.9 dB of gain and noise figures of 2.7 dB, 3.5 dB, and 4.2 dB at 2.5, 3.6 and 5.8 GHz, respectively. The LNA draws 41 mA from a 3.3 V supply